Canadian Spine Society: 25th Annual Scientific Conference, February 25 to 28, 2025, Fairmont Le Manoir Richelieu, La Malbaie, Charlevoix, Que., Canada

doi:10.1503/cjs.020125

. 2025 Dec 12;68(6suppl3):S58–S132. doi: 10.1503/cjs.020125

Canadian Spine Society

25th Annual Scientific Conference, February 25 to 28, 2025, Fairmont Le Manoir Richelieu, La Malbaie, Charlevoix, Que., Canada

PMCID: PMC12705198 PMID: 41386990

Footnotes

The Canadian Spine Society is a collaborative organization of spine surgeons and health care professionals with a primary interest in advancing excellence in spine patient care, research, and education.

Course Background: The program of the 2025 Annual Scientific Conference of the Canadian Spine Society (CSS) offers an unparalleled opportunity for professional contact and collaboration among leaders in spine care and spine surgery from across Canada and around the world. It will again be held in conjunction with the Canadian Paediatric Spine Society (CPSS), enabling the meeting to address a full range of spinal pathologies, from childhood spinal deformities to the problems of spinal fragility in the elderly. The format — a carefully constructed blend of didactic presentations, focused group discussions for specific interest groups, and general interest symposia — both enables and encourages participants to share ideas, solve mutual problems, exchange research proposals, and generate multidisciplinary innovation. This year the program includes an internationally recognized keynote speaker, Dr. Roger Härtl, professor of Neurological Surgery and director of Neurosurgery Spine at Weill Cornell Medicine, New York City, and an outstanding invited guest speaker, Dr. Robert Gunzburg, editor-in-chief of the European Spine Journal. Both will be talking about the benefits and concerns surrounding new technologies, Dr. Härtl on innovations in minimally invasive surgery and Dr. Gunzburg on artificial intelligence in spinal publications. There will be another thought-provoking round of expert debates. Is surgery appropriate for painless, single root weakness? Should you fuse with a single-level decompression for adjacent level degeneration in the elderly spine? Which training is optimal for the spine surgeon: orthopedics or neurosurgery? Symposia will address recent advances in oncology, managing cervical degenerative myelopathy, and spine care in developing countries. The CPSS leads off the conference with an opening day of podium presentations, case studies, and committee reports, along with a limited-time exhibit of specialized equipment from our pediatric vendors. In the following days, a session on starting spine practice is tailored to residents and fellows at the start of their careers in spine, while the Women in Spine Event (WISE) will be a continuation of last year’s successful discussion, offering strategies and support for the growing number of female spine surgeons. Allied health care practitioners can attend case studies designed to address their unique problems and approaches. The Canadian Spine Outcome and Research Network (CSORN) will hold its biannual investigators’ meeting that reviews the ongoing research projects and deals with system-wide structural issues. Providing a nidus for continuing clinical conversations, e-posters will be easily accessible throughout the meeting while dedicated poster-review sessions offer authors and attendees the opportunity to interact. The meeting design deliberately fosters comfortable, extended contact between the attendees and the exhibitors. Spine surgeons can examine the latest surgical tools and implants or discuss technical concerns in a convivial atmosphere without overt sales pressure. The CSS Scientific Conference is fully approved for continuing medical education and remains the best way to fulfill your accreditation needs and keep your clinical knowledge up to date while you establish professional contacts and renew friendships.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S59.

Abstract ID 19. Program Code CPSS01. Pediatric Spine Frailty Index predicts morbidity and mortality in spinal deformity surgery

Vivien Chan ^1,², Adeesya Gausper ¹, Andy Liu ¹, Lindsay M Andras ², Kenneth D Illingworth ¹, David L Skaggs ¹

Background:

The purpose of this study was to develop a frailty index for pediatric patients undergoing posterior spinal fusion for deformity correction.

Methods:

The National Surgical Quality Improvement Program (NSQIP) Pediatric database, years 2016 to 2022, was used for this study. Patients were included in this study if they were 1) < 18 years of age and 2) received posterior spinal fusion for spinal deformity. All spinal deformities were included in this study. Years 2016 to 2021 were used as a derivation cohort and year 2022 was used as a validation cohort. Outcomes of interest were any adverse event, Clavien–Dindo IV adverse event, mortality, and extended length of stay (> 10 days). Univariable logistic regression analysis was used to identify potential variables associated with odds of any adverse event, followed by a multivariable logistic regression analysis using backward likelihood ratio backward selection method. Significant variables from the multivariable regression analysis were used to create a frailty index. The frailty index was assessed using receiver operating characteristic (ROC) curve analysis on each outcome of interest. The frailty index was externally validated with the validation cohort using ROC curve analysis. The rates of the outcomes of interest were expressed as proportions and stratified by the frailty index score.

Results:

There were 34 478 patients included in this study (derivation cohort: n = 28 377; validation cohort: n = 6101). The frailty index included significant respiratory disease, gastrointestinal disease, neuromuscular disease, cognitive/developmental delay, seizure disorder, and asthma. In the derivation cohort, the area under the curve (AUC) for any adverse event, Clavien–Dindo IV adverse event, mortality, and extended length of stay were 0.77, 0.85, 0.91, and 0.79, respectively. On external validation, the AUC for any adverse event, Clavien–Dindo IV adverse event, mortality, and extended length of stay were 0.72, 0.88, 0.90, and 0.78, respectively. Increasing frailty index score was associated with increasing rate of all morbidity and mortality outcomes.

Conclusion:

The frailty index had good to excellent discrimination for morbidity and mortality on internal and external validation. This frailty index allows for better risk stratification and informed decision-making.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S59–S60.

Abstract ID 99. Program Code CPSS02. Evaluation of biplane radiographic systems for scoliotic patients

Rachelle Imbeault ¹, Justin Dufresne ¹, Stefan Parent ^2,³, Sylvain Deschênes ², Marjolaine Roy-Beaudry ²

Background:

Our objective was to compare the difference of radiation dose at skin entrance between 2 biplane imaging systems used for the evaluation of scoliotic deformities. One biplane imaging system emits a stable dose during the entire acquisition, while the other is using dose modulation. Image quality produced by the 2 systems will then be evaluated by 2 orthopedic surgeons to ensure that they are of diagnostic quality.

Methods:

Thirty patients were recruited between February 2024 and July 2024 at a single centre. All patients had a diagnosis of idiopathic scoliosis with an average Cobb angle of 26.5° ± 10.3° and with a mean age of 13.2 (range 8 to 18) years. They underwent 2 successive biplane examinations (posteroanterior and lateral views), the first using the dose modulating device and the second using a fixed-dose device. Optically stimulated luminescence dosimeters were installed at 7 radiosensitive anatomic areas to measure the entrance skin dose during the acquisitions. The minimum detection value of the dosimeters is 50 μSv, with an accuracy of ± 10% (Landauer).

Results:

Dose analysis on 30 patients allowed us to observe an average dose reduction of 48% (range −26% to 71%) when dose modulation was used. Dose distribution shows a 63% reduction in the cervicothoracic region, while the reduction was 29% in the lumbosacral region. Diagnostic quality images were obtained using both systems.

Conclusion:

Results indicate that dose modulation can reduce patient exposure to radiation by 48% while maintaining diagnostic image quality. The greater reduction in the cervicothoracic region suggests better protection of the radiosensitive organs located in this area.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S60.

Abstract ID 180. Program Code CPSS03. Rate of spinal osteochondromas diagnosed via advanced imaging in pediatric patients with hereditary multiple osteochondromas: a systematic review and meta-analysis

Jack Legler ¹, Lee Benaroch ², Ali Ahmadi Pirshahid ², Olivia Serhan ³, Draydon Cheng ⁴, Debra Bartley ², Timothy Carey ², Parham Rasoulinejad ², Supriya Singh ², Patrick Thornley ²

Background:

Hereditary multiple osteochondromas (HMO) is a common pediatric condition characterized by multiple cartilage-capped bony lesions. Spinal osteochondromas are present in up to 68% of HMO patients. Although most remain asymptomatic, cord-encroaching lesions can cause significant neurological symptoms and morbidity. Limited guidelines exist regarding screening for spinal osteochondromas in this population. This study assesses the incidence of spinal osteochondromas detected via advanced imaging in pediatric HMO patients.

Methods:

A systematic review and meta-analysis was conducted in accordance with the Cochrane Handbook for Systematic Reviews. A search was performed across MEDLINE, Embase, CENTRAL, and Cumulative Index to Nursing and Allied Health Literature (CINAHL). Included studies reported on the use of advanced imaging, computed tomography or magnetic resonance imaging (MRI) in HMO patients under the age of 21 years. The primary outcome was spinal osteochondroma incidence detected via advanced imaging, while secondary outcomes included type of imaging, imaging indication, presenting symptoms, incidence of canal-encroaching lesions, incidence of surgical intervention, and postoperative outcomes. A meta-analysis of single proportions was conducted to determine the pooled incidence of spinal osteochondromas, canal-encroaching lesions, and spinal surgery in HMO patients.

Results:

Of 415 eligible articles, 7 met inclusion criteria, encompassing 198 HMO patients with a mean age of 12 ± 1.0 years and 47% female. MRI was the primary imaging modality (99%) with 69% imaged secondary to institutional screening protocols. Approximately 21% presented with neurological symptoms at time of imaging. Overall, the pooled incidence of spinal osteochondromas was 36% (95% confidence interval 24% to 51%), distributed across the cervical (43%), thoracic (38%), and lumbar (19%) regions. Among these, 49% had canal-encroaching lesions, and 21% underwent spinal surgery. Postoperatively, 47% of patients reported symptom resolution, and no long-term complications were noted in 6 studies.

Conclusion:

While spinal osteochondromas are prevalent in HMO patients, standardized screening protocols are limited. Surgical outcomes for symptomatic lesions are favourable, underscoring the need for baseline and serial screening to prevent neurological damage. Nonetheless, multicentre prospective studies are needed to identify optimal spinal screening timing for HMO patients.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S60–S61.

Abstract ID 137. Program Code CPSS04. The impact of adverse childhood experiences on fibromyalgia: a systematic review and meta-analysis of case–control studies

Khaled Skaik ¹, Genevieve Belanger ², Philippe Phan ³, Alexandra Stratton ³, Coyle Matthew ³, Stephen Kingwell ³, Eve Tsai ³, Eugene Wai ³

Background:

Fibromyalgia (FM) is a chronic, disabling condition characterized by widespread musculoskeletal pain and various somatic symptoms. Studies suggest that adverse childhood experiences (ACEs) may contribute to the development of FM. However, existing studies often rely on self-reported diagnoses, which may limit accuracy of findings. This review aims to assess the impact of ACEs on FM using case–control studies that adhere to standardized diagnostic criteria.

Methods:

A literature search was conducted using PubMed, MEDLINE, and Embase databases following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines by 2 independent reviewers. Studies included in the review were case–control studies that used the American College of Rheumatology 1990 or 2010 classification criteria to diagnose FM. Data were extracted qualitatively and the scores for childhood trauma questionnaires (CTQs) were analyzed to calculate the standardized mean differences (SMDs) for ACE categories between FM patients and healthy controls.

Results:

Of 385 screened articles, 6 met the inclusion criteria. All showed a significant association between ACEs and FM. Five studies linked emotional abuse to FM, 3 found significance with physical abuse, 2 with sexual abuse, and 2 with physical neglect. Meta-analyses of the differences in CTQ scores demonstrated a trend toward higher overall scores (SMD 1.29, 95% CI 0.98 to 1.59). A significant association was found between emotional abuse and FM, with a combined SMD of 1.30 (95% CI 0.99 to 1.61). Physical abuse and neglect were also associated with FM (SMD 0.40, 95% confidence interval [CI] 0.12 to 0.68 and SMD = 0.52, 95% CI 0.12 to 0.91, respectively). However, study quality was variable, with only 2 studies using adjusted analyses.

Conclusion:

These findings highlight significant association between ACEs and FM, particularly in the female population. Emotional abuse was most strongly associated with FM. Meta-analyses of CTQ scores indicated higher overall ACEs in FM patients, supporting the relationship between ACEs and FM risk. These findings underscore the importance of considering childhood trauma in understanding and managing FM.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S61.

Abstract ID 61. Program Code CPSS05. Enhanced recovery pathway for patients with adolescent idiopathic scoliosis undergoing posterior spinal instrumentation and fusion surgery: a matched controlled analysis

Hannah Fonteyne ¹, Sarah Southon Hryniuk ², Eric Parent ³, Eric Huang ², Kyle Stampe ²

Background:

We sought to determine the impact of an enhanced recovery pathway (ERP) compared with the conventional pathway (non-ERP) on length of stay (LOS), patient-controlled analgesia (PCA), mobilization, hospital costs, and 30-day complication and readmission rates at a Canadian pediatric tertiary hospital.

Methods:

We conducted a match-controlled retrospective chart review of patients with adolescent idiopathic scoliosis aged 10 to 17 years, treated with posterior spinal instrumentation and fusion (PSIF). Sixty patients in the ERP group (March 2022 to May 2024) were matched for sex, age (± 24 months), preoperative largest Cobb angle (± 10°), and number of vertebral levels fused (± 1 vertebrae) to 60 patients in the control group (January 2017 to September 2021). Paired t tests were used to detect differences between groups in LOS, PCA, and mobilization milestones. We used χ² tests to detect differences in intraoperative intrathecal morphine usage, 30-day emergency department (ED) visits, and 30-day readmissions.

Results:

There were no significant differences (p > 0.05) between group characteristics, including sex (82% female), preoperative largest Cobb angle (mean ± standard deviation 60° ± 12°) and number of fused vertebrae (11 ± 1.7). Mean LOS was significantly shorter at 3.8 ± 1.2 days for the ERP group, compared to 5.5 ± 1.0 days for non-ERP (p < 0.001). The ERP group had PCA discontinued earlier than the non-ERP group (postoperative day [POD] 2.3 ± 0.7 v. 3.5 ± 1.0, p < 0.001). More ERP patients (78%) received intraoperative intrathecal morphine than the non-ERP group (35%, p < 0.001). Patients in the ERP group mobilized earlier than the non-ERP group, walking at POD 1.2 ± 0.6, compared with 2.6 ± 1.2 (p < 0.001), and discharged from physiotherapy at POD 3.1 ± 1.1 compared with 5.0 ± 1.1 (p < 0.001). There were no significant differences between groups for 30-day ED visits (4 in ERP v. 4 in non-ERP, p = 1.00) and 30-day readmissions (4 in ERP v. 1 in non-ERP, p = 0.364).

Conclusion:

Implementation of the ERP protocol for patients with adolescent idiopathic scoliosis undergoing a PSIF led to a significant reduction in LOS, faster mobilization, and discontinuation of PCA with no increases in ED visits or readmissions.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S61.

Abstract ID 193. Program Code CPSS06. Integrated approach to back pain in the adolescent population

Marie J Beaulieu ¹, Monica Chan ¹, Gloria Thevasagayam ¹, Gabriela Marino-Merlo ¹

Background:

Back pain is a common musculoskeletal issue that can affect many adolescents. My Spine Clinic is a specialty clinic created at Shriners Hospital in Montréal where a pediatric nurse practitioner (PNP) and a physiotherapist (PT) collaborate to provide an integrated and comprehensive approach to the assessment of back pain in children aged 11 to 18 years. Our objective is to improve access to care and provide timely treatment to improve patients’ function and well-being.

Methods:

At our centre, we receive more than 200 consultation requests a year for back pain. In the past, these patients would wait 6 to 12 months to see an orthopedist and another 6 months to initiate physiotherapy. Patients are now prioritized according to their answers to a short questionnaire. The triage of patients with back pain is a critical process that ensures timely and appropriate care based on the severity, duration, functional impact, and underlying cause of the back pain. At the appointment, every patient is seen together by the PNP and the PT. This collaborative approach ensures that medical factors such as potential systemic causes or serious underlying conditions are addressed by the PNP, while the PT focuses on the mechanical and functional aspects of back pain.

Results:

Patients are now seen within 2 months of referral. For most, physiotherapy provides effective management for symptom relief, improved mobility, and prevention of recurrence. We believe this integrated approach improves patient outcomes by streamlining care pathways. It enhances the accuracy of diagnosis, reduces health care costs, and ensures that patients receive individualized care, thereby preventing chronic disability and enhancing overall quality of life for individuals with back pain.

Conclusion:

Our next steps are to assess the validity and reliability of our questionnaire so it can be used as a standardized tool in the teenage population, as well as conducting a quality improvement assessment to ascertain that patients and families are satisfied with the services received.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S61–S62.

Abstract ID 38. Program Code CPSS07. Traumatic spinal cord injury in children and adolescents: a 20-year review from the Hospital for Sick Children

Armaan K Malhotra ¹, Christopher S Lozano ¹, Zaid Salaheen ¹, Anahita Malvea ¹, Husain Shakil ¹, Leeor Yefet ¹, Ali Moghaddamjou ¹, Sam Molot-Toker ¹, Christopher D Witiw ¹, Jefferson R Wilson ¹, Eisha Christian ¹, Jennifer L Quon ¹, Peter B Dirks ¹, James M Drake ¹, James T Rutka ¹, Abhaya V Kulkarni ¹, Reinhard Zeller ¹, David E Lebel ¹, George M Ibrahim ¹

Background:

We sought to summarize 2 decades of institutional pediatric spinal cord injury (SCI) experience, with particular emphasis on epidemiology and neurological outcomes.

Methods:

This retrospective observational cohort study identified children and adolescents sustaining traumatic SCI presenting to a quaternary children’s hospital from January 2000 to December 2020. We excluded patients with spinal column injuries without evidence of spinal cord involvement, such as fractures and ligamentous injury alone. Neurologic examinations were abstracted from clinical notes at admission, discharge, 3- to 4-month follow-up, and 12-month follow-up using the American Spinal Injury Association Impairment Scale (AIS). Univariate logistic regression was used to identify associations between acute demographic, injury and treatment variables with conversion of > 1 AIS grade at 12 months.

Results:

There were 75 patients identified with traumatic SCI, of whom 45 were males (60%), and mean age at time of injury was 10.4 years (standard deviation [SD] 4.8 years). Injury mechanisms were most commonly related to motor vehicle collisions (n = 35, 47%), followed by sports and recreation injuries (n = 23, 31%) and falls (n = 9, 12%). There were 27 patients with isolated SCI (36%), 13 patients with SCI without radiographic abnormality (SCIWORA) (17%), and 35 patients (45%) with concomitant non-spinal injuries, including 23 patients (31%) with traumatic brain injury. Surgical intervention was performed for 30 patients (40%) and there were 15 patient deaths (20%) that occurred a median of 1 day after admission (interquartile range 1 to 2 days). For 39 patients who had AIS A–D injuries with complete follow-up information (excluding SCIWORA), 26 patients (67%) improved by > 1 AIS neurologic grade by 12 months. Higher injury severity score (odds ratio [OR] 0.91, 95% confidence interval [CI] 0.83 to 0.98) and spinal cord hemorrhage on magnetic resonance imaging (OR 0.18, 95% CI 0.03 to 0.75) were associated with lower tendency for improvement.

Conclusion:

Death in the acute setting was relatively common, occurring in 1 of 5 patients, particularly for motor vehicle collisions with concomitant head injury and craniocervical junction dissociation. The majority of children and adolescents experienced improvement by > 1 AIS grade by 12 months follow-up.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S62.

Abstract ID 93. Program Code CPSS08. Prevalence and prognosis of scapular pain following surgical treatment of adolescent idiopathic scoliosis: a prospective study to guide preoperative counselling

Antoine Dionne ^1,², Julie Joncas ², Soraya Barchi ², Stefan Parent ^1,², Jean-Marc Mac-Thiong ^1,²

Background:

Developing pain after surgical treatment of adolescent idiopathic scoliosis can be devastating for some patients, particularly when they had no pain prior to surgery. Unfortunately, the prevalence and localization of postoperative pain has been poorly studied in this population, which complicates the preoperative counselling by surgeons. The objective of this study is to report the prevalence, predictors, and evolution of scapular pain pre- and postoperatively.

Methods:

This prospective study included 106 patients undergoing posterior instrumentation and fusion for adolescent idiopathic scoliosis. They were instructed to localize (drawing with a pen) the presence of pain anywhere on a human body pictogram preoperatively, as well as postoperatively 6 and 12 months after surgery. The presence of pain between the medial border of the scapula to the shoulder was defined as scapular pain. In addition to descriptive statistics pertaining to the incidence and evolution of postoperative scapular pain, inferential statistics were performed to identify factors associated with persisting de novo scapular pain 2 years after surgery.

Results:

Of the 106 patients included in this study, 21 (19.8%) had right scapular pain preoperatively. Of these, only 9 (42.9%) had persisting pain at 2 years postoperatively. Out of the 85 patients without preoperative pain, 37 (43.5%) developed de novo postoperative pain, among which 29 (34.1%) had persisting pain 2 years postoperatively. Curve type and severity, preoperative angle of trunk rotation, and fusion levels were not associated with the outcome.

Conclusion:

Patients with adolescent idiopathic scoliosis should be advised about the high risk (50%) of de novo right scapular pain after surgery, and nearly 80% of these patients will remain with persisting pain in the long term. Since there are no apparent predictive factors of this outcome, clinicians should carefully discuss this potential complication with patients before surgery. However, more than 50% of patients with preoperative scapular pain will be pain-free postoperatively.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S62–S63.

Abstract ID 150. Program Code CPSS09. Preoperative zoledronate is safe for children with medical complexity undergoing posterior spinal fusion for neuromuscular scoliosis

Samuel Yoon ¹, Karim Aboelmagd ², Archana Sivakuganandan ², Amna Zulfiqar ³, Anne Murphy ⁴, Stanley Moll ⁴, Julia Sorbara ^5,⁶, Brett Rocos ⁷, David Lebel ^4,⁸, Mark Camp ^1,²

Background:

Children with medical complexity (CMC) and neuromuscular scoliosis (NMS) are prone to bone fragility and secondary osteoporosis. Osteoporotic bone compounds operative challenges, contributing to complications such as implant failure, pedicle screw loosening, proximal junctional kyphosis, and pseudarthrosis. Preoperative optimization of bone fragility has the potential to improve surgical outcomes in CMC. Despite evidence for the safety and efficacy of zoledronate infusions in pediatric conditions (e.g., osteogenesis imperfecta), its tolerance, safety, and efficacy in CMC with NMS is not established. The current investigation aims to establish the safety of preoperative bisphosphonate therapy in CMC and NMS.

Methods:

A retrospective review was conducted of patients who had undergone zoledronate infusions during their preoperative optimization. The protocol included 3 infusions with an initial 0.0125 mg/kg dose, a 6-week 0.0375 mg/kg dose, and 6-month 0.05 mg/kg dose. Surgery was scheduled no sooner than 6 weeks after infusion. Patient demographics, comorbidities, medications, laboratory investigations, infusion protocol, and adverse events were collected.

Results:

Forty-seven patients received at least 1 preoperative zoledronate infusion. Of these, 66% (31) completed all 3 infusions. The most common presenting etiology was cerebral palsy (70%), followed by Rett syndrome (9%), and congenital myopathy (9%). Of patients, 66% were Gross Motor Function Classification System (GMFCS) level 5 and 26% GMFCS level 4. Minor adverse events were noted in 6 patients (13%), including 2 episodes of postinfusion hypocalcemia, 2 episodes of flu-like symptoms, 1 episode of nephrolithiasis, and 1 episode of unspecified hypotension, which resolved following oral fluids. There were no major adverse events requiring presentation to hospital. Twenty-one patients have reached 2 years’ follow-up with no clinical signs of pseudarthroses. One patient had a broken screw on 6 months’ follow-up, but has had no further radiographic concerns to indicate pseudarthrosis.

Conclusion:

No major adverse events were noted after preoperative zoledronate infusions. The minor adverse events were self-resolving or resolved with minimal intervention. Zoledronate infusion can therefore safely be included as part of a preoperative optimization pathway in CMC with NMS.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S63.

Abstract ID 15. Program Code CPSS10. Allogeneic transfusion is associated with adverse events in idiopathic scoliosis surgery

Vivien Chan ¹, Geoffrey Shumilak ², Armaan K Malhotra ³, Jalen Dansby ¹, Andy M Liu ¹, Andrew Michael Chan-Tai-Kong ⁴, David E Lebel ³, Kenneth D Illingworth ¹, David L Skaggs ¹

Background:

Pediatric spinal deformity surgery can be associated with significant perioperative blood loss. Previous studies have shown increased risk of adverse events with allogeneic blood transfusion. The primary aim of this study was to quantify the relative occurrence of adverse events associated with allogeneic blood transfusion in pediatric idiopathic scoliosis surgery.

Methods:

This was a retrospective observational cohort study using the National Surgical Quality Improvement Program Pediatric database from 2016 to 2022. Patients aged 18 years or younger who received posterior arthrodesis with ≥ 7 surgical levels for idiopathic scoliosis correction were included. The primary outcome was a composite 30-day adverse event outcome. Secondary outcomes included infectious and noninfectious adverse events and death. Rates and volumes of blood transfusion were determined. G-tests were used to analyze the risk of adverse events associated with allogeneic blood transfusion. A multivariable logistic regression analysis was performed to assess the association between allogeneic blood transfusion and the occurrence of adverse events.

Results:

A total of 23 106 patients were included in this study. The mean age was 14.4 years. Of the 23 106 patients, 12.3% received allogeneic transfusion. Mean volume for allogeneic transfusion was 56.7 mL. The rate of the composite 30-day adverse event outcome was 1.1%. Patients who received allogeneic transfusion had a higher rate of 30-day adverse events (2.5% v. 0.9%; G2 62.5, p < 0.001). Allogeneic transfusion was associated with a higher rate of renal failure (0.14% v. 0.02%), cardiac arrest (0.14% v. 0.01%), venous thromboembolism (0.2% v. 0.05%), deep wound infection/dehiscence (1.1% v. 0.6%), sepsis/septic shock (0.5% v. 0.1%), pneumonia (0.5% v. 0.2%), and unplanned reintubation (0.6% v. 0.06%). In a multivariable logistic regression analysis, controlling for operative time, number of surgical levels, use of cell salvage, and total blood volume transfused, allogeneic transfusion was associated with a higher risk of the composite 30-day adverse event outcome (odds ratio 1.97, p < 0.001).

Conclusion:

Allogeneic blood transfusion is associated with a higher risk of adverse events. Surgeons should minimize allogeneic transfusion, when possible, through optimization of blood management strategies.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S63.

Abstract ID 56. Program Code A11. Defining the gaps in transitional care to adulthood for patients in pediatric surgical specialties: a scoping review

Daisy A Lu ^1,², Zhi Wang ^1,², Monique Clar ¹, M Fidaa Al-Shakfa ¹, Jesse Shen ¹

Background:

The overall objective of this scoping review is to assess the extent of the literature describing transitional programs dedicated to young patients living with surgical conditions or needing surgical care. This knowledge can then be used to build and adapt new transitional care models for our scoliosis clinic.

Methods:

The scoping review followed guidelines described by the Joanna Briggs Institute manual described by Peters and colleagues in 2020. The review adhered to the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols presentation. The screened concept was the exposure of surgical patients to a transition of care pathway or care programs. Studies were included for any surgical patients aged between 16 and 30 years who are transitioning or have completed the process. Two independent reviewers assessed the papers for eligibility and data extraction using Covidence, and any disagreements were resolved with an additional reviewer’s input.

Results:

A total of 9821 studies resulting from our search strategy were reviewed for this scoping review. After eligibility assessment, 385 manuscripts were included for data extraction. Preliminary data underline the prevalence of a patient-centred approach, transition readiness, patient’s knowledge of the condition, family support, and self-management-related outcomes for a successful transition. An established transition pathway with dedicated personnel and clear guidelines improved continuity of care with increased adherence and reduced loss at follow-up. Recommendations include better framework of transition and more standardized tools to evaluate the impact of transition programs.

Conclusion:

The objective of this evidence synthesis is to obtain the characteristics of current transitional programs in pediatric surgical specialties. The review follows current guidelines and frameworks for developing, performing and reporting results for scoping reviews. Current reports highlight the lack of established framework for a successful transition and of standardized tools to evaluate the effectiveness of such programs. A mapping of the current literature concerning transitional pathways for surgical patients can then be used to improve programs and create novel pathways adapted to specific pediatric pathologies such as scoliosis.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S64.

Abstract ID 81. Program Code A12. Effect of mixing dissimilar metals on serum metal ion levels following spinal deformity surgery

Parham Rasoulinejad ¹, Firoz Miyanji ², Karim Kantar ², Timothy Carey ¹, Chris Bailey ¹, Ravi Ghag ², Brent Lanting ¹, Supriya Singh ¹, Jennifer Urquhart ¹

Background:

To determine whether the post–spinal fusion variation in metal ion concentrations is influenced by the type of implant used, particularly in the case of implants composed of dissimilar metals.

Methods:

Patients undergoing surgery for idiopathic or neuromuscular scoliosis were enrolled at 2 centres. Blood ion levels were measured preoperatively and at 3 months and at 1 year and 2 years postoperatively using High-Resolution Sector Field Inductively Coupled Mass Spectrometry. Log-transformed data were analyzed using mixed models of longitudinal regression for repeated measures.

Results:

A total of 37 patients were enrolled in the cobalt chromium/titanium (CoCr/Ti) group and 35 in the stainless steel/titanium (SS/Ti) group, with a majority of females (68% in CoCr/Ti v. 69% in SS/Ti). There were no significant differences between the groups in age (20 v. 17 years), body mass index (21.8 v. 21.2), number of rod attachments (24 v. 25), or rod surface area (117 v. 114 cm²). Chromium levels increased over time, with higher levels observed at 24 months in the SS/Ti group compared with CoCr/Ti (p < 0.05). Cobalt concentrations also increased in both groups and remained elevated at 24 months, although the CoCr group had a higher proportion above the normal reference limit at all time points (p < 0.05, all time points). Titanium levels increased postoperatively in both groups but showed a continued rise in the CoCr/Ti group (interaction, p = 0.006). Higher titanium concentrations correlated with number of rod attachments and surface area and implant failure in the CoCr/Ti but not the SS/Ti group.

Conclusion:

Chromium and cobalt serum metal ion concentrations decline after surgery irrespective of implant type, whereas titanium concentration shows an increasing trend in CoCr/Ti. It is possible that the primary method of metallic wear is more related to differences in surface hardness as opposed to affinity toward galvanic corrosion.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S64.

Abstract ID 184. Program Code A13. Intraoperative neuromonitoring has poor correlation with postoperative neurological deficits in non-cord level adult deformity surgery

Tiffany Lung ¹, Zeeshan Sardar ², Saumayajit Basu ³, Manish Gupta ⁴, Stephen Lewis ^1,⁵

Background:

The purpose of this study is to evaluate rates of new neural deficits relative to intraoperative neuromonitoring (IONM) alerts in non-cord-level spinal deformity surgery.

Methods:

This is a prospective, international, multicentre cohort study. Twenty international centres documented IONM, including electromyography (EMG), somatosensory evoked potentials (SSEP) and motor evoked potentials (MEP), radiographic findings, and surgical events in adult patients undergoing spinal deformity surgery. Inclusion criteria were neurologically intact, major Cobb angle > 80°, or surgery involving any osteotomy. IONM change was defined as loss of amplitude > 50% in SSEP or MEP from baseline or sustained EMG activity lasting > 10 seconds.

Results:

Of 197 patients, 22 (11.2%) had an IONM alert. More patients were undergoing revision surgery during an alert compared with no alert (40.9% v. 18.9%, p = 0.026). IONM alerts did not correlate with Cobb angle, deformity angular ratio, or sagittal or coronal vertical axis. There were 26 alerts in 22 patients: 4 (18.2%) had 2 alerts, while 18 (81.8%) had 1 alert. MEPs were affected in 21 of 26 alerts (80.8%), and 15 (71.4%) of those recovered. SSEPs were affected in 8 of 26 alerts (30.7%) and EMGs in 2 of 26 alerts (7.7%). Five of 21 MEP alerts (23.8%) were bilateral, whereas 16 were unilateral. The most frequent event preceding an MEP change was an osteotomy in 6 of 21 patients (28.6%). Of 197 patients, 33 (16.8%) developed a new postoperative neural deficit despite no IONM alert in 24 of them. In the presence of an IONM alert, 9 of 22 (40.9%) had a new neural deficit. IONM alerts had a crude negative predictive value of 86.1%.

Conclusion:

In non-cord-level spinal deformity surgery, IONM alerts occurred in 11.2% of patients, with osteotomy being the most frequent preceding surgical event. A new postoperative neural deficit was observed in 16.8% of patients, and in 41% of patients with an IONM alert. A surprising 73% of postoperative neural deficits occurred in patients without an alert. This highlights the need for refining IONM techniques for non-cord-level surgery.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S64–S65.

Abstract ID 94. Program Code A14. Role of somatosensory evoked potential (SSEP) in enhancing intraoperative neuromonitoring for spinal deformity surgery — results from a prospective multicentre study

Abdullah T Eissa ¹, So Kato ², Lawrence Lenke ³, Kristen Jones ⁴, Christopher Nielsen ¹, Saumyajit Basu ⁵, Michael Kelly ⁶, Justin Smith ⁷, Samuel Strantzas ⁸, Yong Qiu ⁹, Ferran Pellise ¹⁰, Ahmet Alanay ¹¹, Nasir Quraishi ¹², Randolph Gray ¹³, Go Yoshida ¹⁴, Amer Aziz ¹⁵, Stephen Lewis ¹

Background:

The objective of the present study was to understand the sensitivity and specificity of somatosensory evoked potential (SSEP) in predicting neurological deficits following spinal deformity surgery, and to investigate the complementary performance of SSEP to motor evoked potential (MEP) or electromyography (EMG).

Methods:

Twenty international centres prospectively documented intraoperative neuromonitoring (IONM), demographic details, radiographic findings, and surgical events for complex spinal deformity surgery. Patients aged 10 to 80 years, with a coronal or sagittal major Cobb angle > 80°, or undergoing posterior column or 3-column osteotomy, were included. A total of 526 cases were analyzed, excluding the patients with multiple alerts during a single operation. SSEPs were predominantly recorded after stimulation of posterior tibial nerves (98.9%) and peroneal nerve was occasionally used (7.2%). An IONM alert was defined as a > 50% loss of amplitude in SSEP or MEP from baseline or sustained EMG activity > 10 seconds. Neurologic examinations were performed pre- and postoperatively, with the occurrence of new neurological deficits being meticulously recorded.

Results:

SSEP alerts were identified in 16 out of 526 (3.0%), either alone (n = 4), or in combination with MEP/EMG (n = 12). Postoperative new sensory deficits were recorded in 13 (2.5%), of which 11 cases did not have intraoperative SSEP alerts (false negatives). Overall, the sensitivity of SSEP was 15.4%, and specificity was 97.3%. All false-negative cases either did not have motor deficits or had deficits confined to only 1 or 2 muscle groups, implicating the root injuries. No neurologic deficits were documented after 4 isolated SSEP alerts without MEP/EMG alerts, and the addition of SSEP to MEP/EMG did not result in an enhancement of the sensitivity in predicting postoperative neurological deficits.

Conclusion:

Although multimodal IONM has been deemed beneficial for predicting postoperative neurological deficits by comprehensively assessing spinal cord function, it was revealed that the current protocol with single nerve coverage of SSEP did not contribute to improved safety in complex spinal deformity surgery. Further studies are warranted to establish the optimal protocol for IONM.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S65.

Abstract ID 9. Program Code A15. Does fat matter? The association between extension of fusion and paraspinal muscle fat infiltration

Jennyfer Paulla Galdino Chaves ¹, Brian Hsu ¹, Stone Sima ², Bhisham Singh ¹, Vinay Kulkarni ³, Ashish Diwan ²

Background:

Fat infiltration of the paraspinal muscles reflects muscle atrophy and degeneration and has been known to lead to dysfunction of the low back. We hypothesize that patients who require extension of a primary lumbar spinal fusion exhibit preoperative higher levels of paraspinal fat infiltration compared with patients who underwent only primary fusion.

Methods:

This study was conducted as a retrospective case–control study. Fat infiltration of the paraspinal muscles was measured at the superior adjacent segment level by 2 investigators using the Goutallier and Four Grade Fat classification. Data are presented as median and interquartile ranges (IQRs). A Kruskal–Wallis test with post hoc Mann–Whitney U test was used to analyze the difference in fat infiltration between the extension of fusion and no-extension of fusion groups.

Results:

Of the 88 patients included in the study, 41 underwent extension of fusion and 47 underwent primary fusion alone. In patients who underwent extension of fusion, the level of paraspinal fat infiltration as measured by the Goutallier T₁-weighted and T₂-weighted classification was more severe in the magnetic resonance imaging (MRI) conducted before the extension compared with MRIs conducted before the primary fusion (median 2 [IQR 1] v. median 1 [IQR 1], U = 19.1, p < 0.01) and (median 2 [IQR 0] v. median 1 [IQR 1], U = 6.2, p < 0.001), respectively. The level of paraspinal fat infiltration as measured by all 3 classifications was more severe in the MRI of patients requiring extension of fusion compared with patients who underwent primary fusion only (median 2 [IQR 1] v. median 1 [IQR 1], U = 16.2, p < 0.05), (median 2 [IQR 0] v. median 1 [IQR 1], U = 7.7, p < 0.01) and (median 2 [IQR 0] v. median 1 [IQR 1], U = 17.9, p < 0.01), respectively. There was no difference between preoperative fat infiltration in the superior adjacent segment when comparing MRI scans before the primary fusion of both groups.

Conclusion:

Extension of fusion is associated with elevated paraspinal muscle fat infiltration in the superior adjacent segment level and should be considered as one of the risks for adjacent segment disease and proximal junctional failure in fusions. Further predictive analytical work with the data is under way.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S65–S66.

Abstract ID 47. Program Code A16. Pelvic incidence to lumbar lordosis association varies by Roussouly morphotype

Taryn Ludwig ¹, Farbod Moghaddam ², Mina Aminghafari ², May Choi ², Fred Nicholls ²

Background:

Pelvic incidence (PI) to lumbar lordosis (LL) mismatch is used as a marker of sagittal malalignment and subsequent risk of disability. Previous work has demonstrated that PI is associated with proximal LL and LL apex, but that this may break down with the apex above L3. The ratio of upper to lower LL has also been assessed by Roussouly morphotype (RM). However, assessment of the true arc of the lordotic segment of the lumbar spine and association to PI has not been quantified.

Methods:

Healthy volunteers (n = 442) aged 20 to 40 years with no pre-existing spine pathology were included. Whole-body 2-D EOS imaging was obtained for all participants. Using a semi-automated image analysis software (KEOPS, by SMAIO), standard measures of spinopelvic alignment were obtained. LL from L1 to S1 (L1S1) and from the cranial end of the lumbar lordotic segment to S1 (trueLL, calculated from raw coordinates) were obtained and compared with PI by linear regression.

Results:

Average LL-L1S1 was 55.0°, significantly lower than LL-true at 58.6° (p < 0.001). The cranial end of the lumbar lordotic arc was distributed as follows (percentage of participants): T7 = 0.9%, T8 = 2.3%, T9 = 7.2%, T10 = 5.0%, T11 = 12%, T12 = 29.6%, L1 = 33.3%, L2 = 8.8%, L3 = 0.9%. Average PI-L1S1 difference was −6.6°, while average PI-trueLL was −10.2° (p < 0.001). PI and LL-L1S1 were significantly associated by linear regression (R² = 0.361, p < 0.001), as were PI and trueLL (R² = 0.339, p < 0.001). Polynomial regression did not provide a better fit. However, when assessed by morphotype, PI and LL (L1S1 and trueLL) were associated only by linear regression for type 2 participants (p < 0.05).

Conclusion:

The cranial end of LL was above L1 for 57% of participants; thus, the conventional L1-S1 measurement does not accurately capture the curvature of the spine for the majority of normal spines. The PI-LL relationship appears to be unique by RM. Future work to characterize the distribution of PI-LL and other markers to quantify alignment of the normal spine will enable more accurate surgical planning for deformity correction in degenerated spines.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S66.

Abstract ID 102. Program Code A17. Association between rod and fusion mass fractures in adult spinal deformity: a retrospective cohort study

Eliana Seider ¹, Lauren Daunt ², Vanessa Vashishth ¹, Aazad Abbas ³, Chloe Cadieux ¹, Stephen Lewis ¹

Background:

Rod fractures are a major issue in adult spinal deformity (ASD) surgery, which can have deleterious implications for patients. While pseudarthrosis is the primary failure mode, fractures of the fusion mass can lead to rod fractures. This study aimed to assess whether fusion mass fractures in a solid posterior fusion mass are a distinct cause of rod fractures.

Methods:

A retrospective review of 200 consecutive ASD cases with thoracic-to-pelvis fusion was conducted, including full chart reviews and post-rod fracture computed tomography (CT) scans. Collected demographics included age, body mass index (BMI), and neurodegenerative disorders. Fusion mass fractures were defined as transverse fractures outside the facet joint area, while pseudarthrosis was identified by mass defects along the facet joint orientation. Disc height and interbody cage presence were recorded. Continuous variables were summarized with mean and standard deviation (SD), and categorical variables using counts (n) and percentages (%). Four trained observers reviewed radiographs and CT scans to determine rod fracture etiology by consensus opinion.

Results:

The study included 161 patients, with 20 requiring revision for rod fractures. Fusion mass fractures were observed in 7 patients, while 13 had pseudarthrosis. Transverse rod fractures were common in patients with disc heights > 10 mm at the fracture site (6/7), without interbody cages. In contrast, 92.3% of pseudarthrosis cases had disc heights < 10 mm, with 23.1% containing cages. No correlation was found between fracture type and age, sex, or BMI. Cobalt chrome rods were more common in transverse fractures. Fusion mass fractures primarily occurred at L2–L4 (71%), while pseudarthrosis mainly involved L3–S1 (77%). All patients had single-stage posterior surgeries with 2-rod constructs.

Conclusion:

This study shows that fusion mass fractures, distinct from pseudarthrosis, accounted for 35% of rod fracture cases in ASD patients. Notably, 6/7 occurred at levels with disc heights > 10 mm without interbody cages. This suggests that motion in the anterior column can occur despite solid posterior fusion. As such, adding anterior support and multirod constructs may help prevent these fractures.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S66.

Abstract ID 8. Program Code A18. Design and implementation of a novel morselized bone interbody cage in posterior lumbar spinal fusion: a biomechanical study

Ali Ahmadi ¹, Pawel Brzozowski ², Asra Toobaie ¹, Parham Rasoulinejad ¹, Renan Rodrigues Fernandes ¹

Background:

Posterior lumbar interbody fusion (PLIF) is a standard surgical procedure for treating degenerative spinal conditions, commonly utilizing synthetic cages like polyetheretherketone (PEEK). However, concerns about the high cost of these cages, their potential for subsidence, and limited osteointegration have driven interest in alternatives. This study investigates the biomechanical performance of a novel autogenous morselized bone interbody fusion (MBIF) cage, designed to utilize the patient’s own bone, compared with the PEEK cage.

Methods:

A novel MBIF cage made from morselized bone obtained from lumbar spinal processes and laminae, reinforced with a stainless-steel mesh for additional structural support, was designed and tested. Biomechanical testing was conducted in 2 phases: (1) axial load testing using polyurethane block models simulating both healthy and osteoporotic bone conditions, and (2) nondestructive biomechanical testing using human cadaveric lumbar spine segments (L2–L5) to assess range of motion and stiffness in PLIF constructs, normalized to the intact cadaveric state. In both phases, the performance of the MBIF cage was compared with that of the PEEK cage.

Results:

In the synthetic bone model, the MBIF cage demonstrated comparable axial load-bearing capacity to the PEEK cage in healthy bone conditions (p = 0.7) and outperformed the PEEK cage in osteoporotic conditions (p < 0.001) by reducing subsidence. In the cadaveric model, both cages exhibited the same range of motion and stiffness when combined with posterior instrumentation, indicating equivalent biomechanical stability. When normalized to the intact state, no significant differences were observed in range of motion or stiffness during axial rotation, flexion-extension, and lateral bending.

Conclusion:

The results suggest that the MBIF cage provides biomechanical performance equivalent to the PEEK cage, with potential advantages in osteoporotic conditions where it showed superior resistance to subsidence. The MBIF cage, by utilizing autogenous bone, could offer a biologically favourable and cost-effective alternative to synthetic cages, potentially reducing the risk of complications such as subsidence and improving long-term fusion outcomes. This study suggests that the MBIF cage may be particularly useful in patients with compromised bone density.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S66–S67.

Abstract ID 86. Program Code A19. Decompression versus decompression plus fusion for stable degenerative lumbar spondylolisthesis: comparing outcomes using propensity score–matched data

James J Young ^1,², Jennifer Urquhart ³, Chris Bailey ³, Greg McIntosh ⁴, Andrew Glennie ⁵, Charles Fisher ⁶, Anthony V Perruccio ^1,⁷, Raja Rampersaud ^1,⁷

Background:

Previous studies have been unable to consider the impact of stability when comparing the effectiveness of decompression alone (DA) versus decompression plus fusion (D+F) for degenerative lumbar spondylolisthesis (DLS). The objective of this study was to estimate the treatment effect of DA versus D+F for a stable DLS subgroup using matched observational data from the Canadian Spine Outcomes and Research Network DLS prospective cohort.

Methods:

Patients with a stable DLS, defined as < 5 mm of slip motion and a neutral or lordotic disc angle, were included. Patients receiving DA were matched 1:1 to patients receiving D+F based on a propensity score derived from a range of 16 pretreatment sociodemographic, clinical, and radiographic covariates. Between-group differences in improvement in Oswestry Disability Index (ODI; 0 best to 100 worst); 12-Item Short-Form Survey physical component score (PCS; 0 worst to 100 best); and EuroQol Visual Analogue Scale (EQ-VAS; 0 worst to 100 best) were estimated at 2-year follow-up using linear mixed models adjusted for pretreatment covariates unbalanced after matching.

Results:

A total of 228 patients were included, of whom 124 were matched (62 in each treatment group). After matching, all pretreatment covariates were balanced between groups except age, education, number of comorbidities, and symptom duration. No statistically significant differences between groups were found at 2-year follow-up on the ODI (mean difference −3.6; 95% confidence interval [CI] −9.3 to 2.1), SF-12 PCS (mean difference 3.2; 95% CI −0.7 to 7.1) or EQ-VAS (mean difference 1.3; 95% CI −6.1 to 8.8). The proportion achieving a clinically significant improvement at 2-year follow-up on the ODI was 67.3% in the DA group versus 71.4% in the D+F group.

Conclusion:

From this well-matched study, we report no statistically or clinically significant effect in favour of D+F over DA across all outcomes for stable DLS, providing further real-world evidence that the addition of fusion is not necessary for patients with < 5 mm of slip motion and a neutral or lordotic disc angle.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S67.

Abstract ID 176. Program Code A20. Reoperation rates for decompression and fusion versus decompression alone for degenerative spondylolisthesis: a comparative analysis

Andrew Glennie ¹, Jennifer Urquhart ², Amir Mishreky ¹, Charles Fisher ³, Raja Rampersaud ⁴, Chris Bailey ²

Background:

We sought to assess rates and causes for reoperation following spine surgery for degenerative lumbar spondylolisthesis (DLS) at early and midterm follow-up time points.

Methods:

Multicentre, prospectively collected data from the Canadian Spine Outcomes and Research Network DLS prospective study was analyzed to compare patient demographic, functional, clinical, and radiological outcomes as well as reoperation rates for decompression alone (DA) or decompression and fusion (D+F) in the treatment of single or 2-level lumbar spondylolisthesis. Logistic regression models were used to analyze the effect of surgical procedure type on multiple characteristics. Cox-adjusted absolute risk differences were calculated accounting for age, sex, grade of spondylolisthesis, back pain at baseline, Oswestry Disability Index (ODI) score at baseline, and pelvic incidence minus lumbar lordosis > 10.

Results:

There were 587 patients eligible for follow-up within the cohort (406 D+F and 181 DA). The average follow-up time was 36.9 months. D+F patients were younger (65.0 ± 8.7 v. 69.06 ± 10.1 years, p = 0.001), were more often female (64.5% v. 53.0%, p = 0.01), had a higher grade of spondylolisthesis (33% v. 13.3%, p = 0.001), and showed lower baseline functional status on the ODI score (45.7 ± 14.6 v. 40.8 ± 14.5, p = 0.001). In total, 64 patients (10.9%) underwent reoperation surgery. D+F had a higher reoperation rate (12.3%) compared with DA (7.7%) (p = 0.115). Reasons for reoperation differed but average time to reoperation was similar (22.7 ± 20 months DA v. 24 ± 21.8 months D+F). Adjacent segment pathology was the most common reason for reoperation in D+F cases (48%), versus 21.4% in DA cases. Irrigation and débridement were higher but not statistically different in D+F (16% D+F v. 7.1% DA, p = 0.670). The absolute adjusted risk difference for reoperation was higher for D+F at the 12-month to 60-month time points.

Conclusion:

D+F patients had higher reoperation rates at all follow-up intervals, which is different from previous work. This may have been driven by higher irrigation/débridement in fusions. Reporting all-cause reoperation provides more precise information on each procedure’s expected outcomes, and may be more representative of the resources required during the follow-up period.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S67–S68.

Abstract ID 186. Program Code B21. Modic change is not associated with occult discitis or poor clinical outcome among patients treated surgically for lumbar disc herniation: prospective cohort study

Mark A MacLean ^1,², Lisa Julien ², Glenn Patriquin ², Jason Leblanc ², Ryan Greene ², Jacob Alant ², Sean Barry ², R Andrew Glennie ², William Oxner ², Sean D Christie ²

Background:

A link has been proposed between Modic change (MC) on magnetic resonance imaging (MRI), occult discitis, and poor clinical outcomes in patients with lumbar disc herniation (LDH). Previous work from our group and others calls this into question. Here, we sought to investigate this association via a blinded, prospective cohort study of patients undergoing microdiscectomy.

Methods:

We enrolled consecutive adult patients with symptomatic LDH. Exclusion criteria included previous epidural steroid use, previous spinal surgery, and recent antibiotic use (< 2 weeks of surgery). Four nuclear tissue and ligamentum flavum (control) samples were obtained per patient using stringent aseptic protocol. All samples underwent 16S polymerase chain reaction and culturing, as per routine laboratory practices. Surgeons and patients were blinded to microbiological data unless species were deemed virulent and warranting treatment, as determined by independent infectious disease specialists. Clinical assessment scores (visual analogue scale, Health Scale, Oswestry Disability Index) were recorded preoperatively, and at 3-, 6-, and 12-month follow-up.

