Abstract
Study Design
Retrospective review of prospective data.
Objectives
Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) may be beneficial for elderly patients due to decreased surgical morbidity and faster postoperative recovery. This study compared the clinical and radiological outcomes of MIS-TLIF in elderly patients and younger controls at minimum 5-year follow-up.
Methods
There were 120 patients who underwent single-level MIS-TLIF for degenerative spondylolisthesis. Elderly patients (≥70 years; n = 30) and controls (<70 years; n = 90) were matched 1:3 for demographics, comorbidities and preoperative patient-reported outcomes (PROs). The Oswestry Disability Index (ODI), 36-Item Short-Form Physical (SF-36 PCS) and Mental Component Summary (SF-36 MCS), Visual Analogue Scale (VAS) back pain, and VAS leg pain were compared at 6 months, 2 years and 5 years. Radiographic fusion, adjacent segment degeneration (ASD) and revision rates were assessed at mean 7.2 ± 2.0 years.
Results
Elderly patients had longer length of stay (4.7 ± 5.8 vs 3.3 ± 1.4 days, P = .035) and more readmissions (10% vs 1%, P = .019), but there was no difference in operative time, transfusions, complications or discharge disposition. All PROs were comparable at 5 years and satisfaction rates were similar (93% elderly vs 91% controls, P = .703). The rates of radiographic fusion in the control group and elderly group were similar (94% vs 97%, P = .605), as were the rates of ASD (40% vs 33%, P = .503). There were 3 revisions (3.3%) in the control group (2 for ASD, 1 for screw loosening) but none in the elderly group (P = .311).
Conclusions
Elderly patients undergoing MIS-TLIF achieved similar improvements in pain, disability and quality of life that were sustained at 5 years.
Level of Evidence: Level III, retrospective cohort study
Keywords: minimally invasive, lumbar, TLIF, age, elderly, outcomes, satisfaction, adjacent segment disease
Introduction
With an aging population, the number of elderly patients requiring treatment for degenerative spinal conditions has been steadily increasing. Transforaminal lumbar interbody fusion (TLIF) is one of the most common surgical procedures to treat degenerative spondylolisthesis and spinal stenosis, which are major causes of pain and functional impairment in the older population.1-3 In spite of this, many elderly patients are often overlooked as surgical candidates due to a higher comorbidity burden, ageism or subjective impressions regarding their fitness for surgery. 4 Conversely, elderly patients are also often unwilling to undergo spinal surgery due to fears of an increased risk of perioperative complications or poorer surgical outcomes.
Previous studies have attempted to elucidate the impact of advanced age on spinal surgery outcomes.5-8 One historical study found a near-threefold increase in the risk of complications in patients 75 years or older compared to younger controls undergoing open spinal surgery. 9 However, recent technological advances in surgical instrumentation have led to the advent of minimally invasive spine (MIS) surgery, allowing a substantial reduction in incision length and soft-tissue disruption. Multiple studies have demonstrated comparable clinical and radiological outcomes following minimally invasive TLIF (MIS-TLIF) and open TLIF,10-12 with the former procedure carrying additional benefits such as reduced blood loss, 13 lower postoperative pain14, shorter hospitalization stays 15 and decreased complication rates.16,17 In view of the reduced exposure-related morbidity associated with MIS-TLIF, some authors have suggested that this procedure may be particularly beneficial for elderly patients in whom increased blood loss, slower perioperative mobilization, and delayed wound healing could have more profound implications.4,18,19
Although some studies have suggested that MIS-TLIF is associated with fewer perioperative complications in elderly patients, there are fewer comparative studies assessing the functional outcomes and quality of life of elderly patients undergoing this procedure.20-25 A recent meta-analysis conducted by Huang et al found 12 studies comparing the complications and functional outcomes after MIS-TLIF in the elderly. 26 However, the study with the longest follow-up referenced by Huang et al was at 3 years, and the outcomes of MIS-TLIF in the elderly have not yet been evaluated at 5-year follow-up.
The purpose of this study was to compare the clinical and radiological outcomes of MIS-TLIF in elderly patients and younger controls at a minimum follow-up of 5 years.
