Abstract
Introduction
Although severe perioperative complications have been reported after occipitocervical fixation surgery for cervical trauma, no studies have specifically evaluated these complications in patients aged over 80 years. This study aimed to assess perioperative complications following occipitocervical fixation surgery for cervical trauma in patients older than 80 years.
Methods
Among the 1,512 patients with cervical injury treated between 2010 and 2020, 41 patients aged ≥65 years who underwent occipitocervical fixation surgery were enrolled at 77 institutions in Japan. Patients were classified into a young-old group (65-79 years, n=21) and an old-old group (≥80 years, n=20). Demographic and surgical data, diagnosis, comorbidities, and perioperative complications were compared between the two groups.
Results
The young-old group included eight atlas fractures and 16 axis fractures, while the old-old group included seven atlas fractures and 15 axis fractures. Perioperative complications occurred in 11 (52%) cases in the young-old group and in four cases (20%) in the old-old group. Reported complications included delirium, dysphagia, pneumonia, implant failure, worsening neurological pain, respiratory disorder, urinary tract infection, diverticular bleeding, cerebral infarction, deep vein thrombosis, and death.
Conclusions
Although there were several selection biases, including trauma severity and surgical indication, advanced age of over 80 years alone does not necessarily lead to a markedly increased risk of perioperative complications following occipitocervical fixation surgery for traumatic cervical spine injuries.
Level of Evidence
Level III
Keywords: occipitocervical fixation surgery, cervical trauma, older patients, perioperative complications, multicenter study
Introduction
Occipitocervical fixation surgery is widely recognized as an effective surgical option for achieving rigid stabilization in cases of atlantoaxial instability or craniovertebral junction injuries associated with cervical trauma1-3). This procedure provides immediate mechanical stability and can prevent further neurological deterioration in patients with marked instability or neurological compromise1).
However, occipitocervical fixation surgery carries inherent complications, including dysphagia, respiratory complications, and postoperative wound infection4-7). Considering the innate deterioration in capacities such as deglutition in the older adults, the potential risks of occipitocervical fixation surgery are notably heightened in this age group8). Although antecedent studies have evaluated the outcomes of occipitocervical fixation surgery in older patients, their scope was confined to those aged around 65 years9,10). With bone quality and deglutition competence diminishing with age, a comprehensive evaluation of safety and complications associated with occipitocervical fixation surgery in the more advanced age group is paramount. In this study, we assessed the perioperative complications after occipitocervical fixation surgery in patients aged 80 years or older, employing data collated from multiple institutions.
Materials and Methods
Study design and setting
This was a retrospective multicenter study conducted between 2010 and 2020 at 77 institutions in Japan. The study was approved by the institutional review boards at each institution. A total of 1,512 patients with cervical injury were investigated, and the inclusion criteria were patients aged over 65 years who underwent occipitocervical fixation surgery due to cervical spine injury. The surgical techniques for posterior occipitocervical fixation surgery comprise occipital plate, cervical pedicle screw, lateral mass screw, lamina screw, and lamina hook fixation. The choice of surgical procedure was at the discretion of surgeons at each institution. Demographic data and perioperative complications after occipitocervical fixation surgery were compared between patients aged 65-79 years and those aged ≥80 years.
Participants
Patients older than 65 years were classified into a young-old group (65-79 years) and an old-old group (≥80 years). The following were excluded from the study: patients with active infection, neoplastic disease, ankylosing spondylitis, or missing values and patients who underwent anterior surgeries.
Variables
The following variables were obtained from medical records and compared between the two age groups: type of injury, systemic combined injury, gender, height, body mass index, operation time, estimated blood loss, fused levels, comorbidities, perioperative complications, and neurological deficit with American Spinal Injury Association (ASIA) motor score. Anderson-D'Alonzo fracture classification was also evaluated for odontoid fractures11). Systemic combined injuries were characterized by requisite supplementary treatments inclusive of subsequent medical assessments. ASIA motor scores were evaluated preoperatively and at the final follow-up appointments. We also evaluated postoperative stability using stable fixation that was defined as the absence of implant loosening at six months12).