Results:

Eighty-one patients were enrolled (mean age 43.3 ± 13.3 years; body mass index [BMI] 28.7 ± 5.3; 51% smokers). Disc samples were culture positive in 15% of cases, 92% of which grew only a single colony (suggestive of contamination). Preoperative MC was present in 52% of patients. Baseline variables (age, sex, BMI, smoking status, previous surgery, Pfirrmann grade on MRI) did not differ between those with and without MC on preoperative MRI (all p > 0.05). Presence of MC was not associated with disc culture positivity (p > 0.05). Neither presence of MC nor disc culture positivity were associated with worse clinical assessment scores at any pre- or postoperative time points (all p > 0.05).

Conclusion:

In this rigorously conducted, blinded, prospective trial of patients undergoing microdiscectomy for symptomatic LDH, we did not find an association between MC, disc sample bacterial cultures, and clinical assessment scores.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S68.

Abstract ID 145. Program Code B22. Machine learning–driven clinical and imaging clustering of degenerative lumbar spondylolisthesis: implications for stratified surgical care

Karlo Pedro ¹, Aazad Abbas ¹, Christopher Bailey ², Jennifer Urquhart ², Greg MacIntosh ³, Andrew Glennie ⁴, Charles Fisher ⁵, Philippe Phan ⁶, Y Raja Rampersaud ¹

Background:

Degenerative lumbar spondylolisthesis (DLS) patients exhibit significant clinical and radiographic heterogeneity that creates substantial variability in surgeon-reported decision-making. In this study, we applied unsupervised clustering techniques to identify distinct DLS groups, aiming to inform clinical decision-making in selecting patients for decompression versus decompression and fusion.

Methods:

Consensus cluster analysis was used based on demographic, clinical, and radiological characteristics of patients enrolled in the Canadian Spine Outcomes and Research Network prospective DLS study from 2015 to 2022 at 8 Canadian sites. We selected clinically relevant variables to guide feature selection and evaluated the optimal number of clusters. Euclidean distance metric was used to determine the cluster number and structure, with up to 7 clusters considered and 50 sampling iterations. Key characteristics of each cluster were identified, and postsurgical outcomes were compared using the Oswestry Disability Index (ODI) with pairwise statistical tests.

Results:

Consensus cluster analysis of 486 DLS patients (mean ± standard deviation [SD] age, 55.4 ± 9.2 years, 180 men [37%]) identified 4 distinct clusters. Cluster 1 (n = 175) included patients with moderate disability, low comorbidity, low depression, and radiographically balanced spine. Cluster 2 (n = 85) comprised predominantly female patients with severe disability, high comorbidity, high depression, and imbalanced spine. Cluster 3 (n = 91) consisted mainly of male patients with moderate disability, low comorbidity, low depression, and imbalanced spine; while Cluster 4 (n = 135) included elderly patients with severe disability, high comorbidity, high depression, and balanced spine. Clusters 1 and 3 showed the most favorable final ODI outcomes at 1- and 2-years follow-up. Cluster 2 had the highest rate of fusion surgery (84%) and the greatest ODI change at 1 year (ODI mean ± SD, 27.97 ± 19.32). Decompression alone provided sustained benefit in Clusters 1 and 3, while improvement regressed in Cluster 2 and to a lesser degree in Clusters 4 at 2 years.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S68–S69.

Abstract ID 68. Program Code B23. Which psychosocial measures are most strongly related to surgical outcomes in patients with degenerative pathology of the spine?

Daniel P Smith ^1,^2,³, Erin E Bigney ^2,^3,⁴, Jeffrey Hebert ⁴, Eden A Richardson ^2,^3,⁵, Neil A Manson ^1,^2,³, Edward Abraham ^1,^2,³, Abdullah Zein ², Kyra Holt ², Hannah Isaac ⁶, Jill Kearney ^2,³, Chris Small ^1,^2,³

Background:

We sought to identify which psychosocial measures best predict postoperative clinical outcomes in patients undergoing spinal surgery.

Methods:

This prospective cohort study enrolled patients from Saint John Regional Hospital and St. Joseph’s Hospital who underwent thoracolumbar surgery for degenerative pathology. Patients completed 6 preoperative psychosocial measures: Tampa Scale for Kinesiophobia (TSK), Pain Catastrophizing Scale (PCS), Chronic Pain Acceptance Questionnaire-8 (CPAQ-8), Mental Health Component Scale-12 (MCS-12), Multidimensional Scale of Perceived Social Support (MSPSS), and Health Questionnaire Depression Scale-8 (PHQ-8). Outcomes were collected 3 and 12 months postoperatively and included numeric rating scales for leg and back pain and the Oswestry Disability Index. All models controlled for age, sex, and preoperative pain or disability. Linear regression models estimated associations with the continuous outcomes. Robust Poisson models identified the probability of achieving minimal clinically important change (MCIC) (30% reduction in pain or disability) or success (50% reduction). Results were reported with standardized β coefficients and risk ratios (RRs).

Results:

At 3 months, PCS predicted leg pain (β = 0.17, p < 0.05). At 12 months, MCS-12 (β = −0.18, p < 0.05) and MSPSS (β = −0.14, p < 0.05) predicted disability; MCS-12 (β = −0.20, p < 0.05), PCS (β = 0.16, p < 0.05), and PHQ-8 (β = 0.22, p < 0.05) predicted back pain; and all psychosocial measures predicted leg pain (PCS β = 0.32, p < 0.05; MCS-12 β = −0.27, p < 0.05; TSK β = 0.23, p < 0.05; CPAQ-8 β = −0.20, p < 0.05; MSPSS β = −0.15, p < 0.05; PHQ-8 β = 0.25, p < 0.05). For MCIC, TSK predicted disability at 3 months (RR = 0.81, p < 0.05). At 12 months, MCS-12 predicted disability (RR = 1.15, p < 0.05), and PCS predicted leg pain (RR = 0.88, p < 0.05). For success, MCS-12 (RR = 1.22, p < 0.05) and MSPSS (RR = 1.21, p < 0.05) predicted disability at 12 months; PCS (RR = 0.86, p < 0.05) and PHQ-8 (RR = 0.82, p < 0.05) predicted back pain; while TSK (RR = 0.85, p < 0.05), MCS-12 (RR = 1.17, p < 0.05), PCS (RR = 0.79, p < 0.05), and PHQ-8 (RR = 0.86, p < 0.05) predicted leg pain.

Conclusion:

Psychosocial measures predicted long-term outcomes better than short-term, and pain more consistently than disability. Surgeons should select the PHQ-8, MCS-12, or PCS depending on their primary outcome of interest and local circumstances.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S69.

Abstract ID 111. Program Code B24. Acceptance and commitment therapy for patients with degenerative spinal disorders and maladaptive psychological processes: an observational study

Nathan Evaniew ¹, Abdullah Alduwaisan ¹, Victoria Smith ¹, Tara Whittaker ¹, Denise Eckenswiller ¹, Elias Soumbasis ¹, Robert Tanguay ¹, W Bradley Jacobs ¹, Kenneth C Thomas ¹, Fred Nicholls ¹, Alex Soroceanu ¹, Ganesh Swamy ¹

Background:

Patients living with chronic pain may experience maladaptive psychological processes that include depression, somatization, kinesiophobia, pain catastrophizing, and anxiety. Spine surgery in the setting of maladaptive psychological processes can lead to poor outcomes, but intervention with acceptance and commitment therapy (ACT), which is a specific form of cognitive-behavioural therapy (CBT), may provide benefits. Our objective was to evaluate the effectiveness of ACT for patients with degenerative spinal disorders awaiting surgery.

Methods:

We performed a retrospective observational cohort study. We analyzed data that were collected in routine clinical practice at a single academic centre. ACT was available as part of a multidisciplinary optimization program, and referrals to ACT were at the discretion of the treating surgeons without standardized criteria. Minimum clinically important differences (MCIDs) were implemented and descriptive statistics were performed.

Results:

Among 63 patients who underwent ACT while awaiting spine surgery, ACT was associated with significant short-term improvements for depression (mean ± standard deviation [SD]: change −3.3 ± 6.5, p < 0.01), somatization (−2.9 ± 4.1, p < 0.01), kinesiophobia (−6.1 ± 10.8, p < 0.01), catastrophizing (−9.9 ± 14.8, p < 0.01), anxiety (−2.1 ± 6.2, p < 0.01), injustice (−5.5 ± 8.5, p < 0.01), and pain disability (−6.4 ± 17.4, p < 0.01), but not symptoms of posttraumatic stress disorder (change −3.5 ± 14.3, p = 0.06). The proportions of patients who achieved the minimum clinically important difference for each of these measures ranged from 27% to 52%, with the greatest effects being observed for catastrophizing, somatization, and kinesiophobia.

Conclusion:

Among selected patients, ACT prior to spine surgery was associated with significant improvements for many maladaptive psychological processes. These results suggest that implementation of ACT in clinical practice may be appropriate and that further research to understand effects on outcomes after surgery is warranted.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S69.

Abstract ID 128. Program Code B25. Assessing construct validity of the Spine Adverse Events Severity System: impact of adverse event severity grade on longitudinal patient-reported outcomes)

Celina Nahanni ¹, Tiffany S Lung ¹, James J Young ², Chloe N Cadieux ¹, Jin Tong Du ¹, Raja Rampersaud ^1,²

Background:

The Spine Adverse Events Severity System (SAVES-V2) tracking tool allows for prospective tracking of perioperative adverse events (AEs) after spine surgery. Higher-grade AEs have a sustained negative impact on patient-reported outcome measures (PROMs). This study aimed to evaluate the construct validity of SAVES-V2 by examining the impact of severity grade on longitudinal PROMs.

Methods:

We analyzed data from 7821 patients enrolled in the Canadian Spine Outcomes and Research Network (CSORN) registry with degenerative lumbar spine conditions. Linear models were used to evaluate the difference in PROM scores between AE grades at the 2-year follow-up. The primary outcome was Oswestry Disability Index (ODI). Secondary outcomes included EQ-5D utility and numeric rating scale for back and leg. Established minimal clinically important difference thresholds were used to determine whether differences between AE grades were clinically significant.

Results:

Most patients had no AEs (84.1%). Grade 1 AEs occurred in 2.2%, grade 2 in 12.6%, grade 3 in 0.9%, grade 4 in 0.2%, and grades 5 and 6 in less than 0.1%. Patients with grades 5 and 6 AEs were therefore excluded. Compared with having no AE, there was no statistically significant difference in ODI scores at 2 years for AE grade 1 (1.2; 95% confidence interval [CI] −4.2 to 6.5). Statistically significant differences were found for AE grades 2 (5.0; 95% CI 2.5 to 7.4) and 3 (11.4; 95% CI 2.8 to 20.0). Only the difference between AE grade 3 and no AE reached clinically significant thresholds. This same pattern was also observed across all secondary outcomes.

Conclusion:

As expected, based on the SAVES-V2 tool, AE grades 1 and 2 had no meaningful impact on PROMs, demonstrating adequate construct validity. However, grade 3 AEs as documented by CSORN surgeons had clinically meaningful and sustained impacts on patient recovery at 2-year follow-up, contrary to the SAVES-V2 tool definition of a temporary (< 6 months) effect on outcomes. This finding warrants further study and possible refinement of the grade 3 classification on the SAVES-V2 tool.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S69–S70.

Abstract ID 72. Program Code B26. A pilot randomized controlled trial comparing traditional midline versus paramedian approaches to the lumbar spine for elective posterior/transforaminal lumbar interbody fusion procedures

Andrew Glennie ¹, Cynthia Dunning ¹, Emma Jones ¹, William Oxner ¹

Background:

Postoperative infection after instrumented spinal fusion surgery is a devastating complication. The primary objective of this study was to compare infection, adverse events, and reoperation rates between paramedian and midline approaches to the lumbar spine for posterior/transforaminal lumbar interbody fusion (PLIF/TLIF) procedures. Secondarily, we sought to determine the feasibility of recruitment for a multicentre trial.

Methods:

A single-centre, pilot randomized controlled trial (RCT) comparing patients undergoing single or 2 level PLIF/TLIF surgery was initiated in 2018. Patients with degenerative/isthmic spondylolisthesis, or degenerative disc disease were included. Patients with previous surgery, immunocompromise, or steroid injection within 3 months of surgery were excluded. Descriptive statistics were used to evaluate differences in outcome. Power analysis was performed for deep surgical infection and reoperation outcomes.

Results:

One hundred patients were consecutively recruited. Three patients declined participation. The average follow-up time was 2.2 years. Fifty patients were randomly assigned to each group. The number of deep postoperative infections was higher in the midline (5/50, 10%) than the Wiltse group (2/50, 4%). Ten of the 50 (20%) patients in the midline group underwent reoperation compared with 3 (6%) in the paramedian group. The paramedian group had a greater incidence of superficial wound infection (12%) versus midline (2%). The overall number of adverse events for each group were similar (16 [32%] midline v. 13 [26%] paramedian). Midline procedures took on average 2:21 ± 29 minutes and paramedian approaches took 2:35 ± 32 minutes. Patient-reported outcomes were also similar between groups (1-year average Oswestry Disability Index change −20 midline and −21 paramedian). Power calculation revealed that 482 patients are required to test a difference in deep postoperative infection, and 226 are required to test differences in reoperation between both groups.

Conclusion:

Patients who underwent the paramedian approach had different deep and superficial wound infection rates, and a lower incidence of requiring revision surgery. These results highlight the value of a multicentre RCT comparing these approaches. A trial appears feasible, especially where recruitment was affected for the pilot study throughout the COVID-19 pandemic.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S70.

Abstract ID 96. Program Code B27. Uniportal versus biportal endoscopic decompression for the treatment of lumbar spinal stenosis: a systematic review and updated meta-analysis

Kaike Lobo ¹, Paweł Łajczak ², Claudia Santos ³, Numa Rajab ⁴, Rafael Oliveira ⁵, Yasmin Picanco Silva ⁶, Ramon Guerra Barbosa ⁷, Yan GMD Silva ⁸

Background:

This systematic review and updated meta-analysis aimed to evaluate the outcomes of uniportal and biportal endoscopic decompression techniques for managing lumbar spinal stenosis (LSS).

Methods:

We systematically searched PubMed, Embase, Cochrane, and Web of Science for randomized controlled trials (RCTs) and observational studies. The outcomes assessed included intraoperative blood loss (IOBL), length of hospitalization (LOH), operative time (OT), visual analogue scale (VAS) scores for leg and back pain, Oswestry Disability Index (ODI), MacNab criteria rated excellent or good, and postoperative complication rate. Mean difference (MD) and odds ratio (OR) were calculated for continuous and binary outcomes, respectively, with 95% confidence interval (CI).

Results:

Of 80 articles screened, 8 studies were included, encompassing 927 patients, of whom 464 underwent uniportal and 463 biportal decompression. No significant differences were found between groups in IOBL (MD −2.66; 95% CI −9.18 to 3.86; p = 0.42; I² = 99%), LOH (MD 0.02; 95% CI −0.23 to 0.27; p = 0.87; I² = 43%), complication rate (OR 1.18; 95% CI 0.60 to 2.72; p = 0.527; I² = 0%), and MacNab criteria rated excellent or good (OR 0.68; 95% CI 0.22 to 2.14; p = 0.511; I² = 64%). However, operative time was significantly longer in the uniportal group (MD 21.77; 95% CI 6.73 to 36.80; p < 0.01; I² = 100%). No significant differences were observed in ODI at 3 months (MD 3.81; 95% CI −2.74 to 10.36; p = 0.25; I² = 99%), 6 months (MD 7.84; 95% CI −3.74 to 19.43; p = 0.18; I² = 100%), or 12 months (MD 0.78; 95% CI −0.11 to 1.67; p = 0.09; I² = 0%). VAS leg pain scores were similar at 3 months (MD 0.12; 95% CI −0.05 to 0.30; p = 0.17; I² = 39%), 6 months (MD 0.11; 95% CI −0.06 to 0.29; p = 0.21; I² = 40%), and 12 months (MD 0.11; 95% CI −0.18 to 0.40; p = 0.47; I² = 70%).

Conclusion:

This meta-analysis demonstrated that the biportal technique had a significantly shorter OT than the uniportal approach. Further high-quality studies are needed.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S70–S71.

Abstract ID 152. Program Code B28. Why business tools are essential for managing a spine program

Aazad Abbas ¹, Gurjovan Sahi ¹, Jin Tong Du ¹, Michael Johnson ², Edward Buchel ², Jay Toor ²

Background:

Spine care delivery in Canada is in a state of crisis, and clinician advocacy to hospital leadership and government is essential to successfully implement positive change. While clinical research and quality improvement work are both well-established domains familiar to surgeons, business techniques such as granular financial quantification and operational modelling are not commonly used but can play a crucial role in advocacy efforts. This study describes 2 instances that business tools were used from October 2023 to October 2024 to successfully advocate for major progress in increasing the capacity of a provincial spine program.

Methods:

The first example of the use of a business technique was granular financial quantification to compare costs of an existing program to export spine surgeries to the United States against the costs of building capacity within the province instead — via capital investment to expand the spine program within the province. The second use case was quantification of the existing wait-list via an operational model in order to accurately ascertain the exact operating room resources required to address a surgical backlog.

Results:

The initiative led to the successful cancellation of surgeries being sent to the US, yielding net savings of $30 949 per case and $4.1 million per annum. The capital procurement for the secondary site expansion ($2.2 million) along with an operating budget ($959 000) was approved owing to the demonstration of a return on investment (ROI) of 27%. The precise quantification of the wait-list demonstrated a 4.3-year wait-list for spine surgery, on track to reach 5.7 years by 2027. These data provided a strong case for additional operating room time, which is being incrementally added, after a 15-year status quo.

Conclusion:

Advocacy for additional resources was unsuccessful until the introduction of business tools resulting in accurate quantification (in this case, net profit/ROI values and precise wait times). We hope these techniques become more widely implemented nationally, as our experience highlights the potential benefits of strategic data-driven decision-making.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S71.

Abstract ID 172. Program Code B29. Relationship between fatty infiltration, frailty, and outcomes after spinal surgery

Ronit Kulkarni ¹, Melanie Bertolino ¹, Chase Walton ¹, Gabriella Rivas ², John Glaser ¹, Charles A Reitman ¹, James Lawrence ¹, Robert Ravinsky ¹

Background:

Frailty has been studied as a measure of risk assessment in the elderly. The Goutallier classification has been used with reliability to assess the degree of fatty infiltration. The purpose of this study is to identify the role of fatty infiltration in the lumbar paraspinal muscles, using the Goutallier classification, to assess perioperative outcomes following elective lumbar surgery, and its association with a frailty index.

Methods:

We conducted a retrospective review of 98 patients at a single institution who underwent elective spinal surgery in 2021 because of lumbar degenerative pathology. Data were collected on patient demographics, medical history, perioperative outcomes, and postoperative complications. Goutallier scores were classified according to lumbar magnetic resonance images.

Results:

Average patient age was 65.77 ± 11.9 years. Mean scores included a Goutallier score of 2.57 ± 1.05 and a Modified 5-Item Frailty Index (MFI-5) score of 1.23 ± 1.08 for all patients. Intraclass correlation coefficient for Goutallier scores was 0.912. Statistically significant relationships were seen between higher Goutallier scores and women (p = 0.039), dependent health status (p < 0.001), and steroid use (p = 0.004). There was no association between Goutallier and MFI-5 scores (p = 0.228). Older age was associated with both higher Goutallier (p = 0.022) and MFI-5 (p < 0.001) scores. There was no significant association between Goutallier scores and race, body mass index, diabetes, chronic heart failure, chronic obstructive pulmonary disease or pneumonia, hypertension, osteoporosis, psychiatric illness, alcohol use, reoperation rate, readmission rate, or length of hospital stay (p > 0.061). Multivariable ordinal regression analysis demonstrated that only increased patient age (p = 0.003) and female sex (p = 0.014) were significant predictors of higher Goutallier scores.

Conclusion:

Despite its use in shoulder pathology, the Goutallier score was not demonstrated to be relevant to lumbar spinal pathology. In patients undergoing elective spinal surgery for lumbar degenerative pathology, there appears to be no association between the Goutallier and MFI-5 scores. Further research is warranted regarding the relationship between fatty infiltration, frailty, and clinical outcomes in elective spinal surgery.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S71.

Abstract ID 143. Program Code C30. Clinical trajectory and outcomes with surgical intervention for traumatic central cord syndrome: impact of mechanism of injury

Karlo Pedro ¹, Michael Fehlings ¹, Mohammed Alvi ¹

Background:

Outcomes in central cord syndrome (CCS) exhibit significant variability, and patient phenotypes continue to evolve over time. High-impact cervical injuries typically result in fractures and rapid cord compression, whereas milder cases often arise from hyperextension injuries without fractures. Despite these distinctions, direct comparisons between these 2 groups using standard CCS criteria are lacking. This study aims to establish a framework to address the heterogeneity of the CCS population by characterizing stable and unstable CCS patients.

Methods:

CCS patients from 4 major spinal cord injury (SCI) trials conducted between December 1991 and March 2017 were stratified into either CCS-S (stable) and CCS-U (unstable). Outcome differences at 1 year, along with the proportion of patients achieving the minimum clinically important difference (MCID), were assessed using American Spinal Injury Association motor and functional independence measure (FIM) scores. A subgroup analysis, adjusted by propensity score matching, compared surgically treated CCS-S patients. Multivariable regression analysis was conducted to identify independent predictors of 1-year outcomes.

Results:

Among the 2452 SCI patients, 268 were diagnosed with CCS. Among these, 124 (46%) patients were classified as CCS-S with significantly older mean age (49.74 v. 44.06 years, p = 0.01) and predominantly male sex, compared with CCS-U. Falls were the primary cause of injury in the CCS-S group, while vehicular crashes dominated in CCS-U. CCS-S patients showed greater improvement in Upper Extremity Motor Score (UEMS) (mean difference [MD] 3.61, p = 0.03), FIM motor (MD 7.07, p = 0.02), and FIM total scores (MD 7.07, p = 0.03). Patients undergoing surgery achieved significantly greater functional independence, with a higher proportion reaching the FIM Motor MCID (67.6% v. 35.7%, p = 0.004). CCS-S emerged as an independent predictor of neurological and functional improvement at 1-year follow up.

Conclusion:

CCS-S patients showed superior neurological and functional improvement despite worse baseline status. Surgical intervention was associated with better functional outcomes. Adopting uniform terminology for CCS-S will facilitate treatment optimization and help address the heterogeneity of this condition.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S71–S72.

Abstract ID 13. Program Code C31. Optimal tracheostomy timing following traumatic complete spinal cord injury: a comparative analysis of ultra-early, early and delayed practice

Ahmad Essa ^1,², Husain Shakil ¹, Armaan K Malhotra ¹, Avery B Nathens ³, Jetan Badhiwala ³, Eva Y Yuan ¹, Yingshi He ¹, Francois Mathieu ¹, Michael C Sklar ¹, Jefferson Wilson ¹, Christopher D Witiw ¹

Background:

We sought to determine the association between adverse events and tracheostomy timing in patients with complete traumatic cervical spinal cord injury (SCI).

Methods:

This multicentre retrospective observational cohort study used data from the Trauma Quality Improvement Program between 2010 and 2020. The study included all traumatic complete cervical SCI patients who underwent spine surgery and tracheostomy. Tracheostomy timing was categorized into ultra-early (≤ 3 days), early (4 to 7 days), and delayed (> 7 days) after spine surgery. The primary outcome was the occurrence of major in-hospital complications (HC). Secondary outcomes included immobility complications (IC), surgical site infections (SSI), hospital and intensive care unit (ICU) length of stay (LOS), and the duration spent on mechanical ventilation. A secondary analysis directly comparing ultra-early and early tracheostomy groups was also performed.

Results:

A total of 2 907 269 patients were analyzed; 307 (10.6%) underwent ultra-early, 1034 (35.5%) early, and 1566 (53.9%) delayed tracheostomy. Adjusted multivariable analyses revealed significant reductions in HC and IC by 33% to 47% and 28% to 32%, respectively, for patients in the ultra-early and early tracheostomy groups compared with the delayed group. Additionally, both ultra-early and early tracheostomy groups experienced similar shorter hospital and ICU stays, as well as shorter durations on mechanical ventilation compared with delayed group. Secondary analysis with direct comparison between the ultra-early and early tracheostomy groups showed a significant reduction of 3 days in ICU LOS in the ultra-early group. However, there were no significant differences in HC, IC, SSI, hospital LOS, or the duration spent on a ventilator between the ultra-early and the early tracheostomy groups.

Conclusion:

Our findings indicate that both ultra-early and early tracheostomy provide comparable benefits compared with delayed tracheostomy. If confirmed in prospective studies, this flexibility in tracheostomy timing would allow physicians to assess patients more thoroughly, ensuing goal-concordant care, and make informed decisions without compromising the advantages of early intervention.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S72.

Abstract ID 123. Program Code C32. Early stabilization improves outcomes in unstable thoracolumbar fractures without neurological injury

Samuel Yoon ^1,², Luke A Reda ^1,², Armaan Malhotra ², Hussain Shakil ², Michael G Fehlings ^2,³, Christopher D Witiw ^2,⁴, Jefferson R Wilson ^2,⁴, Jetan H Badhiwala ^1,²

Background:

We sought to determine whether early thoracolumbar fracture stabilization is associated with decreased complications and define “early” time frame for surgery.

Methods:

This was an observational cohort study with data from trauma centres participating in the American College of Surgeons Trauma Quality Improvement Program. Adults (age ≥ 16 years) with thoracolumbar fracture without spinal cord injury undergoing operative intervention were included. Time between arrival to trauma centre and start of surgery for fracture stabilization was the independent variable. In-hospital complication was the primary outcome. Secondary outcome measures were medical, immobility-related and surgical complications; mortality; hospital length of stay (HLOS); intensive care unit length of stay (ICULOS); and days of mechanical ventilation (DMV).

Results:

The sample included 36 041 patients with a mean age of 49.8 ± 19.7 years. Of these, 12 157 patients (33.7%) were female. Mean time to thoracolumbar fracture fixation was 46.9 ± 36.5 hours. Regression modelling with splines demonstrated an inflection point around the 24-hour mark, after which risk-adjusted probability of major complications, as well as medical, immobility-related, and surgical complications, began to increase. Using 24 hours from arrival to surgery as definition of early surgery, propensity-matched cohort comparisons revealed significantly fewer medical (621 v. 762; adjusted RR [ARR] 1.17%, 95% confidence interval [CI] 0.58% to 1.76%, p < 0.01) and immobility-related (294 v. 390; ARR 0.80%, 95% CI 0.38% to 1.22%, p < 0.01) complications with early surgery. Overall HLOS (11.1 ± 8.9 days v. 9.8 ± 9.5; p < 0.01), ICULOS (6.6 ± 6.4 days v. 5.3 ± 6.2 days; p < 0.01), and DMV (7.1 ± 8.3 days v. 6.3 ± 9.4 days; p < 0.01) were significantly less with early surgery. There were no significant differences in surgery-specific complications and mortality.

Conclusion:

The 24-hour time point marks a significant increase in major complications in unstable thoracolumbar fractures. Comparative analyses reveal decreased complications and improved HLOS and ICULOS with early intervention using this time frame. We suggest early stabilization to constitute intervention within 24 hours to optimize postoperative complications and, wherever possible, to adopt early stabilization of thoracolumbar fractures as overall injury and patient characteristics permit.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S72–S73.

Abstract ID 160. Program Code C33. Functional outcomes between surgical and nonsurgical treatment for neurologically intact patients with thoracolumbar burst fractures

Said Sadiqi ¹, Sander PJ Muijs ², Charlotte Dandurand ¹, Marcel F Dvorak ¹, F Cumhur Oner ²; AO Spine Knowledge Forum Trauma and Infection³

Background:

Controversies remain on the optimal treatment of thoracolumbar (TL) burst fractures. A very first patient-reported outcome measure for spine trauma was developed: AO Spine PROST (Patient-Reported Outcome Spine Trauma), which has shown reliability and validity in short-term prospective studies. This study investigated differences in return to preinjury functional status, as measured by PROST, between surgical and nonsurgical neurologically intact TL burst fracture patients. Secondary objective was long-term prospective validation of PROST.

Methods:

An observational, prospective multicentre cohort study was conducted. Patients (18 to 65 years) with acute traumatic TL burst fracture were included. Patients with neurological deficits, pathologic processes or neoplasia, previous surgery or polytrauma were excluded. The surgical or nonsurgical procedure was per standard of care at each institution. PROST was administered at baseline, and at 6 weeks, 3 months, 6 months, 1 year, and 2 years posttrauma. Descriptive statistics were used to analyze patient characteristics and PROST scores, and the Tukey–Kramer test for p values. Validation analyses for PROST included floor and ceiling effects, internal consistency using Cronbach’s α and item–total correlation; and responsiveness using effect size (ES) and standardized response mean (SRM).

Results:

A total of 98 patients were included, 61 (62.2%) treated nonsurgically and 37 (37.8%) surgically. Both patient groups showed gradual improved functional outcomes (mean [95% confidence interval], p > 0.05): PROST at baseline 38.9 (33.4 to 44.4) versus 35.4 (31.0 to 39.8), and at 2-year follow-up 84.9 (79.7 to 90.1) versus 87.1 (82.9 to 91.4), respectively. Interestingly, from 6 months onward, surgical patients had better functional outcomes: 80.3 (75.2 to 85.4) versus 74.5 (68.3 to 80.8) at 6 months, 84.4 (79.4 to 89.4) versus 77.9 (71.9 to 84.0) at 1 year, and 87.1 (82.9 to 91.4) versus 84.9 (79.7 to 90.1) at 2 years. PROST ceiling effect was seen at 2 years (15.4%). Internal consistency was excellent (α = 0.90 to 1.00) and responsiveness was satisfactory (ES 1.3 to 3.8, SRM 1.6 to 3.2).

Conclusion:

To our knowledge, this is the first study investigating prospective functional outcomes of patients sustaining TL burst fractures, as compared with their preinjury level of function using the AO Spine PROST. From 6 months onward, surgically treated patients showed better functional status. To our knowledge this is also the first study investigating long-term prospective validation of PROST, and showed excellent results.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S73.

Abstract ID 95. Program Code C34. Development of a classification-based algorithm for prognosticating community ambulation following acute traumatic spinal cord injury: a populational cohort study on 1209 patients

Antoine Dionne ^1,², Andréane Richard-Denis ^1,², Philippe Phan ^3,⁴, Pascal Mputu Mputu ², Jean-Marc Mac-Thiong ^1,²

Background:

Recovery of ambulation remains one of the top patient priorities following spinal cord injury (SCI). As a result, patients and their families will often inquire about their prognosis for walking very early after the accident. Unfortunately, existing tools to assist spine surgeons in establishing the prognosis of long-term ambulation have a high probability of error and are scarcely used as a result. The objective of this study was to design a practical algorithm to assist clinicians in this task while reducing the risk of inaccurate prediction.

Methods:

A retrospective cohort study of 1209 patients from the Rick Hansen Spinal Cord Injury Registry was conducted. The outcome was the level of outdoor walking independence 12 months following SCI: dependent/household ambulation, limited community ambulation, and independent community ambulation. Classification and regression tree (CART) analysis was performed to predict community ambulation, while stratifying for initial American Spinal Injury Association Impairment Scale (AIS) grade.

Results:

The proportion of patients achieving dependent/household, limited community, and independent community ambulation were, respectively, 2%, 5%, 94% in AIS grade A, 12%, 16%, 72% in AIS grade B, 28%, 23%, 50% in AIS grade C, and 65%, 24%, 11% in AIS grade D. After performing the CART analyses, the final tree was obtained with 4 prognostic variables: initial AIS grade, AIS lower extremity motor score, age, and mechanism of trauma.

Conclusion:

This study proposes a practical clinical algorithm that provides the expected probabilities of achieving 3 levels of ambulation for individuals sharing the same baseline characteristics, allowing for a more nuanced and comprehensive prognostication of long-term walking ability than proposed prediction rules.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S73.

Abstract ID 100. Program Code C35. Using oral midodrine to accelerate weaning of intravenous vasopressors in traumatic spinal cord–injured patients admitted to the intensive care unit

Vivian Huong Hoang Thien Le ^1,², Pascal Mputu Mputu ^1,², Andreane Richard-Denis ^1,², Francis Bernard ^1,², Yiorgos Alexandros Cavayas ², Antoine Dionne ^1,², Jean-Marc Mac-Thiong ^1,²

Background:

Patients with acute traumatic spinal cord injuries (SCIs) are usually admitted to the intensive care unit (ICU) to ensure hemodynamic stability and adequate perfusion of the spinal cord, mainly through the administration of intravenous vasopressors. However, prolonged use of intravenous vasopressors can lead to complications such as tachyphylaxis, arrhythmia, tissue ischemia, and impaired end-organ function. The administration of oral midodrine may facilitate weaning of intravenous vasopressors such as norepinephrine after acute SCI, while accelerating discharge from ICU and minimizing complications associated with intravenous vasopressors. This study investigates whether midodrine can accelerate the weaning of intravenous vasopressors within 24 hours of its introduction.

Methods:

A retrospective study with a crossover design was performed on a cohort of 28 patients with acute traumatic SCI while in the ICU. The doses of intravenous vasopressors and mean arterial pressure (MAP) were compared from 24 hours before to 24 hours following initiation of midodrine. The length of ICU stay was also noted.

Results:

Midodrine was started on average 4.0 ± 1.9 days after initiation of intravenous vasopressor therapy. Twenty-two patients (78.6%) received less intravenous vasopressors during the 24-hour period after initiation of midodrine. MAP remained similar 24 hours before versus after initiation of midodrine (90.4 ± 3.3 v. 88.6 ± 5.1 mm Hg). Earlier introduction of midodrine was significantly related to more rapid weaning and reduced total duration of intravenous vasopressor therapy. Shorter duration of norepinephrine therapy was associated with shorter length of ICU stay.

Conclusion:

Initiating oral midodrine in the ICU within 7 days of a traumatic SCI resulted in a rapid decrease in intravenous vasopressor requirements in close to 80% of patients. MAP targets were maintained with administration of oral midodrine and decreased doses of intravenous vasopressors. Earlier introduction of oral midodrine resulted in shorter duration of intravenous vasopressor therapy. Therefore, initiating oral midodrine within the first week of an acute traumatic SCI has the potential to accelerate weaning of intravenous vasopressors and facilitate discharge from the ICU.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S74.

Abstract ID 42. Program Code C36. Imaging-confirmed traumatic conus medullaris injury: factors associated with recovery in motor strength, ambulation capacity, bowel and bladder function

Najmedden A Attabib ¹, Heather A Hong ², Dilnur Kurban ², Tianyu Yang ², Nader Fallah ², Christiana L Cheng ², Suzanne Humphreys ², Vanessa K Noonan ², Dana El-Mughayyar ¹, Michael Craig ³, Colleen O’Connell ⁴; the Rick Hansen Spinal Cord Injury Registry Network²

Background:

Traumatic conus medullaris injury (TCMI) can affect leg, bowel, bladder, and sexual function. This study aimed to 1) determine the incidence of TCMI and 2) examine factors associated with recovery of motor strength, ambulation capacity, and bowel and bladder function at discharge from acute/rehabilitation care (if attending) in individuals with TCMI confirmed by imaging data.

Methods:

Participants with a traumatic spinal cord injury at or below T11 were identified in the Rick Hansen Spinal Cord Injury Registry (RHSCIR) 2004 to 2020 data set. TCMI was confirmed by magnetic resonance imaging or computed tomography scans. Descriptive, bivariate, and multivariable regression analyses were performed to examine factors associated with the lower-extremity motor score (LEMS), LEMS change, independent ambulation, and bowel and bladder independence and score change using relevant Functional Independence Measure (FIM) and/or Spinal Cord Independence Measure (SCIM) subscores at discharge.

Results:

Of 8273 RHSCIR participants, 1054 (12.74%) experienced an injury at or below T11, and 168 (2.03%) had imaging-confirmed TCMI. Eighteen participants were excluded owing to polytrauma. Of 150 TCMI cases analyzed, the median LEMS at discharge was 41, with a median LEMS improvement of 6 points; 53% achieved independent ambulation; and 23% and 26% gained FIM/SCIM independence in bowel and bladder functions, respectively. The median improvement in bowel and bladder function FIM scores was 4.5 points. Significant findings from regression analyses showed that the American Spinal Injury Association Impairment Scale (AIS) and LEMS at admission were associated with discharge LEMS; injury level and rehabilitation length of stay (rLOS) correlated with independent ambulation at discharge; age at injury, rLOS, and voluntary anal contraction (VAC) at admission were associated with FIM bowel score change; only VAC at admission was associated with independent bladder function at discharge.

Conclusion:

To our knowledge, this study is the first to report the incidence of TCMI in Canada and provides insights into the outcomes of achieving independent ambulation, and bowel and bladder function at discharge. Notably, AIS, LEMS, VAC, and rLOS were associated with TCMI recovery outcomes, potentially enhancing prognostic accuracy and informing patient education and rehabilitation planning.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S74.

Abstract ID 43. Program Code C37. Development and validation of a computed tomography–based artificial intelligence screening tool for acute cervical spine trauma

Husain Shakil ¹, Zixuan Hu ², Christopher W Smith ², Armaan K Malhotra ¹, Ahmad Essa ², Hui M Ling ², Zakariya M Khan ², Ervin Sejdic ¹, Errol Colak ², Christopher D Witiw ¹

Background:

In the setting of cervical spinal trauma (CST), there is high-quality evidence demonstrating that earlier intervention leads to improved outcomes. This poses a significant triage challenge to regional hospitals reliant on patient transfer for surgical treatment. In this study, we develop and test an artificial intelligence (AI)–based screening tool to predict likelihood of surgical intervention for patients with a traumatic injury to the cervical spinal column and/or spinal cord using computed tomography (CT) imaging obtained in the emergency department.

Methods:

Patients with CST treated at a level-1 adult trauma centre in Ontario, Canada, from 2005 to 2023 were retrospectively included using a local trauma registry. Two channel separated convolutional networks (CSNs), 3 two-dimensional combination convolutional and recurrent neural networks, and 2 vision transformer models were trained, internally validated, and tested using cervical spine CT scans. Binary patient-level labels corresponding to whether the patient received surgical intervention to the spine served as the reference standard.

Results:

There were 3068 trauma patients with spine CT scans included in the study. There were 383 patients (12.5%) who underwent surgery for CST. There were 2254 patients in the training and validation cohort (n = 286 underwent surgery, 12.7%), 398 patients in the internal test cohort (n = 50 underwent surgery, 12.6%), and 416 patients in the hold-out test cohort (47 underwent surgery, 11.3%). The CSN models were found to have the greatest mean sensitivity (91.5%, 95% confidence interval [CI] 80.1% to 96.6%), specificity (94.0%, 95% CI 91.1% to 96.0%), area under the receiver operating characteristic curve (0.93, 95% CI 0.89 to 0.97), negative predictive value (98.7%, 95% CI 96.7% to 99.5%), and positive predictive value (61.4%, 95% CI 48.4% to 72.9%).

Conclusion:

To our knowledge, this study demonstrates, for the first time, that AI-based prediction models can be used to identify patients with CST who are likely to require surgical intervention.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S74–S75.

Abstract ID 103. Program Code C38. The ElectroSacroGram: a point-of-care electrophysiological method for transforming neuro-sacral assessment following spinal cord injury/lesion

Maude Duguay ¹, Juan David Cifuentes Hernandez ¹, Jean-Marc Mac-Thiong ^1,^2,³, Antoine Dionne ¹, Natan Bensoussan ^1,², Andreane Richard-Denis ^2,⁴

Background:

We sought to develop a point-of-care method for quantitative assessment of the neuro-sacral function combining key elements of the digital rectal examination (DRE) using a handheld portable surface electromyography (s-EMG) device providing live results, termed ElectroSacroGram (ESG). We also assessed its content/concurrent validity in 101 neuro-sacral assessments completed among a cohort of 65 individuals suspected of having acute spinal cord injury/lesion (SCI/L).

Methods:

A cross-sectional prospective cohort study was performed (2022 to 2023) in a single level-1 specialized trauma centre. The ESG method was first developed in a cohort of 8 neurologically intact participants to quantify the motor response’s amplitude of the external anal sphincter (EAS) resting tone, maximal voluntary anal contraction (maxVAC), and bulbocavernosus (BCR) reflex. In addition, sacral sensory sparing was assessed using electrical perceptual threshold (EPT) at S4–5 sensory key points. Concurrent and content validity, reliability, and sensibility/specificity were assessed to measure how well the ESG distinguishes between neurologically impaired and neuro-intact individuals, as opposed to the current gold standard (DRE done by a SCI expert).

Results:

Healthy participants presented with a mean anal resting tone of 2.15 ± 0.49 μV, maxVAC of 21.46 ± 7.29 μV, BCR of 4.80 ± 2.49 μV, and EPT of 3.50 ± 2.22 mA. The ESG showed an excellent content validity (> 95%), as rated by experts who agreed on its relevance for neuro-sacral assessment. Concurrent validity was very good to excellent with a Cohen’s κ coefficient of 0.887, and 0.908 for maxVAC and EPT, respectively. Each component of the ESG had excellent intra-rater reliability (intraclass correlation coefficient [ICC] 0.964 to 0.989) and good-to-excellent inter-rater reliability (ICCs 0.808 to 0.968), as well as good-to-excellent sensitivity and specificity to detect neurologically impaired individuals. Moreover, the ESG identified contractions undetected by experienced clinicians in 3% and 15% of cases for maxVAC and BCR.

Conclusion:

The ESG is a valid and reliable point-of-care precision tool providing for the first time a live quantitative assessment of the neuro-sacral function following suspected SCI/L. The ESG is accessible and has the potential to transform the assessment of SCI/L for clinical and research purposes.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S75.

Abstract ID 62. Program Code D39. Rate of surgical site infection following spinal surgery and effectiveness of preoperative intranasal photodynamic disinfection therapy and chlorhexidine gluconate body wipes prophylaxis: a quality-of-care study

Louis Carrier ¹, Jocelyn Blanchard ¹, Bernard LaRue ¹, Ariane Paquette ¹, Yan Gabriel Morais Silva ¹

Background:

Surgical site infections (SSIs) following spine surgery can lead to morbidity and increased hospital costs. To reduce the incidence of spinal SSI, combined use of preoperative intranasal photodynamic disinfection therapy (nPDT) and chlorhexidine gluconate body wipes (CHG) can be utilized and was found to significantly decrease SSI rates in spine patients. In this study, we aimed to determine the rate of SSI following spine surgeries before and after the introduction of nPDT-CHG prophylaxis in our centre (April 2023). Secondary outcomes were to determine the compliance rate in our centre following elective and urgent procedures and to evaluate the effectiveness of nPDT-CHG prophylaxis for reduction in spine SSIs in the as-treated population.

Methods:

This is a single-centre retrospective quality of care study. All adult patients who had spinal surgery in 2023 in our institution were included. Patients without a clinical follow-up were excluded.

Results:

Preliminary results include 336 patients, of which 123 (37%) were before and 213 (63%) were after the introduction of nPDT-CHG prophylaxis. The SSI rate was 5.7% in the first group compared with 4.2% in the second group (p = 0.599). In the group after introduction of prophylaxis, overall compliance rate was 61%. However, subanalysis showed a large difference between elective and urgent procedures (83.8% v. 7.8%, p < 0.001). As-treated analysis showed a statistically significant difference for all SSI (1.5% v. 6.8%, p = 0.0337) as well as for deep SSI (0.8% v. 5.8%, p = 0.0195). When looking only at elective cases, decrease in deep SSI remained statistically significant (0.8% v. 5.1%, p = 0.06).

Conclusion:

Preliminary results show no significant difference in overall SSI rate in an intention-to-treat analysis. However, issues with compliance for urgent procedures likely influenced our results, as demonstrated with the as-treated analysis and elective cases subanalysis. Our data suggest a clear benefit of nPDT-CHG prophylaxis and efforts should be made to increase compliance in emergency cases.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S75–S76.

Abstract ID 153. Program Code D40. Enhancing patient experience: utilization of a cross-sectional patient experience and education survey to identify and implement changes with patient educational videos in ambulatory orthopaedic spine clinic

Christopher J Nielsen ¹, Vaidehi Bhatt ¹, Stephen J Lewis ¹, Y Raja Rampersaud ¹

Background:

Patient experience is the sum of all interactions that influence patient perceptions across the continuum of care. Patient education contributes to overall patient experience, but provider-led education places additional burden on physicians, and digital resources in spine education report low quality of information and production. Educational videos for 5 spine conditions were developed as part of a quality improvement (QI) initiative.

Methods:

Cross-sectional quantitative patient experience and education surveys were administered across orthopedic clinics as a plan-do-study-act initiative. Phase 1 collected baseline data across subspeciality orthopedic clinics. A total of 125 postappointment surveys across orthopedics, and 26 from spine clinics, were collected and identified a need for improved education in spine clinics. Educational videos were created for 5 conditions: spinal stenosis, adult spinal deformity, lumbar radiculopathy, cervical radiculopathy, and cervical myelopathy. Phase 2 collected results after patients watched an educational video specific to their diagnosis.

Results:

Phase 2 included 54 postappointment surveys of spine patients after watching the spine education video. In Phase 1, 66.7% of patients felt that the amount of time spent on education was adequate, which improved to 81.5% in Phase 2. A total of 69.6% of patients reported that the education provided by provider(s) was beneficial in Phase 1 compared with 88.9% in Phase 2. A total of 82.6% of patients in Phase 1 reported that the provider(s) explained in a method patients could understand, compared with 92.6% in Phase 2. Patient-reported satisfaction with information they received about their condition and treatment increased from 82.6% to 87.0% from Phase 1 to Phase 2. Lastly, the percentage of patients who felt better able to manage their condition postappointment increased from 50.0% to 72.2% from Phase 1 to Phase 2.

Conclusion:

This QI patient experience and education initiative demonstrates the efficacy of educational videos in empowering patients to better understand and manage their condition without placing an additional burden on health care providers. For future direction, we can recommend refinement of video content based on patient feedback while expanding to other common diagnoses.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S76.

Abstract ID 127. Program Code D41. Aquatic exercise versus standard care on paraspinal muscle morphology and function in patients with chronic low back pain: a randomized controlled trial

Brent Rosenstein ¹, Chanelle Montpetit ¹, Nicolas Vaillancourt ¹, Geoffrey Dover ^1,^2,³, Christina Weiss ⁴, Lee Ann Papula ⁴, Antonys Melek ⁴, Maryse Fortin ^1,^4,³

Background:

Low back pain (LBP) is a disabling disease and a public health concern. Aquatic exercise is a promising therapy as it reduces spinal loading, increases movement capacity, and facilitates exercises that may be challenging to perform on land. Presently, the effects of aquatic exercise on paraspinal muscle morphology and function, and the relationship between muscle health and patient outcomes are unknown. This study aimed to investigate the effect of an aquatic exercise program (SwimEx) versus standard care (SC) on lumbar paraspinal muscle volume and composition, strength, and patient outcomes in individuals with chronic LBP.

Methods:

This randomized controlled trial included 34 participants with chronic LBP. Participants were randomly allocated to each group (SwimEx, n = 18; SC, n = 16) and underwent a 10-week supervised intervention program twice per week. Magnetic resonance imaging was performed at baseline and 10 weeks to examine the impact of each intervention on multifidus (MF) and erector spinae (ES) muscle volume (cm³) and fatty infiltration (%FI) at L1–L2, L2–L3, L3–L4, L4–L5, and L5–S1.

Results:

Mixed model repeated measures analysis of variance revealed no significant time by group interactions for MF and ES volume and %FI. SwimEX had significant increases in MF volume at L2–L3 and L3–L4, and ES volume at L1–L2. Furthermore, SwimEX also had a significant increase in MF %FI at L2–L3. Both groups displayed significant increases in lumbar strength. Correlations between muscle morphology and patient outcomes showed that improvements in MF volume were moderately correlated with an increase in physical quality of life and decrease in anxiety/depression. Improvements in MF volume, MF %FI, and ES %FI were each moderately correlated with a decrease in sleep disturbance.

Conclusion:

Aquatic therapy may help increase lumbar paraspinal muscle volume and strength in participants with chronic LBP. Our findings support the notion that improvements in paraspinal muscle health are related to improvements in important patient outcomes. More imaging studies are required to examine the impact of exercise on overall paraspinal muscle health in chronic LBP and investigate these associations.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S76.

Abstract ID 3. Program Code D42. Duration of subfascial drainage and the risk of cerebrospinal fluid leak and infection following durotomy

Ali M Fazlollahi ¹, Uri Barak ², Samira Kalhor ¹, Joshua Hien Nguyen ¹, Carlo Santaguida ^1,²

Background:

We sought to determine the optimal duration of postdurotomy subfascial drain use and its impact on complications, including cerebrospinal fluid (CSF) leaks and infections.

Methods:

A retrospective review was conducted on 125 patients who experienced an intentional or unintentional dural tear while undergoing cervical, thoracic, or lumbar spinal surgery between November 2015 and February 2023. All patients received intraoperative dural repair and postoperative subfascial drains. Data on patient demographics, surgical details, drain duration, and postoperative complications were collected. Patients were grouped based on duration of drain removal: ≤ 3 days, 4 days, and ≥ 5 days.

Results:

Eight patients (6.4%) developed complications, including 5 wound infections (4%), 3 CSF leaks (2.4%), and 3 symptomatic pseudomeningoceles (2.4%). Drainage of 4 days was associated with a 12% increase in the likelihood of avoiding complications compared with both premature (≤ 3 days) or delayed (≥ 5 days) drain removal (relative risk [RR] 1.12, p = 0.018 with premature; RR 1.12, p = 0.019 with delayed). The highest incidence of wound infections occurred with drains left for ≥ 5 days (n = 6 [10.5%]), whereas CSF leaks were primarily observed with drain removal of ≤ 3 days (n = 2 [11.1%]).

Conclusion:

Optimal drain removal timing appears to be on postoperative day 4. Compared with drains of longer duration, drainage of 4 days increased the likelihood of avoiding a wound infection, whereas with shorter durations, drainage of 4 days increased the likelihood of avoiding a CSF leak. These findings guide postoperative management of patients following dural repair who receive subfascial drainage.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S76–S77.

Abstract ID 110. Program Code D43. Implementation of the Enhanced Recovery After Surgery perioperative consensus protocol in lumbar fusion surgery at a single Canadian institution in Calgary, Alberta: early results of a 200-patient cohort

Ruheksh Raj ¹, Peter Lewkonia ¹, Kyle Rogan ¹, Allison Marchuk ², Erin Barrett ², Anand Masson ¹, Brandy Pratt ², Danielle Michaud ², Kateryna Skyrda ², Sierra Simms ², Michael Yang ¹

Background:

Implementation of Enhanced Recovery After Surgery (ERAS) Society protocols has been shown to improve patient outcomes after surgery. The ERAS Society protocol for lumbar fusion was published in 2021. The purpose of this study was to describe the early results of implementing the ERAS Society protocol on lumbar fusion surgery at a quaternary hospital in Calgary, Alberta, Canada.