Methods
This study received ethical board approval from the SingHealth Centralised Institutional Review Board (Approval Number: 2020/2311). Informed consent was obtained from all patients in the study. We reviewed all patients who underwent primary, single-level MIS-TLIF for grade 1 or 2 degenerative spondylolisthesis between 2012 and 2014. Patients who underwent spinal fusion for tumor, trauma or infection were excluded. Data was prospectively collected and stored in an institutional spine registry. During the study period, 168 consecutive patients met the inclusion criteria, of which 39 patients were ≥70 years old (“elderly group”) and 129 patients were <70 years old (“control group”). All younger patients completed follow-up, whereas 9 elderly patients had passed away before 5 years (six from cardiorespiratory causes, two from malignancy, one from cerebrovascular accident), leaving 30 elderly patients available for analysis. These patients were propensity score matched in a 1:3 ratio with patients aged less than 70 years to minimize selection bias and control for potential confounders. Covariates included in the matching algorithm were sex, body mass index (BMI), American Society of Anesthesiologists (ASA) class, comorbidities and baseline patient-reported outcome measures (PROMs).
All procedures were performed by three fellowship-trained spine surgeons. First, the operative level was confirmed using a mobile C-arm X-ray. The surgical incision was then made 3-5 cm parallel to midline on the symptomatic side. Tissue dilators were inserted down to the facet complex. Facetectomy was subsequently performed to visualize the posterolateral part of the intervertebral disc, followed by discectomy and preparation of the endplates. Intradiscal spreaders were used to distract the disc space and local autogenous bone, combined with allograft bone was placed anterior and contralateral to the annulotomy along with an appropriately sized interbody cage filled with bone graft. The positioning of the cage was confirmed using fluoroscopy. To ensure decompression, the remainder of the ipsilateral facet and lamina was resected and the lateral margin of the ligamentum flavum was removed to expose the ipsilateral exiting and transversing nerve roots. In the presence of bilateral disease, the patient was tilted and the tubular retractor angled medially to visualize the contralateral side. This was followed by an over-the-top decompression where indicated. After decompression, percutaneous pedicle screws and rod was inserted via the same incision followed by a second contralateral incision with a similar percutaneously placed construct. Compression was applied across the construct to restore lordosis before final locking. Meticulous hemostasis and wound irrigation were performed prior to closure.
Patients undergoing elective spine surgery at our institution embarked on a standardized perioperative pathway. Preoperatively, patients underwent an evaluation for their physical capacity, medical fitness for surgery, cognitive ability, pain control, and nutritional status. They also received a standardized preoperative education package. On the day of surgery, patients received standard antibiotic prophylaxis using cefazolin or vancomycin (if allergic to cephalosporins), multimodal analgesia, antifibrinolytics, goal-directed fluid therapy and transfusions. Postoperatively, all patients received a standardized pain regimen, bowel regimen, early oral fluid and food intake, early rehabilitation and mobilization, early intravenous fluids discontinuation, standardized urinary catheter management, and discharge criteria. Multimodal analgesia included PO and IV acetaminophen, duloxetine or gabapentin and IV opioids according to the discretion of the anesthesiologist. A regular diet was given in recovery room, when possible, on postoperative day (POD) 0. Intravenous fluids were discontinued the morning of POD 1. The urinary catheter (if placed) was removed within 24 hours after surgery. Surgical drains (if placed) were generally removed within 48 hours after surgery. Early mobilization included on-bed movement on the day of surgery, all meals in a chair starting POD 0, as well as sitting and assisted walking on POD 1.
The primary endpoints of the study were PROMs such as the Oswestry Disability Index (ODI), 36-Item Short-Form Physical Component Summary (SF-36 PCS), Mental Component Summary (SF-36 MCS), Visual Analogue Scale (VAS) for back pain, and VAS for leg pain. PROMs were compared at 6 months, 2 years and 5 years. Clinical improvement was defined using the minimal clinically important difference (MCID), which represents a change in score that is considered meaningful to the patient. Published values of 12.8 for ODI, 1.2 for back pain, 1.6 for leg pain, and 4.9 for SF-36 PCS 27 were used to determine whether or not the MCID was achieved. The published value of 15.3 for ODI 28 was used to determine whether the patient acceptable symptom state (PASS) was achieved. Patient satisfaction and expectation fulfilment were assessed using the North American Spine Society (NASS) questionnaire. 29
Secondary outcomes such as perioperative complications, length of stay and 90-day readmissions were recorded. Radiographic fusion was assessed at 2 years and at final follow-up using the grading system of Bridwell et al 30 Radiographic adjacent-segment degeneration (ASD) was determined by comparing radiographs taken preoperatively and at last follow-up, irrespective of clinical symptoms. The following degenerative changes were identified: anterolisthesis or retrolisthesis of more than 3 mm, a decrease in the adjacent-segment disc height of more than 3 mm, or an intervertebral angle of flexion greater than 5°.31,32 Details on any revision procedure were recorded. The mean follow-up was 7.2 ± 2.0 years.