Statistical analysis
Means±standard deviations were used to describe continuous variables and frequencies and percentages were used to summarize categorical variables. Baseline demographics, preoperative scores, and surgical characteristics were compared between the two groups using independent t-tests or chi-square tests, as appropriate. A p-value <0.05 was considered statistically significant in all the analyses.
Results
Descriptive statistics
A total of 41 patients were assessed in this study (mean age 77.1 years; range 65-94 years). Of these, 21 patients (51%) were divided into the young-old group (age 70.4±4.9 years) and 20 patients (49%) were divided into the old-old group (age 84.3±8.2 years). There were no significant differences between the two groups in gender, height, weight, body mass index, follow-up period, and comorbidities (Table 1).
Table 1.
Comparison of Demographic Data between 20 Patients in the Old-Old Group and 21 Patients in the Young-old Group.
| Old-old group (n=20) | Young-old group (n=21) | p-Value | |
|---|---|---|---|
| Demographic characteristics and body composition | |||
| Age in years, mean±SD (range) | 84.3±3.7 (80-94) | 70.4±4.9 (65-79) | |
| Gender (male/ female) | 7/13 | 10/11 | 0.53 |
| Height in meters, mean±SD (range) | 1.50±0.09 (1.35-1.74) | 1.55±0.10 (1.35-1.75) | 0.14 |
| Weight in kilograms, mean (range) | 50.2±10.0 (40.0-75.0) | 49.3±10.0 (33.0-69.4) | 0.78 |
| BMI in kg/m2, mean±SD (range) | 22.3±3.9 (16.6-33.3) | 20.3±3.0 (15.4-28.4) | 0.10 |
| Follow-up period (days) | 39.6±31.8 (15-138) | 58.9±40.6 (14-156) | 0.10 |
| Current smoking, n (%) | 1 (5) | 5 (24) | 0.18 |
| Comorbidities | |||
| Hypertension, n (%) | 12 (60) | 10 (48) | 0.54 |
| Diabetes, n (%) | 3 (15) | 3 (14) | 1.00 |
| Cardiac, n (%) | 3 (15) | 1 (5) | 0.34 |
| Cerebrovascular, n (%) | 3 (15) | 2 (10) | 0.66 |
| Dementia, n (%) | 3 (15) | 1 (5) | 0.34 |
| Respiratory, n (%) | 0 (0) | 2 (10) | 0.49 |
| Chronic Kidney Disease, n (%) | 1 (5) | 1 (5) | 1.00 |
BMI: body mass index; SD: standard deviation
Comparison of the diagnosis of cervical injury and neurological deficit between the two age groups
The young-old group included eight atlas fractures and 16 axis fractures, while the old-old group included seven atlas fractures and 15 axis fractures. In the young-old group, an isolated injury was observed in 14 individuals, including five cases with C2 vertebral fractures, four cases with atlanto-axial dislocations, two cases each with Anderson-D'Alonzo type 2 and type 3 odontoid fractures, and one case with Jefferson fracture, and combined injuries were observed in seven individuals, including two cases with Jefferson and Anderson-D'Alonzo type 2 odontoid fractures, and one case each with Jefferson and Anderson-D'Alonzo type 3 odontoid fractures, Jefferson and lateral mass of C2 fractures, posterior arch and Anderson-D'Alonzo type 3 odontoid fractures, and posterior arch, hangman's, C2, and C5 vertebral fractures. In the old-old group, an isolated injury was observed in 16 individuals, including six cases with Anderson-D'Alonzo type 2 odontoid fractures, three cases with Jefferson fractures, two cases each with Anderson-D'Alonzo type 3 odontoid fractures, hangman's fractures and atlanto-axial dislocations, and one case with C2 vertebral fracture, and combined injuries were observed in four individuals, including two cases with Jefferson and C2 vertebral fractures, and one case each with Jefferson and Anderson-D'Alonzo type 3 odontoid fractures and posterior arch and Anderson-D'Alonzo type 2 odontoid fractures.
