Does the Predominant Pain Location Influence Functional Outcomes, Satisfaction, and Return to Work After Minimally Invasive Transforaminal Lumbar Interbody Fusion For Degenerative Spondylolisthesis?

STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: The objective of this study was to determine how different combinations of preoperative back pain (BP) and leg pain (LP) may influence functional outcomes, patient satisfaction and return to work (RTW) in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for degenerative spondylolisthesis. SUMMARY OF BACKGROUND DATA: Surgical decision-making is often based on the traditional assumption that the predominance of lower extremity symptoms is a stronger indication for lumbar spine surgery. Surprisingly, there is a paucity of literature supporting this notion and the isolated impact of the preoperative pattern of pain on outcome remains unclear. METHODS: Prospectively collected data for patients who underwent primary MIS-TLIF for degenerative spondylolisthesis were reviewed. Patients were categorized into 3 groups depending on predominant pain location: LP predominant (LP>BP), back pain predominant [(BPP); BP>LP] and equal pain predominance (BP=LP). Patients were prospectively followed for at least 2 years. RESULTS: In total, 781 patients were included: 33.4% LP predominant, 28.7% BPP and 37.9% equal pain predominance cases. The BPP group was significantly younger (P=0.005) and showed a trend towards poorer baseline Short-Form-36 Mental Component Summary (P=0.069). After adjusting for baseline differences, there was no significant difference in BP, LP, Oswestry Disability Index (ODI), SF-36 Physical Component Summary, and SF-36 Mental Component Summary between the 3 groups at all time points (P>0.05) except for poorer 1-month ODI in the BPP group (P=0.010). The rate of minimal clinically important difference attainment for ODI and SF-36 Physical Component Summary, satisfaction, expectation fulfilment and RTW were also similar (P>0.05). CONCLUSIONS: The functional outcomes, quality of life and satisfaction after MIS-TLIF were similar, regardless of the predominant pain location. Equal proportions of patients achieved the minimal clinically important difference and RTW. In the context of proper indications, these results suggest that MIS-TLIF can be equally effective for patients with varying combinations of BP or LP. LEVEL OF EVIDENCE: Level III-nonrandomized cohort study.

Smoking Is Associated With Lower Satisfaction in Nondiabetic Patients Undergoing Minimally Invasive Single-level Transforaminal Lumbar Interbody Fusion.

STUDY DESIGN: This was a retrospective review of prospectively collected registry data. OBJECTIVE: The objective of this study was to investigate the effect of smoking on 2 years postoperative functional outcomes, satisfaction, and radiologic fusion in nondiabetic patients undergoing minimally invasive transforaminal lumbar interbody fusion (TLIF) for degenerative spine conditions. SUMMARY OF BACKGROUND DATA: There is conflicting data on the effect of smoking on long-term functional outcomes following lumbar fusion. Moreover, there remains a paucity of literature on the influence of smoking within the field of minimally invasive spine surgery. METHODS: Prospectively collected registry data of nondiabetic patients who underwent primary single-level minimally invasive TLIF in a single institution was reviewed. Patients were stratified based on smoking history. All patients were assessed preoperatively and postoperatively using the Numerical Pain Rating Scale for back pain and leg pain, Oswestry Disability Index, Short-Form 36 Physical and Mental Component Scores. Satisfaction was assessed using the North American Spine Society questionnaire. Radiographic fusion rates were compared. RESULTS: In total, 187 patients were included, of which 162 were nonsmokers, and 25 had a positive smoking history. In our multivariate analysis, smoking history was insignificant in predicting for minimal clinically important difference attainment rates in Physical Component Score and fusion grading outcomes. However, in terms of satisfaction score, positive smoking history remained a significant predictor (odds ratio=4.7, 95% confidence interval: 1.10-20.09, P=0.036). CONCLUSIONS: Nondiabetic patients with a positive smoking history had lower satisfaction scores but comparable functional outcomes and radiologic fusion 2 years after single-level TLIF. Thorough preoperative counseling and smoking cessation advice may help to improve patient satisfaction following minimally invasive spine surgery. LEVEL OF EVIDENCE: Level III-nonrandomized cohort study.

Comparative Demographics and Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion in Chinese, Malays, and Indians.

STUDY DESIGN: This study carried out a retrospective review of prospectively collected registry data. OBJECTIVE: This study aimed to determine whether (1) utilization rates; (2) demographics and preoperative statuses; and (3) clinical outcomes differ among Chinese, Malays, and Indians undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). SUMMARY OF BACKGROUND DATA: There is a marked racial disparity in spine surgery outcomes between white and African American patients. Comparative studies of ethnicity have mostly been carried out in American populations, with an underrepresentation of Asian ethnic groups. It is unclear whether these disparities exist among Chinese, Malays, and Indians. METHODS: A prospectively maintained registry was reviewed for 753 patients who underwent primary MIS-TLIF for degenerative spondylolisthesis between 2006 and 2013. The cohort was stratified by race. Comparisons of demographics, functional outcomes, and patient satisfaction were performed preoperatively and 1 month, 3 months, 6 months, and 2 years postoperatively. RESULTS: Compared with population statistics, there was an overrepresentation of Chinese (6.6%) and an underrepresentation of Malays (5.0%) and Indians (3.5%) who underwent MIS-TLIF. Malays and Indians were younger and had higher body mass index at the time of surgery compared with Chinese. After adjusting for age, sex, and body mass index, Malays had significantly worse back pain and Indians had poorer Short-Form 36 Physical Component Summary compared with Chinese preoperatively. Chinese also had a better preoperative Oswestry Disability Index compared with the other races. Although significant differences remained at 1 month, there was no difference in outcomes up to 2 years postoperatively, except for a lower Physical Component Summary in Indians compared with Chinese at 2 years. The rate of minimal clinically important difference attainment, satisfaction, and expectation fulfillment was also comparable. At 2 years, 87.0% of Chinese, 76.9% of Malays, and 91.7% of Indians were satisfied. CONCLUSION: The variations in demographics, preoperative statuses, and postoperative outcomes between races should be considered when interpreting outcome studies of lumbar spine surgery in Asian populations. LEVEL OF EVIDENCE: Level III-nonrandomized cohort study.