A power analysis was performed prior to the study. To detect an MCID of 12.8 points on the ODI with a standard deviation of 15, a sample size of at least 23 patients in each group would be required to achieve a power of .80. 27 These calculations were done for a two-sided test with an alpha of .05. Patient characteristics and clinical outcomes were compared between the groups using a chi-square test for categorical variables and independent t-test for continuous variables. Statistical analyses were performed using the SPSS software package, version 20.0 (SPSS Inc, Chicago, IL). Statistical significance was defined as P < .05.
Results
There were 30 elderly patients and 90 controls included in the study. The two groups were well matched for sex, BMI, ASA score and comorbidity burden (Table 1). There was no difference in operative time between the groups. Elderly patients had a longer length of stay (4.7 ± 5.8 days vs 3.3 ± 1.4 days, P = .035) and more readmissions (10.0% vs 1.1%, P = .019). However, there was no difference in transfusions, complication rates or discharge disposition (Table 2). Three medical complications occurred in the control group: one patient had sick sinus syndrome, one had severe postoperative vomiting, and the third patient had a gout flare of the knee joint. One elderly patient had cellulitis following a flare of bullous pemphigoid. There were no surgery-related complications encountered.
Table 1.
Baseline Characteristics by Age Group After Propensity Score Matching.
| Control (N = 90) | Elderly (N = 30) | a P-value b | |
|---|---|---|---|
| Age (mean ± SD, years) | 58.3 ± 7.1 | 73.5 ± 3.4 | <.001 |
| Sex % (n) | .688 | ||
| Female | 80.0% (72) | 83.3% (25) | |
| Male | 20.0% (18) | 16.7% (5) | |
| BMI (mean ± SD, kg/m2) | 25.5 ± 3.8 | 24.8 ± 3.4 | .309 |
| ASA (mean ± SD) | 2.1 ± 0.4 | 2.2 ± 0.5 | .293 |
| Comorbidities (mean ± SD) | 1.4 ± 1.2 | 1.8 ± 1.4 | .115 |
| Diabetes % (n) | 16.7% (15) | 20.0% (6) | |
| Hypertension % (n) | 50.0% (45) | 66.7% (20) | |
| Hyperlipidemia % (n) | 44.4% (40) | 43.3% (13) | |
| Ischemic heart disease % (n) | 4.4% (4) | 16.7% (5) | |
| Kidney disease % (n) | 0% (0) | 0% (0) | |
| Stroke % (n) | 1.1% (1) | 0% (0) | |
| Peripheral vascular disease % (n) | 0% (0) | 0% (0) | |
| Asthma % (n) | 3.3% (3) | 0% (0) | |
| Osteoarthritis % (n) | 14.4% (13) | 23.3% (7) | |
| Depression % (n) | 1.1% (1) | 3.3% (1) | |
| No comorbidities % (n) | 23.3% (21) | 23.3% (7) |
BMI: body mass index; ASA: American society of anesthesiologists class.
aP-value was calculated for each category using chi square analysis (categorical) or student’s t-test (continuous).
bBoldface indicates statistical significance.
Table 2.
Perioperative Characteristics by Age Group.
| Control (N = 90) | Elderly (N = 30) | a P-value b | |
|---|---|---|---|
| Diagnosis % (n) | |||
| Degenerative spondylolisthesis | 100 (90) | 100 (30) | 1.000 |
| Number of levels % (n) | |||
| 1-Level | 100 (90) | 100 (30) | 1.000 |
| Operative time (mean ± SD, min) | 162.9 ± 44.8 | 151.2 ± 39.0 | .208 |
| Blood transfusions % (n) | 0 (0) | 0 (0) | — |
| Complications % (n) | 1.000 | ||
| Minor | 3.3 (3) | 3.3 (1) | |
| Major | 0 (0) | 0 (0) | |
| Length of stay (mean ± SD, days) | 3.3 ± 1.4 | 4.7 ± 5.8 | .035 |
| Discharge to rehabilitation % (n) | 0 (0) | 3.3% (1) | .082 |
| Readmissions % (n) | 1.1% (1) | 10.0% (3) | .019 |
aP-value was calculated for each category using chi square analysis (categorical) or student’s t-test (continuous).
bBoldface indicates statistical significance.