Methods:

The comprehensive ERAS protocol was implemented at the Foothills Medical Centre, Calgary, Alberta, on July 1, 2023, with patients receiving standardized ERAS preoperative and postoperative order sets. We randomly selected and compared 100 pre- and post-ERAS implementation patients. Automatic data extraction for patient demographics, along with manual data extraction from our electronic medical record (Epic), was used. Staged and targeted quality-improvement initiatives of high-value ERAS recommendations were performed postimplementation. Univariable analyses were performed to assess the impact of protocol implementation on ERAS compliance measures and postoperative outcomes.

Results:

Mean age in the preimplementation group was 57.4 and 60.1 in the postimplementation group. The most common primary complaint was lumbar radiculopathy in both groups. Five compliance measures were significantly improved postimplementation (preoperative education, preoperative nutritional screening, pre-emptive analgesia, foley discontinued by postoperative day [POD] 0, and any mobilization on POD 0, all p < 0.05). The percentage of patients achieving ≥ 75% compliance rate for all measures improved from 7% to 38.5% (p < 0.001). Reoperation rates at 30 days were 9.9% v. 0% in the pre- and postimplementation cohort, respectively (p = 0.06). Rates of severe complications were 10% in the preimplementation group and 2.3% in the postimplementation cohort (p = 0.1). No significant difference was observed in the length of hospital stay.

Conclusion:

Implementation of an ERAS protocol for lumbar fusion surgery in Calgary has resulted in improved compliance in several ERAS elements. We observed trends toward reduction in severe complications and reoperations rates in the postimplementation cohort. A larger patient sample and ongoing quality-improvement initiatives may result in improvements in other outcome measures and confirm the trends currently seen.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S77.

Abstract ID 5. Program Code D44. Increased risk of surgical site infection after spine surgery with vancomycin surgical antibiotic prophylaxis when compared with cefazolin

Brandon J Herrington ¹, Jennifer C Urquhart ², Parham Rasoulinejad ¹, Fawaz Siddiqi ¹, Kevin Gurr ¹, Christopher S Bailey ¹

Background:

Surgical site infection (SSI) after spine surgery has severe negative health and financial consequences. Surgical antibiotic prophylaxis (SAP) is a routinely used method to prevent SSIs in the spine patient population. The most commonly used antibiotic is cefazolin, with vancomycin often being substituted in the case of penicillin or cephalosporin allergy. Vancomycin as SAP has been associated with increased SSI in the joint replacement literature, but this is not yet well defined in the spinal surgery population. The purpose of this study is to determine whether vancomycin SAP compared with cefazolin SAP is associated with increased risk of SSI.

Methods:

A retrospective analysis was conducted on previously gathered data from a single-centre randomized controlled trial on 552 patients, aged 16 years or older, who underwent elective, multilevel open posterior spinal fusion surgery at the thoracic, thoracolumbar, or lumbar levels. Demographic and operative characteristics, as well as postoperative outcomes, were compared between the following groups: 1) noninfected-cefazolin, 2) noninfected-vancomycin, 3) infected-cefazolin, and 4) infected-vancomycin. The primary outcome measures were superficial and complicated (deep and organ/space) infections. Risk factors were then identified with statistical analysis using multivariate logistic regression.

Results:

The following risk factors for SSI were identified in a logistic regression analysis: vancomycin (odds ratio [OR] 2.498, 95% confidence interval [CI] 1.085 to 5.73; p = 0.031), increasing operating time (OR 1.006, 95% CI 1.001 to 1.010; p = 0.010), weight (OR 1.020, 95% CI 1.006 to 1.034; p = 0.005), revision procedure (OR 2.343, 95% CI 1.283 to 4.277; p = 0.006), and depression (OR 2.366, 95% CI 1.284 to 4.360; p = 0.006).

Conclusion:

In open posterior approach spinal fusion surgery, vancomycin SAP is associated with increased risk of infection compared with cefazolin SAP, and this increased risk is not necessarily a result of inadequate dose or timing of administration. Clinicians should ensure patients with a suspected β-lactam allergy receive appropriate preoperative investigation into the nature of their allergy, in order to prevent unnecessary administration of vancomycin in those who can ultimately tolerate cefazolin.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S77–S78.

Abstract ID 53. Program Code D45. Understanding the influence of cage and instrumentation strategies with oblique lumbar interbody fusion for grade I spondylolisthesis — a comprehensive biomechanical modelling study

Mathieu Chayer ^1,², Philippe Phan ³, Pierre-Jean Arnoux ⁴, Zhi Wang ^5,⁶, Jeremy Rawlinson ^7,⁸, Olumide Aruwajoye ⁸, Carl-Éric Aubin ^2,^7,^6,⁹

Background:

Proper implant selection and placement in oblique lumbar intervertebral fusion (OLIF) are essential to achieve the best possible results for the patient. Challenges remain in selecting appropriate cage characteristics (e.g., height, length, material) to control spinal alignment while minimizing subsidence risk. This study aims to biomechanically model and investigate how variations in interbody cage dimensions, positioning, and material properties influence indirect decompression, realignment, and stresses involved in cage subsidence.

Methods:

A finite element model of the L4–L5 segment with grade I spondylolisthesis was used to simulate 172 OLIF configurations. Key parameters included cage length (40 to 60 mm), height (10 to 14 mm), angle (6° or 12°), material (polyetheretherketone [PEEK] or titanium), and position (anterior, central, posterior). Bilateral pedicle screw (BPS) fixation was also tested. Simulated outcomes measured included disc height, foraminal and spinal canal dimensions, segmental lordosis, vertebral slip, and endplate stresses. Statistical analyses were performed to assess the impact of these variables on surgical outcomes.

Results:

Longer cages (60 mm) reduced vertebral endplate displacements and stresses by 33% compared with shorter cages (40 mm) (p < 0.05). Posterior cage positioning improved the decompression but raised stresses by 45% and reduced segmental lordosis by 28%. Lowering cage height from 14 to 10 mm and increasing the angle from 6° to 12° reduced endplate stresses by 53% and 33%, respectively. BPS fixation decreased stresses by 36% on average. The trends observed concurred with published OLIF clinical studies.

Conclusion:

This study highlights the biomechanical influence of implant characteristics and positioning on OLIF outcomes. The findings indicate that using longer cages reduce endplates stresses, potentially lowering the risk of subsidence. However, posterior placement, despite enhancing decompression, increases stresses and leads to inferior lordosis correction, revealing trade-offs between achieving decompression, obtaining a desired realignment, and minimizing subsidence risk. This study further confirms that the developed tools can accurately simulate the surgical approach to corroborate clinical findings and also offer a relevant framework for in-depth analysis.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S78.

Abstract ID 24. Program Code D46. An aging world, an aging spine: the impact of preoperative frailty and sarcopenia on surgical outcomes in degenerative cervical myelopathy

Hussein Samhat ^1,², Karlo M Pedro ³, Ali Ahmadi Pirshahid ⁴, Raphaële Charest-Morin ⁵, Genevieve Gore ⁶, Kristian B Filion ^1,^2,⁷, Oliver Lasry ^1,^2,⁸

Background:

Degenerative cervical myelopathy (DCM) is the leading cause of nontraumatic spinal cord dysfunction in adults worldwide, resulting in a wide spectrum of neurological deficits. Surgical decompression and stabilization of the cervical spine is the standard treatment, but it carries inherent risks with variable outcomes. As the population ages and DCM cases rise, spine surgeons must make informed surgical decisions, underscoring the need for effective risk stratification. Frailty, a state of reduced physiological reserve, and sarcopenia, the loss of muscle mass and function, have been explored as risk stratification tools in other surgical fields and some spine pathologies. However, their impact in DCM remains poorly understood. Our primary objective is to synthesize evidence on the association between preoperative frailty/sarcopenia and surgical outcomes in adult DCM patients within 1 year post-surgery. Secondary objectives include examining the interaction of frailty/sarcopenia with surgical approaches, underlying DCM causes, and patient characteristics.

Methods:

We systematically searched 8 databases, including MEDLINE and Embase, using comprehensive inclusion criteria based on our registered PROSPERO protocol (CRD42024477896). Two independent reviewers conducted screening, data extraction, and risk of bias assessment using RoBANS-2.

Results:

The search yielded 7021 records, and after we screened 4131 manuscripts, 10 studies met the inclusion criteria — 6 focused on frailty, and 4 on sarcopenia. Higher frailty levels were consistently associated with increased postoperative complications, longer hospital stays, more frequent nonroutine discharges, and higher health care costs. Similarly, sarcopenia was associated with poorer spinal alignment, reduced functional outcomes, and lower patient satisfaction after surgery. These patterns were observed across diverse patient demographics and hospital settings.

Conclusion:

Frailty and sarcopenia play a critical role in preoperative evaluations, improving the prediction of surgical risks and outcomes. These factors should be integral to surgical decision-making, potentially guiding personalized care plans for better postoperative recovery in DCM patients.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S78–S79.

Abstract ID 105. Program Code D47. Effect of symptom duration on postoperative outcomes in degenerative cervical myelopathy: a Canadian Spine Outcomes and Research Network study

Jordan J Levett ¹, Nicolas Dea ², Nathan Evanview ³, Greg McIntosh ⁴, Michael H Weber ⁵

Background:

Surgery is the gold standard treatment for progressive or at least moderate degenerative cervical myelopathy (DCM); however, the impact of surgical treatment on patient outcomes remains unknown. The aims of this study were primarily to evaluate the association between symptom duration and postoperative outcomes, and secondarily, to identify factors associated with extended duration of symptoms prior to surgical consultation for DCM.

Methods:

This study analyzed patients enrolled in the Canadian Spine Outcomes and Research Network from 2015 to 2023. Patients with mild to severe DCM with 1-year follow-up were included. During initial assessment, surgeons recorded symptom duration categorically with 6 choices, which was reduced to a binary variable using a 12-month threshold. Differences between groups were analyzed using unadjusted bivariate analysis, and the associations between delayed surgical treatment on minimal clinically important differences (MCIDs) of patient-reported outcomes (PROMs) were assessed using multivariable logistic regression analysis.

Results:

A total of 483 patients (227 in the standard group and 256 in the extended) were included. Preoperatively, body mass index (BMI)(p < 0.008), number of comorbidities (p < 0.029), and proportion of tobacco users (p < 0.027) were significantly higher among those with symptoms for 12 months or greater, who also had poorer baseline modified Japanese Orthopaedic Association (mJOA) scores (12.5 v. 13.2, p < 0.002). After controlling for baseline confounders, the group with a symptom duration of < 12 months was associated with higher odds of achieving the MCID for the outcomes Neck Disability Index (odds ratio [OR] 1.64; p < 0.030), 12-Item Short-Form Survey, Physical Component Summary (SF-12 PCS) (OR 1.98; p < 0.005) and EQ-5D (OR 2.08; p < 0.002) at 1 year postoperatively. The odds of reaching the MCID for the mJOA did not significantly differ by symptom duration (OR 1.41; p < 0.153).

Conclusion:

DCM patients with a symptom duration of ≥ 1 year before surgery experienced inferior outcomes for disability and health-related quality of life compared with patients waiting < 1 year, despite similar neurologic outcomes. Preoperative factors associated with a longer symptom duration were notably tobacco usage, BMI, and number of comorbidities. These results suggest that efforts to prioritize early diagnosis and referral for surgery are warranted.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S79.

Abstract ID 181. Program Code D48. Laminoplasty for patients with degenerative cervical myelopathy: an observational and comparative study of posterior cervical approaches from the Canadian Spine Outcomes and Research Network

Nadav Rinott ¹, Mathieu Laflamme ², Greg McIntosh ³, Nathan Evaniew ⁴, Michael H Weber ¹, Nicolas Dea ⁵

Background:

Cervical laminoplasty is a motion-preserving procedure that is an alternative to fusion for degenerative cervical myelopathy (DCM). Our objectives were to 1) describe the population of patients selected for laminoplasty in Canada, and 2) compare their characteristics and patient-reported outcomes (PROs) to patients who underwent other types of posterior cervical procedures.

Methods:

Patients enrolled in the prospective DCM study from the Canadian Spine Outcomes and Research Network and underwent laminoplasty were selected. Clinical, surgical, and radiologic data at baseline and 12 months postoperatively were compared. Our primary outcome was achievement of minimal clinically important difference (MCID) on the Neck Disability Index (NDI) at 12 months after surgery. Secondary outcomes included modified Japanese Orthopaedic Association (mJOA), neck and arm pain, 12-Item Short-Form Survey (SF-12), intraoperative data, and cervical sagittal alignment.

Results:

Laminoplasty alone (n = 37) was compared to laminectomy alone (n = 34) and to laminectomy with fusion (n = 240). Mean mJOA was higher than in the fusion group at baseline (12.9 v. 11.8; p < 0.04). There were no significant differences at baseline for NDI, pain, and SF-12 between groups. Laminoplasty patients had significantly smaller sagittal vertical axes (SVAs) than the others at baseline (15.5 v. 27.8 and 29.1 mm, p < 0.05). Laminoplasty patients had significantly longer operative time (184.7 v. 102.2 minutes; p < 0.001), higher blood loss (282.9 v. 184.2 mL; p < 0.03) and more levels decompressed (3.9 v. 2.1; p < 0.001) than laminectomy alone. At 12 months, the proportion of patients reaching MCID on the NDI was smaller for the laminoplasty group (25.7%) than fusion (46.3%; p < 0.04) but similar to the laminectomy group (48%; p = 0.12). Proportions of patients reaching MCID for mJOA, SF-12, and pain were similar among all groups. Adjusting for baseline score, there were no significant differences in 12-month PROs between all groups.

Conclusion:

Patients selected for laminoplasty had significantly better mJOA and smaller SVA at baseline compared with fusion patients; however, the potential advantages of preserving the range of motion did not translate into more improved NDI or any other PROs at follow-up.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S79–S80.

Abstract ID 33. Program Code D49. Cervical laminectomy without fusion versus cervical laminoplasty: comparing rate of conversion to fusion

Andy Liu ¹, Alexander Tuchman ¹, Christopher Mikhail ¹, Vivien Chan ¹

Background:

The theoretical benefit of performing a laminoplasty is to preserve motion while reducing risk of postoperative kyphosis associated with cervical laminectomies. However, there is a paucity of data comparing outcomes between cervical laminectomy without fusion and cervical laminoplasty. The purpose of this study was to compare the rate of conversion to cervical fusion between patients who received cervical laminectomy and cervical laminoplasty for degenerative cervical disease.

Methods:

The PearlDiver database for years 2010 to 2021 was queried for patients who received either a posterior cervical laminectomy or a cervical laminoplasty for a diagnosis of degenerative cervical disease. We excluded neoplastic, infectious, and traumatic etiologies. We excluded patients with previous cervical spine surgery, a diagnosis of cervical kyphosis, and < 2 years of follow-up. Multivariable regression analysis was performed to identify variables associated with conversion to fusion. A matched analysis was performed using the significant variables. Rate of conversion to cervical fusion was determined for each cohort for 2 years, 5 years, and 10 years after surgery. The rates of conversion to fusion between the 2 cohorts were compared using a χ² test. Survival analysis was performed.

Results:

A total of 4406 patients (laminectomy 2258; laminoplasty 2148) were included in this study. In the multivariable logistic regression analysis, age and obesity were significant variables for conversion to fusion. In the matched analysis, the rate of conversion to fusion for laminectomy at 2 years, 5 years, and 10 years were 3.2%, 5.0%, and 5.7%, respectively. The rate of conversion to fusion for laminoplasty at 2 years, 5 years, and 10 years were 2.2%, 3.2%, and 3.5%, respectively. There was no significant difference between the 2 groups at 2 years after surgery (p = 0.07). Patients who received cervical laminectomy had a higher rate of conversion to fusion than cervical laminoplasty at 5 years (p < 0.01) and 10 years (p < 0.01) after surgery.

Conclusion:

In patients with degenerative cervical disease, cervical laminectomy had a higher rate of conversion to cervical fusion than cervical laminoplasty at 5 years and 10 years postsurgery.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S80.

Abstract ID 63. Program Code E50. Treatment modality and outcomes in patients with mild degenerative cervical myelopathy

James McDonald ¹, Julien Zaldivar ¹, Nicolas Dea ¹, Nikolaus Koegl ¹, Greg McIntosh ², Nathan Evaniew ³

Background:

There is a lack of evidence regarding the management of patients with mild degenerative cervical myelopathy (DCM), because there is no consensus on the best treatment modality. Our objective was to compare patient-reported outcomes (PROs) of patients with mild DCM, treated nonoperatively versus surgically.

Methods:

We reviewed data from the ongoing prospective, multicentre, observational cohort study from the Canadian Spine Outcomes and Research Network. All patients in the final cohort were enrolled between January 2015 and August 2024. Mild DCM was defined as a modified Japanese Orthopaedic Association (mJOA) score of ≥ 15. We analyzed each group according to mJOA, radiographic findings, and PROs (numeric pain rating, Neck Disability Index [NDI], 12-Item Short-Form Survey [SF-12] physical (PCS) and mental component summary [MCS] scores, and EQ-5D) at baseline and 1-year follow-up.

Results:

There were 361 patients with mild DCM; 119 were treated nonoperatively and 242 surgically. The overall mean mJOA at enrolment was 16.2 (standard deviation ± 1.0): nonoperative 16.7 (SD ± 0.9), surgical 15.9 (SD ± 0.9). There were no baseline statistically significant sociodemographic differences between groups. The nonoperative groups had significantly lower baseline neck pain, arm pain, and NDI, but higher SF-12 and EQ-5D scores (p < 0.05). Radiographically, there were no differences between groups on alignment, C2–7 cobb angle, T1 slope, C2–7 sagittal vertical axis, instability, or cord signal change. Adjusting for baseline scores, the surgical group had significantly lower neck pain rating (2.72 v. 3.45; p < 0.009) and NDI (20.3 v. 24.2; p < 0.020) and higher PCS (44.7 v. 40.9; p < 0.002) at 1-year follow-up; there were no significant differences in mJOA, arm pain, MCS, or EQ-5D. The surgical group had a significantly higher proportion reaching minimal clinically important difference at 1 year for all PROs (p < 0.001) except MCS.

Conclusion:

Among 2 sociodemographic and radiographically similar groups with mild DCM, patients treated surgically had greater improvement in most PROs at 1-year follow-up, compared with those treated nonoperatively. These findings will facilitate discussion with regard to the initial management of patients with mild DCM.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S80–S81.

Abstract ID 120. Program Code E51. Comparative analysis of lumbar disc herniation treatment outcomes: conventional versus endoscopic techniques in a prospective multicentre study

Guillaume Lonjon ¹, Matthieu Vassal ¹, Alexandre Dhenin ¹, Alexis Perez ², Martin Dupuy ², Vincent Challier ³, Jean-Etienne Castelain ³, Soufiane Ghailane ³, Matthieu Campana ³, Jonathan Lebhar ⁴, Gilles Guerin ⁴, Nicolas Pellet ⁵, Yann Sabah ⁶, Thomas Chevillotte ⁷, Alice Darnis ⁷, Joseph Cristini ⁸, François-Xavier Ferracci ⁸, Jérôme Delambre ⁹, Steffen Queinnec ⁹, Alexandre Delmotte ¹⁰, Paulo Marinho ¹⁰, Rémi Gauthe ¹¹, Pierre Hannequin ¹¹, Vianney Gilard ¹¹, Jean Meyblum ¹², Alexis Perrin ¹³, Raphaël Pietton ¹⁴, Nicolas Lonjon ¹⁵, Antoine Gennari ¹⁶

Background:

Spinal endoscopy for lumbar disc herniation surgery has been reported to enhance early postoperative patient comfort. However, evidence highlighting its benefits on medium-term functional outcomes still needs to be explored. This study aims to fill this gap by evaluating the functional results and complication rates associated with conventional and endoscopic disc herniation surgeries. The objectives are to compare the functional outcomes and medium-term complication rates of lumbar disc herniation surgeries performed using conventional “open” techniques (tube or self-retaining retractor) versus endoscopic approaches (full-endoscopy or unilateral biportal endoscopy).

Methods:

A total of 1055 patients who underwent surgery for herniated discs across 17 French centres by 30 surgeons in 2023 were prospectively included. Eighteen surgeons performed the “open” technique, with an average of 7 years of experience, while the “endoscopic” group involved 12 surgeons with an average 1 year of experience. Functional outcomes assessed included the visual analogue scale for lumbar pain (VAS-L), radicular pain (VAS-R), and the Oswestry Disability Index (ODI).

Results:

The study included 688 patients in the “open” group and 367 in the endoscopic group, with comparable baseline characteristics. The endoscopic group surgeries had a longer average duration (53 v. 41 minutes, p < 0.001). No significant differences between the groups were observed in medium-term improvements in ODI, VAS-L, and VAS-R scores. The surgical site infection rate was lower in the endoscopic group than in the “open” group (0% v. 1.9%, p = 0.011). No technique demonstrated superiority in functional outcomes.

Conclusion:

This multicentre study found no significant difference in medium-term functional outcomes between conventional and endoscopic techniques for lumbar disc herniation surgery, although endoscopic approaches were associated with longer surgery times and a lower rate of surgical site infections. Despite the varied experience levels among surgeons, endoscopic techniques achieved comparable functional results to traditional methods, suggesting their effectiveness and safety for herniated disc treatment.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S81.

Abstract ID 40. Program Code E52. Anterior versus posterior surgery for degenerative cervical myelopathy: a cost-utility analysis

Armaan K Malhotra ¹, Husain Shakil ¹, Ahmad Essa ², Nathan Evaniew ³; Canadian Spine Outcomes and Research Network (CSORN) Investigators⁴, Christopher D Witiw ¹, Jefferson R Wilson ¹, Nicolas Dea ⁵

Background:

Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction worldwide. There is still uncertainty regarding the optimal surgical approach for treatment of this disease. We therefore sought to compare anterior to posterior surgery for the treatment of patients with multilevel (2- to 3-level) DCM.

Methods:

This cost-utility analysis used the health care payer perspective with a lifetime horizon. Patient utility measures were derived from the prospective multicentre Canadian Spine Outcome Research Network study. Costing data were obtained through systematic review and meta-analysis of North American studies. We identified DCM patients undergoing surgery for 2- or 3-level DCM between 2015 and 2022. The primary outcome was the incremental cost-utility ratio (ICUR) of anterior compared with posterior surgery. Utility values were determined from 12-month postsurgical EQ-5D. Propensity score matching between anterior and posterior surgical groups ensured confounder balance. A random-effects meta-analysis was conducted to pool costs derived from the systematic review. A time-homogeneous Markov state transition model was then used to estimate lifetime costs and utilities associated with each treatment.

Results:

We included 142 matched DCM patients (71 anterior group, 71 posterior group) after propensity score matching. At 12 months postsurgery, there was no significant difference in EQ-5D between treatment groups (mean difference [MD] 0.05, p = 0.055 [t test]). Meta-analysis of 10 studies found no significant difference in direct cost between the treatment groups with respect to initial in-patient care (MD −US$4,030.28, p = 0.919 [unpaired t-test]). Lifetime projections found anterior surgery was associated with 0.83 quality-adjusted life years (QALYs) gained at a cost of US$5814.60 relative to posterior surgery, on average. The resulting ICUR was US$6979.54/QALY. After Monte Carlo microsimulation of 10 000 cases, 98.3% were at the willingness-to-pay threshold, highlighting the dominance of the anterior strategy for lifetime cost-effectiveness.

Conclusion:

We found an incremental lifetime health-economic benefit to anterior surgery for multilevel DCM in the setting of clinical equipoise. The absolute gains in QALYs were small, suggesting either surgical approach can be considered depending on patient factors.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S81–S82.

Abstract ID 66. Program Code E53. Advanced imaging markers of spinal cord demyelination enhance the prediction of neurological outcomes in mild degenerative cervical myelopathy

Abdul Al-Shawwa ¹, Michael Craig ², Kalum Ost ¹, W Bradley Jacobs ^2,³, Nathan Evaniew ^2,⁴, Peter Lewkonia ^2,⁴, Fred Nicholls ^2,⁴, Alex Soroceanu ^2,⁴, Ganesh Swamy ^2,⁴, Kenneth C Thomas ^2,⁴, Michael MH Yang ^2,³, Julien-Cohen Adad ^5,^6,⁷, David W Cadotte ^1,^2,^3,⁸

Background:

Degenerative cervical myelopathy (DCM) is the most prevalent cause of nontraumatic spinal cord injury globally. Clinical decisions regarding surgery in patients with mild DCM who experience subtle neurologic deficits remain filled with uncertainty owing to the unpredictable natural history of disease progression. This study aims to define predictive imaging and clinical biomarkers of neurological decline in mild DCM through the use of quantitative magnetic resonance imaging (qMRI) and machine learning models, aiding clinical practice and assisting surgeons in stratifying patients for surgical intervention.

Methods:

This prospective cohort study included 49 patients with nonoperative, mild DCM who underwent advanced MRI scanning protocols, including T₂-weighted imaging, diffusion tensor imaging, and magnetization transfer (MT) imaging. Clinical evaluations were conducted at baseline and 6-month intervals for up to 2 years. qMRI metrics were derived above and below the maximally compressed cervical level (MCCL). Machine learning models integrating both clinical and qMRI metrics were developed to predict 6-month neurologic deterioration, with feature importance examined to identify the most predictive metrics.

Results:

Across 110 6-month interval scans, neurological deterioration was observed in 38% of patients. Models combining clinical and qMRI data achieved superior predictive performance, with a balanced accuracy of 83% and an area under the receiver operating characteristic curve of 0.87. The MT ratio, specifically myelin loss in the dorsal and ventral funiculi above MCCL, emerged as a top predictive feature, along with symptoms of moderate tingling in the upper extremities (Quick Disabilities of Arm, Shoulder & Hand [QuickDASH] item 10). The qMRI-enhanced models significantly outperformed clinical-only balanced accuracy (b.acc): 68.1%) and imaging-only (b.acc: 57.4%) models, underscoring the value of advanced imaging in clinical decision-making.

Conclusion:

This study presents qMRI-derived metrics as valuable, actionable markers for neurologic deterioration in mild DCM. Identifying early myelin degeneration in dorsal and ventral tracts, combined with upper extremity sensory symptoms, may inform surgical decisions in patients with minimal yet progressive deficits. These findings promote a proactive approach in DCM management, reducing uncertainty in surgical decision-making. Multicentre studies are needed to validate these findings, with the goal of supporting timely, targeted intervention.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S82.

Abstract ID 138. Program Code E54. Anterior versus posterior surgery for 2- or 3-level compression in degenerative cervical myelopathy: findings from the Canadian Spine Outcomes and Research Network

Isaac Wangai ¹, Andrew Nataraj ², Osman Hojanepesov ³, David Cadotte ⁴, Matthew Skarsgard ⁴, Nathan Evaniew ⁴, Jerome Paquet ⁵, Perry Dhaliwal ⁶, Najmedden Attabib ⁷, Jennifer Urquhart ¹, Nicolas Dea ⁸, Chris Bailey ¹

Background:

We sought to compare outcomes for patients with 2 or 3 levels of degenerative cervical myelopathy (DCM) treated with either an anterior or posterior surgical approach based on the location of pathologic compression (anterior, posterior, or circumferential).

Methods:

This is a retrospective cohort study of all patients enrolled in the Canadian Spine Outcomes and Research Network DCM prospective study (2015 to 2023) who underwent 2- or 3-level decompression with either an anterior or posterior surgical approach, had a preoperative magnetic resonance imaging scan, and completed a 1-year follow-up. Patients were grouped according to the surgical approach and pathology. Circumferential pathology was grouped with posterior pathology.

Results:

A total of 171 patients were included, with 80 having an anterior approach and 91 a posterior approach. A total of 100 (58%) had a 2-level procedure. Forty-five (26%) had isolated anterior compression, 3 (2%) had isolated posterior compression, and 123 (72%) had circumferential compression. A total of 33 (19.3%) had anterior surgery for anterior compression, 79 (46%) had posterior surgery for circumferential pathology, 47 (27.5%) had anterior surgery for circumferential pathology, and 12 (7%) had posterior surgery for anterior compression. Patients with anterior pathology were more likely to have an anterior approach 33/45 (73%) and patients with circumferential compression were more likely to have a posterior approach 74/126 (63%, p = 0.001). The proportion of patients with mild, moderate, and severe preoperative modified Japanese Orthopaedic Association (mJOA) score was similar between the cohort of patients with anterior compression and those with circumferential compression (p = 0.417). For anterior-based compression, the proportion of patients who achieved a minimal clinically important difference for mJOA did not differ significantly between anterior and posterior approaches (p = 0.163). For circumferential compression, this difference was significant only for those patients with moderate mJOA, in favour of posterior surgery (p = 0.023).

Conclusion:

The location of compression often dictates the direction of surgery, demonstrating that subcohort comparison is important when comparing surgical approach. However, outcomes comparing anterior with posterior surgery for circumferential disease were slightly in favour of posterior surgery, while there was no difference between the two for anterior-based disease.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S82–S83.

Abstract ID 82. Program Code E55. A comprehensive assessment of the influence of frailty in patients undergoing surgery for degenerative cervical myelopathy

Vishwathsen Karthikeyan ¹, Husain Shakil ¹, Armaan Malhotra ¹, Christopher Lozano ¹, Jefferson Wilson ¹, Michael Fehlings ¹, Jetan Badhiwala ¹

Background:

We sought to evaluate the impact of frailty on functional status, disability, and quality of life outcomes in patients with degenerative cervical myelopathy (DCM).

Methods:

Data from 2 prospective cohort studies (AO Spine Cervical Spondylotic Myelopathy [CSM]–North America; AO Spine CSM–International) and 1 randomized controlled trial (CSM-Protect) of DCM were combined. Outcomes included modified Japanese Orthopaedic Association (mJOA), Neck Disability Index (NDI), and 36-Item Short-Form Survey (SF-36) scores. Frailty was assessed using a 30-item DCM-related frailty index (DCM-FI) derived with Searleand and colleagues’ method. Patients were classified as nonfrail (< 0.3) or frail (≥ 0.3) based on DCM-FI. Differences in outcomes between frail and nonfrail groups at baseline and 6 months and 1 year postoperatively were analyzed by mixed-effects regression adjusting for age, baseline mJOA, and baseline outcome score. Multivariable linear regression compared frailty and age associations with 1-year outcome changes.

Results:

A total of 797 patients met eligibility criteria (mean age 56.6 ± 11.4 years; 37.5% female) of whom 230 (28.9%) were nonfrail, and 567 (71.1%) were frail. Frail patients had greater impairment, disability, and poorer quality of life at baseline. On adjusted comparison, the frail group showed greater improvements in mJOA (mean difference [MD] 0.59, p < 0.01), NDI (MD −7.43, p < 0.01), SF-36 physical component summary (PCS; MD 3.38, p < 0.01), and SF-36 mental component summary (MCS; MD 34.40, p < 0.01) at 6 months postsurgery but remained more impaired overall, persisting at 1 year. Adjusting for equal baseline scores, frailty was linked to proportionally smaller improvements in mJOA (MD −0.62, p < 0.01), NDI (MD 3.84, p < 0.01), SF-36 PCS (MD −1.78, p = 0.02), and SF-36 MCS (MD −1.90, p = 0.03) at 6 months, with significant associations for mJOA and SF-36 PCS persisting at 1 year. Frailty was a stronger predictor of changes in mJOA, NDI, SF-36 PCS, and SF-36 MCS at 1 year than age.

Conclusion:

Frail patients had larger postoperative improvements in mJOA, NDI, and SF-36 scores, yet their overall outcomes remained worse than those of nonfrail patients at 6 months and 1 year. Adjusting for baseline scores, frailty was independently associated with smaller incremental improvements after surgical decompression and was a stronger predictor of outcomes than age.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S83.

Abstract ID 37. Program Code E56. Patient characteristics and outcomes associated with severe neck pain presentation in degenerative cervical myelopathy: an observational study from the Canadian Spine Outcomes and Research Network

Nikolaus Koegl ^1,², Greg McIntosh ³, Nicolas Dea ¹, Nathan Evaniew ⁴, Raphaële Charest-Morin ¹

Background:

Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord dysfunction in adults. Little is known about neck pain (NP) as a driver for surgery. The objective of this study was to identify DCM patients with severe neck pain (Numeric Rating Scale for Neck Pain [NRS-NP] ≥ 8) and compare baseline characteristics and their surgical outcomes to those with less severe neck pain.

Methods:

Patients surgically treated for DCM between 2015 and 2022 enrolled in the prospective, multicentre observational cohort study of Canadian Spine Outcomes and Research Network were included. Baseline demographics, clinical/surgical details, and preoperative patient-reported outcomes (PROs) and modified Japanese Orthopaedic Association (mJOA) were compared between the patients with severe NP and those with less severe NP. Between-group improvements at 12 months were assessed using analysis of covariance to adjust for any significant baseline differences between these groups.

Results:

A total of 725 DCM patients were treated surgically within the study period. Of the patients, 31.7 % presented with severe NP. Baseline characteristics differed significantly; patients with severe NP were younger, smokers, unemployed, less commonly retired or married, more likely to use pain medication or to have a history of depression, had more comorbidities, and did less physical activity (p < 0.05). Baseline PROs (NRS AP and NP, Neck Disability Index [NDI], 12-Item Short-Form Survey [SF-12] mental component summary [MCS] and physical component summary [PCS] and EQ-5D) were significantly worse (p < 0.001) in this subgroup. There was no difference in the mean 12 months mJOA score between the 2 groups. The patients presenting with severe NP continued reporting worse NRS neck pain score at 12 months (3.9 ± 2.9 v. 2.6 ± 2.3, p < 0.001). When adjusted for baseline difference, there was no difference between the 2 groups with the following 12-month PROs: NRS arm pain, NDI, SF-12 PCS, EQ-5D. The SF-12 MCS remained significantly worse in the severe baseline NP (p < 0.05).

Conclusion:

A third of the DCM population presented with severe neck pain. These patients presented with significantly worse baseline characteristics and PROs. Despite worse baseline PROs, these patients benefited similarly from surgery as patients with less severe neck pain.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S83.

Abstract ID 185. Program Code E57. Physician prediction of ambulation outcomes from degenerative cervical myelopathy surgery improves with machine learning clinical tool

Daniel Kurtz ¹, Philippe Phan ¹, Christopher Sun ¹

Background:

Accurate prediction of surgical outcomes for patients with degenerative cervical myelopathy (DCM) is challenging owing to the multifactorial factors involved. Literature indicates that surgical DCM treatment leads to improved functional status and patient satisfaction, but prevailing DCM assessment tools do not consider demographic, radiologic, and functional data in a holistic assessment.

Methods:

Data were extracted from an ongoing, prospective national DCM observational cohort study. Patient-related, clinical, and radiologic variables were selected based on relevant features influencing outcomes in literature. Preoperation ambulation status was extracted with the modified Japanese Orthopaedic Association (mJOA) scoring system and divided into nonambulatory, dependent, and independent ambulation groups. xgBoost, random forest (RF), and support vector machine (SVM) machine learning (ML) models were used to predict the change in lower extremity function mJOA between the 12-month follow-up and before surgery. Physician predictive abilities with and without the assistance of the most effective ML model were assessed with an online survey.

Results:

Models were derived from 467 patients who met inclusion criteria, with minority sample sizes increased with the Synthetic Minority Oversampling Technique. Primary model evaluation metrics were area under the curve (AUC) and Brier Score (BS). The xgBoost model (AUC 0.98, BS 0.19) had the best performance compared with the RF (AUC 0.98, BS 0.20) and SVM (AUC 0.89, BS 0.27) models. The survey, completed by 24 spinal surgeons, indicated that the ML model’s predictions enhanced clinician predictive abilities (p = 0.0068), with an average predictive accuracy of 35.4% (± 3.1%) without and 52.1% (± 5.0%) with model predictions, versus 86% accuracy for the model on the testing set.

Conclusion:

The algorithms had good predictive ability for the change in ambulatory mJOA, with some variation between methods. A statistically significant improvement in clinician prediction accuracy was seen when model predictions were provided, indicating the model’s benefits for determining patient functional improvement. Implementing the xgBoost model in clinical practice could improve surgical decision-making and give patients an accurate estimate of surgical success given their unique clinical histories.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S83–S84.

Abstract ID 112. Program Code E58. Assessment of spinal cord tract injury in degenerative cervical myelopathy

Newton Cho ¹, Abdul Al-Shawwa ¹, Bradley Jacobs ¹, Nathan Evaniew ¹, Jacques Bouchard ¹, Steven Casha ¹, Stephan duPlessis ¹, Peter Lewkonia ¹, Fred Nicholls ¹, Alex Soroceanu ¹, Ganesh Swamy ¹, Kenneth Thomas ¹, Michael Yang ¹, Julien Cohen-Adad ², David Cadotte ¹

Background:

Degenerative cervical myelopathy (DCM) is the most common form of atraumatic spinal cord injury (SCI). Surgical intervention is the main therapy to improve neurologic function, although motor dysfunction may still persist. In traumatic SCI, compensatory motor recovery in the presence of corticospinal tract injury has been shown to be mediated by reticulospinal pathways. However, the exact anatomical substrates for compensatory motor recovery in DCM remain elusive. The purpose of this study was to comprehensively assess spinal cord tract integrity in DCM patients to understand which tracts could potentially act as substrates for recovery.

Methods:

Magnetic resonance imaging and diffusion tensor imaging (DTI) sequences of the cervical cord were performed in healthy volunteers and DCM patients. Registration of the imaging to the PAM50 template and an atlas of the key spinal cord white matter tracts was performed with Spinal Cord Toolbox. Fractional anisotropy (FA) was extracted at C3, above the level of maximal compression to compare healthy volunteers and patients with DCM to characterize retrograde degeneration of specific tracts in the spinal cord.

Results:

Six healthy volunteers and 25 patients with DCM (13 mild and 12 moderate to severe on the modified Japanese Orthopaedic Association scale) were analyzed in the study. Twelve annotated spinal cord tracts were analyzed. FA was significantly reduced in the lateral corticospinal tract (mild DCM v. healthy Δ = −0.13, p = 0.018; moderate to severe DCM v. healthy Δ = −0.11, p = 0.047), fasciculus gracilis (mild DCM v. healthy Δ = −0.16, p = 0.010; moderate to severe DCM v. healthy Δ = −0.13, p = 0.039), and fasciculus cuneatus (mild DCM v. healthy Δ = −0.16, p = 0.007; moderate to severe DCM v. healthy Δ = −0.15, p = 0.012) in DCM patients compared with healthy controls.

Conclusion:

In DCM patients, altered DTI signal in the lateral corticospinal tract and posterior column sensory tracts suggest injury to these tracts. No differences were observed in the other tracts examined. Further research needs to be performed to examine whether these other tracts could play a role in compensatory motor recovery.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S84.

Abstract ID 65. Program Code E59. Personalized blood biomarkers in surgically treated chordoma: a pilot study

Raphaële Charest-Morin ¹, Landon Hansen ², Stephen Yip ³, Nicolas Dea ¹, Rory C Goodwin ⁴, Charles G Fisher ¹, Chetan Bettegowda ²

Background:

The aim of this study is to determine whether monitoring circulating tumour DNA (ctDNA) in plasma is a reliable biomarker for monitoring for residual disease, tumour progression, and tumour recurrence in surgically treated chordoma. We aim to establish a reliable workflow with a reproducible assays to measure ctDNA in patient plasma. We assess ctDNA burden from chordoma patient blood samples collected before surgery and at the time of discharge and correlate ctDNA burden and outcomes (local recurrence and metastasis).

Methods:

Plasma was collected preoperatively and at the time of discharge. Whole exome sequencing was performed on patient tumour samples after surgical resection to establish the tumor mutation profile. At least 2 mutations per patient were selected based on whether they occur in driver genes and induce damage to gene function, with preference given to frameshifts or insertions/deletions over missense mutations. Plasma samples were thawed on ice and ctDNA extracted utilizing commercially available kits. We utilized multiple methods successfully to measure ctDNA in plasma including quantitative real-time PCR (qPCR), droplet digital PCR, and rapid amplification of cDNA ends sequencing.

Results:

Whole exome sequencing was performed on a pilot cohort of 9 patients, identifying a total of 2905 somatic mutations, ranging from 14 to 1407 per sample, with a median of 48 mutations per sample. Preoperative plasma ctDNA was extracted using a commercially available kit, with DNA abundance varying from 20 ng/10 mL to 800 ng/10 mL. Utilizing patient-specific customized qPCR assays to amplify mutant and wild-type alleles, we detected circulating chordoma DNA in each patient with a mutant allele fraction between 0.1% and 1%. The amount of preoperative cell-free DNA correlated with local recurrence (p < 0.05) but not the postoperative cell-free DNA.

Conclusion:

We found that ctDNA is readily detectable in chordoma patient plasma samples in the preoperative period. This provides proof of principle for utilizing ctDNA presence as a biomarker of tumour burden in chordoma and shows promise as a tool to supplement current diagnostic methods.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S84–S85.

Abstract ID 67. Program Code E60. Minimal clinically important differences in the Spine Oncology Study Group Outcomes Questionnaire in patients with symptomatic spinal metastases

Anne L Versteeg ¹, Arjun Sahgal ^1,², Ilya Laufer ³, Laurence Rhines ⁴, Daniel Sciubba ⁵, James Schuster ⁶, Michael Weber ⁷, Aron Lazary ⁸, Stefano Boriani ⁹, Chetan Bettegowda ¹⁰, Michael Fehlings ¹¹, Michelle Clarke ¹², Paul Arnold ¹³, Ziya Gokaslan ¹⁴, Charles Fisher ¹⁵

Background:

The Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ2.0) is a validated tool that measures patient-reported health-related quality of life (HRQoL) in patients with spinal metastases. It is currently, however, unknown whether absolute change in SOSGOQ2.0 represents a clinically meaningful change for a patient. The aim of this study was therefore to determine the minimal clinically important difference (MCID) for the SOSGOQ2.0 in patients with spinal metastases.

Methods:

An international multicentre prospective observational study including patients with spinal metastases who were treated with surgery and/or radiotherapy was conducted by the AO Spine Knowledge Forum Tumor. HRQoL was evaluated using the SOSGOQ2.0 at predefined time points. The MCID values for the SOSGOQ2.0 were determined using both distribution-based and anchor-based methods. For the anchor-based method, the posttherapy questions of the SOSGOQ2.0 served as the anchor. A response of “somewhat better or much better” in the posttherapy questions was used to classify improvement. MCID values from the distribution-based methods were derived using the statistical characteristics of the study population.

Results:

A total of 317 patients had SOSGOQ2.0 data available at baseline and 12 weeks posttreatment and were included in the final analyses. Statistically significant MCID scores were found for the SOSGOQ2.0 total score and all the individual domain scores. The MCID value for improvement in the SOSGOQ2.0 total score, physical function, pain, mental health, and social function domain score based on the anchor are 16.5, 10.2, 26.0, 14.4, and 17.2, respectively. Based on the distribution-based approach, there was moderate agreement between the anchor-based approach and the 0.5-standard deviation values for improvement.

Conclusion:

To our knowledge, this is the first study to report MCID values for the SOSGOQ2.0 total score and domain scores. The results of this study will help both clinicians and researchers with the interpretation of the effect of treatment for painful spinal metastases on patient reported HRQoL.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S85.

Abstract ID 70. Program Code E61. Toward defining frailty in the metastatic spine population: an observational study from the Metastatic Tumor Research and Outcome Network

Anne Versteeg ¹, Michael Weber ², Rafael De La Garza Ramos ³, John Shin ⁴, Mark Pahuta ⁵, Alessandro Luzatti ⁶, Alexander Disch ⁷, Alessandro Gasbarrini ⁸, Jorrit-Jan Verlaan ⁹, William Teixeira ¹⁰, Arjun Sahgal ¹¹, Ilya Laufer ¹², Aron Lazary ¹³, Dean Chou ¹⁴, Charles Fisher ¹⁵, Ziya Gokaslan ¹⁶, Michael Fehlings ¹, Laurence Rhines ¹⁷, Addisu Mesfin ¹⁸, Daniel Sciubba ¹⁹, Chetan Bettegowda ²⁰, Tony Goldschlager ²¹, Cordula Netzer ²², Michelle Clarke ²³, John O’Toole ²⁴, Stefano Boriani ²⁵, Ori Barzilai ²⁶, Nori Kawahara ²⁷, Naresh Kumar ²⁸, Nicolas Dea ¹⁵, Jeremy Reynolds ²⁹, Rory Goodwin ³⁰, Raphaële Charest-Morin ¹⁵; AO Spine Knowledge Forum Tumor³¹

Background:

Frailty has been associated with poor outcomes, including increased mortality, adverse events, and longer hospital stays, in the general spine population. Current frailty tools have shown poor performance in the metastatic spine disease (MSD) population. The primary objective of this study was to determine the patient and oncologic predictors associated with 90-day mortality in patients undergoing surgical treatment for MSD.

Methods:

Patients treated surgically for MSD who were enrolled prospectively between Q3/2017 and Q3/2024 in the multicentric Metastatic Tumor Research and Outcome Network study were analyzed retrospectively. The full data set was divided between a training and a testing set (80% v. 20%). The Lasso algorithm was repeated 100 times to perform variable selection with 80% of the training set. The variables selected at least 80% of the time were used with multiple logistic regression models on the testing set. The variables selected are those included by the procedure at least 80% of the time.

Results:

A total of 1267 patients were included. The best model to predict 90-day mortality was the weighted logistic regression model (mean area under the curve 0.72 over 100 repetitions). On logistic regression for the 90-day mortality, having an Eastern Cooperative Oncology Group (ECOG) score of 0–1 at baseline decreased the odds (odds ratio [OR] 0.54, 95% confidence interval [CI] 0.37 to 0.79), each comorbidity increased the odds 24% (OR 1.24, 95% CI 1.10 to 1.40), elevated body mass index had a slight positive effect (OR 0.94, 95% CI 0.90 to 0.97), the presence of brain/visceral metastasis and presence of > 5 bone metastasis at other sites increased the odds by twofold (OR 2.17, 95% CI 1.48 to 3.19; and OR 2.31, 95% CI 1.57 to 3.42, respectively), having received prior treatment for the previous metastasis decreased the odds (OR 0.44, 95% CI 0.30 to 0.63) and not having a prostate or breast cancer primary tumor site increased the odds (OR 2.50, 95% CI 1.20 to 5.09 to OR 2.21, 95% CI 1.41 to 3.57 depending on the histology).

Conclusion:

This study highlights the multidimensional aspect of frailty in the MSD population. We have isolated patients, and oncological variables that are predictive of 90 days mortality.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S86.

Abstract ID 44. Program Code E62. Days alive and at home after treatment of spinal metastases: measurement and validation of a novel patient-centred outcome

Husain Shakil ¹, Armaan K Malhotra ¹, Ahmad Essa ², Vishwathsen Karthikeyan ¹, Christopher S Lozano ¹, Jetan H Badhiwala ¹, Arjun Sahgal ¹, Nicolas Dea ³, Michael G Fehlings ¹, Alex Kiss ¹, Christopher D Witiw ¹, Donald A Redelmeier ¹, Jefferson R Wilson ¹

Background:

Days spent alive and at home (DAH) is a patient-centred outcome that has yet to be examined in patients with spinal metastases. This study investigates the construct and predictive validity of DAH and examines patient factors associated with DAH after first treatment of a spinal metastasis.

Methods:

A retrospective analysis was conducted of population health data from 2007 to 2019 in Ontario, Canada. Primary study outcomes were DAH at 90 days, 6 months (DAH-180), 1 year (DAH-365), and 2 years (DAH-730) after first treatment of a spinal metastasis. Construct validity was assessed using multivariable quantile regression to estimate adjusted median differences (aMD) in DAH. Predictive validity was determined with Spearman correlations.

Results:

We identified 36 233 patients treated for spinal metastasis. Median DAH for patients followed for 90 days, 6 months, 1 year, and 2 years from treatment were 79 days (95% confidence interval [CI] 78.1 to 79.9 days), 114 days (95% CI 111.1 to 116.9 days), 120 days (95% CI 116.7 to 123.3 days), and 121 days (95% CI 117.8 to 124.2 days), respectively. Multivariable regression found that lower home time was associated with older age (aMD −16 days per decade increase in age, 95% CI −17 to −15 days), frailty (aMD −35, 95% CI −39 to −22 days), and several factors indicating high baseline health resource utilization. The primary cancers associated with the lowest home time included gastrointestinal cancer (aMD −161 days, 95% CI −174 to −148 days), lung cancer (aMD −163 days, 95% CI −180 to −150 days), and melanoma (aMD −165 days, 95% CI −180 to −150 days). DAH-180 demonstrated predictive validity with longer-term DAH-365 (rs = 0.64, p < 0.001), and DAH-730 (rs = 0.43, p < 0.001).

Conclusion:

DAH demonstrated evidence of validity among patients treated for spinal metastases. Older age, pre-existing comorbidities, frailty, high health resource utilization, or those with primary hepatobiliary, melanoma, gastrointestinal, or lung cancer had the least favourable outcomes with spinal metastasis.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S86.

Abstract ID 69. Program Code E63. Recurrence and survival outcomes after surgery for spinal and sacral chordoma and chondrosarcoma: a single-centre 14-year retrospective review

William Chu Kwan ¹, Nikolaus Koegl ^1,², Nicolas Dea ¹, Charles Fisher ¹, Raphaële Charest-Morin ¹

Background:

Spinal chordomas and chondrosarcoma are rare primary bone tumours. In this study, we describe the survival outcomes of 3 cohorts (true en-bloc resection with negative margins, contaminated en-bloc [en-bloc resection with positive margins or previous intralesional resection], and planned intralesional resection) and analyzed variables influencing these outcomes.

Methods:

Retrospective review of patients followed for spinal chordoma and chondrosarcoma at a single institution from 2009 to 2023 were included. Data were collected regarding perioperative management and follow-up. Primary outcomes were local recurrence-free survival (LRFS) and overall survival (OS). Multivariate Cox regression identified the effects of independent predictors on primary outcomes.

Results:

Sixty-three patients had an average follow-up of 6.2 ± 4.1 years. All patients who underwent a true en-bloc did not receive postoperative radiation therapy, 52% of the contaminated en-bloc received either neoadjuvant or adjuvant radiation therapy, and 50% of the intralesional received radiation. LRFS at 5 years was 80%, 64%, and 0% for the true en-bloc, contaminated en-bloc, and intralesional, respectively. Independent predictors of LRFS were true en-bloc resection (hazard ratio [HR] 7.71, confidence interval [CI] 1.66 to 35.90, p = 0.02), younger age (HR 1.14, CI 1.02 to 1.26, p = 0.017), and chordoma histology (HR 13.33, CI 1.19 to 149.88, p = 0.036). The 5-year survival rates were 80%, 64%, and 0%% for the true en-bloc, contaminated en-bloc, and intralesional, respectively. Independent predictors of OS were true en-bloc resection (HR 5.41, CI 1.41 to 21.12, p = 0.004), and younger age (HR 1.12, CI 1.01 to 1.25, p = 0.027).