Are Patient-Reported Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion Influenced by Preoperative Mental Health?

STUDY DESIGN: This was a retrospective review of prospectively collected data. OBJECTIVES: Few studies have described the relationship between mental health and patient-reported outcome measures (PROMs) after minimally invasive spine surgery. Prior studies on open surgery included small cohorts with short follow-ups. METHODS: Patients undergoing primary minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for degenerative pathology were retrospectively reviewed and stratified by Short Form (SF-36) Mental Component Summary (MCS): low MCS (<50, n = 436) versus high MCS (≥50, n = 363). PROMs assessed were back pain, leg pain, North American Spine Society Neurogenic Symptoms, Oswestry Disability Index, SF-36 Physical Component Summary, and MCS. Satisfaction, expectation fulfilment, and return to work (RTW) rates also were recorded at 1 month, 3 months, 6 months, and 2 years. RESULTS: Preoperative MCS was 39.4 ± 8.6 and 58.5 ± 5.4 in the low and high MCS groups, respectively (P < .001). The low MCS group had significantly poorer preoperative PROMs and longer lengths of stay. Despite this, both groups achieved comparable PROMs from 3 months onward. The mean MCS was no longer significantly different by 3 months (P = .353). The low MCS group had poorer satisfaction (P = .022) and expectation fulfilment (P = .020) at final follow-up. RTW rates were initially lower in the low MCS group up to 3 months (P = .034), but the rates converged from 6 months onward. CONCLUSIONS: Despite poorer PROMs preoperatively, patients with poor baseline mental health still achieved comparable results from 3 months up to 2 years after MIS-TLIF. Preoperative optimization of mental health should still be pursued to improve satisfaction and prevent delayed RTW after surgery.

Poorer Preoperative Function Leads to Delayed Return to Work After Anterior Cervical Discectomy and Fusion for Degenerative Cervical Myelopathy.

BACKGROUND: The factors that affect return to work (RTW) after anterior cervical discectomy and fusion (ACDF) for degenerative cervical myelopathy (DCM) remain unclear, especially in a non-Workers' Compensation setting. We aimed to (1) identify factors that influence RTW in patients undergoing ACDF (2) determine if early RTW plays a role in functional outcomes, quality of life, and satisfaction. METHODS: Prospectively collected data of 103 working adults who underwent primary ACDF for DCM were retrospectively reviewed. Patients were stratified into 2 groups: early RTW (≤60 days, n = 42) and late RTW (>60 days, n = 61). RESULTS: The mean time taken to RTW was 34.7 and 134.9 days in the early and late RTW groups, respectively (P < 0.001). The early RTW group had significantly better preoperative Japan Orthopaedic Association (JOA) score and Neck Disability Index (NDI) (P < 0.05) and showed a trend toward higher 36-Item Short Form Physical Component Summary (PCS) (P = 0.071). The early RTW group also had significantly better postoperative JOA, NDI, and PCS at 6 months and less arm pain along with a trend toward better NDI at 2 years (P = 0.055). However, there was no difference in the change in outcome scores and a similar proportion in each group attained the minimal clinically important difference for each metric. At 2 years, 85.7% and 77.0% were satisfied in the early and late RTW groups, respectively (P = 0.275). CONCLUSIONS: While working adults that RTW later tend to have poorer function preoperatively and up to 2 years postoperatively, surgeons may reassure them that they will likely experience the same degree of clinical improvement and level of satisfaction after ACDF. LEVEL OF EVIDENCE: Level 3, therapeutic study.

Does the Predominant Pain Location Influence Functional Outcomes, Satisfaction and Return to Work After Anterior Cervical Discectomy and Fusion for Cervical Radiculopathy?