When analyzing PROMs, elderly patients had better VAS leg pain than controls at 2 years (P = .037), although this did not exceed the MCID of 1.6 points. In contrast, there was no difference in ODI, VAS back pain, VAS leg pain, SF-36 PCS and SF-36 MCS at 5 years (Table 3). The percentage of patients that achieved the MCID for each PROM was also similar between the groups (Table 4). The percentage of patients that achieved the PASS for ODI was 80.0% in the elderly group and 71.1% in the control group (P = .340). An analysis of subjective outcomes revealed that 93.3% of elderly patients and 91.1% of controls were satisfied at 5 years (P = .703), whereas 93.3% and 90.0% had their expectations fulfilled, respectively (P = .584).
Table 3.
Patient-Reported Outcomes by Age Group.
| Control (N = 90) | Elderly (N = 30) | a P-value b | |
|---|---|---|---|
| VAS back (mean ± SD) | |||
| Preoperative | 6.0 ± 2.8 | 5.6 ± 2.3 | .416 |
| 6-month | 1.9 ± 2.5 | 1.5 ± 2.4 | .361 |
| 2-year | 1.3 ± 2.2 | 1.1 ± 2.3 | .656 |
| 5-year | 1.1 ± 2.2 | .8 ± 2.1 | .503 |
| VAS leg (mean ± SD) | |||
| Preoperative | 6.4 ± 2.9 | 6.5 ± 2.9 | .788 |
| 6-month | 1.2 ± 2.2 | .5 ± 1.7 | .119 |
| 2-year | .9 ± 2.0 | .1 ± 0.7 | .037 |
| 5-year | .5 ± 1.6 | .0 ± 0.6 | .101 |
| ODI (mean ± SD) | |||
| Preoperative | 48.6 ± 16.9 | 49.8 ± 15.8 | .717 |
| 6-month | 18.1 ± 14.1 | 20.5 ± 14.1 | .423 |
| 2-year | 14.5 ± 16.2 | 16.8 ± 15.1 | .494 |
| 5-year | 11.9 ± 13.7 | 11.9 ± 11.4 | .977 |
| SF-36 PCS (mean ± SD) | |||
| Preoperative | 31.8 ± 8.5 | 31.4 ± 9.0 | .833 |
| 6-month | 45.0 ± 11.1 | 43.2 ± 11.0 | .430 |
| 2-year | 48.5 ± 10.2 | 44.6 ± 12.3 | .092 |
| 5-year | 48.5 ± 9.7 | 44.5 ± 9.7 | .052 |
| SF-36 MCS (mean ± SD) | |||
| Preoperative | 49.0 ± 10.4 | 50.8 ± 10.8 | .416 |
| 6-month | 52.3 ± 11.7 | 53.1 ± 8.8 | .752 |
| 2-year | 53.3 ± 10.5 | 54.0 ± 10.3 | .733 |
| 5-year | 52.8 ± 11.0 | 52.9 ± 11.9 | .954 |
VAS: visual analogue scale; ODI: oswestry disability index; SF-36 PCS: short form-36 physical component score; SF-36 MCS: short form-36 mental component score.
aP-value was calculated for each category using student’s t-test.
bBoldface indicates statistical significance.
Table 4.
Achievement of Minimal Clinically Important Difference and Satisfaction at 5 Years.
| Control (N = 90) | Elderly (N = 30) | a P-value b | |
|---|---|---|---|
| MCID for VAS back % (n) | 80.0% (72) | 80.0% (24) | 1.000 |
| MCID for VAS leg % (n) | 82.2% (74) | 90.0% (27) | .312 |
| MCID for ODI % (n) | 85.6% (77) | 90.0% (27) | .535 |
| MCID for SF-36 PCS % (n) | 83.3% (75) | 66.7% (20) | .052 |
| PASS for ODI % (n) | 71.1% (64) | 80.0% (24) | .340 |
| Satisfaction % (n) | 91.1% (82) | 93.3% (28) | .703 |
| Expectation fulfilment % (n) | 90.0% (81) | 93.3% (28) | .584 |
VAS: visual analogue scale; ODI: oswestry disability index; SF-36 PCS: short form-36 physical component score.
aP-value was calculated for each category using chi square analysis.
bBoldface indicates statistical significance.
Radiographic fusion at the 2-year mark was 60.0% and 64.4% in the elderly and control groups, respectively (P = .669). At final follow-up of 7.2 ± 2.0 years, there was also no difference in fusion rates, with 96.7% of elderly patients and 94.4% of controls achieving radiographic fusion (P = .605). A total of 33.3% and 40.0% were found to have radiological ASD, respectively (P = .503). There were 3 revisions (3.3%) in the control group (2 for symptomatic ASD, 1 for screw loosening), but no revisions in the elderly group (P = .311).