Neurological deficits were detected preoperatively in 12 cases (57%) in the young-old group, including two cases with ASIA grade A, one case with ASIA grade B, four cases with ASIA grade C, and five cases with ASIA grade D, and in eight cases (40%) in the old-old group, including three cases with ASIA grade C and five cases with ASIA grade D. At the final follow-up, a neurological deficit was observed in five cases (25%) with ASIA grade D in the old-old group, although the severity of the deficit was the same as before surgery in the young-old group. There were no significant differences between the two groups in diagnosis of injury and in both preoperative and final neurological deficits (Table 2).
Table 2.
Comparison of Type of Injuries between 20 Patients in the Old-Old Group and 21 Patients in the Young-old Group.
| Old-old group(n=20) | Young-old group(n=21) | p-Value | |
|---|---|---|---|
| Types of injuries | |||
| C1 posterior arch fracture, n (%) | 1 (5) | 3 (14) | 0.61 |
| C1 Jefferson fracture, n (%) | 6 (30) | 4 (19) | 0.48 |
| C2 vertebral body fracture, n (%) | 3 (15) | 6 (29) | 0.45 |
| Odontoid fracture, Anderson-D’Alonzo type 2, n (%) | 7 (35) | 4 (19) | 0.31 |
| Odontoid fracture, Anderson-D’Alonzo type 3, n (%) | 3 (15) | 3 (14) | 1.00 |
| Hangman fracture, n (%) | 2 (10) | 2 (10) | 1.00 |
| No fracture, n (%) | 2 (10) | 4 (19) | 0.66 |
| Isolated injury, n (%) | 16 (80) | 14 (67) | 0.48 |
| Combined injury, n (%) | 4 (20) | 7 (33) | |
| Preoperative ASIA | |||
| A | 0 | 2 | 0.47 |
| B | 0 | 1 | |
| C | 3 | 4 | |
| D | 5 | 5 | |
| E | 12 | 9 | |
| ASIA at final follow-up | |||
| A | 0 | 2 | 0.11 |
| B | 0 | 1 | |
| C | 0 | 4 | |
| D | 5 | 5 | |
| E | 14 | 9 | |
| Unassessable (death) | 1 | 0 |
ASIA: American Spinal Injury Association
In addition, systemic combined injuries were observed in eight cases from the young-old group, including five cases with head injury, two cases with chest injury, and one case with abdominal injury, and in three cases with head injury in the old-old group.
Comparison of perioperative complications and operative features between the two age groups
In the young-old group, perioperative complications were observed in 11 cases (52%), including delirium in four cases, dysphagia and pneumonia in two cases each and implant failure, worsening of neurological pain, respiration disorder, urinary tract infection, diverticular bleeding, and cerebral infarction in one case each. Revision surgeries were performed in three cases, two due to dysphagia and one due to worsening of neurological pain.
In the old-old group, perioperative complications were observed in four cases (20%), including delirium in two cases, death, implant failure, pneumonia, and deep venous thrombosis in one case each. Revision surgery was performed in one case due to implant failure.
All the patients underwent posterior occipitocervical fixation surgery utilizing occipital plate and cervical screws. Although perioperative complications were not significantly different between the two groups, there was a trend toward fewer complications in the old-old group than in the young-old group (p=0.052) (Table 3) and there were no significant differences in surgical time, estimated blood loss, and fused levels between the two groups. Excluding one patient in the old-old group who died one month after surgery and three patients with follow-ups of less than six months (two in the young-old group and one in the old-old group), all the remaining cases demonstrated stable fixation.
Table 3.