STUDY DESIGN: Retrospective review of prospectively-collected registry data. OBJECTIVES: The aim of this study was to determine how different combinations of preoperative neck pain (NP) and arm pain (AP) influence functional outcomes, patient satisfaction, and return-to-work in patients undergoing anterior cervical discectomy and fusion (ACDF) for degenerative cervical radiculopathy (DCR). SUMMARY OF BACKGROUND DATA: Surgeons often base decisions on the traditional belief that the predominance of radicular upper extremity symptoms is a stronger indication for cervical spine surgery than axial pain. However, there is a paucity of literature supporting this notion. METHODS: A prospectively maintained registry was reviewed for all patients who underwent primary ACDF for DCR. Patients were categorized into three groups depending on predominant pain location: AP predominant ([APP]; AP > NP), NP predominant ([NPP]; NP > AP), and equal pain predominance ([EPP]; NP = AP). Patients were prospectively followed for at least 2 years. RESULTS: In total, 303 patients were included: 27.4% APP, 38.9% NPP, and 33.7% EPP cases. The APP group was significantly older (P = 0.030), although there were no other preoperative differences among the three groups. After adjusting for baseline differences, the SF-36 Physical Component Summary was significantly better in the APP group at 6 months (P = 0.048) and 2 years (P = 0.039). In addition, they showed a trend towards better 6-month Neck Disability Index (P = 0.077) and 2-year SF-36 Mental Component Summary (P = 0.059). However, an equal proportion of patients in each group achieved the Minimal Clinically Important Difference for each outcome, were satisfied, and returned to work 2 years after surgery. CONCLUSION: Although patients with NPP had slightly poorer function and quality of life, all patients experienced a clinically meaningful improvement in patient-reported outcomes, regardless of the predominant pain location. High rates of satisfaction and return-to-work were also achieved. In the context of proper indications, these findings suggest that ACDF can be equally effective for DCR patients with varying combinations of NP or AP.Level of Evidence: 3.

The patient acceptable symptom state for the Oswestry Disability Index following single-level lumbar fusion for degenerative spondylolisthesis.

BACKGROUND CONTEXT: The patient acceptable symptom state (PASS) is a valuable tool for interpreting patient-reported outcomes. Previous studies have attempted to define the PASS in a heterogenous cohort with various lumbar spinal disorders and surgical procedures. PURPOSE: We aimed to determine the PASS threshold for the Oswestry Disability Index (ODI) specifically for patients undergoing lumbar fusion for spondylolisthesis-associated functional disability. STUDY DESIGN: Retrospective review of prospectively collected registry data. PATIENT SAMPLE: There were 692 patients who underwent primary single-level minimally invasive transforaminal lumbar interbody fusion for degenerative spondylolisthesis between 2006 and 2014. OUTCOME MEASURES: The ODI was collected pre-operatively, at 6 months and 2 years postoperatively. An anchor question was adapted from the NASS questionnaire, "How would you rate the overall results of your treatment?" while a validation question was taken from the same questionnaire, "Has the surgery for your back condition met your expectations so far?" METHODS: Responses to the anchor question were used to determine whether a PASS was achieved. Receiver operating characteristics curve analysis was performed to assess the ability of the ODI to discriminate between an acceptable/unacceptable symptom state as well as to define PASS thresholds. Sensitivity analyses were performed for different follow-up periods (6 months, 2 years), subgroups (by age, gender, BMI, and comorbidity burden), baseline ODI tertiles, and an alternate definition of PASS. RESULTS: In total, 529 of 692 (76%) patients completed 2-year follow-up, of which, 89% considered their symptom state to be acceptable. Areas under the curve (AUC) ranged from 0.81 to 0.90 for all receiver operating characteristics analyses, indicating that the ODI had an excellent discriminative ability. The PASS threshold was ≤18.09 at 6 months (AUC 0.81, sensitivity 77%, specificity 72%) and ≤15.27 at 2 years (AUC 0.86, sensitivity 79%, specificity 79%). These thresholds proved to be robust in the sensitivity analyses, showing minimal variation across different patient subgroups and baseline score tertiles. CONCLUSIONS: Patients with an ODI of ≤15.27 can be considered to have achieved a PASS after lumbar fusion for degenerative spondylolisthesis. These findings will help surgeons to contextualize a patient's functional recovery after lumbar spine surgery and enable researchers to define clinically relevant benchmarks when designing trials utilizing the ODI.

Women Do Not Have Poorer Outcomes After Minimally Invasive Lumbar Fusion Surgery: A Five-Year Follow-Up Study.

BACKGROUND: Women undergoing lumbar spine surgery report greater preoperative pain and disability and have less improvement after surgery. There is a paucity of literature on sex-related differences after minimally invasive surgery transforaminal lumbar interbody fusion (MIS TLIF) surgery. We aim to determine whether sex influences outcome after MIS TLIF at 5-year midterm follow-up. METHODS: Prospectively collected registry data for 907 patients who underwent MIS TLIF at a single institution from 2004 to 2013 were reviewed. Of these, 296 patients (94 males and 202 females) were reviewed at 5-year follow-up. All patients were assessed preoperatively and postoperatively at 2 and 5 years. Data recorded included patient demographics, Oswestry Disability Index (ODI), Short-Form 36 Physical and Mental component scores (SF-36 PCS and MCS), and the North American Spine Society lumbar spine outcome assessment instrument. RESULTS: Females who underwent MIS TLIF were generally younger (females, 52.2 years; males, 56.1 years; P = .04). Females had significantly poorer preoperative ODI (females, 49.5; males, 41.5; P < .001) and SF-36 PCS (females, 31.9; males, 35.6; P < .01) and MCS (females, 44.9; males, 49.2; P < .01) scores. At 2-year and 5-year follow-up, there were no significant differences in ODI, SF-36, and pain scores between sexes. Both groups reported similar proportions that returned to work and returned to function. There were no differences in proportion of patients who were satisfied or had their expectations fulfilled. CONCLUSIONS: Women who undergo MIS TLIF have poorer preoperative function and quality of life than men. However, women demonstrated greater improvement after surgery, attaining similar clinical outcomes at 5-year follow-up. LEVEL OF EVIDENCE: 3.