Discussion
As life expectancies increase, the number of elderly patients requiring surgical intervention for degenerative spinal conditions will continue to rise. 33 Technological improvements coupled with the growing desire for an improved quality of life have resulted in an increase in the number of spinal procedures performed in elderly patients. Given that MIS spine surgery can reduce soft tissue disruption and expedite functional recovery,4,10,18,19,34 these procedures have been theorized to be beneficial for elderly patients in whom operative morbidity and delayed mobility may have profound consequences.18,19 However, few studies have analyzed the long-term outcomes of MIS-TLIF in this growing subpopulation. The present study found that elderly patients who underwent MIS-TLIF not only had similar perioperative outcomes, but also experienced comparable improvements in pain, disability and quality of life that were sustained for up to 5 years with no long-term deterioration.
Multiple non-comparative studies have examined the perioperative complications in an elderly population, albeit using heterogenous cohorts that included many different spine procedures.5-8 Ragab et al studied a group of 118 patients aged ≥70 years who underwent single- and multi-level laminectomies with or without posterolateral fusion, reporting a complication rate of 20%. 5 This rate was comparable to that reported by Deyo et al, who examined the hospital discharge registry of Washington state and found a morbidity rate of 18% in lumbar spine surgery patients aged 75 years or older. 6 Large database studies have also evaluated the rate of major complications in octogenarians undergoing lumbar fusion, albeit with contrasting findings.7,8 Despite the growing interest in MIS spine surgery over the past decade, there has been scant literature available in regards to the outcomes of MIS-TLIF in elderly patients with degenerative spinal disorders.19,35,36 Lee et al found that 35 patients aged ≥65 years undergoing single-level MIS-TLIF had a similar overall complication rate as patients aged <65 years (20% vs 16%). 35 However, elderly patients had longer hospital stays (3.89 days vs 2.49 days, P = .0071) and were more frequently discharged to subacute nursing facilities or inpatient rehabilitation centers (17.1% vs 0%,). In the same vein, Karikari et al analyzed the results of MIS-TLIF and extreme lateral interbody fusion in 66 patients aged ≥70 years and reported an overall low rate of major complications (7.4%). 19 Nikhil et al also compared 2-year outcomes of MIS-TLIF in 22 patients >75 years old with that of aged 50.0-64.9 and 65.0-74.9 years, and concluded that older patients could obtain comparable outcomes without increased complication risks. 37 The present study found similar results as previous studies, as we did not find any difference in operative time, transfusions, complications or discharge disposition between the elderly and control groups, despite a higher 90-day readmission rate in older patients (10% vs 1%). In addition to one minor medical complication that occurred unrelated to spine surgery, the two additional readmissions in the elderly group were due to a slower rehabilitation course at home and resultant disposition issues. The current findings add to the growing body of literature supporting low perioperative morbidity associated with MIS-TLIF, which could be particularly beneficial in elderly patients with degenerative spine disease.
In addition to traditional endpoints such as perioperative complications and readmission rates, this study sought to evaluate the long-term PROMs of MIS-TLIF in an elderly population, as these outcome measures integrate a subjective, patient-centered assessment of ‘value’ that cannot be measured using traditional 90-day outcomes. Using propensity score matching to ensure baseline comparability in demographics, comorbidities and functional status, we found that older patients experienced similar improvements in pain, disability and health-related quality of life, ultimately achieving PROMs that were no different from that of younger controls at 5-year follow-up. To quantify the degree of clinical benefit following MIS-TLIF and standardize the comparison of outcome scores, the concept of MCID was also applied. Importantly, the proportion of patients that achieved the MCID for each PROM was also similar between the groups. Furthermore, we administered the NASS questionnaire and found that 93% of elderly patients as well as 91% of controls were satisfied with their treatment at 5 years, which was similar to published rates at a shorter follow-up.5,25 The current study not only reinforces previous literature that has shown comparable 2-year outcomes of MIS-TLIF in an elderly population, 25 but also add to the literature by demonstrating the long-term durability of these clinical improvements at 5 years.