Comparison of Surgical Information and Perioperative Complications between 20 Patients in the Old-Old Group and 21 Patients in the Young-old Group.
| Old-old group (n=20) | Young-old group (n=21) | p-Value | |
|---|---|---|---|
| Surgical factors | |||
| Operation time, mean (range) | 235 min (123-557) | 230 min (135-368) | 0.87 |
| Estimated blood loss, mean (range) | 390 mL (31-2049) | 353 mL (32-1260) | 0.79 |
| Lower instrumented vertebrae | |||
| C2, n (%) | 5 (25) | 5 (24) | 0.56 |
| C3, n (%) | 6 (30) | 2 (10) | |
| C4, n (%) | 4 (20) | 6 (29) | |
| C5, n (%) | 3 (15) | 2 (10) | |
| C6, n (%) | 1 (5) | 2 (10) | |
| C7, n (%) | 1 (5) | 3 (14) | |
| T3, n (%) | 0 (0) | 1 (5) | |
| Perioperative complication | |||
| Total, n (%) | 4 (20) | 11 (52) | 0.052 |
| Death, n (%) | 1 (5) | 0 (0) | 0.49 |
| Delirium, n (%) | 2 (10) | 4 (19) | 0.66 |
| Implant failure, n (%) | 1 (5) | 1 (5) | 1.00 |
| Pneumonia, n (%) | 1 (5) | 2 (10) | 1.00 |
| Dysphagia, n (%) | 0 (0) | 2 (10%) | 0.49 |
| Respiration disorder, n (%) | 0 (0) | 1 (5) | 1.00 |
| Others, n (%) | 2 (10) | 4 (19) | 0.66 |
| Revision surgery, n (%) | 1 (5) | 3 (14) | 0.61 |
Discussion
Occipitocervical fixation surgery is required in specific cervical spine injuries or pre-existing deformities4,13). However, potential complications encompass dysphagia, respiratory issues, and postoperative wound infection4-7). Bhimani et al.4) reported a complication rate of 25.0% following occipitocervical fixation surgery, with a 9.1% revision surgery rate in 165 patients aged 16-91 years. In this study, perioperative complications following occipitocervical fixation surgery for cervical trauma were assessed between a young-old group and an old-old group. The perioperative complication rate in the old-old group was 20%, and there was a trend toward fewer complications in the old-old group than in the young-old group. Although the finding that complication rates decreased with increasing age appears counterintuitive, this result may be attributable to biases inherent in the retrospective study design. In this study, no patients classified as ASIA grade A or B were included in the old-old group, suggesting a potential difference in injury severity between the age groups. This imbalance in baseline severity may have influenced the observed complication rates. Therefore, future prospective studies that better control for such biases are warranted. Nevertheless, our findings suggest that advanced age over 80 years alone does not necessarily lead to a markedly increased risk of perioperative complications following occipitocervical fixation surgery for traumatic cervical spine injuries.
Mortality constitutes a critical determinant of clinical outcomes in the older patients. Sasagawa et al.14) reported that an 8% mortality rate was observed following cervical fracture fixation surgery in a cohort of 313 patients aged over 65 years. White et al.15) conducted a systematic analysis revealing an overall mortality rate of 10.1% (ranging between 0% and 22%), with pneumonia emerging as the predominant complication at 9.9% (with a range of 5%-20%) following surgical intervention for upper cervical fractures in patients aged 65 years and above. Smith et al.16) documented a perioperative mortality rate of 10% following surgical procedures for odontoid fractures in octogenarian patients devoid of neurological deficits. This study denoted a reduced mortality and pneumonia incidence associated with occipitocervical fixation surgery compared to those reported in prior literature15,16). From these results, the reduction in the incidence of pneumonia might be a key factor for the decrease in the mortality rate. Several risk factors of postoperative pneumonia following spine surgery had been identified, such as older age, current smoking, and compromised lung function17,18). In this study, none of the patients in the old-old group had respiratory diseases, and the current smoking rate in the old-old group was lower than that in the young-old group, potentially contributing to lower mortality rate. Despite the potential for selection bias in surgical indication, the perioperative complication rate of postoperative pneumonia may not be elevated in the older patients without a history of respiratory disease or smoking.