What Are the Patient-reported Outcomes, Complications, and Radiographic Results of Lumbar Fusion for Degenerative Spondylolisthesis in Patients Younger Than 50 Years?

BACKGROUND: The number of young patients with degenerative lumbar spondylosis is expected to increase, and with it, the number of younger patients seeking surgical treatment is likely to rise. The goals of young patients with degenerative spondylolisthesis may differ from those of older patients, but little is known about the levels of pain and function, complication rates, or radiographic union that young patients achieve after interbody fusion. QUESTIONS/PURPOSES: (1) How likely were patients younger than 50 years to achieve a minimal clinically important difference (MCID) in improvement on any of several validated patient-reported outcomes scores after transforaminal lumbar interbody fusion for degenerative spondylolisthesis at a minimum of 2 years after surgery? (2) What proportion developed complications or underwent reoperations? (3) What proportion achieved radiographic fusion or developed adjacent-segment degeneration? METHODS: Longitudinally maintained institutional registry data of patients undergoing primary, single-level, transforaminal lumbar interbody fusion for degenerative spondylolisthesis at a single institution from 2006 to 2013 were studied in this retrospective case series. Of the 96 patients who met inclusion criteria, 14% (13 of 96) were missing follow-up data, leaving 83 patients younger than 50 years with complete clinical and radiological data at a minimum of 2 years (97%, 93 of 96 had sufficient data to assess complications and radiographic fusion). The mean age of the cohort was 44 ± 7 years. Radiological parameters for each patient with spondylolisthesis were recorded. Clinical outcomes such as the numeric rating scale for back pain and leg pain, Oswestry Disability Index (ODI) and SF-36 were assessed preoperatively and postoperatively at 1, 3, 6 months and 2 years. The proportion of patients who had an improvement greater than the MCID of each outcome instrument was then calculated. The occurrence of any medical, surgical or wound complications, and reoperations for any reason were recorded. Radiographic fusion using Bridwell grading and adjacent-segment degeneration were assessed by an independent observer not involved in clinical care. The mean follow-up was 5 ± 3 years. RESULTS: The proportions of patients younger than 50 years who achieved the MCID for the various patient-reported outcomes were 82% (68 of 83) for leg pain, 75% (62 of 83) for back pain, 87% (72 of 83) for ODI and 71% (59 of 83) for SF-36 physical component summary at 2 years. Two perioperative complications occurred, and two reoperations were performed for implant-related complications. A total of 85% (79 of 93) of young patients achieved stable fusion, 8% (seven of 93) had radiologic adjacent-segment degeneration, and one patient underwent a revision procedure. CONCLUSIONS: Young patients with lumbar degenerative spondylolisthesis commonly, but do not always, experience clinically meaningful gains in pain relief, function, and quality of life after transforaminal lumbar interbody fusion. A low risk of complications, reoperations, nonunion and adjacent-segment degeneration were also noted in this population. LEVEL OF EVIDENCE: Level III, therapeutic study.

Determination of the patient acceptable symptom state for the Japanese Orthopaedic Association Score in patients undergoing anterior cervical discectomy and fusion for cervical spondylotic myelopathy.

BACKGROUND CONTEXT: The patient acceptable symptom state (PASS) has gained attention as a valuable interpretation tool in spine research. While the PASS for the Japanese Orthopaedic Association (JOA) score has been recently proposed, previous analyses demonstrated a weak discriminative ability for the suggested threshold. PURPOSE: To define the PASS for the JOA score in patients undergoing anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy (CSM). STUDY DESIGN: Retrospective review of prospectively collected registry data. PATIENT SAMPLE: 378 patients who underwent ACDF for cervical myelopathy between 2005 and 2014. OUTCOME MEASURES: The main outcome measure was the JOA score. The PASS anchor question was adapted from the NASS questionnaire, "How would you rate the overall results of your treatment?" and the validation question was adapted from same questionnaire, "Has the surgery for your neck condition met your expectation so far?" METHODS: Patients were assessed preoperatively, 6 months and 2 years postoperatively using the JOA. Responses to the anchor question were dichotomized and used as the external criterion in receiver operating characteristics (ROC) analysis to define thresholds on the JOA that corresponded to a PASS at 2 years postoperatively. Sensitivity analyses were carried out for various subgroups (based on age, gender, body mass index, comorbidities), preoperative myelopathy severity, time of follow-up (6 months and 2 years) and an alternate definition of PASS. RESULTS: Of the 378 patients, 312 (83%) completed 2-year follow-up, of which, 78.5% reported their current state as acceptable. The areas under the curve (AUC) for the ROCs were 0.72 to 0.83 for all analyses, indicating a good discriminative ability of the JOA when assessing if a satisfactory state was attained. The PASS threshold was ≥13.25 points at 6 months (AUC 0.74, sensitivity 78%, specificity 59%) and ≥14.25 points at 2 years (AUC 0.76, sensitivity 74%, specificity 66%). Sensitivity analyses revealed that the 14.25-point threshold on the JOA was robust. PASS responders were approximately 6 times more likely to be satisfied (adjusted OR 6.18, 95% CI 2.87-13.30) and 8 times more likely to have their expectation fulfilled (adjusted OR 8.23, 95% CI 3.81-17.77) compared with non-responders. CONCLUSIONS: This study validates the PASS threshold of 14.25 on the JOA in a robust analysis of a large cohort undergoing ACDF. This knowledge will enable clinicians to identify patients who have attained a satisfactory functional status after surgery for CSM and allow researchers to interpret studies utilizing the JOA from a patient-centered perspective.