Stable fusion following lumbar spinal instrumentation is an important consideration, especially for elderly patients who may experience an age-related decline in biological processes involved in bone healing. 38 Noncomparative studies noted stable fusion in the majority of elderly patients undergoing posterolateral fusion.39-41 Costa et al reported a 79% fusion rate following posterolateral fusion in 53 patients aged >75 years at 18 months follow-up, 39 while Wu et al reported a 76% fusion rate in 82 patients aged ≥65 years at minimum 2 years follow-up. 40 In contrast, a comparison by Okuda et al noted a higher incidence of delayed union in 31 elderly patients (≥70 years) undergoing posterior lumbar interbody fusion compared to those younger controls, 42 and Liao et al reported a higher incidence of nonunion and new osteoporotic fractures in 38 octogenarians undergoing posterolateral fusion. 43 The present findings were more similar to that of Jo et al, who reported comparable fusion rates in patients ≥65 and <65 years (92% vs 95%) undergoing open TLIF. 44 At mean 7.2 years, 96.7% of elderly patients achieved stable fusion compared to 94.4% of controls.
As the demand of lumbar fusions continue to grow annually, ASD is another important concern. The reported incidence of ASD following lumbar fusion may varies substantially, with one recent meta-analysis of 94 studies reporting an incidence of 5%-77%. 45 A separate systematic review reported the risk of radiologic ASD to be 8%-100% over a follow-up duration of 36-369 months. 46 Previous studies have suggested a lower risk of ASD in patients younger <60 years of age,46,47 postulating that older patients were more susceptible to degenerative changes and increased mechanical stress in the adjacent segments.37,48 In the present study, however, the rate of radiological ASD at long-term follow-up of 7.2 years was 33% in the elderly group and 40% in the control group, which was not statistically different. Moreover, symptomatic ASD was observed in 2 controls that required revision surgery. It is encouraging to note that most ASD cases were not symptomatic––a finding that was echoed by Zhong et al, who demonstrated that at 27 months, only 11.7% of lumbar fusion patients developed symptomatic ASD. 49 Similar to our study, Liao et al noted that three controls and no octogenarians developed ASD following instrumented lumbar arthrodesis at minimum 2-year follow-up. 50 It is possible that a decreased activity level in elderly patients may account for the decreased the incidence of ASD. Furthermore, Overall, these findings question the assertion that advanced age is a risk factor for ASD, although larger prospective studies are needed to validate the long-term success of MIS-TLIF in the elderly population.
This study has several limitations. This was a retrospective, nonrandomized study. It is possible that selection bias could have been introduced if only elderly patients deemed fit to proceed by the attending surgeon were included in the study cohort. However, outcome measures were prospectively collected according to an established protocol and stored in an institutional spine registry, likely addressing any bias in data collection. Furthermore, we attempted to reduce bias using propensity score matching to control for possible confounding factors, such as sex, BMI, ASA score and baseline PROMs, thus ensuring a degree of homogeneity. Nonetheless, certain variables such as the degree of canal or foraminal stenosis as well as the extent of decompression could not be controlled for and may have affected our results. Potential differences in preoperative bone density could have also confounded the influence of age on the quality of bony fusion following MIS-TLIF. In addition, the fact that MIS-TLIF was performed by a small number of surgeons with over two decades of experience in MIS spine surgery could have biased upward the results, hence reducing generalizability. Further, although the study had sufficient statistical power for the primary endpoints (ie PROMs), the small sample size may limit the conclusions that can be drawn with regards to secondary endpoints such as complication and readmission rates. Last, we did not delineate very elderly patients ≥80 years old from elderly patients as there were only four such patients in the cohort; therefore, it is possible that patients in their ninth decade may have poorer outcomes. Further studies on this subgroup of very elderly patients are warranted.
Conclusion
As the population ages, physicians will encounter more elderly patients who have the desire to maximize their mobility and independence. Traditional assumptions about their expectations should be revisited in light of recent technological advancements that have the potential to improve their quality of life while maintaining high safety standards. Elderly patients undergoing MIS surgery not only had comparable perioperative complication rates to that of younger patients, but also experienced a clinically meaningful improvement in pain, function, and quality of life after MIS-TLIF. These results were sustained for 5 years with no longer-term deterioration, and a high rate of satisfaction and expectation fulfilment was achieved.
Footnotes
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding: The author(s) received no financial support for the research, authorship, and/or publication of this article.
Centralised institutional review board (IRB) approval (CIRB 2020/2311) was obtained.
ORCID iDs
Graham S. Goh https://orcid.org/0000-0002-7337-3321
Reuben Chee Cheong Soh https://orcid.org/0000-0003-2410-5176
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