Postoperative delirium frequently manifests as a perioperative complication, with documented incidences ranging from 5% to 50%19-22). Age has been identified as a potential risk factor for delirium subsequent to cervical surgery20). In our study, the incidence of postoperative delirium aligned with prior literature and did not exhibit an increased trend in patients aged above 80 years. Though, to our knowledge, no existing literature explicitly correlates postoperative delirium with occipitocervical fixation surgery, it can be inferred that patients across all age brackets might be susceptible to delirium following this surgical intervention.
To the best of our knowledge, this is the largest study investigating perioperative complications after occipitocervical fixation surgery for upper cervical trauma in older patients aged over 80 years.
However, there are several limitations to this study. First, this was a retrospective study and the number of patients was limited because upper cervical spine trauma requiring occipitocervical fixation surgery is relatively uncommon in the older adults; therefore the evidence level is inevitably low. Second, selection bias may exist because the indication for surgery and the choice of a surgical method were determined at each institution. Third, the follow-up period was relatively short and long-term effects could not be evaluated because this condition makes long-term follow-up difficult. According to our results, occipitocervical fixation surgery can be considered even for the patients aged over 80 years.
Conclusions
Although there were several selection biases including trauma severity and surgical indication, advanced age over 80 years alone does not necessarily lead to a markedly increased risk of perioperative complications following occipitocervical fixation surgery for traumatic cervical spine injuries.
Author Contributions: N.I., H.F., N.Y., and S.K. designed the study; N.I., H.F., N.Y., H.N., T.F., S.I., K.W., A.Y., N.S., H.S., G.I., H.N., T.H., Y.T., K.H., H.U., K.K., K.K., H.T., M.I., T.K., and S.K. performed the experiments and analyzed the data; M.Y., H.N., K.W., G.I., T.K., and S.K. supervised the experiments; N.I. and H.F. wrote the manuscript. All authors reviewed the manuscript.
Conflicts of Interest: All authors declare that they have no conflict of interest with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers' bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.
Ethical Approval: The study was conducted in accordance with the Declaration of Helsinki and the Ethical Guidelines for Medical and Health Research Involving Human Subjects in Japan and was approved by the institutional review board of Kanazawa University (No. 3352-1).
Informed Consent: Informed consent was obtained from all the subjects involved in the study.
Disclaimer: Hideaki Nakajima is one of the Editors of Spine Surgery and Related Research and on the journal's Editorial Committee. He was not involved in the editorial evaluation or decision to accept this article for publication at all.
Acknowledgments
We would like to appreciate Dr. Kazuhide Inage, Department of Orthopaedic Surgery, Graduate school of Medicine, Chiba University, for the secretariat. We would like to appreciate Dr. Seiji Okada, Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine and Dr. Shiro Imagama, Department of Orthopedic Surgery, Nagoya University, Graduate School of Medicine for their efforts in managing the Japan Association of Spine Surgeons with Ambition (JASA) organization. Furthermore, we appreciate all the members of JASA for collecting and editing the data.