Defining threshold values on the neck disability index corresponding to a patient acceptable symptom state in patients undergoing elective surgery for degenerative disorders of the cervical spine.

BACKGROUND CONTEXT: The patient acceptable symptom state (PASS) has emerged as a novel tool for interpreting patient-reported outcomes. While the minimal clinically important difference values for various spine outcome instruments have been defined, little is known about the PASS thresholds for these measures. PURPOSE: To define threshold values on the neck disability index (NDI) corresponding to a PASS in patients undergoing surgery for degenerative disorders of the cervical spine. STUDY DESIGN: Retrospective review of prospectively collected registry data. PATIENT SAMPLE: The sample includes 613 patients who underwent anterior cervical discectomy and fusion for degenerative spine conditions between 2005 and 2014. OUTCOME MEASURES: The main outcome measure was the NDI. The PASS anchor question was adapted from the NASS questionnaire, "How would you rate the overall results of your treatment?" and the validation question was adapted from the AAOS cervical spine questionnaire, "Would you have the same treatment again if you had the same condition?" METHODS: Patients were assessed preoperatively, 6 months and 2 years postoperatively using the NDI. Responses to the anchor question were dichotomized and used as the external criterion in receiver operating characteristics analysis to define thresholds on the NDI that corresponded to a PASS at 2 years postoperatively. Sensitivity analyses were carried out for various subgroups (age, gender, BMI, comorbidity status), baseline NDI (tertiles), time of follow-up (6 months and 2 years) and an alternate definition of PASS. RESULTS: Of the 613 patients, 503 (82%) completed 2-year follow-up, of which, 81% reported their current state as acceptable. The areas under the curve (AUC) for the receiver operating characteristics were 0.75 to 0.89 for all analyses, indicating a good ability of the NDI to discriminate between attaining a satisfactory state or not. The PASS threshold was ≤15 points at 6 months (AUC 0.81, sensitivity 73%, specificity 79%) and ≤17 points at 2 years (AUC 0.80, sensitivity 86%, specificity 65%). Sensitivity analyses revealed that the 17-point threshold on the NDI was robust. PASS responders were approximately 12 times more likely to be satisfied (adjusted odds ratio 12.11, 95% confidence intervals 6.96-21.07) and 6 times more willing to undergo surgery again (adjusted odds ratio 6.12, 95% confidence intervals 3.47-10.80) compared to nonresponders. CONCLUSIONS: Patients with a NDI of ≤17 consider their postoperative symptom state to be acceptable. This PASS threshold can be used alongside the minimal clinically important difference when defining treatment success in spine outcomes studies. At the individual level, this threshold provides clinically relevant benchmarks for surgeons when assessing a patient's postoperative recovery.

Predictors of Outcomes After Single-level Anterior Cervical Discectomy and Fusion for Cervical Spondylotic Myelopathy: A Multivariate Analysis.

STUDY DESIGN: This was a retrospective study that was carried out using prospectively collected registry data. OBJECTIVE: The objective of this study was to identify preoperative predictors of outcomes after anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy. SUMMARY OF BACKGROUND DATA: Proper patient selection is paramount to achieving good surgical results. Identifying predictors of outcomes may aid surgical decision-making and facilitate counseling of patients to manage expectations. METHODS: Prospectively collected registry data of 104 patients who underwent single-level ACDF for cervical spondylotic myelopathy were reviewed. Outcomes assessed at 2 years were the presence of residual neck pain/arm pain (AP), and attainment of a minimal clinically important difference (MCID) for Neck Disability Index (NDI), Japanese Orthopaedic Association (JOA) score, and Physical Component Score (PCS) of SF-36, as well as patient satisfaction, fulfilment of expectations, willingness to undergo same surgery again, return to work (RTW), and return to function (RTF). Receiver operating characteristic curves and multivariate stepwise logistical regression were performed to identify independent predictors of each outcome using 22 covariates including demographics, comorbidities, and preoperative disease state. RESULTS: Lower preoperative NDI was predictive of the absence of residual neck pain/AP at 2 years. Higher preoperative JOA score was predictive of MCID attainment for PCS, satisfaction, expectation fulfilment, willingness to undergo the same surgery for same condition, and RTF. Poorer preoperative scores of NDI, JOA, and PCS were predictors of attaining MCID of the respective scores. Older patients were less likely to attain MCID for JOA. Higher preoperative AP was a risk factor for unsuccessful RTW. CONCLUSIONS: In general, the preoperative JOA score was the best predictor of outcomes after ACDF. A preoperative JOA cutoff value of 9.25-10.25 predicted satisfaction, expectation fulfilment, willingness to undergo same surgery, and RTF with at least 70% sensitivity and 50% specificity. These findings may aid surgeons in identifying patients at risk of a poor outcome and guide preoperative counseling to establish realistic expectations of the surgical outcome. LEVEL OF EVIDENCE: Level III-Non-randomized controlled cohort/follow-up study.

Elderly Patients Undergoing Minimally Invasive Transforaminal Lumbar Interbody Fusion May Have Similar Clinical Outcomes, Perioperative Complications, and Fusion Rates As Their Younger Counterparts.