Conclusion:

Our findings indicate that en-bloc resection for chordoma and chondrosarcoma is associated with lower risk of recurrence rate and death. Younger age lowers the risk of recurrence and death, while a chordoma diagnosis is associated with decreased recurrence compared with chondrosarcoma. Our findings provide a benchmark for counselling patients with spinal chordoma and chondrosarcoma.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S86–S87.

Abstract ID 90. Program Code E64. Postoperative infections in immunocompromised, metastatic spine tumour patients

Alexandra Rocha ^1,², Matthew Renaud ², Jennifer Urquhart ¹, Supriya Singh ^1,²

Background:

Metastatic spine disease often presents with symptoms including unrelenting back pain and neurologic compromise. Surgical tumour debulking, stabilization, and neurologic decompression are used in treatment of metastatic spine disease. Preventing surgical site infection (SSI) in this cohort is of particular importance, as treatment of the infection delays ultimate systemic therapy for their oncology treatment. Literature has reported a 30% to 50% risk of SSI in patients with primary or metastatic spine tumors following surgery. The aim of this study was to determine the SSI rate at our centre and understand the microbiology of postoperative infections in metastatic spine tumour patients.

Methods:

A retrospective chart review of operatively managed, metastatic adult spine tumour patients over a 5-year period was conducted. Chart review included demographic, clinical, and perioperative data collection. Patients were excluded if they had previous spine procedures or spine infections. Of the identified 137 patients who underwent a primary metastatic tumor procedure, 14 required an irrigation and débridement procedure for postoperative spine SSI. Statistical analysis was completed for between-group differences and descriptive analysis regarding micro-organism profiling.

Results:

There were no statistical differences for demographics including age (68 v. 69 years), body mass index (28 v. 25), biological sex (40% v. 57%), preoperative total radiation dose (54 v. 20 Gy), intraoperative factors including operative minutes (188 v. 205), and intraoperative vancomycin powder (36% v. 57%) between noninfected and infected groups, respectively. A significant difference was demonstrated for all-cause 30-day (23% v. 50%, p < 0.05) and 1-year (12% v. 46%, p < 0.005) adverse events between the groups. Nearly 64% of SSI patients exclusively had postoperative gram-positive coverage, and 75% of culture-positive SSI patients had polymicrobial infections.

Conclusion:

Patients with metastatic spine disease who have postoperative SSI are at increased risk of adverse events in a short- and long-term course. Furthermore, these patients are more likely to develop polymicrobial SSI. Further research is required to establish these findings and strategies should be developed to reduce the risk of polymicrobial infection in this high-risk population.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S87.

Abstract ID 25. Program Code E65. Automated psoas muscle segmentation: imaging features and surgical fitness in spinal metastatic lung cancer

Marco Perez Caceres ¹, Omer Ahmed ¹, Véronique Freire ¹, Jesse Shen ¹, Fidaa Al-Shakfa ¹, Danielle Boulé ¹, Zhi Wang ¹

Background:

Lung cancer’s propensity for spinal metastasis leads to fractures, dysfunction, pain, and reduced quality of life. Spinal interventions are selectively offered to patients deemed fit for surgery. Sarcopenia, assessed by psoas muscle (PM) and whole-abdominal muscle (WAM) measurements, is proposed as a fitness marker, but consensus on thresholds and segmentation tools is lacking. This study aims to validate sarcopenia metrics as imaging biomarkers using both open-source and locally tailored neural networks in the context of bone-metastatic lung cancer and spinal surgery.

Methods:

A retrospective cohort of 63 lung cancer patients (age 64 ± 9 years, 46% female) with spinal metastases who underwent surgery between 2010 and 2020 was analyzed. Psoas muscle and lumbar vertebrae segmentation were validated by a musculoskeletal radiologist on computed tomography scans. A local PM segmentation model was trained using nnUNet, and TotalSegmentator (TS) was applied used for PM and WAM segmentation. Sarcopenia metrics (i.e., psoas muscle index [PMI], psoas:lumbar vertical index [PLVI], skeletal muscle index [SMI], total muscle area [TMA]) and radiomic features were evaluated. Survival analysis was conducted based on sarcopenia classification using the Wilcoxon log–rank test.

Results:

The locally tailored psoas segmentation model outperformed TS in 7 metrics. PMI and PLVI thresholds showed significant survival differences only when measured with the local model (p < 0.05), but not SMI or TMA. Percentile-based classification revealed significant survival differences, especially in local PM metrics (p < 0.001). Of 108 radiomic feature clusters, 38 showed significance with the local models, whereas none did with TS WAM segmentation.

Conclusion:

The locally tailored model demonstrated superior performance compared with TS. Percentile-based thresholds and PM features were more predictive of survival, underscoring the need for disease-specific cut-offs. Radiomic features warrant further investigation.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S87–S88.

Abstract ID 73. Program Code P66. Cervical laminectomy for cervical myelopathy: Is there a role in the modern day? A systematic review and meta-analysis

Christopher S Lozano ^1,^2,³, Armaan K Malhotra ^1,^2,³, Vishwathsen Karthikeyan ^1,^2,³, Husain Shakil ^1,^2,³, Neevya Balasubramaniam ⁴, Jefferson R Wilson ^1,^2,³

Background:

We sought to compare clinical outcomes in patients with degenerative cervical myelopathy (DCM) treated with laminectomy alone (LA) versus laminectomy with fusion (LF) and to establish the incidence of post-laminectomy kyphosis.

Methods:

A systematic review and meta-analysis were conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched PubMed, Scopus, Embase, Web of Science, and MEDLINE for studies comparing LA and LF for DCM. Outcomes assessed included postoperative kyphosis, neurological recovery (modified Japanese Orthopaedic Association [mJOA]/JOA scores), patient-reported outcomes, and complication rates. Meta-analyses were performed using random-effects models.

Results:

A total of 25 studies including 3140 patients (2165 with LA and 975 with LF) met the inclusion criteria. Pooled data showed that the incidence of postlaminectomy kyphosis in the LA patients was 2.02 events per 100 person-years (95% confidence interval [CI] 1.26 to 2.78). Stratifying studies by publication era revealed a notable decline in postlaminectomy kyphosis rates over time, with an incidence of 3.37 per 100 person-years (95% CI 2.57 to 4.18) in studies published before 2003, compared with 1.03 per 100 person-years (95% CI 0.59 to 1.47) in studies published after 2015. No significant differences were observed between LA and LF in pre- to postoperative changes in mJOA/JOA scores (mean difference [MD] 0.13, 95% CI −0.97 to 1.22), Neck Disability Index (MD 3.05, 95% CI −3.11 to 9.22), or neck pain scores (MD −0.10, 95% CI −0.89 to 0.69). Complication rates were comparable between groups, with an odds ratio of 0.50 (95% CI 0.17 to 1.51) for LA compared to LF.

Conclusion:

Although LA is associated with a yearly kyphosis incidence of approximately 2%, functional outcomes, pain scores, and complication rates are similar between LA and LF. These findings suggest that both LA and LF are viable options for DCM treatment. However, further randomized trials are needed to better delineate the benefits of each approach and optimize patient selection.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S88.

Abstract ID 104. Program Code P67. P-15 peptide enhanced bone graft in cervical spine fusion: radiologic and clinical outcomes from a prospective, multicenter clinical study

Christopher Witiw ¹, W Bradley Jacobs ², Zhi Wang ³, Perry Dhaliwal ⁴, Carlo Santaguida ⁵, Chris Bailey ⁶

Background:

Anterior cervical discectomy and fusion (ACDF) and posterior cervical fusion (PCF) are procedures for treating degenerative cervical spine conditions. Fusion techniques and bone graft choices affect arthrodesis success. This abstract reports early clinical and radiologic outcomes of P-15 Peptide Enhanced Bone Graft (ABM/P-15 Matrix) in single and multi-level cervical procedures in a multicentre clinical trial.

Methods:

A prospective on-label study was conducted across 6 Canadian hospitals, which included adults requiring cervical spinal fusion between levels C2 and T2. Neurologic status, relevant clinical history, Neck Disability Index (NDI), 12-Item Short-Form Survey (SF-12), Numeric Pain Rating Scale (NRS), and modified Japanese Orthopaedic Association (mJOA) scores (myelopathic participants only) were collected at baseline, 6 months, and 12 months postoperative. High-risk factors included active smoking, obesity (body mass index > 30), and diabetes. Fusion status was assessed by an independent core-lab (Medical Metrics Inc., US) through thin-cut (< 1 mm) computed tomography at 12 months, reported at both segmental and participant levels.

Results:

A total of 76 participants (PCF 45, ACDF 31; male 47, female 29) with 238 total operative levels (mean age ACDF 57.3 ± 11.9 years, PCF 62.9 ± 10.4 years) were included. Of these, 68.4% had high-risk comorbidities (obese 25, smokers 15, diabetic 12). Forty-two PCF (93%) and 23 ACDF (74%) participants had cervical myelopathy. The mean number of levels operated was 4.1 for PCF (range 1 to 7) and 1.5 for ACDF (range 1 to 2). At 12 months, fusion was observed in 92.3% of the 39 PCF participants (full 28, partial 8) and in 96.9% of the 159 segments (full 146, partial 8). For ACDF, 100% of the 20 participants (full 15, partial 5) and the 29 segments (full 23, partial 6) showed fusion. ACDF mean improvement included NDI (p < 0.001), NRS arm (p < 0.001), NRS neck (p < 0.001), mJOA (p = 0.001), SF-12 mental (p = 0.002) and SF-12 physical component summaries (p = 0.005). PCF mean improvement included NDI (p < 0.001), NRS arm (p = 0.006), NRS neck (p < 0.001), mJOA (p < 0.001), and SF-12 physical (p = 0.008). No device-related adverse events were reported.

Conclusion:

High fusion rates were achieved with ABM/P-15 Matrix at 12 months in cervical interbody and posterior spinal arthrodesis. Approximately 75% of participants had high-risk comorbidities, yet no graft-related complications or index level reoperations at 1 year postoperative.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S88.

Abstract ID 148. Program Code P68. Dual fluroscopy can reveal detailed kinematics following cervical total disc arthroplasty. Can it predict failure?

Emily Bangsboll ¹, Koren Roach ¹, Neil Duncan ¹, Paul Salo ¹, Jacques Bouchard ¹, Janet Ronsky ¹, Ganesh Swamy ¹

Background:

Cervical total disc arthroplasty (CTDA) is an alternative to fusion, hypothesized to restore native intervertebral kinematics. However, implant designs are based on in-vitro kinematic estimates. In-vivo investigations are needed to characterize in-vivo implant behaviour. The aim of this study was to compare pre- and post-CTDA in-vivo kinematics using dual fluoroscopy (DF) imaging.

Methods:

Five asymptomatic male control participants (ages 19 to 24 years) and 2 surgical participants undergoing M6C disc arthroplasty were prospectively recruited (ethics ID: REB18-1660). Data were collected from disc arthroplasty patients preoperatively and 3-months postoperatively. Data were collected from control participants at a single time point. Participants were imaged using DF while performing flexion-extension (FE), axial rotation (AR), and lateral bending (LB) range of motion (ROM). Relative 3-D Cardan angles of each vertebral segment were calculated and visualized for each motion segment throughout each primary movement trial. Cardan angles and ROM contributions were qualitatively compared for pre- and 3 months post-CTDA for each surgical participant, as well as to the control group.

Results:

During AR, both postoperative patients had an increased ROM at the index segments, as well as at the adjacent nonsurgical segments, exhibiting similar ROM magnitudes as those of the control group. Following CTDA for Case 1, the AR ROM increased from 1.5° to 4.8° across segments during AR for both cases. Post-CTDA changes in ROM during the FE movement were more variable across all Case 1 and 2 vertebral segments, with increases in ROM ranging from −3.2° to 3.6°. While changes in LB ROM were comparatively smaller for Case 1, the Case 2 cTDA segments increased in LB ROM post-CTDA by 4.3° and 7.4°. Translations were much higher than expected.

Conclusion:

To our knowledge, this study is the first to characterize cervical spine kinematics in vivo following CTDA. These case studies suggest DF is capable and valuable in imaging spinal kinematics. Given the current concerns with wear of the M6C prosthesis, DF imaging may reveal design limitations, particularly with high ranslations. DF will allow for comparisons between implant types and inform future artificial disc designs.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S89.

Abstract ID 31. Program Code P69. Novel anterior approach to the cervical spine: an operative technique

Germain Sophie Ngana ¹, Zain Nassrullah ¹, Mohamed Alhantoobi ², Suhail S Al-Assiri ³, Abdulaziz Al-Zailaie ³, Geofrey Ngetich ³, Desmond Kwok ⁴, Markian Pahuta ⁴, Amanda Martinyuk ², Daipayan Guha ²

Background:

Among anterior approaches to the cervical spine, the Smith–Robinson, or anterolateral approach, is most commonly used by neurosurgeons and orthopedic surgeons to expose vertebrae in the context of discectomy/fusion, arthroplasty, or corpectomy. However, postoperative dysphagia, associated with extended and continuous retraction of the esophagus, remains a significant complication. Here we describe an alternative paramedian strap-splitting approach that provides a direct window to the cervical spine while requiring less retraction of midline structures compared to the more lateral Smith–Robinson approach.

Methods:

Using a cadaveric model, we demonstrate both the standard anterolateral Smith–Robinson approach and the paramedian strap-splitting approach for anterior cervical exposure.

Results:

Our cadaveric study presents a detailed, step-by-step guide for executing the strap-splitting approach and highlights its advantages over the standard Smith–Robinson approach in terms of reduced retraction and more direct midline trajectory to the spine.

Conclusion:

Our comparison of these approaches provides a comprehensive understanding of the surgical anatomy necessary for the strap-splitting approach in anterior cervical spine surgeries as an alternative to the standard Smith–Robinson approach. This strap-splitting method develops a plane between the tracheoesophageal bundle medially and the infrahyoid strap muscles laterally, providing a greater margin of safety from the carotid sheath. Unlike the more lateral Smith–Robinson approach, the strap-splitting technique aligns more directly with the midline, minimizing the retraction of and potential traction injury to midline structures. This in turn may reduce intraoperative pressure on the esophagus and theoretically decrease the incidence of postoperative dysphagia, one of the most common complications of anterior spinal surgery. This detailed description of the strap-splitting approach, to our knowledge not previously described in the literature, provides surgeons with a viable and more direct alternative for anterior cervical spine surgeries. Clinical data are required to quantify the comparative safety and efficiency of this approach.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S89.

Abstract ID 126. Program Code P70. Implementation of the minimal clinically important difference for the Neck Disability Index is often problematic: a methodological review

Nathan Evaniew ¹, Armaan K Malholtra ², Raphaële Charest-Morin ³, Alex Soroceanu ¹, W Bradley Jacobs ¹, David W Cadotte ¹, Nicolas Dea ³

Background:

The most commonly used minimal clinically important difference (MCID) for the Neck Disability Index (NDI) is 7.5 out of 50, but some users double the scale to report total scores out of 100. Implementation of the MCID can be problematic if users are not attentive to the scale of the NDI. Our primary objective was to determine the incidence of inappropriate or uncertain implementation of the MCID for the NDI.

Methods:

We reviewed studies that cited the MCID for the NDI. We systematically searched via the citation tracking features of Google Scholar, PubMed, and Web of Science. We defined appropriate implementation as congruent magnitude of the scales used for NDI data and the MCID.

Results:

We included 163 studies. Twenty (12%) reported a 0 to 50 scale for the NDI, 66 (40%) reported a 0 to 100 scale, and the remaining 77 (47%) did not report which scale was used. Fifty-seven (35%) reported an MCID of 7.5, 37 (23%) reported an MCID of 15, and the remaining 69 (42%) did not report which value of the MCID used. Appropriate implementation occurred in 39 studies (24%), while implementation was inappropriate in 16 (10%) and uncertain in 108 (66%).

Conclusion:

Inappropriate and uncertain implementation of the MCID for the NDI is problematic and occurs often. Evidence users should be cautious when interpreting studies that report on the MCID for the NDI, and should consider whether the magnitude of the scales used for the NDI and the MCID are congruent.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S89–S90.

Abstract ID 139. Program Code P71. State of the machine: a critical analysis of machine learning for diagnosis and prognostication of degenerative cervical myelopathy — what have we learned, and where are we going?

Negeen Halabian ¹, Jiawen Deng ¹, Mohammed Ali Alvi ¹, Karlo M Pedro ¹, Michael G Fehlings ^1,^2,³

Background:

Traditional prognostic and diagnostic models investigating neurologic, functional, and quality-of-life outcomes in degenerative cervical myelopathy (DCM) use logistic/linear regression with patient-level predictors like demographics, disease severity scores (e.g., modified Japanese Orthopaedic Association), and imaging findings. Machine learning (ML) models can uncover complex, nonlinear relationships between predictors, offering individualized prognostic and diagnostic insights. This scoping review summarizes and critically appraises literature on ML models in DCM diagnosis and management.

Methods:

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses for scoping reviews guidelines, we searched MEDLINE, Embase, Cochrane Library, and Web of Science for studies on supervised and unsupervised ML models used in DCM diagnosis, prognosis, or treatment. The risk of bias was assessed using the Prediction Model Risk of Bias Assessment Tool.

Results:

From 577 records, 55 studies were included, the majority (91%) published after 2021. The primary research areas were DCM diagnosis and phenotyping (n = 20), surgical prognosis (n = 17), and severity classification (n = 11). ML models enhanced DCM management by identifying specific clinical factors, especially when integrating multiple data modalities. Deep-learning algorithms like radiomics, combined with advanced imaging techniques like diffusion tensor imaging, identified imaging biomarkers like T2 texture features that correlated with disease severity and predicted postoperative recovery. ML also identified patient-specific predictors like fat infiltration and higher body mass index, aiding in risk stratification and surgical decision-making. Unsupervised ML algorithms discovered distinct patient phenotypes within mild DCM with better surgical outcomes. However, most studies exhibited a high risk of bias owing to poor adherence to reporting guidelines and lack of external validation, raising concerns about transparency and generalizability. Methodologic issues like unclear feature selection processes and inadequate reporting of predictors limited reproducibility.

Conclusion:

ML models enhance DCM diagnosis and management by identifying imaging biomarkers and patient-specific factors correlating with disease severity and predicting postoperative outcomes, enabling personalized treatments; however, methodological flaws — high bias, poor reporting, and lack of validation — limit their generalizability and clinical application. Future research must focus on methodological rigour, better reporting, and interdisciplinary collaboration to develop robust, clinically relevant ML models.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S90.

Abstract ID 113. Program Code P72. Spinal cord tract–based prediction of clinical deterioration in mild degenerative cervical myelopathy

Newton Cho ¹, Abdul Al-Shawwa ¹, Bradley Jacobs ¹, Nathan Evaniew ¹, Peter Lewkonia ¹, Fred Nicholls ¹, Alex Soroceanu ¹, Ganesh Swamy ¹, Kenneth Thomas ¹, Michael Yang ¹, David Cadotte ¹

Background:

Degenerative cervical myelopathy (DCM) treatment varies depending on severity. While surgical intervention is recommended for patients with moderate to severe severity on the modified Japanese Orthopaedic Association (mJOA) scale, the management of patients with mild DCM is debated. The natural history of these patients is not entirely clear. Previous work has demonstrated the importance of injury to different spinal cord tracts in the pathophysiology of DCM. The purpose of this study was to examine whether injury to specific spinal cord tracts in patients with mild DCM could predict which patients subsequently deteriorated clinically. Predictors of deterioration in mild DCM could help determine which patients may benefit from operation to prevent further neurologic decline.

Methods:

Magnetic resonance imaging and diffusion tensor imaging sequences of the cervical spinal cord were performed in patients with mild DCM. Spinal Cord Toolbox was used to register the images to the PAM50 template, which includes an atlas of spinal cord white matter tracts. Fractional anisotropy (FA) was extracted at C3 to compare patients with mild DCM who deteriorated by at least 1 mJOA point in 1 year follow-up, versus those who did not deteriorate.

Results:

A total of 26 patients with mild DCM (12 deteriorated and 14 did not deteriorate on the mJOA scale) were analyzed in the study. Eight annotated motor spinal cord tracts were analyzed (left and right sides). There was no difference in FA across all motor tracts between the 2 groups (p > 0.05).

Conclusion:

In this study, we were not able to resolve differences in motor spinal cord tracts between patients with mild DCM who deteriorated clinically at 1-year follow-up and those patients who did not deteriorate. Future work looking at longer follow-up duration, as well as patients who deteriorate to a larger degree on the mJOA scale, could help to better characterize these tracts. Machine learning models that incorporate other patient factors into prediction of deterioration are also warranted.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S90.

Abstract ID 131. Program Code P73. Cage subsidence in anterior discectomy and fusion, a comparison between autograft, allograft, and synthetic devices

Omar Siddiqi ¹, Jennifer Urquhart ¹, Renan Rodrigues Fernandes ¹, Isaac Wangai ¹, Taryn Walker ¹, Turki Alanezi ¹, Ruheksh Raj ¹, Chris Bailey ¹

Background:

We compared subsidence rates between patients who had autograft versus allograft versus synthetic interbody devices in anterior cervical discectomy and fusion (ACDF).

Methods:

A consecutive series of patients who underwent ACDF for degenerative indications at a single centre between 2011 and 2022 were retrospectively reviewed. Baseline demographics, interbody device type, revision status, disc height, lordosis, sagittal alignment, and fusion status were obtained from charts with radiographic measurements at 6 weeks and 6 months to 2 years after surgery. Subsidence was calculated as > 3 mm change in anterior or posterior disc height compared with immediate postoperative at any time up to 2 years after surgery.

Results:

In total, 89 had autograft (tricortical iliac strut), 87 had allograft (cornerstone or fibular strut), and 49 had synthetic (polyetheretherketone or Zero-P). More males had an allograft implant (56% v. 43%, autograft, 35% synthetic, p = 0.044). Foraminal stenosis with radiculopathy as an indication for surgery was more common in the autograft group (75% v. 58% allograft, 55% synthetic, p = 0.027). The subsidence rate was 11.8% in the allograft group, 10.2% in the autograft group, and 4.3% in the synthetic group (p = 0.358). There was a greater change in posterior disc height in the allograft group (mean ± standard error [SE], −1.4 ± 0.1 mm) compared with the autograft group (1.1 ± 0.1 mm, p = 0.021) and syntethic group (−1.0 ± 0.1 mm; p = 0.001). The loss in anterior disc height was not different among the groups. Segmental lordosis (mean change, allograft 0.3°, autograft −1.0°, synthetic, −1.3°) and sagittal vertical axis C2–C7 (mean change, allograft −1.4 mm, autograft −1.5 mm, synthetic −2.1 mm) from immediate postoperative to 6 weeks was similar among the groups. The revision rate was 2.3% in the allograft group, 3.4% in the autograft group, and 2.0% in the synthetic group (p = 0.865).

Conclusion:

Subsidence rates were similar between allograft, autograft, and synthetic devices. The loss in disc height was greatest in the allograft group, but alignment and revision rate were not affected. Further study is required to investigate factors associated with subsidence.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S91.

Abstract ID 30. Program Code P74. Posterior versus anterior approach for the treatment of cervical radiculopathy: Which is the best choice?

Ramon Guerra Barbosa ¹, Newton Pimenta ², Yan Silva ³

Background:

The aim of this study is to determine the optimal surgical approach for treating compressive cervical radiculopathy by comparing the indications and reoperation rates of anterior and posterior approaches. The study also seeks to evaluate the clinical outcomes and complication rates associated with each method, drawing on the existing literature to guide decision-making in clinical practice.

Methods:

A comprehensive literature review was performed using PubMed and Cochrane databases. The review focused on meta-analyses, and prospective and retrospective clinical trials comparing the anterior and posterior approaches for cervical radiculopathy. Studies were included if they reported on clinical outcomes, reoperation rates, and complications for either approach.

Results:

Both anterior and posterior approaches demonstrated equivalent clinical improvement in patients with cervical radiculopathy. Reoperation rates were also similar between the two methods. However, complications were more frequent in the anterior approach than in the posterior. The posterior foraminotomy offered several advantages, such as preserving functional mobility, reducing hospitalization costs, and shortening recovery time. Nevertheless, the posterior approach has its limitations, such as the inability to decompress anterior central compressions, potential for instability, and a steeper learning curve, particularly with minimally invasive techniques like tubular and endoscopic foraminotomy.

Conclusion:

While both approaches are effective in treating cervical radiculopathy, the posterior approach provides a viable alternative with certain advantages in suitable patients. The preservation of motion and fewer complications make it an attractive option, though it is important to consider the specific pathology when choosing the surgical approach. The posterior approach should be regarded as a valuable tool in the spine surgeon’s therapeutic arsenal.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S91.

Abstract ID 177. Program Code P76. Hyoid bone level and dysphagia after anterior cervical discectomy and fusions

Jacqueline Tobin ¹, John Martin ¹, Mark Kouame ¹, Gabriella Rivas ², Charles Reitman ¹, John Glaser ¹, James Lawrence ¹, Robert Ravinsky ¹

Background:

Anterior cervical discectomy and fusion (ACDF) is considered an effective, low-risk treatment for a variety of pathologies of the cervical spine. The position of the hyoid preoperatively, in relation to the cervical spine, is considered a possible risk factor for the development of dysphagia following ACDF. Preoperative knowledge of the hyoid position and its anatomical relation to the cervical spine could affect the risk of dysphagia postoperatively. This study is designed to investigate the correlation between hyoid position and ACDF complications.

Methods:

We undertook a retrospective review of patients undergoing ACDF at a single, tertiary-care institution, during a 10-year period. Cases were excluded if the patient had undergone previous cervical spine surgery, if ACDF was performed owing to trauma, any levels outside of C2/3 and C3/4 and C2–4, and any 3-level fusions. Data were collected on patient demographics, surgical characteristics, radiographic determination of the hyoid level via k-line measurement of preoperative films, and 30-day complication rates.

Results:

A total of 25 patients were included, with a 1.3:1 female to male ratio and an average age of 62.7 ± 14.8 years. Average k-line measurement was 91.8 ± 10.9 mm. The hyoid bone was commonly measured at the level of the C3 vertebral body (36%), C4/5 disc (28%), and C4 vertebral body (20%). The rate of dysphagia status post-ACDF in this cohort was 20% (5/25), with 60% (3/5) of these patients requiring referral to speech-language pathologists. Rate of 30-day readmission and mortality was 4% and 0%, respectively. Three of 5 patients who experienced dysphagia had a hyoid body measured at the level of the C3 body. The other 2 patients had hyoid bodies measured at the level of the C4 vertebral body and C4/5 disc.

Conclusion:

Preliminary data demonstrate a trend toward increased rate of dysphagia in patients with higher measured hyoid bones, at the level of the C3 body. Further research is required to better ascertain the relationship between the hyoid position in relation to the cervical spine and the rate of dysphagia in patients undergoing ACDF.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S91–S92.

Abstract ID 147. Program Code P77. Impact of age and preoperative myelopathy severity on surgical outcomes in degenerative cervical myelopathy

Thamer Alfawaz ¹, Tinghua Zhang ¹, Nicolas Dea ², Nathan Evaniew ³, Philippe Phan ¹, Canadian Spine Outcomes, Research Network ⁴

Background:

The interaction and combined effect of age and preoperative myelopathy severity on patient outcomes has not been thoroughly investigated. We aimed to evaluate the impact of age and preoperative disease severity on outcomes of surgically treated degenerative cervical myelopathy (DCM) patients, by stratifying patients based on age and disease severity. We assessed changes in modified Japanese Orthopaedic Association (mJOA) and 12-Item Short-Form Survey (SF-12) scores over 2 years post urgery, and we calculated the minimal clinically important difference (MCID) achievement rates for each group.

Methods:

We carried out a retrospective analysis of DCM Canadian Spine Outcomes and Research Network prospective cohort data. Primary outcome measures were mJOA score and SF-12. Patients were stratified based on age (65 years cut-off) and further stratified based on disease severity using mJOA score. Changes between time points were calculated. Continuous variables were presented with mean (± standard deviation) or median (interquartile range) and categorical variables were presented with number and percentage. Paired t test was used to determine significance at 5% level.

Results:

We included 571 patients. Severe myelopathy patients showed the highest improvements in mJOA across both age groups, with mean mJOA improvement ranging from 3.6 to 3.8 at 24 months. The most significant gains occurred within the first 12 months. For physical component summary (PCS) scores, patients aged ≤ 64 years demonstrated the most consistent improvements across all severity levels. Patients with severe myelopathy showed larger initial improvements in mental component summary (MCS) compared with mild and moderate groups. MCID achievement for mJOA was highest in the older group with severe myelopathy, peaking at 82.5% at 12 months. The younger group had better MCID achievement for PCS, with patients with severe disease in the older group showing the highest MCID achievement at 3 months (58.14%). MCID rates for MCS generally decreased at 12 months compared with 3 months postsurgery, with the older group with severe myelopathy showing the highest rates at both 3 months (58.14%) and 12 months (35%).

Conclusion:

Age and DCM severity significantly influence surgical outcome. Younger patients and severe myelopathy have more consistent and substantial improvements across various outcomes, with most improvement seen in the first 12 months after surgery.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S92.

Abstract ID 83. Program Code P78. Laminoplasty versus laminectomy and fusion in the treatment of degenerative cervical myelopathy: a systematic review and meta-analysis of cost and patient-centered outcomes

Vishwathsen Karthikeyan ¹, Husain Shakil ¹, Armaan Malhotra ¹, Christopher Lozano ¹, Jefferson Wilson ¹

Background:

In this systematic review and meta-analysis, we compare cervical laminoplasty (LP) to laminectomy and fusion (LF) for the treatment of degenerative cervical myelopathy (DCM) with respect to health care costs and patient-centered outcomes.

Methods:

A systematic review of Embase and MEDLINE from inception to September 2024 was performed to identify studies comparing LP to LF for the treatment of multilevel DCM. Outcomes assessed included return-to-work (RTW), opioid use, direct treatment costs, and pain. Meta-analyses were performed using random-effects models to estimate the pooled mean difference (MD) between treatment arms and mean per treatment for study outcomes. The Newcastle–Ottawa Quality Assessment Scale was used to appraise the quality of evidence.

Results:

There were 12 retrospective cohort studies (7581 patients) that met inclusion criteria, with 1848 patients undergoing LP and 5733 receiving LF. LF was found to have higher treatment costs, with an average pooled estimate of US$74 772.8 (95% confidence interval [CI] US$29 503.72 to US$120 041.88; I² = 100%) compared with US$52 109.07 (95% CI US$12 234.14 to US$91 985.43; I² = 100%) for LP. The mean difference (MD) in treatment costs was −US$21 620.69 (LP versus LF; 95% CI −US$35 215 to −US$8 025.53; I² = 95%). LF was also associated with a greater reduction in pain scores, from baseline to postoperative assessment, compared with LP (MD of change in VAS 1.60, LP versus LF; 95% CI 0.36 to 2.84; I² = 63%). Four studies reported outcomes related to postoperative opioid use; however, owing to differences in outcome reporting, meta-analysis was not feasible. One study examining RTW showed higher rates at 12 months for patients treated with LP (88.9%) compared with LF (64.3%). The included studies exhibited substantial heterogeneity, with limited high-quality evidence.

Conclusion:

LF was associated with larger treatment costs but greater improvement in pain outcomes compared with LP. This review emphasizes the need for further studies comparing LP and LF with respect to cost and patient-centered outcomes such as RTW and postoperative opioid use.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S92.

Abstract ID 159. Program Code P79. Isolated decompression for bilateral C1–C2 accessory facet joint with compressive myelopathy: case report and narrative review

Yan GMD Silva ¹, Ramon Barbosa ², Erenaldo de Souza Rodrigues Júnior ¹, Carlos Alberto Assunção Filho ¹, Rodrigo Gomes ¹, Luis Fernando Weber de Oliveira ¹

Background:

We present here a rare case of upper cervical stenosis with myelopathy caused by the C1–C2 accessory facet joint, without signs of instability. It was treated with isolated decompression, preserving the posterior ligament complex and muscular insertion of the C2 spinous process, without complications. We carried out a narrative review of the topic.

Methods:

A 39-year-old woman reported progressive tetraparesis, with a more intense deficit in the left leg (muscle strength grade II/V). She showed signs of myelopathy such as gait imbalance and loss of dexterity in the upper arms. Her modified Japanese Orthopaedic Association score was 13, Nurick 3. Conservative treatment failed. Imaging showed a posterior cervical stenosis with myelopathy at the C1–C2 level generated by the posterior bilateral accessory facet joints. Dynamic cervical radiographs showed no instability. The patient underwent posterior laminectomy of the C1 arch, joint resection of the C1–C2 accessory facets, and flavectomy with preservation of posterior ligament complex and muscular insertion of the C2 spinous process.

Results:

The patient showed satisfactory improvement in muscle strength and sensitivity of the upper limbs with gait improvement on the first postoperative day. Computed tomography performed after the surgery showed a broad decompression, and dynamic radiographs performed after the surgery confirmed no sign of instability.

Conclusion:

Bilateral C1–C2 accessory facet joint with compressive myelopathy is a very rare entity. Without signs of instability, laminectomy of the C1 posterior arch with resection of the accessory facet joint appears to be a safe and effective measure.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S92–S93.

Abstract ID 71. Program Code P80. Variation in analgesia prescribing by surgeon: Which factors affect prolonged opioid use and unexpected follow-up for pain?

Mary Fay ¹, Sean Christie ¹, Sean Barry ¹, Lynn Lethbridge ¹, William Oxner ¹, Emily Johnston ¹, Andrew Glennie ¹

Background:

Managing pain for patients undergoing spine surgery is complex and often involves multimodal analgesia. Despite guideline development for opioid prescribing in 2016, little is known about prescriber variability and how this may affect patient outcomes in the short and long term. We sought to evaluate whether variation in pain medication prescribing affected long-term opioid usage and, secondarily, the incidence of return to the emergency room (ED) or general physician (GP) for pain.

Methods:

The Health Canada Drug Product Database was used to identify opioid and nonopioid analgesics, specifically gabapentinoids, antidepressants, nonsteroidal anti-inflammatory, muscle relaxants, common over-the-counter analgesics and other nonopioid analgesics. International Classification of Diseases, 10th Revision (ICD-10 codes) were linked from the Discharge Abstract Database and the National Ambulatory Care System reporting to the provincial drug information system. Patient data were linked to the primary surgeon and compared using multivariate 2-level hierarchical linear models.

Results:

There were 2830 cases included in the study, with a mean age of 58.0 years (confidence interval [CI] 57.5 to 58.6) and 45.8% (CI 43.9% to 47.6%) female. There was significant variation in postoperative opioid, nonopioid pain medication and return to the ED/GP for pain between surgeons. Overall opioid consumption, however, decreased from 44% preoperatively to 26% postoperatively. There was a significant difference in the proportion of patients consuming preoperative opioid analgesia between surgeons. Return to the ED/GP for pain was not associated with the amount or dosage of postoperative opioid prescribed postoperatively (odds ratio [OR] 1.2, CI −0.9 to 1.4; p = 0.13). Preoperative opioid (within 180 days) was associated with prolonged usage postoperatively (OR 8.6, CI −6.9 to 10.7; p < 0.001). Any opioid 180 days prior was associated with a greater return to ED/GP (OR 2.1, CI −1.8 to 2.5; p < 0.001). Patients consuming other pain medications 180 days prior to surgery had a lower odds of prolonged opioid use (OR 0.58, CI −0.45 to 0.74; p < 0.001). Patients with prolonged opioid pain medication consumption had a higher odds of consuming nonopioid pain medication as well (OR 5.5, CI −4.2 to 6.6; p < 0.001).

Conclusion:

Surgeon variability in postoperative prescribing does not appear to drive prolonged opioid usage. Preoperative opioid usage should be avoided. Future efforts should focus on expedited treatment of vulnerable patients with more severe pain patterns.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S93.

Abstract ID 32. Program Code P81. Adverse childhood experiences and chronic low back pain: a systematic review and meta-analysis

Geneviève L Belanger ¹, Eugene K Wai ², Khaled Skaik ³

Background:

Research highlights the correlation between adverse childhood experiences (ACEs) and chronic pain, but specific diagnoses like chronic low back pain (cLBP) are less frequently discussed. This review aims to determine whether there is a relationship between chronic low back pain (cLBP) in adults (≥ 18 years) and exposure to at least 1 ACE. It also examines whether specific ACE subgroups (e.g., sexual abuse) are related to cLBP.

Methods:

A systematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted. Digital searches in PubMed and Embase identified articles on ACEs and cLBP from the last 30 years. Studies meeting inclusion/exclusion criteria were assessed for quality using the Newcastle–Ottawa risk of bias tool. Data were abstracted for qualitative analysis and meta-analysis. Random effects models were used to calculate pooled adjusted odds ratios.

Results:

Five studies met the inclusion criteria. Study quality was rated good. Evidence supporting a relationship between ACEs and cLBP was inconsistent. The pooled odds of reporting different types of ACEs and cLBP ranged from 1.00 to 1.19 but were not significant. Heterogeneity among studies was high (I² = 89% to 100%), and findings varied between studies.

Conclusion:

The relationship between ACEs and cLBP may not be straightforward owing to the high heterogeneity and inconsistent results. Further research is needed to understand the impact of specific ACE subgroups on cLBP.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S93–S94.

Abstract ID 163. Program Code P83. Innovative spine assessment clinic significantly lowers postoperative emergency department visits

Jenna Smith-Forrester ^1,², Michelle Rowicki ², Justina Gillis ², Karen Jones ², Jason Freeman ², Matt Mitchell ², Emily MacLean ², Renee Hollahan ², Leslie Hardy ², Christina MacDonald ², Alissa Decker ², Sean Barry ^1,², Andrew Glennie ^1,², William Oxner ^1,², Lutz Weise ^1,², Sean Christie ^1,²

Background:

We previously conducted a 6-year review and discovered 24% of patients undergoing posterior decompression surgery, such as laminectomy or discectomy, sought emergency department (ED) care within 3 months postsurgery. To address this issue, we created an integrated Spine Assessment Clinic (SAC), which implemented protocols aimed at enhancing patient outcomes and minimizing unnecessary ED visits. These measures include thorough preoperative education, integration of Enhanced Recovery After Surgery protocols to optimize health, and early postoperative follow-up for all spine surgery patients.

Methods:

To evaluate the early impact, we reviewed all cases of patients undergoing lumbar decompression surgeries for the 3 months following the full implementation of the SAC. These patients received comprehensive preoperative education and follow-up phone calls from SAC nursing staff within 7 days of their surgery or discharge home. We queried all provincial ED databases for any visits within 90 days postsurgery. The outcomes of this group were then compared with data from patients treated with lumbar decompression before the SAC’s implementation.

Results:

Of the 205 patients meeting inclusion criteria, 24 patients (11.6%) accounted for 34 ED visits within 90 days of surgery. This represents a significant drop in the number of patients presenting to the ED (from 24% to 11.6%) and even greater reduction in overall ED utilization (accounting for multiple presentations by the same patient) from 42% to 16.6%. Early intervention measures, such as wound monitoring via text or email and outpatient bloodwork, helped prevent unnecessary ED visits. Patient satisfaction surveys (n = 62) showed 92% reported they were “highly satisfied” with their clinic experience and 100% would recommend it to others undergoing spine surgery.

Conclusion:

The SAC has dramatically reduced the number of patients seeking postoperative ED care by over 50%, enhancing patient outcomes through its individualized, proactive approach. By implementing a dedicated pathway for early postoperative follow-up phone calls, the SAC is not only alleviating health care resource strain, but also showcasing a model with significant potential for expansion across other surgical services.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S94.

Abstract ID 64. Program Code P84. Evaluating the socioeconomic burden for patients with spinal cord injury in Nova Scotia

Lauren Barter ¹, Andrew Glennie ¹, Sean Christie ¹, Cynthia Dunning Zwicker ¹, Bill Oxner ¹

Background:

Our aim was to accurately track and document health care system costs (diagnostic imaging) after spinal cord injury in relation to the level and severity of the injury, utilizing the American Spinal Cord Injury Association (ASIA) grade; assess the impact of place of residence (i.e., rural v. urban) on financial burden; and determine other expenditures and financial difficulties such as change in employment status/income, rehabilitation services, and home modifications in relation to severity and level of injury.

Methods:

An incidence-based approach assessed traumatic spinal cord injury (tSCI) from a limited societal perspective, encompassing inpatient admission, rehabilitation, long-term care, aids and adaptations, unpaid care, and employment. The model accounted for injury severity (ASIA classification), age at onset, and geographic residence.

Results:

The survey participation rate used to estimate out-of-pocket costs for those residing in Nova Scotia was 16.3%. The most common type of SCI from the fiscal years 2014 to 2020 was ASIA D, which had a reduced overall hospital cost ($68,530) compared with type A injuries ($223,259). Patients had greater odds of being from a rural area (odds ratio [OR] 2.03, confidence interval [CI] −1.37 to 2.99, p = 0.0004). Urban patients had a higher average out-of-pocket cost compared with rural patients. Most noteworthy, those with an ASIA C SCI had higher annual out-of-pocket costs compared with ASIA A patients. Those who eventually had a declassed ASIA score A had higher hospital costs compared with the average cost of patients with an ASIA A score when admitted. Those who were upstaged had higher hospital costs overall. Conversion from C to D was the most common. Twenty patients (15%) had passed away within the first year after their injury.

Conclusion:

This estimation of tSCI costs in Nova Scotia is likely conservative, particularly regarding home renovation costs. The findings highlight how economic modelling can inform policy-makers about the financial impacts of SCIs, illustrate how changes in injury patterns affect costs, and guide future support for those living with tSCI.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S94.

Abstract ID 36. Program Code P85. Surgery for degenerative conditions of the spine: a pan-Canadian study of income and employment

Rachael Jaffe ¹, Armaan Malhotra ^1,², Husain Shakil ^1,², Christopher Witiw ^1,²

Background:

This study aims to quantify changes in employment earnings after surgery for degenerative cervical and lumbar spinal diseases.

Methods:

This pan-Canadian retrospective cohort study included adults undergoing surgery for degenerative cervical or lumbar spine disease from January 2007 to December 2017. Patients aged 18 to 65 years were identified using Canadian Classification of Health Interventions codes. A longitudinal linear mixed model was used to estimate the change in employment income from 3 years prior to surgery up to 6 years postsurgery, with prespecified age groups of 18 to 45, 45 to 55, and 55 to 65 years to account for different stages of employment for individual patients. The model adjusted for urban residency, marital status, sex, province of hospitalization, self-employment, Elixhauser Comorbidity Score, surgical level, and preoperative income quartile.

Results:

A total of 33 600 patients received surgery for degenerative cervical or lumbar disease between ages 18 and 65 years, with a mean presurgical income of $35 000. Patients aged 18 to 45 years saw an average $8500 decrease from the year before to the surgery year, then a 2% earnings increase by the third year postsurgery. Patients aged 45 to 55 years had a $3000 decrease over time relative to the youngest group, with a 15% income drop from the presurgery year to surgery year and a 5% recovery within 3 years postsurgery. Patients aged 55 to 65 years showed no income recovery postsurgery, averaging a $10 000 decrease compared with the youngest group. Those in the highest income quartile before surgery had greater income gains postsurgery than those in lower quartiles.

Conclusion:

Among patients treated for degenerative spine disease, significant postsurgery income differences were observed across age groups. This study provides novel insights into the impact of surgery on employment income, informing perioperative counseling for Canadians undergoing spine surgery for degenerative conditions.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S94–S95.

Abstract ID 179. Program Code P86. Review of new patient visits to orthopedic spine surgery: Which referrals are resulting in surgical intervention?

Sarah Bradley ¹, John Martin ¹, Gabriella Rivas ², Sydney Seeger ¹, John Glaser ¹, Charles Reitman ¹, James Lawrence ¹, Robert Ravinsky ¹

Background:

Complaints of neck and low back pain are among the most common reasons for referral to a spine surgeon. With our aging population, specialists in the United States are overwhelmed by new patient appointments for degenerative pathologies, increasing patient wait times. Despite the breadth of published guidelines, patients are still inappropriately referred to spine surgery for nonsurgical problems, further burdening the system. The purpose of this study is to investigate the surgical yield of new patient referrals for spine surgery.

Methods:

This is a retrospective review of patients referred for orthopedic spine surgery consultation at a single tertiary care centre.

Results:

In total, 576 new patients were referred to orthopedic spine surgery at a single academic center. A majority were female (57%) and self-reported white (74%). Only 91 new patient visits resulted in surgery (15.8%), while 190 resulted in referral to Physical Medicine and Rehabilitation (PM&R) or pain management (33%). Most new patients (74%) had provider referrals: 204 from primary care providers (PCP), 114 from surgical subspecialists, and 58 from PM&R or pain management. Referrals from the last category were most likely to yield a surgical intervention (27.6%). Self-referrals and PCP referrals had the lowest surgical yield (14.5% and 11.8%, respectively). PCP referrals were most likely to result in a further consultation from PM&R or pain management (36.3%).

Conclusion:

New patient referral to orthopedic spine surgery at this institution resulted in surgery only 15.8% of the time. PM&R and surgeon referrals were more likely than PCP and self-referrals to result in surgery. Further research must be conducted to investigate methods to further educate our primary care colleagues or better triage patients for surgical care.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S95.

Abstract ID 92. Program Code P87. Surgical intervention enhances social function in older adults with spinal deformity: a Prospective Evaluation Deformity Surgery database study

Lauren I Daunt ¹, Vanessa Vashishth ¹, Eliana Seider ¹, Aazad Abbas ², Mauricio Campos Daziano ³, Anna C Rienmüller ⁴, Christopher Ames ⁵, Stephen J Lewis ¹

Background:

Adult spinal deformity (ASD) significantly affects patients’ lives, particularly their social interactions. While research exists on ASD surgery outcomes, there are limited granular data on how ASD affects social function in older adults. This study aims to examine ASD surgery impacts on the social functioning of patients aged ≥ 60 years.

Methods:

A prospective, multicentre, multicontinental cohort of patients aged ≥ 60 years undergoing primary spinal fusion ≥ 5 levels from the Prospective Evaluation Deformity Surgery (PEEDS) database was reviewed. Demographic variables, work status, and cognitive function via the animal fluency test (AFT) were recorded. Patients were assessed at baseline, 10 weeks, 12 months, and 24 months. Outcome measures of interest were questions 14 (“Does your back condition affect your personal relationships?”) and 18 (“Does your back condition limit your going out with friends/family?”) from the Scoliosis Research Society-22r questionnaire (SRS-22r), as well as question 9 of the Oswestry Disability Index (ODI) (impact of back pain on social life). Descriptive statistics (mean, median, and frequency data) were collated.

Results:

A total of 219 patients were included, with a median age of 67.5 years; 80.4% were female. The mean body mass index was 26.1 (± standard deviation 5.4). Of these, 60.3% were retired, and 25.7% exhibited cognitive impairment, measured through AFT. For SRS-22r Q14, 40.1% of patients reported that their back condition moderately or severely affected their relationships, compared with 15.4% at 2 years. For SRS-22r Q18, 47.7% of patients felt their back often or very often limited their going out, compared with 17.1% at 2 years. Of the 69 patients who were moderately or severely limited preoperatively, 19 (28%) remained so at 2 years; 40 (58%) were rarely or never limited at 2 years. For ODI Q9, 8.7% of patients felt that their social function was normal preoperatively, compared with 44.1% of patients at 2 years.

Conclusion:

ASD surgery had a significant positive impact on patients’ social functions. The data support expected outcomes following surgery and highlight the physical and mental benefits of these complex procedures.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S95.

Abstract ID 192. Program Code P88. L1 pelvic angle and its relationship with pelvic incidence, pelvic tilt and sacral slope: a cross-sectional study

Chien Yew Kow ¹, Farbod Moghaddam ¹, May Choi ¹, Fred Nicholls ¹

Background:

L1 pelvic angle (L1PA) is a relatively novel spinopelvic parameter that measures the sum L1 tilt and pelvic tilt, and represents the lumbar lordotic component of spinal alignment. It is a measurable and modifiable intraoperative parameter in spinal deformity surgeries. This study aims to describe the relationship between L1PA and spinopelvic parameters in asymptomatic adult populations.

Methods:

Full cross-sectional spine imaging of 410 adult volunteers (aged ≥ 18 years) with Oswestry Disability Index (ODI) score < 10 were performed and segmented using the Kheops online imaging platform. Radiologic spinopelvic parameters measured include pelvic incidence L1PA, pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), and Roussouly morphotypes. Correlation between L1PA and patients’ demographics and spinopelvic parameters were analyzed using linear regression analysis.

Results:

Significant correlation was identified between L1PA and PI, and can be defined using the function of L1PA = 0.47*PI −18.5 (R² = 0.61). In addition, each Roussouly morphotype s appears to have a distinctly different L1PA-PI relationship. Multivariate linear regression analysis showed that L1PA in our cohort could be fairly accurately predicted by using sacral slope and pelvic tilt as independent variables, with the following equation: L1PA = 0.25*SS + 0.75*PT − 12 (R² = 0.79).

Conclusion:

Our study validated the association between L1PA and PI previously published by Hills and colleagues, with significant improvement of L1PA prediction by inclusion of positional parameters of PT and SS.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S95–S96.

Abstract ID 133. Program Code P89. Risk factors for intraoperative neuromonitoring alerts

Chloe Cadieux ¹, Anna C Rienmüller ², Kenny Yat Hong Kwan ³, Yong Qiu ⁴, Ferran Pellise ⁵, Ahmet Alanay ⁶, Justin Smith ⁷, Nasir Quraishi ⁸, Randolph Gray ⁹, Saumyajii Basu ¹⁰, Go Yoshida ¹¹, Lawrence Lenke ¹², Stephen J Lewis ¹

Background:

Intraoperative neuromonitoring (IONM) is a standard of care that provides real-time feedback on the integrity of neural structures to prevent neurologic injury. Alerts during surgery identify potential intraoperative events, requiring prompt intervention to mitigate damage. Identifying risk factors associated with these alerts is crucial for optimizing surgical outcomes and minimizing postoperative complications.

Methods:

A large multicentre study was conducted to assess IONM alerts, including patients aged between 10 and 80 years undergoing spinal complex deformity surgery. An IONM alert was defined as somatosensory evoked potential (SSEP) and/or motor evoked potential (MEP) amplitude loss > 50% in 2 of 3 muscle groups, and/or electromyogram (EMG) sustained activity for > 10 seconds. Univariate tests were performed to explore patient-specific and surgical risk factors for having an IONM alert. Subgroups regarding SSEP and uni- or bilateral MEP changes were assessed.