Funding Statement
Source of Funding: None
References
- 1.Nockels RP, Shaffrey CI, Kanter AS, et al. Occipitocervical fusion with rigid internal fixation: long-term follow-up data in 69 patients. J Neurosurg Spine. 2007;7(2):117-23. [DOI] [PubMed] [Google Scholar]
- 2.Newman P, Sweetnam R. Occipito-cervical fusion. An operative technique and its indications. J Bone Joint Surg Br. 1969;51(3):423-31. [PubMed] [Google Scholar]
- 3.Sonntag VK, Dickman CA. Craniocervical stabilization. Clin Neurosurg. 1993;40:243-72. [PubMed] [Google Scholar]
- 4.Bhimani AD, Chiu RG, Esfahani DR, et al. C1-C2 fusion versus occipito-cervical fusion for high cervical fractures: a multi-institutional database analysis and review of the literature. World Neurosurg. 2018;119:e459-66. [DOI] [PubMed] [Google Scholar]
- 5.White AA 3rd, Panjabi MM. The clinical biomechanics of the occipitoatlantoaxial complex. Orthop Clin North Am. 1978;9(4):867-78. [PubMed] [Google Scholar]
- 6.Hong J, Lim S. Dysphagia after occipitocervical fusion. N Engl J Med. 2017;376(22):e46. [DOI] [PubMed] [Google Scholar]
- 7.Martinez-Del-Campo E, Turner JD, Kalb S, et al. Occipitocervical fixation: a single Surgeon's experience with 120 patients. Neurosurgery. 2016;79(4):549-60. [DOI] [PubMed] [Google Scholar]
- 8.Aslam M, Vaezi MF. Dysphagia in the elderly. Gastroenterol Hepatol (N Y). 2013;9(12):784-95. [PMC free article] [PubMed] [Google Scholar]
- 9.Clarke MJ, Toussaint LG 3rd, Kumar R, et al. Occipitocervical fusion in elderly patients. World Neurosurg. 2012;78(3-4):318-25. [DOI] [PubMed] [Google Scholar]
- 10.Guppy KH, Brara HS, Bernbeck JA. Occipitocervical fusions in elderly patients: mortality and reoperation rates from a national spine registry. World Neurosurg. 2016;86:161-7. [DOI] [PubMed] [Google Scholar]
- 11.Anderson LD, D'Alonzo RT. Fractures of the odontoid process of the axis. J Bone Joint Surg Am. 1974;56(8):1663-74. [PubMed] [Google Scholar]
- 12.Traynelis VC, Fontes RBV, Abode-Iyamah KO, et al. Posterior fusion for fragility type 2 odontoid fractures. J Neurosurg Spine. 2021;35(5):644-50. [DOI] [PubMed] [Google Scholar]
- 13.Hamblen DL. Occipito-cervical fusion. Indications, technique and results. J Bone Joint Surg Br. 1967;49(1):33-45. [PubMed] [Google Scholar]
- 14.Sasagawa T, Yokogawa N, Hayashi H, et al. A multicenter study of 1-year mortality and walking capacity after spinal fusion surgery for cervical fracture in elderly patients. BMC Musculoskelet Disord. 2022;23(1):798. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.White AP, Hashimoto R, Norvell DC, et al. Morbidity and mortality related to odontoid fracture surgery in the elderly population. Spine. 2010;35(9)(suppl):S146-57. [DOI] [PubMed] [Google Scholar]
- 16.Smith HE, Vaccaro AR, Maltenfort M, et al. Trends in surgical management for type II odontoid fracture: 20 years of experience at a regional spinal cord injury center. Orthopedics. 2008;31(7):650. [PubMed] [Google Scholar]
- 17.Bohl DD, Mayo BC, Massel DH, et al. Incidence and risk factors for pneumonia after posterior lumbar fusion procedures: an ACS-NSQIP study. Spine. 2016;41(12):1058-63. [DOI] [PubMed] [Google Scholar]
- 18.Bohl DD, Ahn J, Rossi VJ, et al. Incidence and risk factors for pneumonia following anterior cervical decompression and fusion procedures: an ACS-NSQIP study. Spine J. 2016;16(3):335-42. [DOI] [PubMed] [Google Scholar]
- 19.Radcliff K, Ong KL, Lovald S, et al. Cervical spine surgery complications and risks in the elderly. Spine. 2017;42(6):E347-54. [DOI] [PubMed] [Google Scholar]
- 20.Tamai K, Terai H, Nakamura H, et al. Delirium Risk Score in Elderly Patients with Cervical Spinal Cord Injury and/or Cervical Fracture. J Clin Med. 2023;12(6):2387. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Ushida T, Yokoyama T, Kishida Y, et al. Incidence and risk factors of postoperative delirium in cervical spine surgery. Spine. 2009;34(23):2500-4. [DOI] [PubMed] [Google Scholar]
- 22.Brown CH, LaFlam A, Max L, et al. Delirium after spine surgery in older adults: incidence, risk factors, and outcomes. J Am Geriatr Soc. 2016;64(10):2101-8. [DOI] [PMC free article] [PubMed] [Google Scholar]