BACKGROUND: Although several studies have suggested that minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) may be especially beneficial in the elderly population due to lower operative morbidity and faster postoperative recovery, there are limited studies investigating the functional outcomes, quality of life, and satisfaction in elderly patients after MIS-TLIF. Furthermore, existing studies had substantial clinical, diagnostic, and surgical heterogeneity. QUESTIONS/PURPOSES: We asked if elderly patients could experience comparable (1) patient-reported pain, disability and quality of life, (2) perioperative complications, and (3) radiological fusion rates as their younger counterparts after MIS-TLIF. METHODS: Prospectively collected registry data of patients undergoing primary, single-level, MIS-TLIF for degenerative spondylolisthesis between 2012 and 2014 were reviewed. We included 168 patients, 39 of whom were at least 70 years old. Of the 129 patients younger than 70 years old, propensity-score matching was used to select 39 younger controls with adjustment for sex, BMI, American Society of Anesthesiologists score, and baseline clinical outcomes. Perioperative complications and radiologic data were compared. RESULTS: There was no difference in back pain (mean difference -0.3 [95% confidence interval -1.0 to 0.5]; p = 0.52); leg pain (mean difference -0.1 [95% CI to 0.6-0.5]; p = 0.85); Oswestry Disability Index (mean difference -2.9 [95% CI -8.0 to 2.2]; p = 0.26); and SF-36 physical (mean difference 3.0 [95% CI -0.7 to 6.8]; p = 0.107); and mental component summary (mean difference 1.9 [95% CI -4.5 to 8.2]; p = 0.56); up to 2 years postoperatively; 85% of younger patients and 85% of elderly patients were satisfied (p > 0.99) while 87% and 80%, respectively, had fulfilled expectations (p = 0.36). Four perioperative adverse events occurred in each group. There was also no difference in the rate of fusion (87% in younger patients and 90% in elderly patients; p = 0.135). CONCLUSIONS: When clinical and surgical heterogeneity were minimized, elderly patients undergoing minimally invasive transforaminal lumbar interbody fusion not only had comparable rates of perioperative complications but also experienced similar improvements in pain, function, and quality of life. A high rate of satisfaction was achieved. LEVEL OF EVIDENCE: Level II, prognostic study.

Severity of Preoperative Myelopathy Symptoms Affects Patient-reported Outcomes, Satisfaction, and Return to Work After Anterior Cervical Discectomy and Fusion for Degenerative Cervical Myelopathy.

STUDY DESIGN: Retrospective review of prospectively-collected registry data. OBJECTIVE: To compare the patient-reported outcomes, satisfaction, and return to work among a large cohort of patients stratified by preoperative myelopathy severity undergoing Anterior Cervical Discectomy and Fusion (ACDF) for Degenerative Cervical Myelopathy. SUMMARY OF BACKGROUND DATA: Recent clinical practice guidelines noted a lack of studies stratifying their sample based on preoperative disease severity. The benefits of early surgical intervention for patients with mild myelopathy remain uncertain. METHODS: A prospectively-maintained registry was retrospectively reviewed for all patients who underwent primary ACDF for Degenerative Cervical Myelopathy. Patients were stratified based on severity of preoperative myelopathy symptoms according to the Japanese Orthopaedic Association (JOA) scale: mild (>13), moderate (9-13), or severe (<9). Patients were prospectively followed for at least 2 years. RESULTS: In total, 219 patients were included: 74 mild, 94 moderate, and 51 severe cases. The mild group had significantly better Neurogenic Symptoms (NS), Neck Disability Index (NDI), SF-36 Physical (PCS), and Mental Component Summary at baseline (P < 0.05). Neck and arm pain scores were similar at all time points. At 2 years, the severe group still had significantly worse patient-reported outcomes and lower rates of satisfaction, expectation fulfilment and return to work. However, they had significantly greater improvement in JOA, Neurogenic Symptoms, NDI, PCS, and Mental Component Summary, and a larger proportion attained minimal clinically important difference (MCID) for NDI and PCS. All three groups had similar proportions attaining MCID for JOA. CONCLUSION: Patients with severe myelopathy experienced a greater improvement after ACDF. Although fewer patients attained MCID, early surgical intervention for patients with mild myelopathy should also be considered, as this may allow patients to maintain their higher functional status. They also had high rates of postoperative satisfaction and return to work. The clinical trajectory outlined in this study may provide valuable prognostic information for patients. LEVEL OF EVIDENCE: 3.

Patients With Poor Baseline Mental Health May Experience Significant Improvements in Pain and Disability After Minimally Invasive Transforaminal Lumbar Interbody Fusion: A 5-Year Follow-up Study.