Results:

In total, 555 patients were included in this study (349 cord-level, 197 non-cord-level, and 9 spondylolisthesis). IONM alerts occurred in 84 patients (15.1%), with 57 occurring in cord-level surgeries, 22 in non-cord-level, and 5 in spondylolisthesis surgeries. Significant risk factors for having an IONM alert included the primary diagnosis (spondylolisthesis), revision surgery, sex (female), higher coronal Cobb angle, coronal deformity angular ratio (DAR), higher body mass index (BMI), and intraoperative traction use. Significant risk factors for MEP alerts were similar, whereas risk factors for SSEP alerts were only female sex and BMI. The most common surgical event leading to an alert was correction/rod placement (64%), and nonsurgical event was anesthesia-related (60%).

Conclusion:

Various risk factors were identified for IONM alerts during adult deformity surgery. Large coronal deformities, especially with high DAR and patients undergoing surgery for high-grade spondylolisthesis, were at particular high risk of IONM alerts. Rod placement/correction was identified as the surgical step most likely associated with IONM alerts, highlighting the need for extra vigilance during this part of the procedure.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S96.

Abstract ID 154. Program Code P90. How is reciprocal change in the unfused thoracic spine related to the preoperative thoracic compensation in patients with adult spinal deformity undergoing low thoracic to pelvis fusion?

Christopher J Nielsen ¹, Fatemeh Alavi ¹, Francois Dantas ¹, Y Raja Rampersaud ¹, Stephen J Lewis ¹

Background:

Long fusions from the low thoracic spine to the pelvis are commonly performed in patients with adult spinal deformity (ASD). Identifying optimal alignment and construct requires predicting anticipated reciprocal changes in the unfused thoracic spine. The aim of this study is to determine the incidence of thoracic reciprocal changes following fusions from lower thoracic spine to the pelvis.

Methods:

Ninety-one consecutive patients (mean age 66.7 ± 10.8 years, 65.9% female) with fusion from low thoracic spine to the pelvis in a single institution were retrospectively reviewed. Upper-instrumented vertebra (UIV) was T9–T12 in all cases and all patients had a minimum 1-year follow-up. Measurements on preoperative and immediate postoperative spinopelvic parameters were performed. Patients were stratified by preoperative T4 to UIV kyphosis (T4_UIV) into 3 categories: hypokyphosis (< 3°/level), normokyphosis (between 3° and 5°/level), hyperkyphosis (> 5°/level). Patients were classified based on their post-to-preoperative changes in T4_UIV kyphosis into 3 groups: no reciprocal change (NRC; < 5°), minimal reciprocal change (MRC; between 5° and 10°), and reciprocal change (RC; > 10°). A χ² test was used to determine the association between thoracic kyphosis and reciprocal changes.

Results:

NRC was present in 36.3% (33/91), MRC in 37.4% (34/91), and RC in 26.3% (24/91) of patients. Over half of patients (58.3%) with RC were hypokyphotic as baseline, while 25.0% and 16.7% were hyperkyphotic and normokyphotic preoperatively. Conversely, 48.5% of patients with NRC were hyperkyphotic preoperatively, with 24.2% and 27.3% in the normokyphotic and hypokyphotic groups. There was a significant association between the preoperative thoracic compensation and postoperative upper thoracic reciprocal change (p = 0.005). The overall incidence of upper thoracic reciprocal change following lower thoracic to pelvis fusions in ASD patients was 26.3%.

Conclusion:

There was an association between postoperative reciprocal thoracic kyphosis and the presence of preoperative thoracic compensation. Although more postoperative thoracic change was observed in hypokyphotic patients, significant compensation or reciprocal change should not be expected in spinal fusions for ASD from the lower thoracic spine to the pelvis.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S96–S97.

Abstract ID 151. Program Code P91. 3-D-printed versus freehand technique for pedicle screw placement in congenital scoliosis surgery: a systematic review and meta-analysis

Paweł Łajczak ¹, Yasmin Picanco Silva ², Ayesha Ayesha ³, Enzo Von Quednow ⁴, Rabbia Jabbar ⁵, Mariana Zamprogno Zottele ⁶, Gabriela Fonseca Nascimento ⁷, Fabio Victor Vieira Rocha ⁸, Oguz Kagan Sahin ⁹, Eshita Sharma ¹⁰, Ramon Barbosa ¹¹, Walter Fagundes ^8,¹², Yan GMD Silva ¹³

Background:

Congenital scoliosis, a significant pediatric spinal deformity, often necessitates surgical intervention. Pedicle screw fixation is a common technique, but accurate screw placement can be challenging, especially in complex cases. 3-D-printed templates (3-D) offer a potential solution to enhance precision and reduce complications compared with the traditional freehand (FH) technique. However, the optimal surgical approach remains controversial. This systematic review and meta-analysis aimed to compare screw placement accuracy and complication rates between 3-D and FH techniques.

Methods:

A systematic review of studies published up to Nov. 1, 2024, was conducted using PubMed, Embase, Scopus, Cochrane Library, and Web of Science. Outcomes of interest were screw placement accuracy and complication rates. Meta-analyses were performed using random-effects models to calculate odds ratios (ORs) with 95% confidence intervals (CIs). Heterogeneity was assessed with I².

Results:

In total, 231 patients were included from 6 studies; 117 patients were treated with 3-D and 114 with FH technique. On accuracy, 3-D considerably outperformed the FH technique: Grade 0 insertions (OR 2.18, 95% CI 1.29 to 3.69; p = 0.004, I² = 67%), Grade 1 insertions (OR 3.20, 95% CI 2.32 to 4.43; p < 0.001, I² = 0%). In addition, the Grade 2/3 insertions when using 3-D printing were significantly lower (OR 0.31, 95% CI 0.22 to 1.42; p < 0.001, I² = 0%). 3-D presented 73% lower rates of complication compared with FH (OR 0.27, 95% CI 0.09 to 0.80; p = 0.018, I² = 0%). There was no significant difference in operative time between the techniques.

Conclusion:

Our findings suggest that 3-D provides enhanced insertion accuracy and lower complication rates than FH and has the potential to enhance safety and effectiveness during surgical interventions. Further studies with more patients are needed to definitely assess these results.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S97.

Abstract ID 115. Program Code P92. Thoracic kyphosis morphology: a cross-sectional, descriptive study of 440 asymptomatic adults

Chien Yew Kow ¹, Farbod Moghaddam ², May Choi ¹, Fred Nicholls ¹

Background:

This study aims to describe normal thoracic kyphosis in asymptomatic adult populations, with particular focus on providing a morphologic description, and its correlation with other spinopelvic parameters.

Methods:

Full cross-sectional spine imaging of 440 international asymptomatic adults (aged ≥ 18 years, Oswestry Disability Index < 10) was performed and segmented. Segmental angulations at each spinal level were calculated, which were used for identification of spinal inflection points. For thoracic kyphosis curvature — defined as the curve between the cervicothoracic and thoracolumbar inflection points — the apex of the kyphotic curve, corresponding pelvic angles, and number of upper and lower segments of the kyphosis were calculated. These were subsequently correlated with spinopelvic parameters, such as pelvic incidence, Roussouly morphotypes, and pelvic angle at the thoracolumbar inflection points.

Results:

This remains a work in progress, with analysis of collected data being carried out at this stage. Unfortunately, technical difficulty was encountered in identifying spinal inflection points, which we define as the level where change of segmental angulation turns from positive to negative, and vice versa. Change of segmental angulation between levels was also smoothed using Gaussian filter. Despite this, in some cases, multiple inflection points were still identified and/or had inaccurate inflection point(s).

Conclusion:

We expect to report on the predictability of morphology of thoracic kyphosis, including its apical level, based on spinopelvic parameters and pelvic angles at inflection points.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S97.

Abstract ID 4. Program Code P93. The Hsu-lace: a novel technique to prevent proximal junction failure

Jennyfer Paulla Galdino Chaves ¹, Brian Hsu ¹, Stone Sima ², Bhisham Singh ¹, Ashish Diwan ²

Background:

This retrospective study assesses the efficacy of the Hsu-lace technique in creating a “soft landing” for patients submitted to thoracolumbar–pelvic reconstruction, intending to reduce proximal junction failure and reoperation rates. The present study aims to show a new technique in adult spine deformity (ASD) surgery, looking into the effects of the artificial interspinous nylon and tendon soft stabilization on proximal junction kyphosis/failure (PJK/PJF) and extension of fusion rates.

Methods:

A retrospective review was conducted on 53 patients who had undergone thoracolumbar–pelvis fusion for ASD since 2019. Patients were categorized into 2 groups based on artificial interspinous stabilization, in which the use was determined based on the instrumentation chosen in each case: Nile–LifeHealthcare (LHC; n = 27) or Tendon/Ausbio–APM (n = 26). Data collection included demographics, surgical details, follow-up, PJK, time of PJK, reoperation, and extension of fusion.

Results:

Eight patients developed PJK before 6 months, and 5 were submitted to extension of fusion; 80% of these patients extended were from the Nile-LHC group. Despite this, we had 3 patients who developed PJK but had no PJF.

Conclusion:

We believe the Hsu-lace technique is valid and changed our practice, reducing our PJF and extension of fusion rates.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S97–S98.

Abstract ID 132. Program Code P95. Research priorities for patients with adult spinal deformity — a modified Delphi approach from the Canadian Spine Outcomes and Research Network

Victoria Smith ^1,², Nathan Evaniew ^1,², Alex Soroceanu ^1,², Steve Lewis ³, Fred Nicholls ^1,², Ganesh Swamy ^1,²

Background:

Adult spinal deformity (ASD) is a common pathology causing pain and disability in adults. Spine surgeons from across Canada, with specific interest in ASD, are participating in the Canadian Spine Outcomes and Research Network (CSORN) ASD Substudy, with the goals of advancing patient care, understanding practice variations, and measuring and optimizing outcomes.

Methods:

Deformity spine surgeons across Canada completed a survey-based 3-step research priority-setting exercise, using a modified Delphi approach. In step 1, electronic questionnaires were distributed to identify priority research questions, which were then rated in step 2 using a 5-point Likert scale for 5 criteria: Scientific Merit, Significance, Innovation, Relevance, and Feasibility. Questions that met a threshold score of > 20/25 progressed to step 3 — a group discussion at a consensus meeting — and were then scored again by the surgeons in attendance, using a 9-point Likert scale to finalize research priorities for the future.

Results:

Of the 61 questions/suggestions put forth by 22 respondents in step 1, 32 questions were rated in step 2. The 10 highest-scoring questions were then reviewed at the step 3 consensus meeting. These 10 questions were grouped into 4 research themes that will form the framework for future studies by the surgeons participating in the CSORN ASD Substudy: alignment, small surgery/frailty, cost-effectiveness, and patient outcomes/decisional regret/decision aide/preoperative optimization. Participating surgeons then agreed to contribute their expertise and efforts to 4 theme-specific study groups and the implementation of prioritized research endeavours.

Conclusion:

The results of this study will serve as a foundation for the long-term research strategy for the CSORN ASD Substudy. Furthermore, these results will guide data collection to ensure the registry is gathering the most relevant data to address the high-priority research questions/topics, and will also provide a strong rationale for future collaborative multicentre research project funding applications.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S98.

Abstract ID 169. Program Code P96. Do surgeon characteristics influence variability in decision-making in management of patients with adult spinal deformity?

Mark Abdelnour ¹, Tanya Cierson ², Rohail Mumtaz ¹, TingHua Zhang ¹, Mamdoh Alhowsawi ¹, Ganesh Swamy ³, Kenneth Thomas ³, Alex Soroceanu ³, Zhi Wang ⁴, Alexandra Stratton ¹, Stephen Kingwell ¹, Eugene Wai ¹, Eve Tsai ¹, Philippe Tran Nhut Phan ¹

Background:

Adult spinal deformity (ASD), which includes conditions such as high-grade spondylolisthesis (HGS), neglected adolescent idiopathic scoliosis (NAIS), degenerative scoliosis (DS), and iatrogenic flatback syndrome (FBS), is a major source of back pain and disability. Previous studies have found significant variability in the treatment of these conditions. The goals of this study were to describe the spine surgeon population in Canada and to evaluate whether surgeon characteristics affect the variability observed in the general and surgical management of ASD patients.

Methods:

Twenty-five spine surgeons participated in an online survey. The first 7 questions addressed basic surgeon demographics and specifics of their practice, and the remainder of questions involved general management of ASD patients and decision-making based on presented cases of HGS, NAIS, DS, and FBS. P values from a Fisher exact test were calculated, to look for associations between surgeon characteristics and the variability in responses for the remainder of the survey questions.

Results:

Time in practice was associated with significant variability in use of intraoperative neuromonitoring during ASD cases (p = 0.0254) and type/level of osteotomy used (p = 0.0202). The region of practice was associated with variability in having a dedicated anesthesiologist for ASD patients (p = 0.0001). The method of billing of surgeons had statistically significant variability in having a dedicated anesthesiologist for ASD patients (p = 0.0026), the choice to use minimally invasive surgery (p = 0.0416), and for the primary surgical approach for a high-grade spondylolisthesis case (p = 0.0281).

Conclusion:

To our knowledge, the current study is the first to identify surgeon characteristics that influence the variability in ASD management, including time in practice, billing method, volume of ASD surgeries in practice, and region of practice. Our findings may serve as the foundation for future studies to further understand the associations between surgeon characteristics and variability in ASD management.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S98–S99.

Abstract ID 136. Program Code P97. Underreporting of proximal junctional kyphosis and failure in adult spine deformity surgery: a multicentre radiologic review using multiple diagnostic criteria

Chloe Cadieux ¹, So Kato ², Eric Klineberg ³, Caglar Yilgor ⁴, Michael Kelly ⁵, Lawrence Lenke ⁶, Christopher Shaffrey ⁷, Kenneth Cheung ⁸, Sigurd Berven ⁹, Yukihiro Matsuyama ¹⁰, Ferran Pellise ¹¹, Benny N Dahl ¹², Maarten Spruit ¹³, Ahmet Alanay ⁴, Stephen J Lewis ¹

Background:

Proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) are common adverse events following adult spine deformity (ASD) surgery; however, they are frequently underreported. Reports of PJK may be affected by the fact that there are several PJK criteria described in the literature and that subjective clinician diagnoses may be prone to bias. The purpose of this study was to review radiologic data from an international, multicentre group to determine PJK/PJF rates based on different diagnostic criteria and compare them with clinicians’ diagnostic reports.

Methods:

A prospective, international, multicentre cohort study was conducted by AO Spine. Patients aged ≥ 60 years undergoing primary spinal fusion surgery of ≥ 5 levels for coronal, sagittal, or combined deformity (Prospective Evaluation Deformity Surgery [PEEDS]) were enrolled. Patients with preoperative and 2-year postoperative standing whole spine radiographs were included (n = 166). PJK/PJF was diagnosed using the following criteria: Glattes’ PJK, Adult Symptomatic Lumbar Scoliosis-1 (ASLS-1) PJF, and consensus-based PJF (review by 4 experts). Adverse events were collected from the case report form (CRF), and PJK was defined when designated as “junctional pathology” or “compression fracture” by 2 years postoperatively.

Results:

Radiographic review identified PJK in 84/163 (51.5%) cases using Glattes PJK criteria and in 75/164 (45.7%) cases using ASLS-1 PJF criteria. Only 58 cases (35.6%) fulfilled both criteria. Consensus-based PJF was reported in 87/165 (52.7%) cases. The k values against ASLS-1 PJF were 0.47 (95% confidence interval [CI] 0.34 to 0.61) for Glattes PJK, showing moderate agreement, and 0.81 (95% CI 0.72 to 0.90) for consensus-based PJF, indicating almost perfect agreement. However, PJK was reported in only 15 cases in the CRF, indicating significant underreporting, with a k value of 0.19 (95% CI 0.09 to 0.29).

Conclusion:

Rates of PJK/PJF varied based on different radiologic criteria used, which likely contributes to the underreporting of PJK/PJF in the literature. Additionally, PJK was underreported in the PEEDS study in CRFs filled by clinicians, in contrast to the radiologic assessment of PJK/PJF, indicating the need for objective measures.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S99.

Abstract ID 98. Program Code P98. Is a 50% loss in intraoperative neuromonitoring signal the appropriate threshold in spinal deformity surgery?

Abdullah T Eissa ¹, So Kato ², Lawrence Lenke ³, Kristen Jones ⁴, Christopher Nielsen ¹, Saumyajit Basu ⁵, Michael Kelly ⁶, Samuel Strantzas ⁷, Yong Qiu ⁸, Ferran Pellise ⁹, Ahmet Alanay ¹⁰, Nasir Quraishi ¹¹, Randolph Gray ¹², Go Yoshida ¹³, Amer Aziz ¹⁴, Stephen Lewis ¹

Background:

We examined whether a 50% loss in intraoperative neuromonitoring (IONM) signals the appropriate threshold in spinal deformity surgery.

Methods:

A prospective international multicentre study was conducted to better understand the strengths and weaknesses of IONM in spinal deformity surgery. In total, 546 pediatric and adult patients in 20 centres undergoing complex spinal deformity surgery and multimodality IONM through standardized protocols were prospectively reviewed, with data collected in real time through specially designed forms. An alert was defined as a minimum 50% loss of IONM signal amplitude in motor evoked potentials or somatosensory evoked potentials.

Results:

Of the 546 patients, 2.4% sustained a > 50% to < 75% IONM alert; 8.4% sustained a > 75% to < 100% alert; and 3.7% sustained a 100% alert. The surgical team performed manoeuvres in response to the alert that included systemic optimization, releasing correction, further decompression, and implant removal. Despite manoeuvres, neurologic deficits occurred and were recorded in 8.1% (n = 38) of patients with no alerts, 15.4% of those with > 50% to < 75% alerts, 23.9% with > 75% to < 100% alerts, and 45% of patients with 100% IONM loss. Of the 79 patients who had minimum 50% loss, 46 had > 75% loss and 20 had 100% loss. Raising the minimum threshold of signal loss alerts from > 50% to > 75% led to a similar proportion of false negatives from 8.1% to 8.3%, and a similar proportion of true positives from 27.8% to 30.3%.

Conclusion:

This series validates a 50% cut-off for IONM loss in complex spinal deformity surgery to provide the surgical team with sufficient opportunity to address the cause of the signal loss and prevent permanent neurologic injury. The high rate (8.1%) of new neurologic deficits in patients without IONM alerts is concerning and questions the accuracy of our current protocols.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S99.

Abstract ID 18. Program Code P99. Are preoperative hematological screening tests associated with allogeneic transfusion in idiopathic scoliosis surgery?

Vivien Chan ¹, Suhas Etigunta ¹, Armaan K Malhotra ², Geoffrey Shumilak ³, David E Lebel ², Kenneth D Illingworth ¹, David L Skaggs ¹

Background:

Previous studies have suggested routine preoperative laboratory assessment may be unnecessary or excessive. The utility of routine screening tests remains unclear. The primary aim of this study was to determine the association between preoperative laboratory screening tests on allogeneic transfusion in pediatric patients receiving posterior spinal fusion for idiopathic scoliosis correction.

Methods:

The National Surgical Quality Improvement Program Pediatric database for years 2016 to 2022 was used. Patients who were aged < 18 years, received posterior arthrodesis for idiopathic scoliosis correction, and had recorded preoperative laboratory tests were included in this study. Preoperative blood work values of interest were hematocrit, albumin, platelet count, international normalized ratio (INR), and partial thromboplastin time (PTT). Descriptive statistics were used to characterize patient demographics, surgical metrics, and preoperative laboratory values. Rate of allogeneic transfusion was stratified by laboratory value cut-offs and compared using G-test. Standardized cut-offs were used to define abnormal values. A multivariable logistic regression analysis was used to assess the impact of abnormal bloodwork values on rate of allogeneic transfusion. A multivariable linear regression analysis was used to investigate the impact on allogeneic transfusion volume.

Results:

There were 6057 patients included in this study. The mean age was 13.8 years and 76.1% were female. There were 13.6% that received allogeneic transfusion. The mean transfusion volume was 62.1 mL. Patients with abnormal preoperative INR (13.1% v. 20.0%; p < 0.001), hematocrit < 35 (12.4% v. 25.9%; p < 0.001), and albumin < 3.4 (13.4% v. 25.8%; p = 0.004) had higher rates of transfusion. In the multivariable logistic regression analysis, abnormal INR (odds ratio [OR] 1.4, p = 0.023) and hematocrit < 35 (OR 2.3, p < 0.001) were significantly associated with higher odds of allogeneic transfusion. In the multivariable linear regression analysis, abnormal INR (34.8, p < 0.001), hematocrit < 35 (B = 50.9, p < 0.001), and albumin < 3.4 (B = 64.8, p = 0.003) were associated with increased allogeneic transfusion volume.

Conclusion:

Preoperative INR and hematocrit values can aid in risk stratification for allogeneic transfusion requirements. PTT and platelet count did not significantly affect perioperative transfusion rates or volumes.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S100.

Abstract ID 108. Program Code P100. Methodology for the Spinal Deformity Intraoperative Monitoring study: standardizing intraoperative neuromonitoring in complex spinal deformity surgery

Ariel Zohar ¹, Janneke Loomans ², Ferran Pellise ³, So Kato ⁴, Zeeshan Sardar ⁵, Lawrence G Lenke ⁵, Stephen J Lewis ¹

Background:

Controversy surrounds the use of intraoperative neuromonitoring (IONM) in complex spinal deformity surgeries, with most studies being retrospective and limited in linking alerts to neurologic outcomes. This prospective multicentre study uses standardized forms to improve understanding and interpretation of IONM changes in spinal deformity surgery.

Methods:

Twenty centres with established IONM programs performing deformity surgeries were recruited. A standardized neuromonitoring protocol was communicated to all centres. A custom standardized form was completed by each centre, incorporating demographics, radiographic features and measurements, procedural data, pre- and postoperative neurologic examination, and recorded details of IONM modalities and muscle and sensory regions. For each IONM alert, detailed information in real time on the time, hemoglobin, and blood pressure at the time of the alert; which modalities were affected; which muscle groups or sensory regions were involved; the events preceding the alert; the actions taken in response to the alert; and details of the recovery of the signal was collected.

Results:

In this cohort, there were 117 alerts. The causes included surgical issues (76%), anesthesia-related factors (12%), systemic factors (6%), and technical problems with the leads (15%). Most alerts (89.7%) involved a loss of motor evoked potential) signal, 17.9% involved a loss of somatosensory evoked potential signal, and 13.7% included prolonged electromyography activity. Interventions included systemic measures (51.3%), surgical manoeuvres (43.6%), and technical corrections (6%). The IONM signal returned to baseline in 70.1% of patients, while 15.4% did not recover. New neurologic deficits appeared in 28.2% of patients, with 19.7% still present at discharge. Compliance for completing the form during alerts was over 95% for most components, except hemoglobin data (61.5%) and diastolic (94%) and mean arterial pressure (94%) measurements.

Conclusion:

The standardized IONM forms used in this study effectively gathered real-time data on IONM changes. This information will enhance our understanding and contribute to the refinement of algorithms that will assist surgical teams in managing these stressful situations.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S100.

Abstract ID 87. Program Code P102. Staging growing rod insertion does not lower complication rate compared with nonstaged procedures in early-onset scoliosis

Lily Switzer ¹, Karim Aboelmagd ¹, Alison Anthony ¹, Emma Nadler ¹, Jennifer A Dermott ¹, Mark Camp ¹, David E Lebel ¹

Background:

Anchor-related complications are the leading cause for unplanned surgery in early-onset scoliosis (EOS). One strategy to reduce unplanned surgery is staging implant insertion. This study compares the outcomes of staged (S) versus non-staged (NS) growing rod (GR) insertion, focusing on complication rates.

Methods:

This retrospective cohort study examined EOS patients who received GR surgery at a single institution between 2006 and 2023. Patients were grouped according to S and NS GR insertion. Radiographic measurements were obtained at preoperative, postinstrumentation, and 1-year follow-up to determine radiographic change between and within each group. Complications were recorded until posterior spinal fusion (PSF) or until most recent follow-up if no PSF was performed, and compared between groups using the Kaplan–Meier estimate. Patients were included if they had a minimum follow-up of 1 year.

Results:

Twenty-four patients received S, and 24 patients received NS dual GR insertion. S and NS patients had similar preoperative Cobb angles (p = 0.20), kyphosis angles (p = 0.92), and thoracic height (p = 0.87). NS patients had significantly greater Cobb angle correction (46.6 ± 15.9% v. 31.5 ± 13.3%; p < 0.001). There were no significant differences in kyphosis correction (p = 0.87) and thoracic height growth (p = 0.31) between groups. In total, 58% of S patients and 29% of NS patients experienced a GR-related complication. There were no significant differences in PJK development between S (n = 3, 12%) and NS (n = 7, 29%) patients (p = 0.30). The mean survival time before complication was longer in NS patients (291.6 weeks, 95% confidence interval [CI] 240.9 to 342.3) compared with S patients (196.0 weeks, 95% CI 32.0 to 133.3) (χ ²₁ = 4.4, p = 0.04). Average insertion-associated length of stay was longer in the S group (10.7 ± 4.2 days) than in the NS group (5.8 ± 4.0 days) (p < 0.001).

Conclusion:

Staged and unstaged GR instrumentation results in acceptable coronal correction. However, based on these results, staged insertion cannot be routinely justified.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S100–S101.

Abstract ID 161. Program Code P103. High-grade pediatric spondylolisthesis: pelvic retroversion corrects spontaneously after posterior spinal fusion

Karim Aboelmagd ¹, Anne Versteeg ¹, Mark Camp ¹, Reinhard Zeller ¹, David Lebel ¹

Background:

Debate exists regarding in-situ fusion versus reduction and fusion in patients with high-grade L5/S1 spondylolisthesis. Proponents of reduction highlight the improvement in global sagittal alignment, most obvious in patients with preoperative pelvic retroversion. The purpose of this study is to assess the radiographic sagittal alignment of patients with high-grade (> 50%) spondylolisthesis treated with in-situ fusion using the Jackson technique.

Methods:

We carried out a retrospective review of all patients treated for high-grade spondylolisthesis at a single centre between 2009 and 2022 with at least 2 years’ postoperative follow-up. Patient demographic data collected included age, sex, age at time of operation and weight. Radiographic data collection was undertaken on preoperative, postoperative, and 2-year postoperative radiographs. Radiographic parameters measured included pelvic incidence, sacral slope (SS), pelvic tilt, L5 incidence, L4 incidence, lumbar sacral angle, Meyerding grade, Spinal Deformity Study Group grade of spondylolisthesis, lordosis, and number of vertebrae included in the lordosis. Patients were excluded if the radiographs were unsuitable for measuring (e.g., did not include whole spine, hips covered by radiation guards).

Results:

Of the 54 patients treated surgically for high-grade spondylolisthesis, 17 underwent a Jackson procedure and had a complete radiograph set for the study (12 female, 5 male; average age 13.6 years, range 10 to 16 years). Spontaneous alignment in a prone position was secured with a Jackson type fixation with no further attempt of correction. Eight patients improved on average by 1 Meyerding grade. A solid fusion was obtained in all patients. Nine patients presented with a vertical sacrum (SS < 35°), which remained unchanged on the first standing radiograph. Follow-up showed an increase at 2 years by an average of 14.9° (3.1° to 32.1°). There were no postoperative complications or revisions.

Conclusion:

In-situ fusion with the Jackson technique did not lead to a worsening of sagittal alignment. All patients with a sacral slope below 35° managed with an in-situ fusion showed an increase in sacral slope at 2-years’ follow-up to > 35°.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S101.

Abstract ID 59. Program Code P104. Clinical outcomes and complications of halo-gravity traction in the management of severe neuromuscular and syndromic scoliosis: a retrospective cohort study at a tertiary pediatric centre

Nuno M Batista ¹, Taylor Liu ¹, Jessica Romeo ¹, Andrew Tice ¹, James Jarvis ¹, Kevin Smit ¹

Background:

Spinal deformities within surgical magnitude can be managed with posterior spinal fusion (PSF). However, correction of large and rigid deformities during single-stage procedures increases the risk of neurological injury. Halo-gravity traction (HGT) can be used prior to PSF to achieve gradual correction. Most centres admit HGT patients from time of HGT application until time of PSF, ranging from 4 to 12 weeks, which creates a burden for patients, families, and the health care system. Our goal is to evaluate the clinical outcomes and complications of the home-based HGT program developed at our institution.

Methods:

A retrospective single-institution review was conducted on patients who underwent HGT for scoliosis since 2017, recording demographics, scoliosis characteristics, length of hospital stay (LOS), complications, and unplanned returns to the operating room (OR). One-way analysis of variance assessed the impact of time on Cobb angle, while a χ² test evaluated the effect of pin number on revision incidence.

Results:

Twelve patients (5 females) were identified. The average age was 12.1 ± 2.2 years at the time of HGT application, with LOS averaging 2.3 ± 2.3 days. Ten of 12 patients had subsequent PSF and spent 108.3 ± 37.1 days in HGT. Two patients had HGT as their main treatment owing to medical fragility. Patients had a mean pre-HGT Cobb angle of 110.7° ± 22.9°, corrected to 90.9° ± 23.1° (p = 0.0058) in HGT and further corrected to 63.4° ± 20.9° (p = 0.0011) after PSF. Complications occurred in 58% of patients, with the most frequent being pin-site infection (n = 7) and screw displacement (n = 3). Three required unplanned return to the OR. Neurologic deficits were reported in 1 patient, which improved by decreasing the traction weight. A lower number of screws (4 v. 8) was associated with a higher risk of returning to the OR (n = 12, χ² = 4.286, p = 0.0384).

Conclusion:

The home-based HGT program is a safe and effective way to treat severe scoliosis. Families must be well educated to monitor for neurological complications and to provide effective pin-site care. Application of 8 screws may help reduce the need for unplanned return to OR.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S101.

Abstract ID 89. Program Code P105. Vertebral body tethering for immature idiopathic scoliosis: prospective evaluation of radiologic results and surgical complications

Rachelle Imbeault ¹, Jesse Shen ², Stefan Parent ^3,⁴, Abdulmajeed Alzakri ⁵, Olivier Turcot ⁶, Marie Beauséjour ⁶, Marjolaine Roy-Beaudry ³, Soraya Barchi ³, Isabelle Turgeon ³

Background:

Vertebral body tethering (VBT) aims to gradually correct scoliosis by utilizing patient’s growth, while preserving spine motion. VBT is an effective procedure, but the clinical results and complication profile need to be defined. The objective of this study was to report outcomes at 5 years post-VBT and surgical complications in skeletally immature patients.

Methods:

We reviewed the clinical, perioperative, radiologic, and postoperative complications in prospectively collected data of patients who received VBT at our institution. The preoperative, first erect, 6 months, 1-year, 2-year and 5-year postoperative data were analyzed. Means and standard deviations of specific parameters were calculated.

Results:

All 74 patients were skeletally immature, mean age at surgery was 11.8 ± 1.3 years, and mean follow-up time was 63.4 ± 8.4 months. VBT was performed on an average of 7.4 vertebral levels. Instrumented Cobb angle was 48.7° ± 9.2° preoperative, 17.1° ± 12.3° at 2 years postoperative, and 25.7° ± 14.0° at 5 years postoperative. Revision surgery was performed in 12 patients (16.2%). Four patients needed either partial or complete release of the tether owing to overcorrection. Two patients needed revision of VBT owing to curve progression. Four patients required posterior spinal fusion (PSF) owing to curve progression despite VBT. One patient needed revision of VBT followed by PSF. One patient developed a small dural tear, recognized postoperatively, initially treated by a blood patch. This patient complicated by developing an iatrogenic Chiari-like malformation and then needed revision surgery for screw reposition. Forty-nine patients (66%) had a suspected broken tether at the last follow-up. The mean time of the first tether breakage was 38.1 ± 15 months.

Conclusion:

In our cohort, 66% (49 patients) had a suspected radiologic tether break after 5 years and 6.8% (5 patients) required PSF. VBT offers a significant correction in the coronal and transverse planes postoperatively with a reoperation rate of 16.2%.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S102.

Abstract ID 26. Program Code P106. Bipolar fusion in neuromuscular scoliosis: Improved operative time and recovery, but at what cost?

Samuel Yoon ^1,², Erich Rutz ¹, Mia Percival ¹, Michael B Johnson ¹, Kris Lundine ¹

Background:

The objective of this investigation is to compare complication profiles between traditional posterior spinal fusion (PSF) and less-invasive bipolar fusion (BP) surgeries in patients with neuromuscular scoliosis and assess purported surgical benefits in a quaternary pediatric referral center.

Methods:

Consecutive, prospectively collected data were reviewed, identifying 46 patients undergoing traditional PSF and 74 patients BP between January 2010 and June 2023. Demographic data, complication details, and mortality data were collected. Surgical details including operative time, blood loss, transfusion rates, intensive care, and hospital length of stay data were recorded.

Results:

There were no significant differences in patient demographics, preoperative Cobb angle, or severity of underlying neuromuscular diagnosis. Patients undergoing BP had significantly decreased operative time (3.8 hours, 95% confidence interval [CI] 2.75 to 6.0; v. 4.5, 95% CI 2.8 to 7.0; p < 0.001) and shorter length of stay (6.5 days, 95% CI 2.0 to 177.0; v. 8.0 days, 95% CI 4.0 to 54.0, p = 0.0007). Intensive care admission and length of stay were not significantly different. Blood loss was significantly favourable for BP measured by cell salvage return (113 mL, 95% CI 0 to 486; v. 326 mL, 95% CI 0 to 1534; p < 0.0001), postoperative hemoglobin (99.8 ± 17.3 v. 89.6 ± 17.4; p = 0.002), and intra- and postoperative transfusion rates (p < 0.001). There were 20 reoperations required for 14 BP patients, excluding planned lengthening of growing rod constructs, compared with 9 reoperations in 7 PSF patients. There were no significant differences in postoperative mortality between PSF and BP groups.

Conclusion:

Bipolar instrumentation offers significant perioperative benefits including significantly decreased operative time, blood loss, and length of inpatient stay. Despite its intraoperative benefits, reoperation rates remain higher in the BP group than the PSF group with comparable levels of ICU care postoperatively. Higher reoperation rates underscore the need for careful patient selection to maximize long-term outcomes, including factors such as etiology, primary neuromuscular abnormality, and patient-related factors. Bipolar instrumentation remains a useful technique to minimize immediate perioperative risk for medically complex patients with severe neuromuscular scoliosis.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S102.

Abstract ID 14. Program Code P107. Intraoperative cell salvage reduces the rate of allogeneic transfusion in spinal deformity surgery

Vivien Chan ¹, Geoffrey Shumilak ², Armaan K Malhotra ³, David E Lebel ³, Kenneth D Illingworth ¹, David L Skaggs ¹

Background:

Pediatric spinal deformity surgery is associated with high perioperative blood loss, often requiring allogeneic blood transfusion. The purpose of this study was to characterize the association between cell-salvage therapy in pediatric patients undergoing posterior arthrodesis for spinal deformity correction and allogeneic transfusion rate in the perioperative period.

Methods:

This was a retrospective observational cohort study using prospectively collected data from the National Surgical Quality Improvement Program Pediatric database between 2016 and 2022. Patients younger than 18 years who received posterior arthrodesis with ≥ 7 surgical levels for spinal deformity correction were included in this study. Rates of intraoperative cell-salvage transfusion and allogeneic transfusion were determined. We assessed the impact of cell-salvage on the rate of allogeneic transfusion using a χ² test and multivariable logistic regression.

Results:

There were 34 241 patients included in this study. The mean age was 14.1 years. The overall rate of allogeneic transfusion was 21.6% (n = 7407). The allogeneic transfusion rates for idiopathic, neuromuscular, and congenital/syndromic scoliosis were 12.3%, 50.8%, and 25.9%, respectively within 30 days of surgery. Cell salvage was used in 71.1% of patients (n = 24 344). Mean volume for allogeneic transfusion was 111.4 mL. Mean volume for cell-salvage transfusion was 178.7 mL. In the multivariable regression analysis, longer operative time (p < 0.001), nonidiopathic scoliosis (p < 0.001), hematocrit < 35 (p < 0.001), and > 13 surgical levels (p < 0.001) were associated with higher odds of allogeneic transfusion. Use of cell salvage (p < 0.001), increasing age (p < 0.001), and increasing patient weight (p < 0.001) were associated with significantly lower odds of allogeneic transfusion. In a subanalysis, use of cell salvage was associated with reduced rate of allogeneic transfusion in patients with idiopathic scoliosis (7 to 12 levels: p = 0.003; > 13 levels: p < 0.001). Cell salvage was not associated with reduced rates of allogeneic transfusion in neuromuscular (7 to 12 levels: p = 0.07; > 13 levels: p = 0.06) and congenital/syndromic scoliosis (7 to 12 levels: p = 0.495; > 13 levels: p = 0.116).

Conclusion:

To our knowledge, this is the largest study investigating the impact of cell salvage on rate of allogeneic transfusion in pediatric spinal deformity surgery. Use of cell salvage is associated with reduced allogeneic transfusion rates in idiopathic scoliosis surgery.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S102–S103.

Abstract ID 155. Program Code P108. Predicting change in pelvic tilt following low thoracic to pelvis fusion in adult spinal deformity using a machine-learning approach

Christopher J Nielsen ¹, Fatemeh Alavi ¹, Francois Dantas ¹, Y Raja Rampersaud ¹, Stephen J Lewis ¹

Background:

Adult spinal deformity (ASD) often involves compensatory mechanisms such as pelvic retroversion to maintain sagittal balance. Surgical correction of ASD aims to restore sagittal alignment without compensation, but elevation of pelvic tilt (PT) is common, especially with age-adjusted alignment targets. The aim of this study is to determine a machine learning (ML)–based model to predict postoperative PT based on preoperative and surgical planning variables.

Methods:

A consecutive series of 91 patients (mean age 66.7 ± 10.8 years, 65.9% female) with ASD underwent corrective spinal fusion from the lower thoracic spine (T9–T12) to the pelvis in a single institution from 2010 to 2023, with minimum 1-year follow-up. In total, 56 spinopelvic parameters were measured on preoperative and immediate postoperative images. A predictive model was built for postoperative PT from 91 patients (80% training, 20% validation). Multiple preoperative spinopelvic parameters were included as well as planned postoperative upper instrumented vertebral pelvic angle (UIVPA) to build a PT predictive model. To validate the ML model, the postoperative PT was compared against the predicted values. Patients were divided into 2 groups according to their preoperative C2 pelvic angle (C2PA): low (≤ 30°), high (> 30°).

Results:

We observed that the patients with high C2PA had higher PT and UIVPA preoperatively (p value < 0.001), had more anterior C2 tilt (4.8° v. 1.3°, p = 0.01), experienced more change in UIVPA (24.3° v. 19.5°, p = 0.01), and consequently more change in PT (8.3° v. 4.6°, p = 0.003). It was found that change in PT is significantly correlated with preoperative C2 tilt and the change in UIVPA. The ML-based model had a r² = 0.74. Mean absolute error between observed and predicted PT were 3.4° and 3.2° for training and validation groups, which locates within the acceptable error of measurement.

Conclusion:

This ML model accurately predicted postoperative PT and highlights the importance of preoperative alignment parameters such as C2PA, UIVPA, PT, C2 tilt, and postoperative UIVPA, which accounts for planned surgical correction. A larger cohort will enhance the accuracy of the presented predictive model.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S103.

Abstract ID 17. Program Code P109. Longer operative time is associated with higher risk of adverse outcomes in pediatric idiopathic scoliosis surgery

Vivien Chan ¹, Andrew Michael Chan Tai Kong ², Adeesya Gausper ¹, Suhas Etigunta ¹, Andy M Liu ¹, Kenneth D Illingworth ¹, David L Skaggs ¹

Background:

The purpose of this study was to analyze the relationship between operative time and rates of adverse outcomes in pediatric idiopathic scoliosis surgery.

Methods:

The National Surgical Quality Improvement Program pediatric database (2016 to 2022) was used for this study. Patients were included in this study if they were aged < 18 years and received posterior spinal fusion for idiopathic scoliosis. Revision surgery and anterior approaches were excluded from the study. The primary outcome was rate of adverse events. Secondary outcomes were surgical site infection, allogeneic transfusion, and length of stay. Logistic regression analyses were performed to determine the association between operative time and adverse events, surgical site infection, and allogeneic transfusion. Linear regression analysis was performed to determine the association between operative time and length of stay. Adverse event rate, surgical site infection rate, transfusion rate, and mean length of stay were stratified by operative time.

Results:

There were 23 107 patients included in this study. Mean age was 14.4 years. Mean operative time was 4.5 hours. The rate of adverse events increased with operative time (< 3 hrs: 0.5%, 3 to 5 hrs: 0.5%, 5 to 7 hrs: 0.9%, 7 to 9 hrs: 1.3%, > 9 hrs: 3.1%). The rate of surgical site infection increased with operative time (< 3 hrs: 0.2%, 3 to 5 hrs: 0.5%, 5 to 7 hrs: 0.9%, 7 to 9 hrs: 0.8%, > 9 hrs: 2.2%). The rate of allogeneic transfusion increased with operative time (< 3 hrs: 4.9%, 3 to 5 hrs: 8.5%, 5 to 7 hrs: 15.6%, 7 to 9 hrs: 25.7%, > 9 hrs: 33.2%). The mean length of stay increased with operative time (< 3 hrs: 3.2, 3 to 5 hrs: 3.5, 5 to 7 hrs: 3.9, 7 to 9 hrs: 4.3, > 9 hrs: 6.2). In adjusted regression analyses, controlling for number of surgical levels, 3-column osteotomies, and pelvic instrumentation, each operative hour was associated with higher odds of adverse event (odds ratio [OR] 1.19; p < 0.001), higher odds of surgical site infection (OR 1.12; p = 0.028), higher odds of allogeneic transfusion (OR 1.39; p < 0.001), and longer length of stay (β = 0.26, p < 0.001).

Conclusion:

Increasing operative time is associated with higher risk of adverse event, surgical site infection, transfusion, and longer length of stay in idiopathic scoliosis. Surgical strategies that reduce operative time should be utilized to optimize outcomes.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S103–S104.

Abstract ID 182. Program Code P110. Comparison of safety and effectiveness of freehand to intraoperative navigation, and robotically performed posterior spinal instrumented fusion for adolescent idiopathic scoliosis: a systematic review and meta-analysis

Paweł Łajczak ¹, Eshita Sharma ², Iago Nathan Simon Petry ³, Rabbia Jabbar ⁴, Yasmin Picanço Silva ⁵, Fabio Victor Vieira Rocha ⁶, Oguz Kagan Sahin ⁷, Kaike Eduardo da Silva Lobo ⁸, Ayesha Ayesha ⁹, Aisha Rizwan Ahmed ¹⁰, Walter Fagundes ^8,¹¹, Yan GMD Silva ¹²

Background:

Adolescent idiopathic scoliosis is a common spinal deformity that often requires surgical intervention. Posterior spinal instrumented fusion is a standard surgical technique, and various guidance systems, including freehand, intraoperative navigation, and robotic-assisted surgery, are used. This meta-analysis aimed to compare the safety and effectiveness of this freehand technique with navigation and robotic-assisted surgery in treating adolescent idiopathic scoliosis.

Methods:

We conducted a comprehensive literature search to identify relevant studies. The outcomes of interest were the Gertzbein–Robbins (GR) grade A/0 and AB/0+1, the screw placed without malposition, and satisfactorily/accurately placed screws.

Results:

Our analysis included a total of 8 studies. Overall, the freehand technique was less effective than other interventions for grade A/0 (odds ratio [OR] 0.43, 95% confidence interval [CI] 0.23 to 0.78; p < 0.01), grade A+B/0+1 (OR 0.28, 95% CI 0.17 to 0.47; p < 0.01], screw placed without malposition [OR 0.39, 95% CI 0.23 to 0.65; p < 0.01), accurately placed screws (OR 0.33, 95% CI 0.20 to 0.56; p < 0.01). The subgroup analysis showed freehand was inferior to navigation for grade A/0 (OR 0.39, 95% CI 0.12 to 1.23; p < 0.01), grade A+B/0+1 (OR 0.36, 95% CI 0.23 to 0.58; p < 0.01), screw placed without malposition (OR 0.34, 95% CI 0.16 to 0.75; p < 0.01), accurately placed screws (OR 0.20, 95% CI 0.06 to 0.60; p < 0.01). Similarly, freehand was inferior to robotics for grade A/0 (OR 0.52, 95% CI 0.40 to 0.68; p < 0.01), grade A+B/0+1 (OR 0.20, 95% CI 0.06 to 0.60; p < 0.01), screw placed without malposition (OR 0.54, 95% CI 0.40 to 0.68; p < 0.01), accurately placed screws (OR 0.43, 95% CI 0.27 to 0.70; p < 0.01).

Conclusion:

The freehand technique had inferior accuracy in pedicle screw placement compared with robotics and navigation-based techniques. Further research is needed to assess long-term outcomes and cost-effectiveness of these approaches.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S104.

Abstract ID 157. Program Code P111. Comprehensive analysis of the prognostic factors associated with reaching minimal clinically important differences across degenerative lumbar conditions: a Canadian Spine Outcomes and Research Network study

Aazad Abbas ¹, Karlo Pedro ², Christopher Bailey ³, Philippe Phan ⁴, Jennifer Uruqhurt ³, Greg McIntosh ⁵, Y Raja Rampersaud ⁶

Background:

Up to one-third of patients experience limited benefit following surgical intervention for common degenerative lumbar conditions. There is significant variability in reported prognostic factors with studies being limited by the number of variables and/or sample size as well as a specific diagnosis. As such, the aim of this study is to determine prognostic factors associated with achieving minimal clinically important difference (MCID) across common lumbar degenerative conditions (lumbar spinal stenosis [LSS], degenerative disc disease [DDD], disc herniation [LDH], degenerative [DLS] and isthmic spondylolisthesis [IS], and degenerative scoliosis [DS]). A secondary objective is to examine sex-specific differences.

Methods:

Data from the Canadian Spine Outcomes and Research Network database (2015 to 2023) were analyzed for patients with degenerative lumbar conditions. Multivariate logistic regression models were created to predict achievement of MCID based on 30% improvement in the Oswestry Disability Index (ODI) at 1-year follow-up. Patient diagnosis and a comprehensive list of patient factors (n = 110 variables) were used as inputs. Stepwise selection minimized the Akaike Information Criterion, with significance set at p < 0.05. Odds ratios and 95% confidence intervals were calculated for each variable.

Results:

The study included 6214 patients, with diagnoses LSS (2175), DDD (456), LDH (1279), DLS (1591), IS (361), and DS (352). The average (± standard deviation) age was 60.1 ± 13.4 years with males and females evenly distributed (3142 [50.6%] and 3072 [49.4%], respectively). Statistically significant prognostic factors across all patients included age, body mass index (BMI), baseline pain levels and ODI score, comorbidities, Patient Health Questionnaire-9 (PHQ-9) score, diagnosis, living arrangement, education, smoking status, work status, presence of compensation, and medication use. Differential predictors for females were BMI and back and leg pain, while PHQ-9 score, education level, and expected functional change were more significant for males.

Conclusion:

This study outlines prognostic variables related to achieving surgical MCID outcome (ODI) across common degenerative lumbar conditions, highlighting differences by sex. Future work will employ machine learning to create identifiable patient clusters for more tailored care, improving preoperative outcome-risk stratification.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S104.

Abstract ID 107. Program Code P112. Influence of pelvic parameters on disc degenerative patterns and pathology: Is there a difference between patients with lumbar disc herniations compared with spinal stenosis?

Chloe Cadieux ¹, Tiffany Lung ¹, Jin Tong Du ¹, Celina Nahanni ¹, Christopher Nielsen ¹, Stephen J Lewis ¹, Raja Y Rampersaud ¹

Background:

The innate relationship of the pelvis to the load-bearing axis of the lumbar spine may be the mechanical driver behind different degenerative patterns. The objective of this study was to assess if there is a difference in the pelvic parameters and disc degeneration patterns in surgical patients with lumbar disc herniations (LDH) compared with lumbar spinal stenosis (LSS).

Methods:

One hundred patients who underwent discectomy for LDH were reviewed and compared with 87 patients who underwent decompression alone for LSS. Primary parameters of interest included pelvic incidence (PI), intervertebral disc grade, and level of surgery. Pre- and postoperative radiographs were reviewed and pelvic parameters including PI, pelvic tilt, and sacral slope were measured. The intervertebral discs based on magnetic resonance imaging were graded based on the Pfirrmann grading system. Statistical significance was established at p < 0.05.

Results:

The mean age was 41.68 ± 9 years in the LDH group and 68.66 ± 9 years in the LSS group. The most common operative level was L5–S1 in the LDH group, compared with L4–5 in the LSS group. The PI in the LDH group was significantly lower than in the LSS group (50.5° v. 57.8°, p = < 0.001). Comparing the PI for males and females in the LDH group was 51.7° and 49.6°, compared with 57.9° and 57.7° in the LSS group, respectively (p = 0.007, p ≤ 0.001). The Pfirrmann disc grade was significantly higher at all levels, except for L5–S1, in the LSS group (L1–2, p < 0.001; L2–3, p < 0.001; L3–4, p < 0.001; L4–5, p < 0.048). However, the grade at the operative level was higher in the LDH group (4.30 v. 4.13, p = 0.040). Prior discectomy was rare in the LSS group (5/87, 5.7%).

Conclusion:

Patients having surgery for disc herniation have a lower pelvic incidence than patients with stenosis. In addition to other factors such as injury, age, or systemic inflammation, our findings suggest that the lumbar load-bearing axis imparted by innate pelvic parameters may play an important role in degenerative patterns and pathologies.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S105.

Abstract ID 121. Program Code P113. Tubular versus unilateral biportal endoscopy: magnetic resonance imaging analysis after a unilateral laminectomy for bilateral decompression in lumbar spinal stenosis

Nicolas Ross ^1,², Carlos Aleman ^2,³, Alexandre Dhenin ¹, Matthieu Vassal ¹, Guillaume Lonjon ¹

Background:

Degenerative lumbar spinal stenosis (LSS) frequently requires surgical intervention when conservative treatments fail. Minimally invasive techniques, such as unilateral laminectomy for bilateral decompression, have largely replaced traditional open laminectomy owing to their effective decompression and reduced tissue damage. This study aims to compare the radiologic and clinical outcomes between tubular decompression and unilateral biportal endoscopy (UBE) in patients with severe LSS.

Methods:

A retrospective, monocentric, nonrandomized trial analyzed 103 patients (52 in the tubular group, 51 in the UBE group) with severe LSS from July 2020 to April 2024. The primary radiologic outcomes were changes in anteroposterior (AP) diameter and dural sac surface area, assessed via magnetic resonance imaging. Clinical outcomes included operative time, complication rates, and patient-reported outcomes using the Oswestry Disability Index (ODI) and visual analogue scale (VAS) for pain, evaluated preoperatively and at 3 months postoperatively.