STUDY DESIGN: A retrospective study using prospectively collected registry data. OBJECTIVE: Examine the influence of preoperative mental health on outcomes after Minimally Invasive Transforaminal Lumbar Interbody Fusion (MIS-TLIF). SUMMARY OF BACKGROUND DATA: Prior studies investigating the relationship between mental health and outcomes after lumbar spine surgery included small cohorts with short follow-up and heterogenous fusion techniques. The effect of MIS-TLIF on mental health also remains unclear. METHODS: Prospectively collected registry data of 226 patients who underwent single-level MIS-TLIF at a single institution were reviewed. Patients had completed 5-year follow-up data and were assigned into propensity score-matched groups: poor baseline mental health, that is, low Mental Component Summary (MCS) (<50, n=113) and normal baseline mental health, that is, high MCS (≥50, n=113). Outcomes assessed were visual analog scale for back pain (BP), leg pain (LP), Oswestry Disability Index (ODI), Short-Form 36, North American Spine Society-Neurogenic Symptoms (NS), return to work, return to function, satisfaction, and expectation fulfillment. Length of operation and length of stay were recorded. RESULTS: Preoperative MCS was 40.6±8.2 and 58.5±5.4 in the low and high MCS groups, respectively, after propensity score matching (P<0.001). At 5 years, the high MCS group had significantly lower LP (P=0.020) and NS (P=0.009). Despite a significantly poorer baseline (44.3 vs. 38.7, P=0.007) and 6-month ODI (20.3 vs. 15.7, P=0.018) in the low MCS group, both groups achieved a comparable ODI at 5 years (P=0.084). There was no significant difference in proportion that achieved minimal clinically important difference for ODI, PCS, BP, and LP (P>0.05). Both groups reported similar proportions that return to work. However, the low MCS group had a smaller proportion of patients that return to function at 5 years (P=0.025). CONCLUSIONS: Although patients with poorer baseline mental health had greater pain and worse NS preoperatively and up to 5 years postoperatively, a similar proportion experienced a clinically significant improvement in all outcomes. LEVEL OF EVIDENCE: Level III-nonrandomized cohort study.

The Influence of Body Mass Index on Functional Outcomes, Satisfaction, and Return to Work After Single-level Minimally-invasive Transforaminal Lumbar Interbody Fusion: A Five-year Follow-up Study.

STUDY DESIGN: Retrospective study using prospectively collected registry data. OBJECTIVES: To evaluate the effect of obesity on patient-reported outcome measures of pain, disability, quality of life, satisfaction, and return to work after single-level minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). SUMMARY OF BACKGROUND DATA: MIS-TLIF is an appealing alternative for obese patients with potentially lower complication risk. However, there is limited data investigating the influence of obesity on outcomes 5 years after MIS-TLIF. METHODS: Prospectively collected registry data of 296 patients who underwent single-level MIS-TLIF at a single institution were reviewed. Patients had complete 2- and 5-year follow-up data. Patients were stratified into control (<25.0 kg/m), overweight (25.0-29.9 kg/m), and obese (≥30.0 kg/m) groups. Outcomes assessed were visual analogue scale for back pain, leg pain, Oswestry Disability Index, Short-form 36, North American Spine Society score for neurogenic symptoms, return to work (RTW), return to function (RTF), satisfaction, and expectation fulfilment. Length of operation, length of stay, and comorbidities were recorded. RESULTS: Among the patients, 156 (52.7%) had normal weight, 108 (36.5%) were overweight, and 32 (10.8%) were obese. There was no difference in length of operation or hospitalization (P > 0.05). All three groups had comparable preoperative scores at baseline (P > 0.05). At 5 years, the control group had significantly higher PCS compared with the overweight (P = 0.043) and obese groups (P = 0.007), although the change in scores was similar (P > 0.05). The rate of MCID attainment, RTW, RTF, expectation fulfilment, and satisfaction was comparable. CONCLUSION: Nonobese patients had better physical well-being in the mid-term, although obese patients experienced a comparable improvement in clinical scores. Obesity had no impact on patients' ability to RTW or RTF. Equivalent proportions of patients were satisfied and had their expectations fulfilled up to 5 years after MIS-TLIF. LEVEL OF EVIDENCE: 3.

Time Taken to Return to Work Does Not Influence Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion: A 5-Year Follow-Up Study.

STUDY DESIGN: Retrospective cohort study using prospectively collected registry data. OBJECTIVE: To determine factors which influence return-to-work (RTW) in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and to determine if early RTW affects functional outcomes. SUMMARY OF BACKGROUND DATA: MIS-TLIF has been associated with accelerated return to work. RTW in non-WC working-age adults after MIS-TLIF is not well understood. METHODS: Prospectively collected registry data of 907 patients who underwent MIS-TLIF at a single institution from 2004 to 2013 were reviewed. One hundred ten working adults who underwent single-level MIS-TLIF with complete preoperative and 5-year postoperative follow-up data were included. Patients were assigned into Early RTW (≤60 d, n = 40) and Late RTW (>60 d, n = 70). All patients were assessed pre- and postoperatively at 2 and 5 years. Length of operation, length of stay, and comorbidities were also recorded. RESULTS: The Early RTW group had significantly lower Oswestry Disability Index (ODI), North American Spine Society score for neurogenic symptoms (NASS NS), numerical pain rating scale (NPRS) back and leg pain scores than the Late RTW group (<0.01) There were no significant differences in age, body mass index (BMI) and prevalence of medical comorbidities (P > 0.05). In addition, there were no differences in terms of duration of surgery or length of hospitalization. There were no significant differences in ODI, NASS NS, Short-form 36 physical and mental component scores (SF-36 PCS/MCS), NPRS, satisfaction/expectation fulfilment between the Early and Late RTW groups at 2-year and 5-year follow-up. Both groups reported similar proportions that RTW without limitations and return-to-function (RTF) at 2-years and 5-years. CONCLUSION: Patients who RTW late have significantly poorer preoperative SF-36 physical component scores and higher ODI, NASS NS, NPRS back/leg pain scores. Surgeons should be cognizant that working adults with poorer preoperative function will tend to return to work later, but should reassure them that they will likely achieve similar clinical outcomes, satisfaction and expectation fulfilment when compared with patients who returned to work early. LEVEL OF EVIDENCE: 3.