Results:

UBE resulted in significantly greater increases in AP diameter (+4.9 mm v. +3.75 mm; p < 0.001) and dural sac surface area (+95.83 mm² v. +85.4 mm², p = 0.038) compared with tubular decompression. However, both techniques showed similar clinical improvements at 3 months, with no significant difference in ODI, VAS scores, or patient satisfaction. The complication rate, including reoperation, was low in both groups, but UBE had a higher incidence of symptomatic hematoma.

Conclusion:

Both tubular decompression and UBE are effective for LSS treatment, with UBE providing superior radiologic decompression, even in the early learning phase. However, clinical outcomes were comparable between the techniques at 3 months. Further studies are required to assess long-term results and refine patient selection criteria.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S105.

Abstract ID 6. Program Code P114. Comparison of fusion rate, improvement of radiologic parameters in patients who underwent L5/S1 posterior fusion surgery using polyetheretherketone versus titanium cages

Hamidullah Salimi ^1,², Hidetomi Terai ¹, Koji Tamai ¹, Masato Uematsu ¹, Hiroshi Katsuda ²

Background:

The purpose of this study is to review fusion rate and radiographic parameters after posterior lumbar interbody fusion (PLIF) as a comparative analysis between titanium and polyetheretherketone (PEEK) cages.

Methods:

A retrospective study of 60 consecutive patients with an average age of 58.8 years (ranging from 20 to 81 years), who underwent posterior fusion for degenerative indications from January 2014 to December 2022 operated by spine surgeons. Plain standing radiographs and computed tomography scans were obtained at 1 to 2 weeks, 8 to 12 weeks, and 12 months postoperatively. The primary outcome measures were the evaluation of fusion status based on the cage type (titanium v. PEEK). Secondary outcomes were evaluation of radiologic parameters such as lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), L5/S1 angle, and the clinical outcomes visual analogue scale and Japanese Orthopaedic Association scores, which were compared based on confounding factors such as age, sex, and type of cage used for fusion.

Results:

In total, 60 patients with an average age of 58.8 years (20 female, 40 male) who underwent L5/S1 PLIF were included in this study. The average operation time was 136 minutes. The average preoperative L5/S1 angle in titanium cage group increased from 4.6° to 8.5° while the average L5/S1 angle in the PEEK group decreased from 7.8° to 6.6°, which indicates a higher subsidence in PEEK cages than titanium. Also, LL, SS, and PT increased in the titanium group. The fusion rate analysis of both groups revealed that the titanium cage group had an absolute union rate in all gender and age groups, but the PEEK group showed lower union, especially in females, and was not correlated to the age of the patients.

Conclusion:

Titanium cages had significantly higher fusion and radiologic correction rates, as well as improved clinical outcomes compared with PEEK cages in patients undergoing PLIF. Titanium cages had lower subsidence rates than PEEK cages in the current study.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S105–S106.

Abstract ID 97. Program Code P115. Comparative efficacy of endoscopic discectomy versus microdiscectomy for L5–S1 lumbar disc herniation: a systematic review and meta-analysis

Eshita Sharma ¹, Ayesha Ayesha ², Kaike Eduardo Silva Lobo ³, Beatriz Westphalen Pomianoski ⁴, Jose Martin Kotochinsky ⁵, Yan GMD Silva ⁶

Background:

Lumbar disc herniation (LDH) is a common cause of back and leg pain. L5–S1 LDH is usually treated with a microdiscetomy (MD). However, with the introduction of endoscopic techniques, it is unclear which patients would benefit the most from endoscopic discectomy (ED).

Methods:

We systematically searched PubMed, Embase, and Cochrane Central for studies comparing patients who underwent L5–S1 LDH repair with MD or ED. Postoperative pain was evaluated using the visual analogue scale and quality of life with the Oswestry Disability Index. Weighted mean differences (WMD) and odds ratio (OR) were pooled using a random-effects model.

Results:

We screened 3506 articles and included 4 studies with 264 patients, of whom 134 (51%) underwent MD and 130 (49%) were treated with ED. ED was associated with reduced back pain at 1 month (WMD −0.59, 95% CI −1.06 to −0.11; I² = 0%). However, no significant differences were noted in leg pain at 1 month (WMD 0.16, 95% CI −0.78 to 1.10; I² = 0%), 6 months (WMD 0.23, 95% CI −0.76 to 1.22; I² = 0%) and 12 months (WMD 0.17, 95% CI −0.81 to 1.15; I² = 0); back pain at 6 months (WMD 0.29, 95% CI −0.79 to 0.20; I² = 0%) and 12 months (WMD −0.22, 95% CI −0.71 to 0.28; I² = 0%); operative time (WMD 2.45, 95% CI −31.09 to 63.74; p = 0.89, I² = 92%); or recurrence (OR 0.85, 95% CI 0.22 to 3.35; I² = 0%).

Conclusion:

No significant differences were found between ED and MD for treating L5–S1 LDH regarding clinical outcomes. While ED may offer a less invasive option and reduce early postoperative pain, further trials are needed to evaluate the long-term benefits, especially in minimizing postoperative pain and improving recovery.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S106.

Abstract ID 27. Program Code P116. Comparative efficacy of uniportal and biportal endoscopic techniques in the treatment of lumbar spinal stenosis: a meta-analysis

Ramon Guerra Barbosa ¹, Newton Pimenta ², Yan Silva ³

Background:

Endoscopic spine surgery has been increasingly consolidated as a minimally invasive technique for decompressing lumbar spinal stenosis (LSS). However, there remains uncertainty regarding which of the 2 techniques — uniportal or biportal endoscopy — yields superior outcomes in treating LSS. This meta-analysis aimed to compare the results of these 2 approaches to provide clearer evidence on their relative efficacy and safety.

Methods:

A comprehensive search was conducted in the PubMed and Cochrane databases using the MeSH terms “laminectomy” and “endoscopy.” A total of 217 articles were initially identified. After 24 duplicates were removed, 193 articles were further screened. Of these, 66 were excluded for lack of relevance to the topic. Finally, only 2 studies met the inclusion criteria by directly comparing uniportal and biportal endoscopic approaches for LSS. Statistical analysis was performed using the Cochrane RevMan software.

Results:

The 2 studies included a total of 174 patients. Both approaches demonstrated significant clinical improvements postoperatively, with reductions in visual analogue scale (VAS) scores and Oswestry Disability Index (ODI) scores. Biportal endoscopy was associated with a shorter operative time, while uniportal endoscopy was associated with shorter hospitalization time. Blood loss, as well as VAS scores for back and leg pain and ODI scores, were similar between the 2 techniques.

Conclusion:

Both uniportal and biportal endoscopic techniques offer effective decompression for LSS, with similar clinical outcomes. Operative time and complication rates were lower in the biportal group, but these differences were not statistically significant. Further research is needed to substantiate these findings and aid in surgical decision-making for the treatment of LSS.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S106.

Abstract ID 10. Program Code P117. Subfascial drain after incidental durotomy and postoperative courses: a retrospective observational study

Jieun Kim ¹, Richard Roberts ¹, Frank Kortbeek ¹

Background:

Incidental durotomy (ID) is a common iatrogenic complication in lumbar spine surgery with a reported incidence of 1.7% to 14%. ID can lead to a range of clinical sequelae, including chronic headache, wound complications, or new neurological deficits, warranting readmission and reoperation. Subfascial drain is commonly employed in spine surgery to reduce risk of postoperative hematoma or seroma. In the setting of ID, it remains unclear whether subfascial drain can prevent postoperative complications.

Methods:

Using the International Classification of Diseases-10 billing codes, adult patients with degenerative lumbar spine surgeries and ID between January 2012 and December 2022 in Alberta, Canada, were identified. Exclusion criteria were as follows: no information on intraoperative ID and management; intrathecal lumbar drain use; thoracic spine involvement; associated trauma, tumour, or infection; and prolonged admission owing to preoperative neurologic deficits or comorbidities including active substance use disorder. The following was collected: age, sex, comorbidities, surgical indications, primary versus revision, number of levels operated and surgery types (laminectomy, discectomy, posterior lumbar interbody fusion (PLIF), or PLIF + transforaminal lumbar interbody fusion), ID repair method, immobilization period, length of hospital stay, and readmission or reoperation owing to ID.

Results:

A total of 100 patients were eligible (n = 71 for no-drain group; n = 29 for subfascial drain group). Patient characteristics were comparable except the age at the time of index surgery (56.9 ± 15.2 years v. 66.8 ± 11.2 years; p = 0.002). More fusion surgeries and greater number of levels operated were observed in subfascial drain group (both χ² p < 0.0001). Length of hospital stay and readmission or reoperation rate were comparable. More patients had complications in the no-drain group (n = 22/71 v. n = 5/29). The fusion subgroup had similar trends (n = 9/24 v. n = 4/22). Multivariable modelling identified inflammatory disease as the most significant predictor for 1-year total complications and reoperation in the fusion subgroup (hazard ratio 59.952, 95% confidence interval 6.9 to 518.7).

Conclusion:

Subfascial drain use may be associated with fewer complications when managing ID in adult degenerative lumbar spine procedures. Further research into the effect of patient-level factors, including inflammatory disease, on subsequent health care utilization is warranted.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S106–S107.

Abstract ID 187. Program Code P118. The degenerative spondylolisthesis instability classification system and the challenges of creating a surgical decision aid

Mark A MacLean ^1,², Y Raja Rampersaud ³, Chris Bailey ⁴, Charles Fisher ⁵, R Andrew Glennie ²

Background:

The Degenerative Spondylolisthesis Instability Classification (DSIC) system categorizes 3 different types of degenerative lumbar spondylolisthesis (DLS): stable, potentially unstable, and unstable. Surgeons consider various clinical and radiographic determinants of stability, and the system suggests a corresponding procedure. Despite its potential decision-making utility, it remains unclear if surgeons select a procedure that aligns with this instability-based classification system.

Methods:

We conducted a cross-sectional survey of 20 fellowship-trained spinal surgeon members of the Canadian Spine Society. Respondents were presented with 14 case-based scenarios including clinical, radiographic, and magnetic resonance imaging data. Instability was classified according to the DSIC system and surgeons were asked to select a surgical strategy: decompression alone or decompression and instrumented fusion. Percent agreement estimates were determined for instability classification and procedure selection using ordinal weighting and comparison of the proportion of agreeing and disagreeing pairs.

Results:

Among combined responses across all cases, percent agreement pertaining to instability classification using the DSIC system was 82%, whereas procedural selection was 66%. Decompression alone was selected 78% of the time when surgeons classified instability as DSIC Type 1 (stable). Decompression and instrumented fusion was selected in 63% of cases classified as DSIC Type 2 (potentially unstable) and 100% of cases classified as DSIC Type 3 (unstable). Percent agreement estimates pertaining to the classification of instability according to DSIC type exceeded 80% in 10 of 14 cases. Despite this, agreement estimates regarding procedural selection exceeded 80% in only 3 of 14 cases.

Conclusion:

In this case-based survey of fellowship-trained spinal surgeons, good agreement was observed regarding the classification of instability using the DSIC system. Despite this, poor agreement was observed regarding procedural selection based on instability.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S107.

Abstract ID 124. Program Code P119. Comparison of functional results following lumbar discal herniation surgery by conventional technique or unilateral biportal endoscopy: a propensity score matched analysis

Guillaume Lonjon ¹, Alexandre Dhenin ¹, Matthieu Vassal ¹

Background:

Spinal endoscopy for lumbar disc herniation surgery (LDH) has been reported to enhance early postoperative patient comfort. However, evidence highlighting its benefits on long-term functional outcomes still needs to be discovered. The objective of this study is to evaluate the medium and long-term functional improvement of patients operated for LDH using conventional technique (open) or unilateral biportal endoscopy (UBE).

Methods:

A retrospective, monocentric, nonrandomized trial analyzed all 363 patients operated for LDH between Jan. 2022 and Sept. 2023 in 1 medical center by 3 spine surgeons. From April 2022, the start date of endoscopy use in the centre, the surgical technique was left to the surgeon’s discretion. Patients were followed for 1 year with functional analysis (Oswestry Disability Index [ODI], lumbar and radicular pain [visual analogue scale, VAS-L and VAS-R]), and patient satisfaction evaluation. Clinical evaluation was conducted at 1, 3, and 12 months. Complications and reoperation rates were analyzed.

Results:

After using a propensity score to improve comparability of the groups, we included 302 patients in the analysis (151 in each group). Clinical outcomes were significantly improved compared with preoperative (decrease in ODI and VAS), with no differences between the 2 groups at any time point. At 1 year postoperative, mean ODI decrease was 33.4 points in open group versus 33.8 in the UBE group (p = 0.872), with respectively 85% and 83% of patients reaching the minimal clinically important difference (13 points ODI decrease). Pain decrease was, respectively, 3.4 versus 3.5 for VAS-L (p = 0.458) and 4.9 v. 5 for VAS-R (p = 0.494). Regarding complications, no significant difference was found between the 2 groups on accidental intraoperative dural tears (2.7% in each group; p > 0.999), reoperations for spinal hematoma (0% open group v. 1.3% UBE group; p = 0.498), and reoperations for recurrent disc herniation (2.6% v. 0%; p = 0.123). No infections were observed.

Conclusion:

The results of this study show that the UBE technique, even in the early stages of a surgeon’s practice, is at least as effective as conventional techniques for surgical treatment of LDH.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S107–S108.

Abstract ID 74. Program Code P120. The effects of preoperative psychological health on the outcomes of lumbar discectomy for radiculopathy owing to disc herniation

Hannah Van Brenk ^1,², Erin E Bigney ^1,^2,³, Neil A Manson ^2,^3,⁴, Chris Small ^2,^3,⁴, Edward Abraham ^2,^3,⁴, Najmedden Attabib ^2,^4,⁵, Jill Kearney ^2,³, Eden A Richardson ^2,^3,⁶, Gwyneth deVries ⁷, Stephan Dombrowski ¹; CSORN Principal Investigators⁶, Jeffrey Hebert ¹

Background:

We undertook to estimate the effects of preoperative psychological factors on postoperative pain and disability in patients undergoing discectomy for lumbar radiculopathy.

Methods:

This retrospective cohort study utilized data of patients in the Canadian Spine Outcomes and Research Network registry who underwent discectomy for lumbar radiculopathy caused by disc herniation. Preoperative psychological measures included the Patient Health Questionnaire-8 (PHQ-8) and the 12-Item Short-Form Health Survey mental component summary score (MCS). PHQ-8 ≥ 10 indicates moderate-to-severe depression risk, and MCS < 46 indicates depression and < 37 indicates severe psychological symptomology. Outcomes included numeric rating scale (NRS) for back pain, NRS-leg pain, and the modified Oswestry Disability Index collected preoperatively and at 3, 12, and 24 months after surgery. Confounding variables controlled for age, sex, education, smoking status, baseline physical functioning, and wait times. Recovery trajectories for leg pain and overall recovery were identified with latent class growth models. Doubly robust estimates of the average treatment effects were constructed. Results were reported with risk ratios (RR). Sensitivity analysis assessed potential bias.

Results:

Data from 1104 patients (52% female; mean age 43.90 years) were included. The leg pain recovery trajectory showed that 11.4% of patients experienced a poor outcome, while 28% had poor overall recovery. More than half (60%) were at moderate-to-severe risk of depression, increasing risk of poor leg pain recovery (RR 1.61, 95% confidence interval [CI] 1.07 to 2.43) and poor overall recovery (RR 1.90, 95% CI 1.46 to 2.4). Similarly, 57% of patients experienced preoperative depression, increasing poor leg pain recovery risk (RR 1.92, 95% CI 1.20 to 3.08) and poor overall recovery (RR 2.07, 95% CI 1.51 to 2.86). Finally, 30% of patients indicated severe psychological symptomology, increasing risk of poor leg pain recovery (RR 1.78, 95% CI 1.21 to 2.61) and overall recovery (RR 1.93, 95% CI 1.55 to 2.40). Sensitivity analysis indicated substantial unmeasured confounding would be needed to explain away the observed effects.

Conclusion:

Most patients undergoing discectomy for lumbar radiculopathy exhibit poor preoperative psychological health, adversely affecting outcomes.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S108.

Abstract ID 23. Program Code P121. Recurrent disc herniation: Does endoscopic surgery offer advantages over open microdiscectomy?

Ramon Guerra Barbosa ¹, Newton Pimenta ², Yan Silva ³

Background:

Recurrent lumbar disc herniation (rLDH) presents a clinical challenge, often necessitating reoperation. Traditional open surgery poses risks such as dural tears and increased recovery time. Endoscopic techniques have emerged as minimally invasive alternatives, offering potential advantages in reducing complications and improving recovery times. This study systematically reviews the outcomes of endoscopic approaches for rLDH, supported by illustrative case.

Methods:

A comprehensive search was conducted in PubMed using the keywords “recurrent disc herniation” AND “endoscopy” for studies published between 2004 and 2024. A total of 296 articles were initially identified, with 19 selected based on relevance to the surgical treatment of recurrent disc herniation. Outcomes related to pain relief, recurrence, and complications were analyzed. Additionally, we present illustrative cases, highlighting the practical application of endoscopic reoperation techniques.

Results:

Endoscopic surgery demonstrated shorter surgical times than open surgery, with differences of up to 52 minutes. Additionally, blood loss was significantly reduced in the endoscopic group, with average reductions ranging from 53 mL to 151 mL. Both approaches showed similar recurrence rates, approximately 5.7%, with no significant differences. The complication rate was lower in the endoscopic group, with fewer dural tears and infections. In terms of pain relief and functional improvement, both techniques yielded comparable outcomes, with no significant differences in long-term follow-up. Endoscopic surgery also resulted in shorter hospital stays, with most patients being discharged within 24 hours.

Conclusion:

Endoscopic reoperation for rLDH is a safe and effective alternative to traditional open surgery, with comparable recurrence rates and a lower incidence of complications. The minimally invasive nature of endoscopy allows for faster recovery and lower morbidity, making it an ideal option for patients with recurrent disc herniation.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S108.

Abstract ID 134. Program Code P122. P-15 Peptide Enhanced Bone Graft in posterolateral fusion: a prospective, multicentre clinical study

Renan Rodrigues Fernandes ¹, Bradley Jacobs ², Christopher Witiw ³, Zhi Wang ⁴, Perry Dhaliwal ⁵, Carlo Santaguida ⁶, Christopher Bailey ¹

Background:

Posterolateral lumbar fusion (PLF) is frequently used to treat degenerative lumbar spine conditions, where successful fusion is essential for favorable outcomes. Fusion technique and graft material selection significantly influence arthrodesis. The P-15 Peptide Enhanced Bone Graft (ABM/P-15 Matrix) is a bone graft alternative that integrates P-15, a synthetic peptide mimicking the cell-binding domain of Type I collagen. This study reports early clinical and radiologic outcomes using ABM/P-15 Matrix in single- and multilevel PLF procedures across multiple centres.

Methods:

A prospective study was conducted in 6 Canadian hospitals. Adults needing lumbar spinal fusion between L1 and S1 were enrolled. Baseline, 6-month, and 12-month postoperative evaluations included neurological assessments, Oswestry Disability Index (ODI), 12-Item Short-Form Survey (SF-12), and Numeric Pain Rating Scale (NRS). High-risk factors included smoking, obesity (body mass index [BMI] > 30), and diabetes. A thin-cut (< 1 mm) computed tomography scan assessed fusion status at 12 months, classified as absent, partial, or fused, by an independent core lab. Adverse events and reinterventions at the index level were documented.

Results:

Forty-five participants (62 levels; mean age 67.9 ± 11.9 years, 14 male, 31 female) were included. High-risk comorbidities were present in 76% of patients (16 with BMI > 30, 7 smokers, 11 with diabetes). The mean operated levels were 1.4 (range 1 to 3). Among 33 participants with data, 90.9% showed full (n = 26) or partial (n = 4) fusion at 12 months. In total, 93.3% of 45 segments were fused or partially fused. Significant improvements were observed in NRS back and leg scores, ODI, SF-12 mental and physical component summary scores at 12 months (all p < 0.05). No device-related adverse events or index-level reoperations were reported.

Conclusion:

High 12-month fusion rates were achieved with P-15 Peptide Enhanced Bone Graft despite a challenging environment and high patient comorbidities. No graft-related complications or reoperations were noted at 1 year postoperatively.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S108–S109.

Abstract ID 21. Program Code P123. Examining the impact of successive revision spine surgeries on pain, disability, mental health, satisfaction, and length of stay: a Canadian Spine Outcomes and Research Network study

Sufyan Faridi ^1,², Erin Bigney ^2,^3,⁴, Jeffrey Hebert ^5,⁶, Neil Manson ^1,^2,³, Edward Abraham ^1,^2,³, Chris Small ^1,^2,³, Eden Richardson ^2,^3,⁷, Jill Kearney ^2,³, Najmedden Attabib ^1,^2,⁸

Background:

We aimed to estimate rates of revision and successive revision spine surgeries in Canada and compare outcomes among patients undergoing primary surgery, 1 revision, and ≥ 2 revisions.

Methods:

This retrospective cohort study utilized data from the Canadian Spine Outcomes and Research Network, collected preoperatively, and 3 and 12 months after surgery. Patients who underwent thoracolumbar surgery for degenerative conditions were categorized into primary, 1 revision, or ≥ 2 revision cohorts. Outcomes included Numeric Rating Scales (NRS) for leg and back pain, Oswestry Disability Index (ODI), mental component summary (MCS) score of the 12-Item Short-Form survey, patient satisfaction, and length of stay. Linear mixed models controlled for confounders. Model results were reported with difference scores (DS).

Results:

Among 6068 patients, 9.8% underwent 1 revision, and 1.1% ≥ 2 revisions. All cohorts showed significant improvement in NRS-leg pain, NRS-back pain, and ODI. Compared with the 1-revision cohort, the ≥ 2 revision cohort demonstrated greater NRS-leg pain at 3 months (DS 1.33) and 12 months (DS 1.31), NRS-back pain at 3 months (DS 0.92) and 12 months (DS 0.93), and ODI at 3 months (DS 9.24) and 12 months (DS 10.16). Compared with the primary cohort, the ≥ 2 revision cohort also demonstrated greater NRS-leg pain at 3 months (DS 2.06) and 12 months (DS 2.15), NRS-back pain at 3 months (1.58) and 12 months (DS 1.77), and ODI at 3 months (DS 16.60) and 12 months (DS 18.36). The ≥ 2 revision patients had worse baseline MCS scores than those of the 1 revision (DS −13.45) and primary (DS −13.71) cohorts, but scores improved at 3 months (DS 10.44) and 12 months (DS 15.70). Most patients were satisfied with their surgery: ≥ 2 revision 3 months, 72%; 12 months, 65%; 1-revision 3 months, 81%; 12 months, 76%; primary 3 months, 89%; 12 months, 87%. The ≥ 2 revision (6.97) and 1 revision (4.90) cohorts had longer hospital stays than the primary cohort (3.44).

Conclusion:

Patients who underwent ≥ 2 revisions experienced improvements in mental health and reduced pain and disability, though less so than patients who underwent a single revision or primary surgery. They also had longer hospital stays and were less satisfied at 12 months. This information aids in expectation management and shared decision-making.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S109.

Abstract ID 75. Program Code P124. The impact of overall lumbar disc degeneration burden on Oswestry Disability Index outcomes following surgery for lumbar spinal stenosis owing to osteoarthritis

Y Raja Rampersaud ^1,^2,³, J Denise Power ^1,², Mohit Kapoor ^1,², Anthony V Perruccio ^1,^2,^3,⁴

Background:

Up to one-third of patients experience limited benefit following surgical intervention for lumbar spinal stenosis owing to osteoarthritis (LSS-OA). Identifying contributing factors to this is important. Patients with LSS-OA often have disc degeneration at multiple levels beyond the surgical level(s), yet this has received limited attention. We documented the occurrence and evaluated the influence of overall lumbar disc degeneration (LDD) burden on Oswestry Disability Index (ODI) outcomes.

Methods:

A total of 121 patients undergoing decompression surgery with or without fusion for LSS-OA completed the ODI before and 12 months after surgery. Other presurgery factors were age, sex, education, body mass index, fusion, smoking, comorbidities, symptomatic appendicular joints, depression, and anxiety symptoms. Modified Pfirrmann disc grading was performed for each lumbar level (grades 1 to 5 were scored as 0 [grade 1: none], 1 [grade 2/3: mild], 2 [grade 4: moderate], and 3 [grade 5: severe]), and summed to yield an overall LDD score (possible range: 0 to 15). Based on preliminary work, individuals were grouped as follows: LDD score 0 to 6 (group 1), 7 to 10 (group 2), and ≥ 11 (group 3). The influence of LLD group on 12-month postsurgery outcomes ODI score and ODI percentage change were examined using linear regression adjusting for presurgery factors.

Results:

Patients’ mean age was 67.2 years; 43.8% were female. The mean LDD score was 8.9/15. 19.8% were in the LDD group 1, 54.6% in group 2, and 25.6% group 3. Group 1 had a mean 12-month ODI score of 18.8, and percentage change of 57.3%; group 2, 20.0 and 52.2%; group 3, 26.7 and 28.1%. Adjusted analyses : showed the ODI percentage change in group 3 (highest LDD burden) to be 21.5 percentage points lower than those in group 1 (p = 0.04), and 12-month ODI scores were 10.7 units lower (p = 0.007). Also, higher joint count and greater anxiety symptoms were associated with poorer outcomes.

Conclusion:

Independent of a number of factors, overall LDD burden is strongly associated with outcome. Findings point to a need to consider multilevel, and multijoint, burden to understand spine-specific disability outcomes. Similar to appendicular OA, this overall burden may reflect a systemic, largely inflammatory profile for a subgroup of LSS-OA patients.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S109–S110.

Abstract ID 101. Program Code P126. Minimally invasive decompression versus open laminectomy in multilevel lumbar stenosis: a meta-analysis

Eshita Sharma ¹, Kaike Eduardo Silva Lobo ², Ayesha Ayesha ³, Paweł Łajczak ⁴, Beatriz Westphalen Pomianoski ⁵, Yan GMD Silva ⁶

Background:

Lumbar spinal stenosis is a common spinal condition. Surgical intervention is often the choice of treatment. Two primary surgical approaches for treating lumbar spinal stenosis are open laminectomy surgery (OLS) and minimally invasive decompression (MID), with or without an endoscopic approach. Therefore, this meta-analysis aims to compare MID with OLS.

Methods:

We systematically searched PubMed, Embase, and Cochrane Central for randomized controlled trials and observational studies comparing patients with multilevel lumbar stenosis treated with MID with and without an endoscopic approach, versus OLS. Primary outcomes were length of hospital stay (LHS), operative time (OT), complication rate (CR), intraoperative blood loss (IBL), reoperation due to recurrence (RDR), and low back pain 1 year after surgery (LBP). Mean differences (MD) and odds ratio (OR) were used for all outcomes. The p < 0.05 presented a significant statistical result, and I² < 40% showed low heterogeneity.

Results:

Of 3695 articles screened, 4 studies and 618 patients were included, of whom 291 (47%) were treated with MID and 327 (53%) were treated with OLS. There were no significant differences between the groups in OT (MD 7.68, 95% CI −20.53 to 35.88; p = 0.59, I² = 96%), CR (OR 0.72, 95% CI 0.04 to 14.73; p = 0.83, I² = 80%), RDR (OR 0.34, 95% CI 0.06 to 1.860; p = 0.21, I² = 0%), LBP (MD −0.38, 95% CI −1.83 to 1.08; p = 0.61, I² = 64%), and LHS (MD −3.25, 95% CI −7.25 to 0.74; p = 0.11, I² = 99%). Furthermore, IBL was reduced in MID compared with OLS (MD −55.20, 95% CI −105.73 to −4.67; p = 0.03, I² = 95%), decreasing the need for transfusions and complications. Only the RDR presented a low heterogeneity, while the rest of the outcomes conferred a high heterogeneity.

Conclusion:

Our study showed important statistical differences between the groups analyzed, probably owing to the lack of standardized approach and decompression techniques used across the studies. MID offers an advantage in terms of intraoperative blood management when compared with OLS, which presents a safer treatment of lumbar spinal stenosis.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S110.

Abstract ID 122. Program Code P127. P-15 Peptide Enhanced Bone Graft in lumbar spine surgery for degenerative disc disease: radiologic and clinical outcomes from a Canadian prospective multicentre study

Zhi Wang ¹, Bradley Jacobs ², Christopher Witiw ³, Perry Dhaliwal ⁴, Carlo Santaguida ⁵, Chris Bailey ⁶

Background:

Transforaminal lumbar interbody fusion (TLIF) and posterior lumbar interbody fusion (PLIF) are widely used to treat degenerative lumbar spine conditions. The success of these procedures largely depends on achieving effective arthrodesis, influenced by both the fusion technique and bone graft material. P-15 Peptide Enhanced Bone Graft (ABM/P-15 Matrix) is a composite graft that incorporates P-15, a synthetic peptide mirroring the cell-binding region of Type I collagen. This abstract summarizes early clinical and radiologic outcomes of ABM/P-15 Matrix in TLIF and PLIF procedures from a multicentre clinical trial.

Methods:

This prospective study included adult participants across 6 Canadian hospitals who required lumbar spinal fusion (TLIF/PLF or PLIF/PLF) between levels L1 and S1. Baseline, 6-month, 12-month, and 24-month assessments included neurologic status, Oswestry Disability Index (ODI), 12-Item Short-Form survey (SF-12), and Numeric Pain Rating Scale (NRS) scores. High-risk factors, including smoking, obesity (body mass index [BMI] > 30), and diabetes, were noted. At 12 months, a thin-cut computed tomography scan assessed fusion status, reviewed independently. Adverse events and reinterventions were tracked.

Results:

Ninety-four participants (116 operative levels, mean age 63.1 years) underwent TLIF or PLIF with posterior fusion (PLF). Of these, 60.6% had ≥ 1 high-risk comorbidities (33 with BMI > 30, 7 smokers, 17 with diabetes). Mean operated levels were 1.2 for both TLIF/PLF and PLIF/PLF. Full or partial fusion was observed in 100% of both TLIF/PLF and PLIF/PLF participants and segments. Improvements in NRS back and leg scores, ODI, and SF-12 physical and mental component summary scores were significant at 12 months for TLIF/PLF (all p < 0.001) and for PLIF/PLF in NRS back and leg scores (p < 0.001), ODI (p < 0.001), and SF-12 scores (physical, p = 0.044; mental, p = 0.008).

Conclusion:

ABM/P-15 Matrix yielded high 12-month fusion rates in lumbar arthrodesis, even among patients with risk factors affecting fusion. Therefore, ABM/P-15 Matrix is a viable option for high-risk patients needing lumbar fusion.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S110–S111.

Abstract ID 174. Program Code P128. The association between improvements in hip strength, low back strength, and low back pain following a 10-week exercise intervention

Alicia Wright ¹, Brent Rosenstein ¹, Chanelle Montpetit ¹, Nicolas Vaillancourt ¹, Maryse Fortin ^1,^2,³

Background:

Low back pain (LBP) is a global health problem and leading cause of disability worldwide. Chronic LBP is associated with lower physical function and reduced trunk and hip strength. While conservative treatment for LBP typically consisted of exercise interventions focusing on the trunk area, few studies have examined the direct impact of hip and lumbar strength gains on patient-reported outcomes. The purpose of this study was to examine whether greater improvement in hip and lumbar strength following a 10-week exercise intervention program are correlated with greater improvements in patient-reported outcomes.

Methods:

This was a secondary analysis of a previous randomized controlled trial including participants with chronic LBP. Thirty-four participants were randomly allocated to either aquatic therapy (n = 18) or standard care exercise therapy (n = 16) and underwent a 10-week supervised intervention program twice per week. Pre- and postintervention measures of pain (Numerical Pain Rating Scale [NPRS]), disability (Oswestry Disability Index [ODI]), quality of life (12-Item Short-Form Story [SF-12]) and depression (Hospital Anxiety and Depression scale [HADS]) were captured via questionnaires, lumbar strength was measured using a MedX lumbar extension machine, and hip strength was measured using a hand-held dynamometer.

Results:

Pearson correlations revealed that a significant moderate negative correlation was present between changes in mean (r = −0.44, p = 0.014) and max (r = −0.44, p = 0.015) lumbar strength and NPRS score. A significant moderate negative correlation was present between changes in mean (r = −0.45, p = 0.012) and max (r = −0.37, p = 0.044) lumbar strength and ODI score. A significant moderate positive correlation was present between changes in average GMax strength and physical quality of life SF-12 score (r = 0.40, p = 0.006).

Conclusion:

Our results suggest that greater gains in lumbar and hip muscle strength were associated with a decrease in pain rating, and greater improvement in disability as well as greater improvements in quality of life (physical function). These findings highlight the importance of integrating hip and lumbar strength exercises to rehabilitation programs for chronic LBP.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S111.

Abstract ID 129. Program Code P129. The effect of a multimodal physical training program versus no exercise on paraspinal muscle morphology and patient outcomes in chronic low back pain

Brent Rosenstein ¹, Maxime Bergevin ^2,³, Florian Bobeuf ³, Louis Bherer ^3,⁴, Benjamin Pageaux ^2,³, Mathieu Roy ^4,^5,⁶, Maryse Fortin ^1,⁴

Background:

While multimodal physical exercise programs that do not specifically target lumbar musculature have improved pain and function in individuals with low back pain (LBP), little is known regarding their effects on paraspinal muscle health. This study investigated the effect of a 14-week high-intensity physical training program versus a waitlist group on paraspinal muscle size and composition, and clinical outcomes in individuals with chronic LBP.

Methods:

Out of 92 participants with chronic LBP enrolled in a larger trial, 34 underwent lumbosacral magnetic resonance imaging (MRI) at baseline and postintervention, and were included in the current analysis. Participants were randomly allocated to each group (exercise, n = 8; wait-list, n = 26) and completed a 14-week high-intensity training program (3 sessions per week) including cardiovascular training, progressive upper body and lower body strength-training, and stretching. Dixon fat and water MRI images from L3 to S1 were used to examine the impact of each intervention on multifidus (MF) and erector spinae (ES) volume (cm³) and fatty infiltration (%FI). Self-reported outcomes including pain, disability, quality of life, and psychological factors were also examined.

Results:

Mixed-effects analysis of variance with repeated-measures revealed no significant time group interactions for MF and ES volume and %FI. The exercise group displayed a significant increase in MF volume and %FI at L5–S1. The wait-list group displayed a significant increase in MF %FI at L3–L4, L4–L5, and L5–S1, and a significant increase in ES %FI at L5–S1. Furthermore, there were significant time group interactions for pain, disability, catastrophizing and kinesiophobia, with greater improvements in the exercise group (all p < 0.01). For quality of life, there was a significant main effect of group in physical (p = 0.001) and mental (p = 0.03) health, with larger improvements in the exercise group. No significant results were found for anxiety.

Conclusion:

This study provided preliminary evidence suggesting that multimodal physical exercise may help prevent paraspinal muscle atrophy and %FI, and lead to concomitant improvements in pain, self-reported disability and pain-related fear in individuals with chronic LBP.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S111–S112.

Abstract ID 125. Program Code P130. Effect of a 10-week neuromuscular electrical stimulation intervention with the StimaWELL 120MTRS system on multifidus morphology and function in patients with chronic low back pain

Daniel Wolfe ¹, Geoffrey Dover ¹, Mathieu Boily ², Maryse Fortin ¹

Background:

Patients with chronic low back pain (CLBP) present with morphologic and functional deficits to the lumbar multifidus. Neuromuscular electrical stimulation (NMES) can be used to improve activation and strength in atrophied skeletal muscle, but its effect on multifidus morphology and function in CLBP patients is understudied. The primary aim of this study was to compare the effect of 2 NMES protocols on lumbar multifidus morphology (cross-sectional area, fatty infiltrate) in CLBP patients. The secondary aims were to assess their effect on lumbar multifidus function (thickness, stiffness) and patient-reported outcomes.

Methods:

We carried out a 2-arm randomized control trial (RCT). Individuals with CLBP were randomized to receive either the “phasic” (3kHz, modulation 50Hz) or “combined” (3kHz, modulation 50Hz and 4Hz) muscle therapy protocol with the StimaWELL 120MTRS. Participants received 20 supervised sessions, twice a week, with a progressive increase in treatment time. Multifidus morphology was assessed with magnetic resonance imaging, and function with ultrasound. Imaging-based outcomes were measured at baseline and postintervention. Pain intensity, pain interference, disability, and catastrophizing were measured at baseline, midpoint, and postintervention. We used t tests and nonparametric equivalents to assess change in imaging-based outcomes, and a repeated-measures analysis of covariance was used for patient-reported outcomes.

Results:

In total, 28 participants (15 phasic, 13 combined) completed the intervention. Apart from a significant within-group decrease in fatty infiltration at left L5–S1 in the combined group (MD −1.51, 95% CI −2.79 to −0.23; p = 0.024), results revealed no significant within- or between-group changes to multifidus morphology or function. Pairwise comparisons revealed significant improvements in both groups in average LBP intensity, LBP with motion, LBP with sitting, from pre- to post-treatment (all p < 0.01), and significant improvements in the phasic group in disability, pain interference, and pain catastrophizing (all p < 0.01). Additionally, there were significant group by time effects for LBP with sitting (p = 0.019) and pain interference (p = 0.032) favouring the phasic group.

Conclusion:

A 10-week NMES intervention produced no between-group differences in multifidus muscle morphology or function. Participants in both groups experienced significant improvements in a variety of patient-reported outcomes.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S112.

Abstract ID 80. Program Code P131. 3-D topographic acquisitions to estimate curve magnitude in adolescent idiopathic scoliosis

Emma Nadler ¹, David E Lebel ¹, Dorothy J Kim ¹, Jennifer A Dermott ¹

Background:

This study aims to determine the accuracy and inter-rater reliability of an artificial intelligence–powered mobile phone health application that estimates curve magnitude from 3-D topography captured through a smartphone video.

Methods:

This is a prospective observational validation study of this health application during 2 clinic visits and at home. Adolescent idiopathic scoliosis patients, aged 10 to 18 years, with Cobb angles ≤ 45° were recruited. Participants were assisted in downloading the application onto their personal smartphone. Spinal radiographs were taken in the clinic as per standard of care, and curve magnitudes were measured by spine specialists blinded to the study. A phone scan was performed in the clinic by a single, trained research assistant and participants were asked to complete a scan themselves at home later that same day, and once a month for the next 6 months. Successful versus failed scans were tracked. Interclass correlation (ICC) analyses were employed to determine the accuracy of the application’s Cobb angle predictions against radiographic measures, and the inter-rater reliability of the application by comparing in-clinic and initial at-home scan predictions. Then the application’s accuracy of detecting curve progression > 5° between 2 clinic visits was determined.

Results:

Fifty patients had a successful in-clinic scan, 23 (46%) completed at least 1 home scan on the same day or 1 month after their clinic visit, and 22 (44%) returned for a follow-up. There was moderate agreement between first visit radiographic measurements and scan predictions (ICC = 0.72, 95% CI 0.52 to 0.83; p < 0.001), with a mean absolute error of 6.2° ± 4.9°. There was moderate agreement between in-clinic and home scans (ICC = 0.70, 95% CI 0.42 to 0.86; p < 0.001) with an average absolute error of 5.8° ± 5.8°. The scan accurately predicted progression in 59% of patients seen for follow-up. In all, 46% of home scans failed on the first attempt.

Conclusion:

The application shows potential for remote monitoring of scoliosis. However, the accuracy and number of failed scans suggest it is not yet a reasonable replacement for radiographs and/or in-person clinical evaluation.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S112.

Abstract ID 88. Program Code P132. The effect of a mindfulness-based intervention and peer support on quality of life and brace compliance in adolescents with idiopathic scoliosis: a qualitative study

Emma Wagman ¹, Dorothy J Kim ¹, Emma Nadler ¹, David E Lebel ¹, Jennifer A Dermott ¹

Background:

This study aimed to qualitatively assess and compare the effectiveness and acceptability of an online mindfulness-based intervention (MBI) versus peer support group in improving brace compliance and quality of life in patients with adolescent idiopathic scoliosis.

Methods:

One-on-one exit interviews were conducted with 24 AIS patients who had recently been prescribed a brace and were quasi-randomized to, and completed, either a weekly online MBI or peer support group, over 8 weeks. Interviews were recorded, transcribed, and coded using thematic analysis. Significant statements and phrases were organized into themes to understand adolescents’ experiences with an online MBI with peer support.

Results:

Seventeen and 7 participants completed exit interviews following MBI and peer support sessions, respectively. Participants’ age averaged 12.0 ± 1.6 years with an average Cobb angle of 32.0° ± 7.1°. Thematic analysis revealed 6 major themes: importance of peer connection and sense of community, barriers to benefitting from the program, impact on compliance, impact on coping mechanisms, impact on self-confidence, and recommendation for future patient use. Both the MBI and peer support groups fostered a sense of community among participants. The MBI effectively taught stress management and improved self-confidence. However, participation and engagement with the exercises was hindered by the online format, time conflicts, and limited active involvement. Sentiments of improved brace compliance were more frequently reported by participants in the peer support group, but a need for greater session structure and brace-specific content was also expressed. All peer support and nearly all MBI participants (94%) said that they would recommend the intervention to a friend.

Conclusion:

Both MBI and peer support benefited patients with adolescent idiopathic scoliosis in meaningful ways. Future programs should integrate elements of both approaches, combining mindfulness techniques with structured peer support sessions to address the emotional and practical needs of participants.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S112–S113.

Abstract ID 146. Program Code P133. M-iBrace smart orthosis to improve adolescent idiopathic scoliosis patient empowerment and adherence to treatment

Myriam Provost ¹, Nikita Cobetto ², Marie Beausejour ^1,³, Julie Joncas ¹, Francisca Rojas ⁴, Shi-Jia Tran ⁴, Dhawal Sharma ⁴, Aurelien Balondona ⁴, Hubert Labelle ^1,⁵, Carl-Eric Aubin ^1,²

Background:

As a treatment for moderate adolescent idiopathic scoliosis, us of an orthopedic brace is prescribed 20 to 23 hours per day. The average wearing time is much lower (13.4 h/day, compliance rate 64%), highlighting a problem with adherence to the treatment. The aims were to design and validate with the target population a connected orthosis to improve patient autonomy and adherence to brace treatment.

Methods:

Working sessions (engineers/scientists, ex-patients, clinicians, and mobile health specialists) enabled us to codesign a system integrating a multifunctional monitoring sensor, a mobile application for the patient, and a Web application for the care team. Practical, technological, and regulatory aspects were considered in the solution. A prototype compatible with Android, iOS, and Web platforms was developed. Its acceptability was explored with adolescent patients through a focus group discussion. The interview grid was elaborated from Sekhon’s (2016, 2022) health intervention acceptability framework.

Results:

The M-iBrace system includes a Bluetooth sensor in the brace shell linked to a mobile application for autonomous monitoring (measurement of wearing time and various aspects of patient well-being). The application also includes a series of validated interactive questions on barriers to brace adherence. It also includes a Web-based application enabling the care team to provide personalized monitoring based on the patient’s needs and data provided by the app and sensor. The 6 participants in the focus group felt very good about the app and considered the tool to be useful especially to monitor their daily wearing time in relation to their personal goal. Participants would have accepted to try the system at home and to share their data with the clinical team. They also highlighted some improvement suggestions for the development team.

Conclusion:

The M-iBrace system implies a change in practices, placing the patient at the centre of the treatment process. For the health care team, this involves a better ability to monitor and support the patient during treatment. A pilot pragmatic acceptance and effectiveness trial will be carried out to pursue the validation of the M-iBrace system.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S113.

Abstract ID 16. Program Code P134. Extension stretching exercises improves thoracic hyperkyphosis

Vivien Chan ¹, George Michael ¹, Kenneth D Illingworth ¹, David L Skaggs ¹

Background:

Excessive thoracic kyphosis is one of the most common postural abnormalities in pediatric patients. Hyperkyphosis can negatively affect health status, physical activity, spine health, and quality of life. Exercise therapy is a conservative intervention that may be useful in correcting hyperkyphosis. The purpose of this study was to investigate the utility of extension stretching exercises in treating thoracic hyperkyphosis.

Methods:

This was a retrospective review of data from 2 academic institutions. Patients younger than 18 years with thoracic hyperkyphosis, defined as > 45°, with 6-month follow-up data, were included in this study. Extension stretching exercise using a standard foam roller was prescribed to each patient. The outcome of interest was change in thoracic kyphosis at 6-month follow-up. Descriptive statistics were used to characterize patient demographics and thoracic kyphosis. The change in kyphosis was reported for 3 compliance groups: 1) exercises 0 days/week, 2) exercises 2–4 days/week, and 3) exercises 5–7 days/week.

Results:

A total of 33 patients were included in this study. Mean age at initial visit was 14.3 years and 73.3% were male. Mean height, weight, and body mass index were 1.7 m, 64.1 kg, and 20.9, respectively. There were 5 patients who had Scheuermann’s kyphosis and 1 patient who had kyphoscoliosis. The mean maximum kyphosis angle at initial visit was 59.7° (range 48° to 83°). There were 3 patients who did not perform the exercises, 10 patients who did the exercises 2 to 4 days per week, and 20 patients who performed the exercises 5 to 7 days per week. The mean change in kyphosis was 0° in the group that did not perform the exercises. The mean change in kyphosis was −4.9° in the group that did the exercises 2 to 4 days per week. The mean change in kyphosis was −8.9° in the group that did the exercises 5 to 7 days per week.

Conclusion:

Extension stretching exercises can reduce thoracic kyphosis in pediatric patients and should be utilized as a conservative management strategy.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S113.

Abstract ID 165. Program Code P136. All-posterior corpectomy with cage reconstruction and fusion for metastatic spinal cord compression : a retrospective study of 52 cases

Jérémie Thibault ^1,², Antoine Dionne ^1,², Jean-Marc Mac-Thiong ^1,²

Background:

The incidence of metastatic spinal cord compression (MSCC) is increasing owing to the aging population and evolution in the management of neoplastic lesions. Surgical decompression of MSCC can improve neurofunctional outcomes and survival. With the advent of new treatments for primary tumours that increase the survival of these patients, there will be a shift toward surgical techniques aimed at improving the long-term outcomes after surgery. This study reports the radiologic outcomes after all-posterior corpectomy with cage reconstruction and fusion for the surgical management of MSCC.

Methods:

This retrospective study evaluated 53 patients undergoing surgical decompression and stabilization for MSCC. Patients with predominant anterior spinal cord compression between T1 and T12 were included. The surgical technique consisted of total corpectomy from an all-posterior approach with vertebral body reconstruction using a mesh cage filled with autologous rib bone graft, in addition to posterior decompression and instrumented fusion. Radiologic evaluation was performed to assess the reduction/reconstruction and instrumentation. The need for reoperation was also noted.

Results:

A total of 53 cases were evaluated, including 32 (60%) females and 21 (40%) males aged 64.4 ± 11.3 years. The average follow-up was 317 ± 521 days. Corpectomies were performed on 1 level in 45 patients (84.9%) and 2 levels in 8 patients (15.1%). On average, 5.6 ± 1.4 levels were instrumented posteriorly. Four cases consisted of revision surgery for instrumentation failure and/or local metastatic recurrence, while 47 cases were index procedures. There was no event of neurologic deterioration from surgery. One patient required a revision of the cage owing to migration 14 months after surgery. Partial screw pullout was noted in 1 case but did not require a revision since it did not progress and the patient was asymptomatic.

Conclusion:

This retrospective study supports the safety and feasibility of all-posterior corpectomy with cage reconstruction and fusion for the surgical treatment of MSCC. This technique is also associated with excellent long-term radiologic results, consistent with the current trend for increasing survival in patients with MSCC.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S114.

Abstract ID 116. Program Code P137. Experience of a centre for spine surgery in metastatic breast cancer: development of a large database and preliminary analysis of prognostic variables

Leonardo Olijnyk ¹, Vivian Huong Hoang Thien Le ², Fidaa Al-Shakfa ³, Edisond Florial ³, Daniel Shedid ¹, Sung-Joo Yuh ¹, Ghassan Boubez ¹, Jesse Shen ¹, Zhi Wang ¹

Background:

Our objective was to report the experience of a single centre in spine surgery for metastatic breast disease and analyze variables associated with prognosis reported in the literature.

Methods:

Retrospective chart review was performed over a 13-year period and an updated electronic database was developed. Demographic, clinical, radiographic, surgical, and histologic data were retrieved. Initially, 97 patients were identified, operated by 5 surgeons. Four variables previously reported to have impact in survival were analyzed: preoperative neurologic status, hormonal receptors, and presence of HER2 protein.

Results:

Patients’ median age was 58.6 years (27 to 83 years) and 30% were older than 65 years. There was 1 man in the series. Eighty percent of the diagnoses were made during follow-up for a previous treated breast cancer. At the moment of surgery, 29% had visceral metastasis and 63% had at least 1 extraspinal bone implant. Lesions were distributed as follows: 9.7% on cervical spine (C2–C6), 9.7% on cervicothoracic junction (C7–T1), 50.5% thoracic (T2–T11), 7.8% on thoracolumbar transition (T12–L1), 14.7% lumbar (L2–L4), 5.8% on lumbosacral region (L5–S1), and 1.9% in the sacrum. Survival rate at 1 year was 69.2%. Neurologically intact patients at moment of operation accounted for 53% and had significant longer overall survival than those who were not (Frankel E versus Frankel D–A) (p < 0.05). Both estrogen and progesterone hormonal receptors were independently associated with better prognosis when positive. The presence of HER2 protein did not show significant change in survival.

Conclusion:

To the best of our knowledge, this is the largest cohort of patients operated for spine breast metastasis at a single centre in Canada. Updated demographic data contribute to the better understanding of profiles in this population. Reporting the outcomes from aggressive surgical treatment helps to clarify the prognosis and reinforce the importance of spine surgeons in the multidisciplinary management of this complex condition. Finally, molecular markers play a substantial role in the systemic therapies for breast cancer and there are only a few reports in the literature about the subject on spinal disease.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S114.

Abstract ID 191. Program Code P138. The correlation between Spinal Instability Neoplastic Score score and overall survival in 103 consecutive patients operated for spine metastasis of breast cancer

Vivian Huong Hoang Thien Le ¹, Leonardo Olijnyk ², Fidaa Al-Shakfa ³, Edisond Florial ³, Daniel Shedid ², Sunj-Joo Yuh ², Ghassan Boubez ², Zhi Wang ²

Background:

Our aim was to analyze the influence in outcomes of the Spinal Instability Neoplastic Score (SINS) on patients operated for metastatic spine disease of breast cancer in our institution.

Methods:

We carried out a retrospective study of a single academic centre of patients operated for spine lesions secondary to breast cancer from Jan. 2010 to Oct. 2023. Information was retrieved from an updated database from patients’ electronic charts and stored imaging. Patients were considered stable, potentially unstable, and unstable according to SINS score (0 to 6, 7 to 12, > 13, respectively).

Results:

In total, 103 surgeries were performed in 97 patients. Overall survival rate in 1 year was 69.2% and in 2 years was 57.4%. Median age at the time of operation was 58.6 years. Potentially unstable and unstable patients accounted for 38% and 62%, respectively. The overall survival rate was similar in both groups (40.6 months ± 5.6 and 43.5 months ± 5.8). A higher SINS score was also not associated to increased complications rate in the first 30 postoperative days; neither had significant difference in length of hospital stay. The length of instrumentation was significantly longer for unstable lesions (5.4 ± 2.6 versus 3.7 ± 2.5 levels instrumented; p < 0.01). There was no significant difference in age, preoperative ambulating status, and rates of smokers between the groups.

Conclusion:

To our knowledge, this is one of the largest cohorts in the literature of patients operated for spine breast metastasis in a single centre. The SINS score is widely used in the decision-making for surgery in this population and evaluation depends on radiographic findings, clinical presentation, and level of lesion. At our institution, patients are discussed in a multidisciplinary manner and often those with intermediate score are offered operative treatment, considering their long life expectancy seen with modern systemic therapies. Operating on patients with a SINS score considered potentially unstable offers them the chance to treat the local disease aggressively with radiotherapy and preserves spine stability in the long term, which preserves neurologic status and quality of life.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S114–S115.

Abstract ID 119. Program Code P139. Impact of the number of spinal metastases on the survival of lung cancer patients

Van Tri Truong ^1,², The Khanh Dang ³, Galil Osman ¹, Fidaa Al-Shakfa ¹, Danielle Boulé ¹, Philippe Phan ⁴, Jesse Shen ^1,⁵, Zhi Wang ^1,⁵

Background:

Lung cancer is one of the most common malignant diseases. Around 40% of lung cancer patients develop bone metastases, in which the vertebral column is the most frequent site involved. The prognostic factors of the survival of lung cancer patients with spinal metastasis have been reported, but there have been few studies about the association between their survival and the number of vertebrae affected with metastases. The present study aimed to verify whether the number of spinal metastases significantly influenced the survival of lung cancer patients.

Methods:

A retrospective study of patients with lung cancer spinal metastasis was performed. Variables collected included age, gender, smoking history, tumour histology, region of spinal metastasis, number of spinal metastases, visceral metastasis, ambulatory status, postoperative adjuvant therapy, hemoglobin, platelet, albumin, and survival. Data were analyzed to identify the factors significantly affecting survival.

Results:

We recruited 234 patients, including 11 cervical spine metastasis, 78 thoracic spine metastasis, 16 lumbar spine metastasis, 4 sacrum metastasis, and 125 patients with metastases located at different spinal regions (combined group), who were treated in our centre from January 2008 to September 2023. The mean age was 64 years. The median overall survival was 3.8 months (95% confidence interval [CI] 3.13 to 4.63). The survival of cervical spinal, thoracic, lumbar, sacral, and combined spinal metastasis groups was 6.17 months (95% CI 1.4 to 15.9), 3.7 months (95% CI 2.57 to 6.1), 2.53 months (95% CI 0.70 to 7.67), 10.7 months, and 3.7 months (95% CI 2.83 to 4.47), respectively (p > 0.05). The median survival of patients with 1 spinal metastasis, 2 to 3 spinal metastases, and ≥ 4 spinal metastases was 11.66 months (95% CI 6.04 to 18.20), 4.63 months (95% CI 3.75 to 6.93), and 4.47 months (95% CI 3.45 to 6.04), respectively (p < 0.05). The independent walking ability, good Eastern Cooperative Oncology Group, good Karnofsky Performance Score, albumin level above 35g/L, and targeted therapy were found to have significant influence on survival (p < 0.05).

Conclusion:

The number of spinal metastases might significantly influence the survival of lung cancer spinal metastasis patients.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S115.

Abstract ID 173. Program Code P140. Primary bone tumours of the spine in the pediatric population: a single-centre experience

Anne Versteeg ^1,², Karim Abdoelmagd ², Mark Camp ^1,², David Lebel ^1,², Sevan Hopyan ^1,², Stephen Lewis ^1,³

Background:

Primary bone tumours of the spine are rare and management is often challenging owing to complex anatomy such as involvement of the epidural space and nerve roots. Despite a consensus on the importance of a multidisciplinary approach, there is a lack of definitive guidelines. Literature reporting on treatment and survival is sparce and is often limited to the adult population. The aim of this study was to report treatment, survival, and local recurrence data regarding surgically treated primary spinal bone tumours within the paediatric population.

Methods:

We performed a retrospective review of patients who underwent surgical management of a primary spinal tumour at a single tertiary paediatric spinal centre. Patients were eligible for inclusion if they were younger than 18 years at time of treatment. Patient data regarding demographics, diagnosis, surgical treatment, adjuvant systemic treatment, cross-sectional survival, and local recurrence were collected.

Results:

Between March 2013 and March 2024, 16 patients underwent surgical treatment for a primary spinal tumour, with a median age of 14.5 years (range 5 to 17). Six patients were male and 10 were female. Twelve patients received treatment for a malignant spinal tumour, including 6 Ewing sarcomas, 3 osteosarcomas, 1 chondrosarcoma, and 2 other sarcomas. Four patients were treated for a benign aggressive spinal tumour, including 2 osteoblastomas, 1 chondromyxoid fibroma, and 1 benign aggressive fibrocartilage tumour. A biopsy to confirm the diagnosis was performed in all patients. All except 1 patient with a primary malignant tumour underwent en-bloc resection. Three patients suffered a local recurrence; all patients who suffered a local recurrence died, with a median survival of 43 months. All other patients remained disease free.

Conclusion:

Primary spinal tumours are rare and generally require a multidisciplinary approach. This single-centre study offers vital insights into managing primary spinal tumours, demonstrating the effectiveness of surgical en-bloc resection with adjuvant systemic therapy.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S115.

Abstract ID 11. Program Code P141. Early versus delayed surgery for central cord syndrome: an observational cohort analysis exploring real-world clinical practices, trends, and safety profile

Ahmad Essa ^1,², Husain Shakil ¹, Armaan K Malhotra ¹, Avery B Nathens ³, Eva Y Yuan ¹, Yingshi He ¹, Andrew S Jack ¹, Francois Mathieu ¹, Yoram Anekstien ², Tej D Azad ⁴, Jefferson R Wilson ¹, Christopher D Witiw ¹

Background:

Our objective was to assess real-world clinical practices regarding central cord syndrome (CCS) surgical timing and evaluate the safety profile of early versus delayed surgery concerning major adverse events.

Methods:

This multicentre retrospective observational study utilized Trauma Quality Improvement Program database data between 2010 and 2020. All surgically treated CCS patients were included. Surgical timing was categorized into early (≤ 24 hours) and delayed (> 24 hours). An adjusted mixed-effects model was used to identify factors associated with surgical timing and trauma centres variability. Propensity score matching was used and outcomes of interest included in-hospital complications (HC), immobility (IM) complications, surgical site infections (SSIs), and mortality rates.

Results:

The study included 6881 CCS patients across 470 trauma centres. In total, 2679 (39%) patients received surgery within 24 hours of hospital arrival. The odds of early surgery increased annually between 2017 and 2020, compared with 2010. Patients admitted to centres known for early surgery were 67% more likely to receive it. Early surgery was associated with a 22% reduction in HC compared with delayed surgery (odds ratio 0.78, 95% confidence interval 0.65 to 0.94), with no significant differences in IM complications, SSI, or mortality rates.

Conclusion:

Despite the low proportion of early CCS surgery, a significant increase was noted in recent years. Early surgery was associated with fewer complications, supporting the potential benefits of timely surgery for CCS patients.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S116.

Abstract ID 51. Program Code P142. Risk factors for complications in traumatic spinal cord injury: a retrospective analysis

Michael Bond ¹, Aidan Beresford ¹, Vanessa K Noonan ², Naama Rotem-Kohavi ², Marcel F Dvorak ³, Brian K Kwon ³, Guiping Liu ¹, Jason M Sutherland ¹

Background:

Traumatic spinal cord injury (tSCI) is a devastating condition that has long-lasting negative effects. Measuring mortality, adverse events, and length of stay (LOS) during acute care can identify clinical or health system factors that put patients at increased risk, and the information is needed for proper planning and delivering health care for tSCI. This study’s objective is to investigate the factors associated with in-hospital mortality, adverse events, and acute LOS among tSCI patients in British Columbia, between 2001 and 2017.

Methods:

A retrospective analysis of population-based hospital records linked with health care administrative databases was utilized to measure in-hospital mortality, adverse events, and acute LOS between 2001 and 2017. Multivariable logistic regression was used to identify factors associated with death and adverse events. A Cox proportional hazard model was used to identify factors associated with shorter hospitalizations.

Results:

In total, 2647 individuals with tSCI were included in the study. All-cause in-hospital mortality was 6.8%. The average age of patients was 51.6 years (standard deviation 19.64), 76.7% were males, and 68.5% incurred a cervical spine injury. Multivariable analysis demonstrated that patients who were aged 65 years, male, had more medical comorbidities, an injury at the cervical level, complete cord injuries, severe injury severity score (25), traumatic brain injury, and treated nonoperatively were at risk for in-hospital mortality (p < 0.05). Similar findings were seen for adverse events, except in relation to nonoperative care (odds ratio 0.3, 95% confidence interval 0.2 to 0.3). LOS was found to have similar predictors, but incomplete cord injuries led to a longer stay than complete, and more comorbidities did not significantly increase LOS (p > 0.05).

Conclusion:

This study identified several patient-level factors associated with in-hospital mortality, adverse events, and longer acute LOS. All patients had an increased risk if they were older, sustained a cervical injury, or sustained higher severity initial traumatic injuries. Coupled with primary prevention, this study identified opportunities for managing clinical risks to improve outcomes among the older, and those with cervical spine injuries.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S116.

Abstract ID 183. Program Code P145. Outcomes following surgical management of spinopelvic dissociation

Gareth Ryan ¹, Victoria Smith ¹, Fred Nicholls ¹

Background:

Spinopelvic dissociation (SPD) is a rare high-energy injury with poor outcomes. Most patients require surgical stabilization; however, the optimal construct is unknown. In our institution, triangular osteosynthesis (TOS) has become the standard of care in recent years. Given the rarity of these injuries, there are limited data on patient and injury characteristics, and postoperative outcomes. The objective of this study was to describe outcomes following surgical management of SPD.

Methods:

Ethical approval was granted for this study. Patients who underwent surgical fixation for SPD were identified using surgeon billing and case logs from 2011 to present. All patients underwent a comprehensive chart review to collect patient, injury, and surgical factors. Radiographs and computed tomography scans were reviewed to determine injury classification and postoperative spinopelvic parameters. Statistical analysis was performed using a combination of descriptive statistics and t tests.

Results:

In total, 33 patients were included with a mean age of 42 years (standard deviation [SD] ± 18.6). Of these patients, 69.7% were male and 33.3% had an existing psychiatric diagnosis. Mechanism of injury was motor vehicle–related in 48.5% of patients and attempted suicide in 27.3%. Mean injury severity score was 28.6 (SD ± 15.88) with 48.5% of patients admitted under intensive care; 66.66% of injuries were AO Spine Classification System Type C3. Neurologic deficits were present in 32% of patients. Fifty percent of patients had a sacral dysmorphism score > 70. In all, 54.5% of patients underwent TOS, while the remainder were treated with lumbopelvic fixation. The surgical team consisted of orthopedics and spine surgeons in 48.5% of cases, increasing to 77.8% of cases of TOS. Mean postoperative spinopelvic parameters were all within normal ranges. Patients treated with TOS had significantly lower mean pelvic incidence than other constructs (p = 0.03). There were no cases of in-hospital mortality or mechanical failure; however, 36.4% of patients required reoperation, and 36.4% were lost to follow-up.

Conclusion:

This is one of the largest studies on outcomes following surgical management of patients with SPD. Our results will provide surgeons with valuable data to help when counselling patients and in surgical decision-making.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S116–S117.

Abstract ID 60. Program Code P146. Traumatic spinal cord injury in Manitoba: an epidemiologic study

Jennifer R Lischynski ¹, Karnvir Brar ¹, Aasiyah Siddiqui ¹, Jennyfer Galdino ¹, Uchenna Ajoku ^1,², Miguel Vega ¹, Arsilan Alizadeh ¹, Faisal Siddiqui ¹, Frederick Zeiler ¹, Perry Dhaliwal ¹

Background:

Traumatic spinal cord injury (tSCI) is a highly morbid and common neurologic presentation. In Manitoba, tSCI is a prevalent presentation given the large geographic catchment of the tertiary care centre and represents a substantial portion of surgical and intensive care unit (ICU) practice. Trends in tSCI have changed throughout time in Manitoba, including the mechanism of injury, demographics of those affected, conservative versus surgical management, time to surgery, rehabilitation opportunities, and functional outcomes. Understanding the epidemiologic trends and outcomes for patients with tSCI can be vital in determining optimal treatment guidelines for surgical intervention, injuries that are of higher risk, and complications seen by the affected patients.

Methods:

A retrospective cohort study involving chart review for patients between 2007 and 2021 was conducted, including data from 251 patients with tSCI. Extensive data were collected to determine the epidemiologic trends among those affected by tSCI in Manitoba, including ICU, surgical, and functional outcome data to analyze and understand the population affected and their long-term outcomes. Of 251 patients enrolled, complete data were collected for 240.

Results:

Of 251 screened, 240 patients were included in the study. The median age of tSCI patients was 40 years (interquartile range [IQR] 25 to 57) and 181 of 240 (75%) were male. Of 240 patients, 186 (78%) underwent surgical intervention, 136 (57%) required ICU admission, and median time to surgery was 31 hours (IQR 10 to 69). Of 240 patients, 101 (42%) presented as an American Spinal Injury Association (ASIA) A on the ASIA Impairment Scale.

Conclusion:

This study described and characterized the epidemiologic risk factors, trends, and outcomes of patients with tSCI in Manitoba, which presents most commonly in young-middle aged men with ASIA A impairment of presentation. Early surgical management and ICU-level care is the predominant model of care. This study offers insight into the demographics of those affected by tSCI in Manitoba, the pace at which surgical management is implemented, and the extensive use of our ICU resources to mitigate secondary injury and improve functional outcomes at discharge.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S117.

Abstract ID 141. Program Code P147. Incidence of nontraumatic spinal cord injury in Canada

Tara A Whitten ^1,², Naama Rotem-Kohavi ³, Nancy Thorogood ^4,⁵, Suzanne P Humphreys ³, Vanessa K Noonan ³, Chester Ho ^2,⁶, Jeffrey A Bakal ^1,²

Background:

Spinal cord injury is a relatively rare condition but has a tremendous impact on the person, family, and health care system. Incidence and prevalence estimates for traumatic spinal cord injury (tSCI) and nontraumatic spinal cord injury (NtSCI) are needed for planning and delivering care. A recent meta-analysis estimated that global incidence of tSCI is 26.5 per million population, while incidence of NtSCI is 18.0 per million. However, most current epidemiologic studies are focused on tSCI, resulting in a significant research gap. The objective of this study is to use health administrative data to estimate national incidence rates of NtSCI over time and stratified by age, sex, and etiology.

Methods:

Linked Discharge Abstract Database and National Rehabilitation System data were requested from the Canadian Institute for Health Information from Apr. 1, 2004, to March 31, 2021, for all Canadian provinces and territories (excluding Quebec). NtSCI patients were identified using an administrative case definition based on International Classification of Diseases, 10th Revision (ICD-10) codes, capturing both neurologic impairment (paraplegia, tetraplegia, cauda equina) and etiology (e.g., degenerative, infection, vascular) of NtSCI. A 4-year washout period was used to estimate incidence, and data from 2020 were excluded owing to the COVID-19 pandemic.

Results:

The crude incidence rate in Canada for NtSCI from 2009 to 2019 was estimated to be 32.9 per million population, with annual rates relatively stable over the time period. The incidence rate increased with age, from 4.3 per million for ages 0 to 19 years, to 97.4 per million for ages ≥ 80 years. Male had higher rates (40.5 per million) than females (25.5 per million). Paraplegia was the most common impairment (46%), followed by cauda equina (35%) and tetraplegia (19%). The most common etiologies were degenerative conditions (30%), myelopathies (19%), and infections (11%).

Conclusion:

The incidence of NtSCI appears to be higher in Canada than reported in recent global meta-analyses, and similar to the reported incidence of tSCI in Canada (32.0 per million). Accurately estimating the incidence of NtSCI in Canada is important for understanding the burden of disease, planning public health strategies, and allocating resources to best support this important population.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S117.

Abstract ID 144. Program Code P148. The influence of fracture status in determining the effectiveness of surgical intervention in central cord syndrome

Karlo Pedro ¹, Michael Fehlings ¹, Mohammed Alvi ¹

Background:

The management of stable central cord syndrome (CCS-S) resulting from spondylosis remains controversial. A common practice involves an initial nonoperative intervention until spontaneous recovery occurs, or delaying surgery until a neurological plateau is reached. This conservative approach lacks robust evidence, with conflicting results from studies. This study aims to compare surgical and nonsurgical interventions for patients with both CCS-S and unstable central cord syndrome (CCS-U), utilizing consistent diagnostic criteria and adjusted analyses from a large cohort of spinal cord injury (SCI) patients.

Methods:

This ambispective study analyzed 2583 patients from 5 multicentre SCI studies. A propensity score–matched analysis between surgically and nonsurgically treated patients was conducted, adjusting for age, injury mechanism, neurological level, total motor score, and American Spinal Injury Association (ASIA) grade. Neurological outcomes were assessed using ASIA motor scores while functional outcome was measured using the Functional Independence Measure (FIM). Outcome differences at 1 year, including the proportion of patients achieving the minimal clinically important difference (MCID), was compared between CCS-S and CCS-U patients.

Results:

A total of 291 CCS patients were included, of whom 205 (70%) underwent surgery, while 86 (30%) received nonoperative treatment. A significantly higher proportion of patients in the surgical group achieved the FIM-Motor MCID (57.1%) at 1 year (p = 0.018). Stratified analysis showed that surgery was mainly beneficial for CCS-S patients, with 66.7% achieving MCID versus 34.2% in the nonsurgical subgroup (p < 0.001). In the propensity-matched cohort, CCS-S patients demonstrated greater benefit from surgery than CCS-U patients. The presence of fracture significantly reduced the odds of favorable functional outcomes at 1 year (p value for interaction = 0.04, odds ratio 0.32, 95% confidence interval 0.11 to 0.98).

Conclusion:

Surgical intervention significantly improved functional outcome at 1 year compared with conservative management in CCS patients, with particularly pronounced benefits in the CCS-S subgroup. This underscores the need for individualized treatment strategies tailored to specific patient characteristics in managing CCS.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S118.

Abstract ID 140. Program Code P149. Early surgery improves neurologic, functional, and quality of life outcomes in acute traumatic spinal cord injury: a global end-point analysis of 470 patients from the Spine Trauma Study Group prospective cohort

Karlo Pedro ¹, Michael Fehlings ¹, Mohammed Alvi ¹

Background:

The optimal timing for surgery after spinal cord injury (SCI) remains controversial, despite the Surgical Timing in Acute Spinal Cord Injury Study (STASCIS) advocating for early surgical intervention (< 24 hrs). Recent studies show heterogeneity in findings, with varied time cut-offs, degrees of spinal decompression, and insensitive outcome measures. Motor improvement alone does not fully capture the spectrum of clinically meaningful recovery postinjury. Incorporating patient-reported outcomes enhances the ability to detect treatment effects across the diverse SCI population.

Methods:

Patients enrolled in the prospective Spine Trauma Study Group (STSG) (2002 to 2009) were analyzed using a composite end point that integrates 3 outcome measures: Total Motor Score, Functional Independence Measure, and 36-Item Short-Form Health Survey. The combined scores were assessed using the Global Statistical Test (GST) to determine whether early surgery (< 24 h) resulted in overall improvement at 1 year. The analysis was conducted using both the complete and propensity-matched cohort adjusted for age, etiology, and baseline neurologic and functional status.

Results:

A total of 470 patients in the complete cohort (mean age 47.86 years, 25.1% female) and 340 in the matched group were included. Among these, 247 received early surgical decompression (< 24 h) while 223 underwent late surgery. In the unadjusted complete case analysis, early surgery was associated with a significantly higher rank sum across all 3 end points compared with late surgery (median rank sum 729.0, interquartile range [IQR] 544.8 to 910.8, v. 678.5, IQR 500.2 to 848.0; p = 0.01). The propensity-score matched analysis yielded similar result favoring early surgery (median rank sum 523.2, IQR 401.1 to 656.4, v. 497.0, IQR 348.9 to 622.1; p = 0.04). Early surgery results in a 54% higher probability of global improvement at 1 year after SCI.

Conclusion:

Early surgery (< 24 h) leads to concurrent global improvement in motor, functional, and quality of life domains after SCI. This analysis reinforces the STASCIS trial and supports the GST as an efficient trial methodology encompassing multidimensional outcome scales.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S118.

Abstract ID 12. Program Code P150. Disparities in surgical timing following traumatic complete spinal cord injury: the role of insurance coverage and race

Ahmad Essa ^1,², Armaan K Malhotra ¹, Husain Shakil ¹, Avery B Nathens ³, Eva Y Yuan ¹, Yingshi He ¹, Andrew S Jack ¹, Francois Mathieu ¹, Jefferson R Wilson ¹, Christopher D Witiw ¹

Background:

We aimed to quantify the influence of insurance coverage and race on time to surgery in patients with traumatic complete spinal cord injury (SCI).

Methods:

This multicentre retrospective observational study was performed using data obtained from the American College of Surgeons Trauma Quality Improvement Program database between 2010 and 2020. We evaluated the impact of insurance coverage and race on surgical timing using a multivariable Poisson regression model, adjusted for clinically important covariates. A secondary analysis to assess the influence of these factors on access to surgery within 24 hours of injury was performed.

Results:

The study included 8222 patients with traumatic complete SCI. Among these, 4095 (49.8%) were privately insured, 3239 (39.4%) were publicly insured, and 888 (10.8%) were uninsured. A total of 5597 (68.1%) patients identified as White, and 2625 (31.9%) patients identified as non-White. The mean time to surgery was 28.9 (± 32.8) hours. Both publicly insured and uninsured patients experienced a significant mean delay to surgery of 3.5 and 5.6 hours, respectively, when compared with privately insured patients (95% confidence interval [CI] −5.3 to −1.7, and 95% CI −8.4 to −2.7). Similarly, non-White patients had a mean wait time of 4.3 hours longer to surgery compared with White patients (95% CI −5.9 to −2.7). These differences remained significant after adjusting for potential confounders. Lack of insurance was associated with a 16% (95% CI 1.05 to 1.28) increase, public insurance with an 8% (95% CI 1.03 to 1.14) increase, and non-White race with a 14% (95% CI 1.07 to 1.21) increase in time to surgery, respectively. Secondary analysis showed a 30% increased odds of delayed surgery for non-White and uninsured patients. Likewise, publicly insured patients had an 18% increased odds of delayed surgery, thus challenging adherence to the 24-hour surgical guideline.

Conclusion:

This study demonstrates significant disparities in time to surgery following complete SCI associated with insurance coverage and race. Non-White, publicly insured, and uninsured patients were more likely to experience delay to surgery compared with White and privately insured patients.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S118–S119.

Abstract ID 142. Program Code P151. The sodium-glutamate antagonist riluzole improves outcome after acute spinal cord injury: results from RISCIS randomized controlled trial using a global statistical analytic technique

Michael Fehlings ¹, Karlo Pedro ¹, Mohammed Alvi ¹

Background:

In spinal cord injury (SCI) trials, a single scale typically serves as the primary measure of intervention, limiting the study’s power to detect the true effect of intervention, especially when outcomes are highly heterogeneous. It is essential to concurrently consider functional and quality-of-life measures for more comprehensive outcome assessment.

Methods:

A total of 131 randomized patients in the Safety and Efficacy of Riluzole in Acute Spinal Cord Injury Study (RISCIS) were included. Patients were assigned to receive either riluzole or placebo. Riluzole was administered at 100 mg orally twice daily for the first 24 hours, followed by 50 mg twice daily for the subsequent 13 days. Combined assessment at 6 months utilized the total American Spinal Injury Association (ASIA) Impairment Scale (AIS) motor score (neurologic status), Spinal Cord Independence Measure (SCIM) (functional status), and 36-Item Short-Form Survey (SF-36) physical component summary (PCS) (quality of life). A global statistical method with a modified O’Brien’s rank-sum test was used to compute for a global treatment effect (GTE).

Results:

Riluzole was given to 65 patients, while 66 received placebo drug. Individual unadjusted mean difference (MD) at 6 months showed favourable outcomes in the riluzole group compared with placebo for total AIS motor score (MD 2.86, 95% confidence interval [CI] −6.79 to 12.52; p = 0.2864), SCIM (MD 6.02, 95% CI −2.47 to 14.51; p = 0.0921), and SF-36 PCS (MD 2.0, 95% CI −2.25 to 6.24; p = 0.1372). Using GST to simultaneously assess total ASIA motor score, SCIM, and SF-36 PCS, a higher rank sum was observed in the riluzole group (median rank sum 207, interquartile range [IQR] 166 to 246 in riluzole v. 185.20, IQR 146 to 236 in placebo; p = 0.04). Subgroup analysis revealed the greatest treatment benefit among ASIA A patients (GTE 0.16, p = 0.02). Riluzole was associated with a 55% higher probability of global improvement at 6 months compared with placebo.

Conclusion:

A multidimensional representation of SCI outcomes can enhance the power to estimate treatment effects. Riluzole demonstrated a global beneficial effect in acute traumatic SCI when considering motor recovery, functional ability, and health-related quality of life.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S119.

Abstract ID 156. Program Code P152. Do patients with nontraumatic versus traumatic spinal cord injury have similar complication profiles during acute care? A comparative study

Antoine Dionne ^1,², Andréane Richard-Denis ^1,², Émile Brouillard ^1,², Ismail Lassassy ^1,², Etienne Bourassa-Moreau ^1,², Paul Khoueir ^1,², Zhi Wang ^1,³, Jean-Marc Mac-Thiong ^1,²

Background:

Historically, spinal cord injuries (SCI) have largely had traumatic etiologies (tSCI). However recent epidemiologic changes have shifted the balance such that spinal tumours are now the leading cause of SCI. This paper aims to compare the care pathways and acute complication rates of patients with tSCI versus NtSCI caused by spinal tumours, in an effort to prepare the system for the upcoming influx of NtSCI patients.

Methods:

We conducted a retrospective cohort study of 441 consecutive patients with tSCI, or NtSCI due to spinal tumour, recruited at a single level-1 trauma centre in Montréal, Canada. Sociodemographic variables and injury characteristics were collected for all patients. The rates of pneumonia, urinary tract infection (UTI), and pressure injury, as well as the length of stay (LOS) in the acute care before transfer to rehab, were compared between patients with NtSCI versus tSCI. Multivariate analyses were then performed to determine whether the etiology of SCI was independently associated with the outcomes above.

Results:

Of the 441 patients recruited, 124 presented with NtSCI and 317 with tSCI. Compared with patients with tSCI, those with NtSCI were less likely to be male, were older, had more comorbidities, and were more likely to present incomplete paraplegia. In addition, they had lower rates of pneumonia (8.1% v. 19.2%; p = 0.004), UTI (10.5% v. 20.5%; p = 0.013), and shorter average acute length of stay (21.7 ± 18.4 v. 28.3 ± 20.2; p = 0.002), while the rates of pressure injuries were similar. At the multivariate level, a NtSCI was associated with lower odds of UTI (odds ratio 0.235; p = 0.013) and shorter LOS (β = −0.189; p = 0.004) while controlling for relevant confounders.

Conclusion:

Despite often being older and presenting more comorbidities, patients with NtSCI have lower rates of acute complications and shorter length of stays in acute hospitalization. This result challenges the notion that patients with NtSCI due to spinal tumours place a heavier burden on acute hospitals than their traumatic counterparts.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S119.

Abstract ID 49. Program Code P153. Epidemiology of spinal cord injury in British Columbia, Canada: 20 years of population-based administrative data

Michael Bond ¹, Aidan Beresford ¹, Vanessa K Noonan ², Naama Rotem-Kohavi ², Marcel F Dvorak ^3,⁴, Brian K Kwon ^3,⁵, Guiping Liu ¹, Jason M Sutherland ¹

Background:

Traumatic spinal cord injury (tSCI) is a debilitating condition that affects both young and an increasing proportion of older individuals. The mechanisms can vary from high-energy transport accidents to low-energy falls from standing height. There has been a recent increase in the number of elderly patients with tSCI. This study’s objective is to describe the epidemiology and demographic characteristics of patients who experience tSCI in a Canadian province between 2001 and 2017.

Methods:

A retrospective analysis of population-based hospital records linked with health care administrative data sets was conducted to measure age-standardized rates, demographics, and clinical characteristics of tSCI. Linear regression was used to measure trends over time, adjusting for age and sex.

Results:

A total of 2817 tSCI patients were identified. The average age at the time of injury was 49.3 years (standard deviation ± 21.09) and 76.3% were male. The annual age-standardized rate in British Columbia was 42.3 per million. The rate remained consistent throughout the study period. The mean age at injury increased from 41.5 to 52.4 years over the study period of 2001 to 2017 (p < 0.001). Overall, the most frequent causes of injury were falls (47.4%) and motor vehicle injuries (38.3%). The proportion of injuries related to falls increased over the study period (p < 0.001). Motor and sensory complete tSCI were seen in higher rates among younger patients, and cervical spine injuries were most common among all age groups.

Conclusion:

The rate of tCSI was consistent during the study period, although the demographic of patients and their injury mechanism changed considerably; elderly low-energy falls comprised an increasing proportion of patients. Continued vigilance in elderly fall prevention is needed to reduce the incidence of tCSI among the elderly.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S120.

Abstract ID 188. Program Code P154. Timing of gastrostomy relative to tracheostomy following complete cervical spinal cord injury: impact on hospitalization outcomes and complications rates

Ahmad Essa ¹, Armaan K Malhotra ¹, Husain Shakil ¹, Avery B Nathens ², Eva Y Yuan ¹, Yingshi He ¹, Francois Mathieu ¹, Michael C Sklar ¹, Jefferson R Wilson ¹, Christopher D Witiw ¹, Jetan Badhiwala ²

Background:

Tracheostomy and gastrostomy are frequently performed to facilitate prolonged ventilation and nutritional support in spinal cord injury (SCI) patients. This study aims to evaluate the impact of the timing of gastrostomy relative to tracheostomy on in-hospital outcomes and complications in patients sustaining complete traumatic cervical SCI.

Methods:

A multicentre retrospective observational study was performed using data from the Trauma Quality Improvement Program of the American College of Surgeons, between 2010 and 2020. The study population comprised patients diagnosed with complete traumatic cervical SCI who underwent both tracheostomy and gastrostomy. Gastrostomy timing was categorized relative to tracheostomy timing using the following groupings: same-day (within 24 hours of tracheostomy) and delayed (more than 24 hours after tracheostomy). Outcomes of interest included intensive care unit (ICU) and hospital length of stay (LOS), duration of mechanical ventilation, and the incidence of major in-hospital complications, immobility complications, and surgical site infections. Univariate and multivariable models were constructed to assess associations. We conducted a sensitivity analysis using propensity score matching to determine the robustness of our findings.

Results:

Of 2958 patients included, 2168 underwent same-day tracheostomy and gastrostomy, and 790 underwent delayed gastrostomy after tracheostomy. Patients in the same-day group had significantly shorter ICU and hospital LOS and reduced duration of mechanical ventilation (adjusted mean difference [MD] −5.83, 95% confidence interval [CI] −7.51 to −4.16, p < 0.001; adjusted MD −8.98, 95% CI −11.33 to −6.63, p < 0.001; and adjusted MD −5.93, 95% CI −7.80 to −4.07, p < 0.001, respectively). There was no evident difference noted in the occurrence of major hospital adverse events between the groups. The sensitivity analysis recapitulated the primary analysis findings, demonstrating the consistency and robustness of effect estimates.

Conclusion:

Same-day tracheostomy and gastrostomy in patients with complete traumatic cervical SCI was associated with better outcomes than with delayed gastrostomy. Specifically, grouping these procedures may shorten ICU and overall hospital LOS, as well as reduce ventilation duration.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S120.

Abstract ID 190. Program Code P155. Impact of surgical timing on patients undergoing emergency spine surgery without neurologic symptoms: a systematic review

Ojasvi Sharma ¹, Jordan J Levett ², Michael H Weber ¹

Background:

Emergency spine surgery for patients without neurologic symptoms often has lower priority than for those with neurologic deficits, leading to longer wait times for surgery. The impact of delayed surgical intervention on patient outcomes in this population remains unknown. This systematic review compares the outcomes of early versus delayed surgical intervention in patients with spinal emergencies without neurologic symptoms.

Methods:

A comprehensive search of MEDLINE, Embase, Scopus, PubMed, and CENTRAL was conducted from inception to August 2024. Data were reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies reporting clinical data of patients undergoing surgery for non-neurologic emergency spinal injuries were included. In 2 studies, early intervention was defined as surgery within 72 hours from the initial injury, while in 3 studies, early intervention was defined as surgery within 72 hours from diagnosis.

Results:

A total of 5 retrospective studies with 1028 patients (early: 438; delayed: 590) met the inclusion criteria. The mean age at surgery was 43.81 years (range 16 to 95) for the early surgery group and 62.21 years (range 17 to 93) for the delayed surgery group. The Injury Severity Score, measured preoperatively, was lower in the early surgery group, with a mean score of 14.46 compared with 18.86 in the delayed surgery group. The mean complication rate was slightly higher (22.9% v. 21.9%) than in the delayed group. Hospital length of stay and intensive care unit (ICU) length of stay were shorter in the early surgery group, with mean values of 7.08 v. 14.21 days and 0.97 v. 3.69 days, respectively. Mortality was also lower in the early surgery group, at a rate of 3.38% compared with 13.4% in the delayed group.

Conclusion:

This systematic review indicates that early surgical intervention for patients with spinal emergencies without neurologic symptoms is associated with shorter hospital and ICU length of stay and reduced mortality, despite a marginally higher complication rate compared with delayed surgery. Given the retrospective nature of the included studies, further research is warranted to guide priority-setting in emergency spine care.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S120–S121.

Abstract ID 22. Program Code P156. Endoscopy beyond disc herniation and spinal stenosis: Is there a place for spine endoscopy in the treatment of burst fracture?

Ramon Guerra Barbosa ¹, Gustavo Lages ², Johmeson Alencar ²

Background:

Burst fractures are a serious consequence of trauma, commonly managed with traditional open surgeries involving either anterior or posterior approaches. However, in recent years, the use of minimally invasive techniques, including endoscopy, has gained traction in the treatment of various spinal conditions. The main objective of this study is to explore the application of spinal endoscopy beyond the conventional indications of disc herniation and stenosis, focusing on its potential role in managing burst fractures that require fixation.

Methods:

A comprehensive literature review was conducted using the terms “spine fracture” and “endoscopy” across PubMed. Two key studies were identified: 1 utilized transforaminal endoscopy for decompression and percutaneous fixation, while the other applied biportal endoscopy for similar purposes. We also present a case of a 42-year-old female with an L4 burst fracture, where we performed percutaneous screw fixation with interlaminar uniportal endoscopic decompression. To our knowledge, this is the first documented case to utilize a uniportal interlaminar endoscopic approach for the decompression of fracture fragments in a burst fracture.

Results:

Both the transforaminal and biportal techniques demonstrated favourable outcomes in their respective studies, achieving successful decompression and neurologic recovery with minimal complications. The transforaminal approach showed complete decompression within 3 days and maintained sagittal alignment. Meanwhile, the biportal approach demonstrated improvement in neurologic function and spinal alignment in a cohort of 10 patients. In our case, the interlaminar uniportal approach allowed for the removal of fracture fragments with significant pain relief (visual analogue scale score reduced to 2/10), motor recovery, and successful decompression, as confirmed by postoperative imaging.

Conclusion:

The preliminary results suggest that spinal endoscopy, traditionally used for treating disc herniation and stenosis, can be effectively adapted for burst fractures. This minimally invasive technique offers the advantages of reduced surgical trauma, shorter recovery time, and fewer postoperative complications, including infection and hemorrhage. Further research is necessary to establish standardized protocols for its broader application in trauma cases.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S121.

Abstract ID 167. Program Code P157. Validation of the AO Spine PROST (Patient Reported Outcome Spine Trauma) version 1.1 in patients with longstanding spinal cord injury

Said Sadiqi ¹, Aline J Hakbijl-van der Wind ², Sylvia Egberts ², Janneke Stolwijk ², Rutger Osterthun ³, Tijn van Diemen ⁴, F Cumhur Oner ⁵, Marcel WM Post ²; AO Spine Knowledge Forum Trauma and Infection⁶

Background:

The AO Spine Patient Reported Outcome Spine Trauma (PROST) is a validated measure of health-related quality of life (HRQoL) designed for use in individuals with spine trauma with no neurologic deficit or incomplete spinal cord injury (SCI). It has gained worldwide adoption, and has already been translated into more than 15 languages. For use in individuals with motor-complete traumatic or nontraumatic spinal cord disease (SCI/D), a slightly adapted PROST 1.1 was developed. This study investigates the reliability and validity of PROST 1.1 in people with long-standing motor-complete SCI/D.

Methods:

A multicentre validation study was performed among 4 centres. Individuals with motor complete SCI/D within 4 years post-onset of the lesion were included. Exclusion criteria were slow-progressive pattern of onset (> 1 month) and not being able to complete PROST 1.1 owing to cognitive impairments. Floor and ceiling effects, internal consistency (Cronbach’s α), test–retest reliability (intraclass correlation coefficients [ICC] with 95% confidence interval [CI]) and concurrent validity (Spearman correlations ≥ 0.50 with reference measures) were investigated.

Results:

A total of 72 participants were included: 75% were male, with a median age of 54 years (interquartile range [IQR] 40 to 64), 63% American Spinal Injury Association Injury Severity grade A, 79% with paraplegia, median time since onset 20 months (IQR 8 to 34). Of these, 62 also completed the second administration after a median of 7 days (IQR 5 to 11). An approximately normal distribution without floor or ceiling effects was observed in the total PROST 1.1 score. The α was excellent (0.90) and ICC was good (0.84, 95% CI 0.75 to 0.90). Most correlations between the PROST 1.1 and the reference measures were strong (≥ 0.50) as expected, ranging from 0.27 with the visual analogue scale score of the EuroQoL 5D-5L up to 0.70 with the sum-score of the EuroQoL 5D-5L.

Conclusion:

The slightly adapted AO Spine PROST (version 1.1) appears to be applicable in people with motor-complete SCI to evaluate their HRQoL. Treating physicians are encouraged to use the PROST in the clinical setting and research to contribute to further evidence-based and patient-centred spine trauma care.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S121–S122.

Abstract ID 168. Program Code P158. The International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) examination: an evaluation of performance in persons with traumatic and nontraumatic spinal cord injury in acute and rehabilitation facilities across Canada

Heather A Hong ¹, Jessica Parsons ¹, Jijie Xu ¹, Kristen Walden ¹, Nader Fallah ¹, Christiana L Cheng ¹, Najmedden Attabib ², Sean D Christie ³, Cathy B Craven ⁴, Michael Fehlings ⁵, Daryl R Fourney ⁶, Hardeep S Kainth ⁷, Brian K Kwon ⁸, Gary A Linassi ⁹, Saranjan Moganathas ¹⁰, Jerome Paquet ¹¹, Jean-Marc Mac-Thiong ¹², Andrea F Townson ¹³, Jennifer Urquhart ¹⁴, Eve Tsai ¹⁵, Alex J Whelan ¹⁶, Vanessa K Noonan ¹; the ISNCSCI Working Group¹

Background:

Although the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) exam is considered a best practice, its clinical use is inconsistent. Few studies have thoroughly documented ISNCSCI use across the spinal cord injury (SCI) care continuum. This study aims to compare exam use in people with traumatic (tSCI) and nontraumatic spinal cord injury (NtSCI) across Canadian acute and rehabilitation facilities.

Methods:

We used the Rick Hansen Spinal Cord Injury Registry 2015–2022 database to review all participants with tSCI and NtSCI. The 5 cohorts were (A) tSCI-acute-admission (n = 4461); (B) tSCI-rehabilitation-admission (n = 2673); (C) tSCI-rehabilitation-discharge (n = 2316), (D) NtSCI-rehabilitation-admission (n = 728); and (E) NtSCI-rehabilitation-discharge (n = 619). Assessment of ISNCSCI use included exam performed (yes or no), timing (≤ or > 72 hours of admission/discharge), completeness (partial: missing ≥ 1 ISNCSCI items; full: having all ISNCSCI items), and presence or absence of individual exam items. Descriptive statistics were used to characterize ISNCSCI use across all cohorts.

Results:

Across all cohorts, the frequencies for Yes-Exam-Performed were A 81%, B 79%, C 54%, D 89%, and E 36%. Of these, most exams were performed within ≤ 72 hours of admission or discharge (A 83%, B 78%, C 59%, D 72%, and E 72%). Of the exams performed within ≤ 72 hours, overall, 41% were partially complete (A 55%, B 37%, C 44%, D 25%, and E 42%). Notably, the frequency of partial exams was lower at admission than at discharge for people with tSCI (37% v. 44%) and NTSCI (25% v. 42%). When reviewing the presence or absence of individual items from partial exams, the rectal components (voluntary anal contraction and deep anal pressure) had the highest rate of absence (44%), and the motor scores had the highest rate of presence (92%).

Conclusion:

We thoroughly detailed ISNCSCI exam use throughout the care continuum and identified vast differences in exam use and completeness at different time points in care. Further work is needed to determine barriers to completion at these different time points and establish consensus on the ISNCSCI elements considered clinically important to collect, given these variations and the implications for clinical care.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S122.

Abstract ID 29. Program Code P159. Rates of nonoperative management and secondary overtriage of spine fracture patients transferred to level I or II trauma centres

Vincent C Ye ¹, Armaan K Malhotra ¹, Husain Shakil ¹, Ahmad Essa ^1,², Christopher D Witiw ^1,³

Background:

The primary objective is to assess the extent of nonoperative management and secondary overtriage (SOT) among patients with traumatic spine fractures, defined as transfer to a Level I or II trauma centre (LI or LII TC) with subsequent discharge within 48 hours without surgical intervention. The secondary objective is to identify patient and hospital factors associated with SOT.

Methods:

This retrospective observational cohort study used data from the American College of Surgeons Trauma Quality Improvement Program database between 2017 and 2020. The study included adult patients with traumatic spine fractures transferred to L1 or LII TCs. Patients with multisystem polytrauma and spinal cord injuries were excluded from the analysis. A total of 29 951 patients from 629 centres were analyzed. The primary outcome was the rate of SOT among spine fracture patients transferred to LI or LII TCs. Secondary outcomes included identifying factors associated with SOT, using mixed-effects logistic regression.

Results:

The majority of spine fracture patients transferred to a LI or LII TC are managed nonoperatively (n = 24 007, 81.1%), with a high rate of SOT (18.2%). Factors associated with a lower likelihood of early discharge included lumbar spine fractures (odds ratio [OR] 0.75, 95% confidence interval [CI] 0.69 to 0.82; p < 0.001) and age older than 60 years (OR 0.42, 95% CI 0.39 to 0.46; p < 0.001). There was significant variability in centre-dependent rates of early discharge, and interfacility transfer, but this variance appears to not be affected by patient volume.

Conclusion:

Approximately 1 in 5 patients with traumatic spine fracture transferred to higher-level trauma centres are discharged within 48 hours without undergoing surgical intervention, suggesting a substantial rate of SOT. Efforts to optimize triage protocols, particularly for older patients and those with lumbar spine fractures, may reduce unnecessary transfers and improve health care resource utilization.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S122–S123.

Abstract ID 50. Program Code P160. Long-term survival for traumatic spinal cord injury in British Columbia, Canada: a retrospective evaluation of 20 years of linked health care data

Michael Bond ¹, Aidan Beresford ¹, Vanessa K Noonan ², Naama Rotem-Kohavi ², Marcel F Dvorak ³, Brian K Kwon ³, Guiping Liu ¹, Jason M Sutherland ¹

Background:

Patients living with traumatic spinal cord injury (tSCI) have seen many improvements in care and treatment, but life expectancy still falls below the general population. Measuring long-term survival rates and characterizing causes of death are required to identify ways of improving well-being and reducing premature mortality. This study’s objective is to measure long-term survival of patients with tSCI in British Columbia, Canada, using population-based data.

Methods:

We carried out a retrospective analysis of population-based hospital records linked with administrative databases of patients in B.C. with tSCIs from 2001 to 2017. Demographic and clinical summary statistics were calculated. Mortality rates for 1-, 5-, 10-, and 15-year survival were calculated using Kaplan–Meier methods. Factors associated with mortality throughout the study period were identified with Cox models.

Results:

During the study period, 2817 patients were identified with tSCI. The mean age was 49.3 years (standard deviation ± 21.09) and 2150 (76.3%) were male. Mortality rates at 1, 5, 10, and 15 years were 10.5%, 19.5%, 28.1%, and 34.1%, respectively. Factors associated with mortality included cervical spine injuries, more comorbidities, older age, lower household income, presence of traumatic brain injury, and greater severity of initial injury (p < 0.001). Accidental death from injury or subsequent trauma (20.9%) was the most common cause of death in tSCI patients, followed by cardiac diseases (16.0%), respiratory diseases (6.7%), and neoplasms (5.4%).

Conclusion:

The reduction in long-term survival of tSCI patients is a significant concern, and preventive measures to avoid injury are critical. Among those suffering tSCI, particularly high death rates are observed in those with cervical injuries, multiple comorbidities, and advanced age. Interventions are needed to reduce premature death among tSCI patients compared with the population.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S123.

Abstract ID 84. Program Code P161. Evaluating trends in cervical spinal cord injury without instability

Vishwathsen Karthikeyan ¹, Christopher Lozano ¹, Armaan Malhotra ¹, Husain Shakil ¹, Jefferson Wilson ¹, Christopher Witiw ¹, Jetan Badhiwala ¹

Background:

There is an increasing proportion of cervical incomplete spinal cord injuries (SCIs) like central cord syndrome (CCS) in older patients. CCS encompasses those with and without spinal instability. This study aims to compare the demographics, injury characteristics, and in-hospital outcomes of spinal cord injury without instability (SCWI) patients to other incomplete cervical SCI subtypes.

Methods:

We conducted a multicentre observational study using data from trauma centres in the American College of Surgeons Trauma Quality Improvement Program from 2010 to 2020. Patients older than 16 years with cervical spinal cord injuries were included. Abbreviated Injury Scale codes identified patients with cervical fractures. The cohort was divided into 2 groups: those with spinal column injury (fracture or dislocation) and those without instability (SCWI). Univariate comparisons were made using t tests for continuous variables and χ² tests for categorical variables.

Results:

We identified 26 677 incomplete cervical SCI patients, of whom 11 628 had cervical fractures. Hospital complications occurred in 1886 (16.2%) patients with fractures compared with 658 (8.6%) without fractures (odds ratio [OR] 0.49, 95% confidence interval [CI] 0.44 to 0.54; p < 0.01). Immobility-related complications were more frequent in the fracture group (8.8%) than in the nonfracture group (4.8%) (OR 0.52, 95% CI 0.46 to 0.59; p < 0.01). Surgical site infections occurred in 1.1% of patients with fractures and 0.5% in the nonfracture group (OR 0.47, 95% CI 0.30 to 0.74; p < 0.01). Patients with fractures had longer intensive care unit (ICU) stays (9.4 ± 9.9 v. 6.7 ± 7.0 days; p < 0.01), more days on mechanical ventilation (10.7 ± 12.3 v. 8.3 ± 9.8 days; p < 0.01), and longer hospital stays (14.8 ± 15.1 v. 11.1 ± 11.5 days; p < 0.01).

Conclusion:

Patients with incomplete cervical SCIs with fractures experienced more complications, including immobility-related issues, surgical site infections, and longer ICU stays, mechanical ventilation, and hospital stays. These findings suggest that SCWI represents a distinct clinical entity with implications for patient management and rehabilitation strategies. Further research is necessary to explore long-term outcomes and refine the classification of cervical SCIs to optimize clinical care.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S123.

Abstract ID 170. Program Code P162. Postoperative spinal epidural hematomas: Are we excessively aggressive with thromboprophylaxis?

Alexandre Chenevert ¹, Charlotte Lanoue ², Jérôme Couture ¹, Sonia Bédard ^1,²

Background:

Postoperative spinal epidural hematoma (PSEH) is a rare but serious complication that requires urgent medical intervention, with an incidence rate between 0.52% and 1.15%. Known risk factors include coagulopathy, hypertension, excessive intraoperative blood loss, multilevel spinal surgery, and minimally invasive techniques. However, the role of perioperative anticoagulation in PSEH risk remains unclear, and there is no consensus on perioperative anticoagulation protocols in spinal surgery. High-quality literature on this subject is limited, hindering informed clinical decisions. This study aims to investigate potential risk factors for PSEH, focusing on the role of thromboprophylaxis and anticoagulation.

Methods:

We conducted a retrospective review of all spinal surgeries performed at a single tertiary care centre from January 2017 to November 2024. A total of 24 cases of PSEH were identified. A descriptive analysis of sociodemographic data, preoperative and postoperative parameters, and the use of thromboprophylaxis and anticoagulation was performed.

Results:

Since 2017, a total of 24 cases of PSEH were identified, according to archived records. Thromboprophylaxis was administered to 75% of patients, with a mean initiation time of 49.5 hours postoperative. We identified a positive correlation between the onset time of new neurologic symptoms after surgery and the interval between the surgical intervention and the initiation of postoperative thromboprophylaxis treatment (p = 0.024). There was also a positive correlation between time from surgery to new neurologic symptoms and the time from surgery to drain removal (p = 0.001).

Conclusion:

Our findings suggest an association between the onset of new neurologic symptoms after surgery and the timing of postoperative thromboprophylaxis initiation and drain removal. Future research will incorporate a control group without hematoma to further investigate this relationship.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S123–S124.

Abstract ID 171. Program Code P163. Sex disparities in Medicare reimbursement, case volume, and practice characteristics among cervical spine surgeons in the United States

Juliette Gammel ¹, Jason Silvestre ¹, Gabrielle Rivas ², James Lawrence ¹, Robert Ravinsky ¹

Background:

Although medical schools now have seemingly equal representation of males and females, there remains a significant disparity in the number of females in surgical specialties, including orthopedics and neurosurgery. Addressing sex disparities among spine surgeons may help promote more effective spine care delivery in the United States. This study assessed the representation of female spine surgeons in the US Medicare database.

Methods:

The Medicare Provider Utilization and Payment Dataset was used to identify neurosurgical and orthopedic surgeons performing anterior cervical discectomy and fusion (ACDF) surgery from 2013 to 2021. The data set was linked to the Medicare National Downloadable File to determine hospital affiliations and medical training details. All hospitals included were queried to determine association with residency or fellowship training programs.

Results:

There were 2492 surgeons who performed at least 11 ACDFs over the study period, accounting for 139 456 total cases. Of these, there were 58 female spine surgeons (2.3%) who performed 2733 cases (2.0%). The percentage of female surgeons increased from 0% (0/1124) in 2013 to 1.8% (12/651) in 2021 (p < 0.001). The average volume of ACDFs performed by females (16.8 ± 3.6) was similar to males (17.2 ± 7.6; p = 0.712). Among female surgeons, 13.9% were affiliated with a hospital that had an orthopedic or neurosurgery residency program, compared with 11.8% of male surgeons (p = 0.697). Mean standardized reimbursement by Medicare for ACDFs was $1304, with no difference between female and male surgeons during the study period (p = 0.145). There were no significant differences in the beneficiary demographics between male and female surgeons, except for in 2021, when female surgeons saw a higher proportion of female patients (56.8 ± 2.7% v. 55.0 ± 4.7%; p = 0.043).

Conclusion:

Despite some progress observed over the study period, profound sex disparities persist among practising spine surgeons performing ACDF. Strategies are needed to increase the number of female medical students and residents interested in a career in spine surgery.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S124.

Abstract ID 52. Program Code P164. Epidemiologic trends in adolescent idiopathic scoliosis in Ontario: validating a population-based health administrative data algorithm for patient identification

Jennifer A Dermott ^1,², Liisa Jaakkimainen ^2,^3,⁴, Teresa To ^2,^4,⁵, Maryse Bouchard ^1,², Andrew W Howard ^2,⁴, David E Lebel ^1,²

Background:

This study aimed to estimate provincial epidemiologic trends of adolescent idiopathic scoliosis (AIS) over 10 years, by validating a population-based health administrative data (HAD) algorithm for patient identification.

Methods:

This case ascertainment validation study developed 93 algorithms to identify 10- to 18-year-olds with AIS, using a combination of diagnostic, specialty, and/or fee codes related to scoliosis, gathered from physician billings, emergency room records, and discharge data over various look-back periods. A validation cohort was established to evaluate algorithm performance, consisting of 2732 patients with confirmed AIS (positive reference) and 49 049 youth without AIS (negative reference), approximating the population prevalence reported in the literature. Performance was evaluated based on measures of sensitivity, specificity, and positive and negative predictive value (PPV and NPV) with 95% confidence intervals (CIs). The top-performing algorithm was used to derive a provincial cohort of youth diagnosed with AIS between 2005 and 2021 to estimate annual incidence and prevalence between 2012 and 2021. The age/sex-adjusted estimates were directly standardized to the 2016 Census population.

Results:

The algorithm selected was “2 physician billings for scoliosis within 2 years” with sensitivity 83.1% (95% CI 81.6 to 84.5%), specificity 99.3% (95% CI 99.2 to 99.3%), PPV 86.3% (95% CI 85.0 to 87.6%) and NPV 99.1 (95% CI 99.0 to 99.1%). The algorithm-derived cohort included 27 125 youth, 18 358 females (62%) with a mean age of 13.9 ± 1.8 years. Age/sex-standardized AIS incidence ranged from 118.3 (2020) up to 147.6 (2021) per 100 000 persons. Age/sex-standardized prevalence ranged from 491.7 (2012) up to 541.9 (2021) per 100 000 persons.

Conclusion:

Identification of youth with AIS is possible using a HAD algorithm, with strong discriminative ability. Provincial epidemiologic trends were relatively stable between 2012 and 2021. Our results support this being a promising avenue for conducting population-level AIS surveillance and longitudinal outcome studies in the future.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S124.

Abstract ID 109. Program Code P165. Microbial colonization of orthopedic and spinal implants

Curtis A Ostertag ^1,^2,³, Tara Whittaker ³, Fred H Nicholls ^1,^2,³

Background:

Implant-associated infections in spine surgery are a complication with potentially devastating outcomes. Presence of clinical signs makes diagnosing acute infection mostly straightforward, allowing for prompt therapeutic intervention. Chronic low-grade infections, including colonization of implants, are insidious in their clinical presentation — or lack thereof. As such, diagnosing low-grade infections is challenging and is often possible only after revision surgery with implant removal and culture. Recent literature suggests colonization of implants may contribute to aseptic screw loosening. The prevalence of implant colonization and its impact on patient outcomes remains unclear and there is no consensus on treatment. This study aimed to retrospectively analyze Canadian Spine Outcomes and Research Network (CSORN) patients from a single site who underwent revision spine surgery with removal of metal implants to establish the local prevalence of bacterial colonization and its effects on health-related quality of life, with and without directed antibiotic therapy. This study also aimed to clarify diversity in local colonizing microbial flora.

Methods:

A chart review was performed to determine eligibility of patients identified within the CSORN database. Exclusion criteria were preoperative suspicion of or known surgical site infection.

Results:

In total, 313 patients with a total of 468 operations were eligible (270 female; age 62.06 ± 11.24 years; 1.48 ± 0.79 cases included per participant). In 114 operations, cultures were obtained, with 32.5% culture positivity. In all, 73% of positive cultures grew Cutibacterium acnes. 51% of culture-positive patients were treated with antibiotics. Initial statistical analysis shows no significant differences between cases with positive and negative cultures with respect to Oswestry Disability Index, visual analogue scale, and surgical satisfaction reporting at 6- to 18-week, 1-year and 2-year follow-ups.

Conclusion:

Preliminary results do not demonstrate any effect of colonization on outcomes, although the groups are heterogeneous. Case–control matching of culture-positive patients with patients who underwent similar revision surgical procedures is under way to properly assess the effects of colonization and guide treatment.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S125.

Abstract ID 78. Program Code P166. Validation of a fast-solving rigid-flexible body dynamic model of the spine for use in muscle recruitment optimization problems

Siril Teja Dukkipati ^1,², Mark Driscoll ^1,²

Background:

Traditional spine biomechanical models in literature are broadly categorized into finite-element (FE) models and rigid body dynamic (RBD) models. FE models provide geometry-wide deformation and stress distributions but are computationally intensive. In contrast, RBD models neglect deformation within bodies, predicting only the relative forces and displacements between bodies. While this simplification improves computational speed, it limits RBD models’ ability to accurately represent flexible structures essential for modelling soft tissues like intervertebral discs (IVDs). This study introduces an improved RBD spine model incorporating flexible bodies to capture realistic IVD stiffness, validating its performance against conventional FE methodology.

Methods:

The rigid-flexible body dynamic (RFBD) model included L1–S1 vertebrae, IVDs, and the interspinous, supraspinous, and intertransverse ligaments. Vertebrae were represented as rigid bodies with a uniform density (181.5 mg/cm³), while the IVDs were modelled as reduced-order flexible bodies with incompressible, linear-elastic properties. Ligaments were modelled as nonlinear, tension-only springs. For comparison, an FE model was developed with identical geometry and material properties as the former. Both models were fixed at S1 and subjected to pure bending flexion moment up to 7.5 Nm in 2.5 Nm increments, alongside follower compression load up to 1500 N in 500 N increments, generating a total of 16 load cases. Subsequently, ligaments were removed from each model and tested again, adding 16 more. Range of motion (ROM) and run time were recorded to benchmark differences between models.

Results:

Without ligaments, the maximum ROM variation between the RFBD and FE models was 11.3%. The RFBD model recorded an average run time of 8.1 ± 0.7 seconds, while the FE model required 9.2 ± 0.2 seconds. When ligaments were included, the maximum ROM variation between the models was similar (10.4%). The RFBD model run time remained consistent (9.8 ± 0.8 seconds), while FE models’ run time increased significantly to 20.3 ± 1.5 seconds.

Conclusion:

The RFBD modelling approach preserved accuracy while significantly reducing solution time as model complexity increased, demonstrating its suitability for high-fidelity applications like optimization problems and machine learning. Clinically, this model could be used to simulate muscle activation patterns in patients with disabilities.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S125.

Abstract ID 58. Program Code P167. A novel 2-staged technique for large soft tissue defect reconstruction following multiple dorsolumbar surgeries

Daisy A Lu ^1,², Oussama Sahraoui ³, Alain Danino ^1,³, Zhi Wang ^1,^2,³

Background:

Spine reoperation is a possible outcome of primary dorsolumbar surgery, especially in patients with significant comorbidities. Wound closure in some cases can be particularly complex and challenging because of the sizable area and limited flap options due to previous surgeries and flap coverage. We describe a case of complex reconstruction of substance loss and local infection control in a multioperated spine patient requiring joint intervention between spine orthopedics and plastic surgery.

Methods:

After an extensive preoperative evaluation, an innovative joint intervention between spine orthopedics and plastic surgery selected a more cautious and staged therapeutic approach of a propeller flap autonomization during a first surgery, then a second surgery for mobilization to improve surgical outcome. Perforators of a larger calibre were determined to be a valid propeller flap option for dorsolumbar coverage with a delayed surgical phenomenon that increases blood supply and minimizes donor site defect and functional morbidity of wound closure. This technique highlights the adaptive nature of reconstructive surgery, relying on the biological process of neovascularization to enhance perfusion, and therefore allowing for a safer transfer of tissue and more robust coverage while minimizing donor site defect and functional morbidity.

Results:

The patient recovered without any major complications, achieving a reliable and lasting closure on the 2 muscle and fascia layers of the dorsolumbar area over the osteosynthesis material. The wound was completely healed at 11 months’ follow-up.

Conclusion:

To our knowledge, the use of this innovative staged procedure to close such a massive area has not yet been described in current literature. Our successful wound closure therefore increases future therapeutic flap coverage options in the case of large and complex wounds.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S125–S126.

Abstract ID 149. Program Code P169. The Spinal Invasiveness Score can better quantify surgical wait-lists across Canada

Gurjovan Sahi ¹, Jin Tong Du ¹, Aazad Abbas ¹, Sager Hanna ², Neil Berrington ², Alysa Almojuela ², Michael Johnson ², Stephen Lewis ¹, Michael Goytan ², Jay Toor ²

Background:

Canadian spine care delivery is in crisis owing to inordinate patient wait times. Relying on the current method of a simple count of patients awaiting surgery leads to disproportionate wait time estimations depending on pathology; for example, patients with scoliosis wait longer than those needing simple discectomies. Using the Spinal Invasiveness Score (SIS) to categorize surgeries is a comprehensive solution; it is a validated scoring system that assigns points based on surgical invasiveness across 6 parameters. Wait-lists can then be calculated based on SIS score, with additional benefits such as subcategorization of wait times and initiatives to target specific subcategories of procedures. This study aims to evaluate spine surgeons’ and hospital administrators’ perceptions of adopting the SIS model for spine surgery wait-list management.

Methods:

A qualitative descriptive study was conducted surveying spine surgeons and hospital administrators across Canada. Participants reviewed a case study comparing the current waitlist model with the SIS-based approach and were surveyed on their preferred method for wait time calculation. Responses were analyzed using thematic analysis to identify recurring themes around SIS’s perceived benefits, limitations, and barriers to adoption.

Results:

Of the 21 respondents, 17 (81%) preferred the SIS approach over the existing system, including 9 of 11 surgeons and 8 of 10 administrators. Thematic analysis revealed several key perceived benefits of SIS including subcategorizing wait-lists (e.g., multilevel v. single-level; instrumented v. noninstrumented), better triaging of cases, and more accurate wait time calculation. Barriers identified included difficulty for the health system to capture SIS score for each surgery, cost of implementation, and SIS not capturing full complexity of cases such as elevated body mass index or revision status.

Conclusion:

The SIS method was overwhelmingly well received, with numerous benefits identified as well as potential barriers and room for improvement. The SIS score has shown early success in advocating for more tailored operating room (OR) scheduling, such as longer OR days to accommodate complex surgeries. With careful implementation and adaptation, SIS could become a key part of nationwide wait-list management strategies.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S126.

Abstract ID 162. Program Code P170. Hospital utilization profile of surgical management of degenerative spine diseases: a comparative analysis of planned and unplanned procedures

Jin Tong Du ¹, Tiffany Lung ¹, Celina Nahanni ¹, Chloe Cadieux ¹, Gavin Dandal ², Nicola Anderson ², Stephen Lewis ^1,², Christopher Nielsen ^1,², Eric Massicote ^1,², Raja Rampersaud ^1,²

Background:

We aimed to evaluate the utilization impact and differences between patients with degenerative spinal diseases (DSD) undergoing unplanned v. planned procedures.

Methods:

Data were collected retrospectively from a large academic hospital in Canada. Patients admitted electively and through the emergency department who underwent surgery for DSD were included. The pre-COVID-19 period was defined as July 2017 to 2019, and the post-COVID-19 period as July 2022 to 2024. The period of July 2019 to 2022 was excluded owing to health service disruptions secondary to the COVID-19 pandemic.

Results:

The total number of unplanned degenerative cases in the pre- and post-COVID-19 periods were 162 and 151, respectively. Of unplanned cases, 61% were completed within 48 hours of admission. In the post-COVID-19 period, patients were significantly older (60.56 ± 16.25 years v. 56.67 ± 16.25 years; p = 0.035) and had significantly longer length of stay (LOS) (11.63 ± 12.94 days v. 8.70 ± 7.02 days; p = 0.014). There were no significant differences in the number of cervical cases completed via the anterior versus posterior approach (p = 0.818) between planned and unplanned cases. Unplanned cervical patients were significantly older than planned patients (63.21 ± 13.28 years v. 59.34 ± 11.44 years; p = 0.007). The duration of cervical procedures was not significantly different between planned and unplanned cases (p = 0.134). However, the in–operating room duration was significantly longer in unplanned cases (269.46 ± 88.26 minutes v. 235.25 ± 57.78 minutes; p < 0.001). There were no significant differences in the number of lumbar cases undergoing decompression or fusion between planned and unplanned cases (p = 0.909). Unplanned lumbar patients were significantly younger than planned patients (55.23 ± 17.50 years v. 68.82 ± 10.29 years; p < 0.001). In both cervical and lumbar patients, LOS was significantly longer for unplanned patients (p < 0.001), with significant differences in the discharge disposition (p < 0.001), such that more patients were discharged home after planned procedures.

Conclusion:

Unplanned procedures for DSD resulted in higher resource utilization, reflected in prolonged in–operating room duration and extended LOS. Notably, nearly 40% of unplanned cases were completed more than 48 hours postadmission. Thus, it is possible to establish a pathway to manage these cases in an urgent and planned fashion.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S126.

Abstract ID 135. Program Code P171. Comparison of primary versus revision lumbar spine surgery patients’ preoperative expectations

Khaled Skaik ¹, Philippe Phan ², Genevieve Belanger ³, Stephen Kingwell ², Alexandra Stratton ², Matthew Coyle ², Eugene Wai ²

Background:

Addressing preoperative expectations is important for realistic surgical outcomes and to enhance satisfaction and support informed decisions. Our primary question is whether in Canadian elective posterior lumbar spinal surgery patients, there were differences in preoperative expectations between primary and revision surgery groups. Given that revision surgery patients had previous experience with surgery, we hypothesized that they might have different preoperative expectations.

Methods:

This multicentre, retrospective cohort study analyzed adult elective lumbar spine surgery patients from the Canadian Spine Outcomes and Research Network (2017 to 2023). Two cohorts were examined: posterior decompression alone and posterior decompression with fusion, each divided into primary and revision surgery groups. Exclusions were trauma, tumours, infection, and anterior-only surgeries. Expectation scores, rated from 0 (no change) to 3 (much better), covered 2 dimensions — overall functional well-being and pain relief — with higher scores indicating higher preoperative expectations. Propensity score matching adjusted for confounders like age, sex, labour force status, number of comorbidities, depressive symptoms, primary pathology, physical activity, leg and back pain, and self-rated health status, using greedy algorithm with nearest neighbor matching and a 0.2 caliper for balanced comparisons.

Results:

After matching, in the decompression-alone cohort, there was no significant difference in pain relief expectation scores between primary (n = 181; mean 2.49 ± 0.63) and revision surgery patients (n = 181; mean 2.45 ± 0.63; p = 0.3455), nor in overall functional well-being scores (primary mean 2.22 ± 0.63; revision mean 2.19 ± 0.62; p = 0.469). In the decompression and fusion cohort, there was no significant difference in overall functional well-being expectation scores between (n = 180) in primary surgery patients (n = 180; mean 2.24 ± 0.66) and in revision surgery patients (n = 178; mean 2.12 ± 0.68; p = 0.095), nor in pain relief scores (primary mean 2.53 ± 0.63; revision mean 2.41 ± 0.69; p = 0.469).

Conclusion:

There were no differences seen in preoperative expectations between primary and revision patients, despite the revision patients having previous experience with surgery. Surgeons should maintain consistent preoperative discussions for both primary and revision surgery patients.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S127.

Abstract ID 118. Program Code P172. Closing dura with nonpenetrating metal clips: experience of a centre, technique description, and brief operative video

Leonardo Olijnyk ¹, Paul Kaiser ², Tristan Brunette-Clément ¹, Daniel Shedid ¹, Sung-Joo Yuh ¹

Background:

Our objective was to report the experience in closing the dura mater with nonpenetrating metal clips in operations for intradural extramedullary (IDEM) spine lesions with minimally invasive surgery (MIS), as opposed to traditional suturing.

Methods:

Eleven consecutive cases of IDEM spine lesions operated under MIS by 2 surgeons from January 2022 to June 2024 were retrospectively reviewed. Information about length of stay, complications during the immediate postoperative time, complications with wound, and follow-up imaging were collected. Surgical and pathology reports were accessed.

Results:

IDEM spine lesions were operated on with a fixed tube of diameter between 21 mm and 24 mm (SpotlightR system). Docking is performed with guidance of fluoroscopy. Hemilaminectomy and exposure of the dura are achieved under microscope. Incision in the middle of the operative field is done in sharp manner. Tumour dissection and resection are followed by hemostasia. Then, steps for dura closure are performed as follows: identification of approximate dura-mater borders with aid of sutures; identification of intact margins, free of adherences; placement of nonpenetrating clip under microscopic view; progression of the closure with clips every 1 mm or 2 mm and concomitant removal of anchoring sutures; and finalization of closure not further than 1 mm from upper and lower incision limits. Clips HorizonR (Teleflex Medical), sizes small or medium, are ideally positioned as horizontally as possible to prevent canal stenosis and increase dura coverage. No patient had length of stay longer than 7 (mean 4.1) days. There were no intraoperative complications related to dura closure. No patient presented with a cerebrospinal fluid leak, clinical pseudomeningocele, or wound infection. Nine meningiomas and 2 schwannomas were operated on in the series. Total gross resection was achieved in all cases. The metal clips did not cause artefacts in follow-up imaging.

Conclusion:

Nonpenetrating metal clips are an effective alternative for dura closure in MIS surgery. In our experience, they are safe, are not associated with an increase in postoperative complications, and do not interfere with follow-up imaging.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S127.

Abstract ID 28. Program Code P173. Endoscopic spinal cord stimulator paddle electrode implantation: a review of techniques and feasibility

Ramon Guerra Barbosa ¹, Gustavo Lages ², Newton Pimenta ³

Background:

Failed back syndrome is a common complication in spine surgery. Implantation of spinal cord stimulators is the gold standard for treating it. The main objective of this paper is to describe the use of spinal endoscopy for the implantation of paddle electrodes in spinal cord stimulation (SCS), highlighting its advantages, technical aspects, and challenges when compared with conventional techniques.

Methods:

A comprehensive literature review was conducted using PubMed, focusing on articles published between 2014 and 2024. The search was restricted to English-language publications related to endoscopic techniques for SCS paddle electrode implantation. Of the 26 identified articles, only 4 directly discussed this topic. These included 1 article on biportal endoscopy, a cadaveric feasibility study, and 2 clinical reports by the authors, detailing the monoportal endoscopic implantation technique. The technical feasibility, clinical outcomes, and limitations of the techniques were analyzed.

Results:

The monoportal interlaminar approach for paddle electrode implantation, as first described by the authors, involves a small 10-mm parasagittal incision, insertion of a working cannula, and visualization of the lamina and ligamentum flavum under direct endoscopic guidance. A high-speed drill is used to perform a partial laminectomy, allowing for the safe passage of the paddle electrode. Under fluoroscopic guidance, the electrode is advanced to the target location without compressing the dural sac. This technique offers advantages such as minimal bleeding, reduced postoperative pain, and a lower risk of infection. However, it requires specialized equipment and comes with a steeper learning curve than traditional methods. The biportal technique and cadaveric studies also demonstrated feasibility, but they similarly highlighted increased cost and technical complexity as significant challenges.

Conclusion:

Endoscopic spinal cord stimulator implantation is a minimally invasive alternative to traditional open surgeries, with promising results in terms of safety, reduced complications, and improved patient recovery. Nevertheless, the higher cost associated with endoscopic equipment and the extended learning curve limit its broader adoption. Further clinical trials are needed to validate the long-term benefits and address these barriers.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S127–S128.

Abstract ID 166. Program Code P174. Role of thoracolumbar fascia structure in lumbar spine stability: a finite element investigation

Sean A Murray ¹, Mark Driscoll ¹

Background:

Properties of the thoracolumbar fascia (TLF) tend to be variable with low back pain (LBP) due to physiological changes or treatments. Analysis of its properties and role in the multifactorial pathomechanism of LBP has been hindered by various challenges in modelling the thin, fibrous tissue. Consequently, clinical practice has minimally accounted for its important biomechanical influence. This study evaluated the hypothesis that model form in the TLF would affect its contribution toward flexural stiffness in the lumbar spine.

Methods:

A novel TLF model was derived from segmenting the Visible Human Project histologic slices. The geometry was transformed to match a prior osseoligamentous spine finite element model, which was validated within the context of use. Two models were derived from the TLF geometry. Their effect on lumbar stiffness was evaluated by comparing intervertebral rotations. In the first, stiffness was allocated to discrete fibres, reinforcing a low-stiffness ground substance. In the second, the ground substance was isotropic with fibres removed and was allocated the full share of TLF stiffness. In combined loading nonlinear analysis, a 7.5 Nm flexion moment was applied at L1 and T9, with a 500 N follower force. Loading and boundary conditions were matched in both model forms.

Results:

Without TLF, baseline L1–S1 rotation was 25.7°. Both model forms significantly increased stiffness. Sensitivity of the fibre model to stiffness of the ground substance was analyzed for Young’s modulus, ranging between 10 MPa and 25 MPa. Lumbar rotation decreased from 12.3° to 7.9°, respectively. The isotropic model was notably stiffer, as L1–S1 rotation decreased to 4.8°.

Conclusion:

The results indicate that particular attention is needed in accurately representing model form when evaluating the function of TLF. The biomechanical advantage of the long fibre structure is highlighted, as it can relay tensional forces from muscles, while reducing the cost of added intrinsic rotational stiffness. Clinically, it can also be interpreted that to regain healthy biomechanics, care should be taken to avoid altering TLF fibre structure and form during operation and suturing.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S128.

Abstract ID 164. Program Code P175. Elevated preoperative glycated hemoglobin is associated with perioperative glucose dysregulation in spine surgery patients

Tiffany Lung ¹, Chloe Cadieux ¹, Jin Tong Du ¹, Jed Lazarus ¹, Celina Nahanni ¹, Christopher Nielsen ^1,², Raja Rampersaud ^1,²

Background:

In spine surgery patients, poorly controlled diabetes has been shown to be an independent risk factor for surgical site infections (SSI) and all-cause complications. Despite this being a modifiable risk factor, preoperative glycated hemoglobin (HbA_1c) is not routinely measured at our institution. The objectives of this quality improvement study are to evaluate the proportion of spine surgery patients with undiagnosed prediabetes or diabetes, and assess the relationship between HbA_1c and perioperative hyperglycemia.

Methods:

This is a prospective study evaluating patients undergoing spine surgery at a single institution between June 2022 and May 2024 with a HbA_1c measurement within 90 days of surgery. The primary outcomes of interest are the number of patients with elevated HbA_1c levels without a preoperative diagnosis of prediabetes or diabetes, and the association of HbA_1c levels and perioperative hyperglycemia.

Results:

In total, 430 patients had a preoperative HbA_1c measured. Of these, 150 patients (34.9%) had a preoperative HbA_1c at or above 6.0. In patients without a prior diagnosis, 40 patients (9.3%) had a HbA_1c level in a prediabetic range, and 5 patients (1.2%) had a HbA_1c level in a diabetic range. On postoperative days 0 to 3, 326 patients had glucose levels measured. Of these patients, 118 (27.4%) had a glucose measurement above the recommended level of 10 mmol/L. Higher HbA_1c levels are associated with hyperglycemia perioperatively (χ² (2, n = 326) = 5.99; p < 0.001). There is a moderate correlation between preoperative HbA_1c and hyperglycemia perioperatively (r = 0.565) with HbA_1c explaining 31.9% of glucose level variance (R² = 0.329).

Conclusion:

We found a 10.5% prevalence of abnormal preoperative HbA_1c levels in patients without a prior diagnosis of prediabetes or diabetes. Furthermore, patients with higher HbA_1c levels had more glucose dysregulation perioperatively. As glycemic control is a modifiable risk factor, this study supports consideration for routine preoperative HbA_1c screening and protocols for better glycemic control in the acute postoperative period in patients with and without a history of diabetes.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S128.

Abstract ID 178. Program Code P176. Evaluating the validity of simulation-based education models for spine surgery training: a scoping review

Arim Yoo ¹, Pranjan Gandhi ^1,², Nathasha Rajapaksege ², Shannon L Hart ¹, Victoria Shi ¹, Markian Pahuta ¹, Daipayan Guha ¹

Background:

Given the development of new methods of simulation training as a supplement and alternative to real-life procedural training, this scoping review aims to synthesize the current literature on evaluation methods of the face, content, and construct validity of simulation-based educational models for spine surgery.

Methods:

Systematic searches from database inception to March 2023 were conducted in MEDLINE, Embase, Web of Science, and Cochrane Central Register of Controlled Trials. All screening and parts of data extraction were completed using the Covidence systematic review software. The Preferred Reporting Items for Systematic Review and Meta-Analyses statement was followed at all stages. The scope of the current study did not necessitate a meta-analysis; however, relevant counts, percentages, and qualitative supplements were compiled to summarize the available evidence.

Results:

We identified 54 studies eligible for inclusion. The studies included a variety of simulation techniques, including commercial products, new in-house models, and combinations of these. The most frequently used simulation platforms were physical phantom (30.0%) or virtual reality (29.6%). Other platforms included cadaveric models or augmented reality. Of the included 54 articles, 27 (50.0%) measured face validity, each of which used an original measurement method. Only 2 (7.4%) of these used an established measurement method in addition to an original method. Of the included studies, 47 (87.0%) measured content validity; 34 of these (72.3%) exclusively used an original measurement method; and 9 more studies (19.1%) used both original and established methods. Only 4 studies (8.5%) exclusively used an established method of content validity measurement. None of the included studies measured construct validity, based on our definitions.

Conclusion:

The current article provides a detailed description of the current landscape of simulation techniques in spine surgery education. The majority of the literature assesses the face or content validity of the simulators, with a lack of construct validity evaluation. Future research should therefore involve more longitudinal studies investigating the correlation between trainees’ performance on simulation-based models and patient outcomes after real-life surgery.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S129.

Abstract ID 57. Program Code P177. Transitioning from pediatric to adult scoliosis care: defining the perspectives of these patients during this critical period

Daisy A Lu ^1,², Zhi Wang ^1,², M Fidaa Al-Shakfa ², Jesse Shen ^1,²

Background:

This prospective study seeks to define parents’ and patients’ expectations, needs, and experience with pediatric spinal deformity upon “graduation” from their pediatric centre. As a sub-aim, administrative and health care workers (nurses, physicians, schedulers, secretaries who are in contact with patients) will also be interviewed to obtain their experience and perspective on connecting patients between pediatric and adult hospital centres.

Methods:

Patients between the ages of 18 and 35 years who have had a diagnosis of scoliosis and have been previously treated at a pediatric hospital, parents of such patients, and current members of either pediatric or adult spine care teams managing such patients were included in our study. The patients, families, and providers were interviewed in groups of 6 to 8 on themes centering on current experiences, knowledge of the condition, needs within the transition program, challenges, and potential elements to facilitate the process. A single interviewer moderated the discussion. All conversations were recorded and transcribed for qualitative analysis using QDA-Miner to identify themes, concepts, and patterns.

Results:

Preliminary results suggest the need for an integrative standardized transition protocol with increased communication and information-sharing among all parties involved.

Conclusion:

Transitioning from pediatric to adult care presents distinct challenges for patients with scoliosis, often resulting in fragmented care and diminished health outcomes. Effective transition models that integrate patient education, coordinated provider communication, and individualized accompaniment plans may enhance patient engagement and continuity of care. There is a need for further refining and standardizing transition plans to better support young adults in managing chronic spine conditions as they enter adult care settings.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S129.

Abstract ID 130. Program Code P178. Endoscopic spine surgery: a scoping review of the literature

Drew Mulhall ¹, Chien Yew Kow ¹, Anand Oliveira Masson ¹, Catherine Veilleux ¹, Stephan du Plessis ¹, Steve Casha ¹, Ken Thomas ¹, Michael Yang ¹

Background:

Scoping reviews identify the depth of evidence within a given field, often highlighting areas where evidence is lacking. As a result, scoping reviews may be used to inform research agendas and identify implications for policy or practice. The Calgary Endoscopic Spine Surgery Research and Advancement (CESSRA) program has an immediate need to understand what has been published with respect to endoscopic spine techniques. This knowledge will inform CESSRA research priorities. This study aims to summarize the available themes within the literature reporting on endoscopic spine surgery, to identify knowledge gaps and direct future research initiatives.

Methods:

This scoping review was conducted following Preferred Reporting Items for Systematic reviews and Meta-Analyses for scoping reviews guidelines. After we refined the search strategy and keywords, systematic searches were conducted across MEDLINE, Embase, CINAHL, and the Cochrane Library, covering studies available up to Sept. 19, 2024. Two reviewers independently screened publications based on predefined eligibility criteria, with any conflicts resolved by 2 additional reviewers. We included human studies on patients of all ages and excluded non-English studies and publication types such as conference abstracts, policy statements, and case reports.

Results:

The search yielded 8504 titles, from which duplicates were removed, resulting in 5424 unique titles for screening. Following the screening process, studies will be classified according to patient age, clinical presentation, spinal pathology, type of endoscopic surgery, reported outcomes, study design, country of origin, and overall research theme.

Conclusion:

We anticipate a research trend toward specific types of endoscopic procedures, with a focus on comparative outcomes between endoscopy and more conventional, open-type spine surgery. Moreover, we expect to identify knowledge gaps that will direct future research endeavours in the field of spine endoscopy.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S129–S130.

Abstract ID 76. Program Code P179. Automatic spinal cord magnetic resonance imaging analysis using Spinal Cord Toolbox

Jan Valošek ^1,^2,³, Maxime Bouthillier ¹, Julien Cohen-Adad ^1,²; Spinal Cord Toolbox team^1,²

Background:

Spinal Cord Toolbox (SCT) is an open-source software for processing and analyzing spinal cord magnetic resonance imaging (MRI) data. This abstract introduces SCT, highlights its recent features, and opens a discussion on how to improve its accessibility for health care professionals.

Methods:

Key SCT features include anatomical spinal cord segmentation, including white and grey matter; anatomical landmarks identification, such as vertebral levels and the pontomedullary junction; spinal cord pathologies segmentation, including spinal cord injury (SCI) and multiple sclerosis lesions; a spinal cord template and atlas for group-level analyses; alignment capabilities for multimodal and template registration; and utilities for quantitative MRI analysis. These tools can be combined into analysis pipelines, enabling efficient parallel processing across multiple patients. SCT also includes a Web-based quality control interface for reviewing critical processing steps, allowing users to quickly identify problematic images or segmentations requiring manual correction.

Results:

SCT contains more than 55 functions that can be applied to MRI analysis of patients with or without spinal cord pathologies regardless of contrast, magnetic field strength, or manufacturer. Such features led to SCT adoption by many research facilities globally, reaching more than 600 citations on Google Scholar. SCT continues to evolve and is being actively developed: a recent update (v6.4) introduced several new features, such as automatic segmentation of SCI lesions and cervical spinal nerve rootlets segmentation.

Conclusion:

SCT is extensively used in spinal cord research, but its adoption by clinicians remains limited. We recently collaborated with Praxis and the Rick Hansen Spinal Cord Injury Registry to collect clinical MRIs from individuals with SCI, to establish a National Imaging Repository. The next steps involve promoting the tool and facilitating knowledge transfer within the clinical community, to encourage further development and eventual implementation in the clinical setting. To support users in maximizing the software’s capabilities, we offer comprehensive tutorials, provide user assistance through an active online forum, and organize an annual SCT course. For more information, visit https://spinalcordtoolbox.com/ and https://spinalcordmri.org/.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S130.

Abstract ID 35. Program Code P180. Bibliometric analysis of the literature on spine surgery based on data mining

Ling Jing Li ¹

Background:

To explore the global landscape of spine surgery research, identify trends and hotspots, and examine how Canada’s contributions align with international advancements to provide insights that inform both research and clinical practice.

Methods:

Spine surgery was indexed as the main keyword for data mining in the Web of Science Core Collection database (2015 to present) as the primary source. Publications were analyzed to compare countries, institutions, research focuses, and citation distributions, highlighting trends and hotspots in the field.

Results:

Since 2015, more than 1000 spine surgery–related papers have been published annually, and increasing each year. Notably, since 2020, annual publications have exceeded 2000, reflecting a growing research focus in this field. A total of 16 939 papers were identified in the data set. Globally, the United States leads in publishing quantity, with 6721 papers and 49 398 citations. Canada ranks sixth, contributing 766 papers and 11 075 citations. The most prolific global institutions are the University of California system, Harvard University, and Johns Hopkins University. In Canada, the top contributors are the University of Toronto, the University of British Columbia, and the University Health Network Toronto. Research focuses in Canada align with global priorities. This alignment underscores shared areas of interest and possible collaboration in advancing spine surgery research.

Conclusion:

Spine surgery continues to emerge as a popular research field worldwide with a high and growing number of publications. While Canada contributes a smaller volume, the average citation rate of 17.77 per paper shows its quality. Research hotspots primarily focus on neurosciences, neurology, orthopedics, and surgery. This alignment between the world and Canada demonstrates collaborative potential in advancing the field of spine surgery.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S130.

Abstract ID 77. Program Code P181. Development of a novel rigid-flexible body dynamic model as a high-fidelity parametric biomechanical digital twin of the human torso

Siril Teja Dukkipati ^1,², Mark Driscoll ^1,²

Background:

Numerous finite-element spine models and supporting soft tissues exist in the literature with varying levels of agreement to in-vivo spinal biomechanics. However, they tend to be computationally intensive and are not suitable for iterative solving applications like machine learning. As such, there is a need for fast-solving spine models that can easily adapt to patient-specific properties like geometry and stiffness without compromising accuracy. This study presents a parametric biomechanical model of the spine and its soft tissues, with patient specificity as the focus.

Methods:

The model consisted of rigid skeletal components including the pelvis, sacrum, L1–L5 vertebrae, corresponding intervertebral discs (IVDs), a lumped thoracic spine, and ribcage. The interspinous, supraspinous, and intertransverse ligaments were modelled as nonlinear tension-only springs. The IVDs and the abdominal cavity were modelled as reduced-order flexible bodies with incompressible linear elastic properties. Parametrizing the elastic modulus of these flexible soft tissues enables the model to adapt to different patient-specific spinal and abdominal stiffnesses. To demonstrate this, first, ex-vivo lumbar spine level-by-level stiffness in flexion was sourced from multiple literature studies with and without follower compression loading. Then the model’s IVD elastic moduli were varied using a gradient descent optimization routine to match the model’s spinal stiffness with the literature targets at follower loads varying from 0 to 1500N, and pure bending flexion moment of up to 7.5 Nm at L1.

Results:

The model successfully optimized its IVD elastic moduli at all variations of follower load up to 1500 N and 7.5 Nm flexion moment to maintain the required ex-vivo range of motion within 5% margin of error. The average IVD elastic modulus of all 5 lumbar levels increased linearly (2.0 ± 0.6 MPa to 13.8 ± 5.6 MPa) as the follower load increased (0 to 1500N). Model average run time was 8.9 ± 1.1 seconds.

Conclusion:

The results demonstrate the model’s ability to represent a varied range of patient-specific spinal stiffness. The lower run time shows that the model is suitable for applications where fast solving is needed, such as preoperative planning or intraoperative biomechanical support.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S130–S131.

Abstract ID 45. Program Code P182. SimuSpine: design of a realistic simulator for minimally invasive pedicle instrumentation

Taryn Ludwig ¹, Mina Mina ², Stephanie Gibbon ², Oluwakanyinsola Bello ², Sarah J Anderson ², Lian Willetts ², Peter Lewkonia ²

Background:

Minimally invasive surgery (MIS) pedicle screw instrumentation (PSI) is a technically demanding procedure with risks of injury to adjacent structures. Current training for residents involves nonstructured operating room feedback, and current simulation models do not include realistic soft-tissue layers. This study aims to evaluate PSI by residents trained with observation of conventional models compared with those trained with a novel simulator. We hypothesize that the novel simulator will offer more realistic training and improve accuracy of pedicle screw placement.

Methods:

Hollow vertebral cortical shells were 3-D printed from representative patient computed tomography (CT) scans and injected with a rigid polyurethane foam mimicking cancellous bone. Vertebrae were molded in ballistics gelatin that simulates muscle tissue, and skin layers were manufactured with opaque Dragon Skin. Orthopedic and neurosurgical residents from the authors’ institution (n = 20) were recruited. Standardized presimulation training was provided in the training phase of the study. Participants were divided into 2 groups; 1 used the novel simulators, and the other group used passive observation of needles in conventional models under radiograph. Each participant instrumented 4 pedicles. In the assessment phase (2 weeks’ post-training phase), each participant performed MIS PSI on 2 thoracic and 2 lumbar vertebrae in cadaveric specimens. Postprocedure CT scans were obtained to assess accuracy of PSI. Accuracy data are currently being accrued.

Results:

Participants trained on the novel simulators rated the realistic nature of the model significantly higher than those trained with observation only (p < 0.05). There was no significant difference between the 2 model groups regarding participant confidence to obtain adequate imaging pre- and post-training phase (p = 0.56). The task trainers were low-cost, high-fidelity, exhibiting tactile feedback , and fluoroscopic imaging capability.

Conclusion:

This novel simulator familiarized residents with PSI in a low-cost, low-risk environment using a standardized educational platform. The simulator aims to address gaps in teaching specific technical skills in residency using accessible task-specific model technology. Future directions include assessment of simulator fidelity on the cognitive load required by participants during MIS PSI.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S131.

Abstract ID 114. Program Code P184. Bilingual accessibility with artificial intelligence: assessing the ability of ChatGPT to answer patient queries on scoliosis in English and French

Andy Deprato ¹, Kieran Chalmers ¹, Andrew Tice ^2,³, Jessica Romeo ², Sasha Carsen ^2,³, Kevin Smit ^2,³

Background:

In a bilingual Canadian context, the increasing prevalence of artificial intelligence (AI) use (e.g., ChatGPT) could help promote patient access to medical information in their first language; however, there is considerable concern about the reliability of medical information provided by this free-to-use, widely available chatbot, particularly when used in a different language from its primary programming. We therefore investigated the ability of ChatGPT to respond to common patient queries about scoliosis in both English and French, assessing response quality and readability.

Methods:

Ten questions from the American Academy of Orthopedic Surgeons patient information summaries on scoliosis were presented to ChatGPT-4o mini, with instructions to generate answers in both English and French. Four English-French bilingual orthopedic practitioners assessed response quality on a 5-point Likert scale (1 being poor, 5 excellent) across 5 domains (accuracy, relevance, clarity, completeness, evidence-based), with the option to comment on responses. Readability was assessed through Flesch–Kincaid Grade Level. The quality and readability of responses were respectively analyzed through Kruskal–Wallis and 1-way analysis of variance testing.

Results:

ChatGPT responses did not significantly differ between English and French for any quality domains. Individual quality domains were consistently scored as good to excellent for accuracy (mean ± standard deviation [SD] for both English and French: 4.15 ± 0.74), relevance (4.28 ± 0.75), and clarity (4.28 ± 0.78). Answer completeness was good (3.95 ± 0.85) and responses were satisfactorily evidence based (English: 3.20 ± 1.29, French: 3.18 ± 1.30). Raters did not identify any harmful information, but reported imprecise or incomplete answers, particularly for questions on management and surgical risks. Readability level was significantly more difficult than the grade 8 level recommended by accessibility guidelines (English: 11.81 ± 1.57, French: 13.51 ± 1.52; p values both < 0.0001).

Conclusion:

The overall ability of ChatGPT to provide information on scoliosis in English and French demonstrates its potential as an effective patient tool for a Canadian context. Despite noted inaccuracies, it may be an important option for increasing patient accessibility in both official languages.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S131–S132.

Abstract ID 41. Program Code P185. Enhancing accuracy of adolescent idiopathic scoliosis diagnosis in community radiology: machine learning versus manual measurement of Cobb angles

Ayesha Hadi ¹, Dorothy J Kim ², Andrea S Doria ², Farzad Khalvati ², Chaojun Chen ², Jennifer A Dermott ², David E Lebel ²

Background:

Approximately 25% of the measurement variation made by community radiology can be attributed to error. Inaccuracies between community radiology and tertiary care may have a significant impact on the timely presentation of adolescent idiopathic scoliosis patients. The study objective was to evaluate the effectiveness of a machine learning (ML) model to quantify curve magnitude on community-acquired spine radiographs and to subsequently identify adolescent idiopathic scoliosis patients with moderate and severe deformity for triage.

Methods:

A retrospective review of adolescent idiopathic scoliosis patients (n = 116) at a tertiary-care pediatric hospital with community-acquired spine radiographs was conducted. Reference standard evaluations were obtained on community-acquired spine radiographs by independent measurements from 2 blinded raters (orthopedic spine specialist; pediatric radiologist). The ML model was a 2-step segmentation-based deep learning architecture, previously validated on 3-foot standing spine radiographs. Community radiology readings were retrieved from imaging reports. Cobb angle readings obtained by the ML model and by community radiologists were compared to the reference standard. The agreement was computed using intraclass correlation coefficient (ICC). Brace and surgical candidates were identified by reference standard and corresponding Scoliosis Research Society management categories (> 25°, > 50°).

Results:

On community-acquired spine radiographs, the agreement in Cobb angle readings between ML model and reference standard was excellent (ICC 0.93, 95% confidence interval [CI] 0.90 to 0.95; ICC 0.90, 95% CI 0.86 to 0.93) with acceptable precision (standard error of the mean [SEM] 3.97°; SEM 4.79°). Comparatively, the agreement between community radiologist and reference standard was fair (ICC 0.68, 95% CI 0.51 to 0.79; ICC 0.67, 95% CI 0.54 to 0.76) with a greater margin of error (SEM 8.28°; SEM 8.85°). The ML model correctly identified 85.4% of brace candidates (n = 49) and 83.9% of surgical candidates (n = 31), increased from the 63.2% and 67.7% identified by community radiologist. Of those brace candidates who were missed, the ML model underestimated curve magnitude by 3.84°, on average.

Conclusion:

There was greater reliability of the Cobb angle readings obtained by the ML model compared with manual measurements obtained by community radiologists. There may be important clinical utility of an ML model to enhance measurements obtained in the community, which may expedite appropriate referrals to tertiary care.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S132.

Abstract ID 191. Program Code P187. Three-dimensional reconstructions based on a new artificial intelligence algorithm provides rapid access to accurate and personalized representation of the spine: Toward a new paradigm in 3-D analysis of scoliotic deformities

Justin Dufresne ¹, Benjamin Aubert ², Rachelle Imbeault ¹, Marjolaine Roy-Beaudry ³, Thierry Cresson ², Stefan Parent ¹

Background:

Three-dimensional reconstructions of the spine have been used for more than 30 years, mainly in a research environment. The main limitation to their clinical use has been access to rapid and accurate 3-D reconstructions. This study assesses the accuracy and reliability of a newly developed artificial intelligence (AI)–powered software for generating 3-D spine reconstructions from 2-D radiograph images, focusing on idiopathic scoliosis.

Methods:

This retrospective cohort data study focused on validating the accuracy of the AI-powered software by comparing 100 automatic reconstructions with those performed using a semiautomatic tool, which were validated by a third party (surgeon/3-D reconstructions expert). Clinical parameters, including Cobb angle, thoracic kyphosis, lumbar lordosis, pelvic tilt, and plane of maximal deformity, were assessed. Radiographs were sourced from a specialized centre’s research image database spanning the years 2014 to 2019.

Results:

Mean absolute differences (MAD) were observed for the Cobb angle (4.1° ± 4.4), thoracic kyphosis (4.9° ± 3.9), lumbar lordosis L1–L5 (4.8° ± 4.3), lumbar lordosis L1–S1 (3.1° ± 2.2), pelvic tilt (1.1° ± 1.2), and the plane of maximal deformity (6.2° ± 6.7). The intraclass correlation coefficient for each variable, respectively, was 0.84, 0.87, 0.82, 0.94, 0.95, and 0.84. Strong positive correlation coefficients were found: 0.76 for the Cobb angle, 0.89 for thoracic kyphosis, 0.76 for lumbar lordosis L1–L5, 0.89 for lumbar lordosis L1–S1, 0.92 for pelvic tilt, and 0.72 for the maximum plane angle. Notably, the AI-powered software reduced the time required for a single 3-D reconstruction to 2.21 minutes, demonstrating significant efficiency gains compared with the semiautomatic software, which took on average 74 minutes per reconstruction.

Conclusion:

This study confirms the reproducibilty of 3-D spine reconstructions produced by the AI software for database creation, highlighting the successful automation of a large-scale data set. However, individual variability remains, and clinicians should exercise caution when using these methods interchangeably. The implementation of this AI-powered software for rapid database generation provides a unique opportunity to systematically investigate and provides an efficient method to make 3-D reconstruction available in the clinical setting.

Can J Surg. 2025 Nov-Dec;68(6suppl3):S132.

Abstract ID 85. Program Code P188. Detecting and monitoring scoliosis without radiography: validating the use of Momentum Spine artificial intelligence against gold standard radiographic imaging

Taylor Liu ¹, Andrew Tice ¹, Jessica Romeo ¹, Kevin Smit ¹

Background:

Frequent monitoring is essential for assessing the progression of adolescent idiopathic scoliosis, especially during years of growth. Standard practice involves radiographic measurement of Cobb angles every 4 to 6 months; however, this may not align with curve progression, given unpredictable growth patterns. The emergence of clinical artificial intelligence (AI) tools, such as the Momentum Spine smartphone application, have been developed to address monitoring concerns. Video-imaging technology is used to measure extraspinal, topographic markers that are correlated to the magnitude of spinal deformity. The purpose of the current study is first, to validate the AI-generated Cobb angle produced via Momentum Spine, and second, to assess the AI’s ability to track disease progression over time.

Methods:

Eligible adolescent idiopathic scoliosis patients (n = 131) consented to partake in the study and underwent same-day radiographic imaging and AI scan at the baseline visit. Subsequent same-day AI scans were performed at any follow-up visits with radiographic imaging, with 17 patients having completed an additional follow-up visit thus far. Paired t test was used to compare all same-day radiographic and AI-generated Cobb angles. Two-way analysis of variance was used to assess the accuracy of AI-generated Cobb angles compared with radiographic Cobb angles over time.

Results:

Paired t test results of all scans demonstrated that mean Momentum Spine main curve Cobb angle differed by an average of 6.72° compared with the radiographic measurement (MAI 26.8 ± 12.7° v. Mradiograph 33.5 ± 14.2°). Despite this difference being statistically significant, (−6.72°, 95% confidence interval [CI] −8.19° to −5.26°; t₁₂₇ = 9.09, p < 0.0001), it falls within the accepted range for interrater variability of approximately 7° between clinicians. In the population with follow-up, post hoc analysis showed that agreement between AI-predicted Cobb angle and radiographic measurement improved to an average difference of 4.05° (AI 24.24 ± 13.4° v. radiograph 28.29 ± 14.0°; p = 0.6788).

Conclusion:

Momentum Spine can estimate Cobb angles within the accepted range of interrater variability between clinicians when compared with same-day radiographic Cobb angles. Therefore, it can be used to detect and monitor adolescent idiopathic scoliosis remotely.

PERMALINK

Canadian Spine Society

Footnotes

Abstract ID 19. Program Code CPSS01. Pediatric Spine Frailty Index predicts morbidity and mortality in spinal deformity surgery

Vivien Chan

Adeesya Gausper

Andy Liu

Lindsay M Andras

Kenneth D Illingworth

David L Skaggs

Background:

Methods:

Results:

Conclusion:

Abstract ID 99. Program Code CPSS02. Evaluation of biplane radiographic systems for scoliotic patients

Rachelle Imbeault

Justin Dufresne

Stefan Parent

Sylvain Deschênes

Marjolaine Roy-Beaudry

Background:

Methods:

Results:

Conclusion:

Abstract ID 180. Program Code CPSS03. Rate of spinal osteochondromas diagnosed via advanced imaging in pediatric patients with hereditary multiple osteochondromas: a systematic review and meta-analysis

Jack Legler

Lee Benaroch

Ali Ahmadi Pirshahid

Olivia Serhan

Draydon Cheng

Debra Bartley

Timothy Carey

Parham Rasoulinejad

Supriya Singh

Patrick Thornley

Background:

Methods:

Results:

Conclusion:

Abstract ID 137. Program Code CPSS04. The impact of adverse childhood experiences on fibromyalgia: a systematic review and meta-analysis of case–control studies

Khaled Skaik

Genevieve Belanger

Philippe Phan

Alexandra Stratton

Coyle Matthew

Stephen Kingwell

Eve Tsai

Eugene Wai

Background:

Methods:

Results:

Conclusion:

Abstract ID 61. Program Code CPSS05. Enhanced recovery pathway for patients with adolescent idiopathic scoliosis undergoing posterior spinal instrumentation and fusion surgery: a matched controlled analysis

Hannah Fonteyne

Sarah Southon Hryniuk

Eric Parent

Eric Huang

Kyle Stampe

Background:

Methods:

Results:

Conclusion:

Abstract ID 193. Program Code CPSS06. Integrated approach to back pain in the adolescent population

Marie J Beaulieu

Monica Chan

Gloria Thevasagayam

Gabriela Marino-Merlo

Background:

Methods:

Results:

Conclusion:

Abstract ID 38. Program Code CPSS07. Traumatic spinal cord injury in children and adolescents: a 20-year review from the Hospital for Sick Children

Armaan K Malhotra

Christopher S Lozano

Zaid Salaheen

Anahita Malvea

Husain Shakil

Leeor Yefet

Ali Moghaddamjou

Sam Molot-Toker