Poor Baseline Mental Health Does Not Influence Improvement in Patient-reported Outcomes, Satisfaction, and Return to Work Two Years After Single-level Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective study using prospectively collected registry data. OBJECTIVE: The authors examine the influence of preoperative mental health on outcomes after anterior cervical discectomy and fusion (ACDF) and determine the impact of ACDF on postoperative mental health. SUMMARY OF BACKGROUND DATA: While studies have reported a negative correlation between preoperative mental health and outcomes following lumbar spine surgery, the influence on outcomes following cervical spine surgery remains relatively understudied. METHODS: Prospectively collected registry data of 104 patients who underwent single-level ACDF for cervical spondylotic myelopathy were reviewed. Patients were dichotomized into top and bottom halves based on preoperative SF-36 MCS (Mental Component Summary) using a cutoff of 48. Outcomes assessed were visual analogue scale for neck pain, arm pain, AAOS Neck Pain and Disability, Neurogenic Symptoms, Neck Disability Index, Short-Form 36, Japanese Orthopaedic Association myelopathy score, return to work, return to function, satisfaction and expectation fulfilment up to 2 years postoperatively. RESULTS: The preoperative MCS was 37.5 ±â€Š8.1 and 57.4 ±â€Š6.3 in the Low and High MCS groups respectively (P < 0.001). The Low MCS group had poorer preoperative scores (P < 0.05). There was no significant difference in length of stay or comorbidities (P > 0.05). The High MCS group had less neck pain (P = 0.002) and showed a trend towards lower Neck Disability Index (P = 0.062) at 2 years. The Low MCS group demonstrated greater improvement in Japanese Orthopaedic Association (P = 0.007) and similar improvement in other scores (P > 0.05). There was no significant difference in proportion that achieved minimal clinically important difference for each score (P > 0.05). Both groups had similar rates of return to work, return to function, expectation fulfilment, and satisfaction (P > 0.05). Lower preoperative MCS was predictive of greater improvement in MCS (r = -0.477, P < 0.001). CONCLUSION: Despite relatively greater pain and disability at 2 years, patients with poor baseline mental health experienced similar improvement in clinical outcomes, return to work, and satisfaction rates. LEVEL OF EVIDENCE: 3.

Poorer Fusion Outcomes in Diabetic Cervical Spondylotic Myelopathy Patients Undergoing Single-level Anterior Cervical Discectomy and Fusion Does Not Compromise Functional Outcomes and Quality of Life.

STUDY DESIGN: Retrospective matched pair cohort study using prospectively collected registry data. OBJECTIVES: The aim of this study was to determine whether patients with DM have poorer patient-reported outcomes and poorer fusion rates after undergoing a single-level anterior cervical discectomy and fusion (ACDF) for cervical myelopathy. SUMMARY OF BACKGROUND DATA: ACDF remains the most common procedure in the treatment of cervical spondylotic myelopathy (CSM); however, there is a paucity of literature with regards to patient-reported outcome measures (PROMs), health-related quality-of-life (HRQOL) scores, and fusion rates post-ACDF in diabetic patients with CSM. METHODS: From 2002 to 2012, 29 diabetic patients were matched with 29 nondiabetic controls. Patient demographics, perioperative data, and validated spine-specific scores including the Numerical Pain Rating Scale on Neck Pain and Upper Limb Pain, American Academy of Orthopaedic Surgeons (AAOS) neck pain and disability scores, AAOS Neurogenic Symptoms Score, Neck Disability Index, Japanese Orthopaedic Association Cervical Myelopathy Score, and Short Form 36 Physical/Mental Component Summaries were recorded. Fusion rates based on Bridwell grading were assessed at 2 years. RESULTS: After matching, there were no significant preoperative differences in patient demographics, clinical outcomes, PROMs or HRQoL measures between the DM and control group (P > 0.05). There was no difference in either length of hospital stay (P = 0.92) or length of surgery (P = 0.92) between the two groups. At 2 years postoperatively, there were no significant differences between validated spine-specific scores, PROMs, HRQoL scores, satisfaction rates, or fulfilment of expectations between the two groups. Significant poorer Bridwell fusion grades were noted in the DM group at 2 years postoperatively (P < 0.05). Subgroup analysis within the DM group demonstrated that glycated hemoglobin levels had no impact on functional outcomes, fulfilment of expectations, or patient satisfaction at 2 years (P > 0.05). CONCLUSION: Despite poorer fusion outcomes following single-level ACDF for symptomatic CSM, there was no significant difference in validated spine outcome scores, PROMs, HRQoL measures, or satisfaction levels when compared to nondiabetic controls at short-term follow-up. LEVEL OF EVIDENCE: 3.

Single-Level Minimally Invasive Transforaminal Lumbar Interbody Fusion Provides Sustained Improvements in Clinical and Radiological Outcomes up to 5 Years Postoperatively in Patients with Neurogenic Symptoms Secondary to Spondylolisthesis.

STUDY DESIGN: Retrospective review of prospective registry data. PURPOSE: To determine 5-year clinical and radiological outcomes of single-level instrumented minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in patients with neurogenic symptoms secondary to spondylolisthesis. OVERVIEW OF LITERATURE: MIS-TLIF and open approaches have been shown to yield comparable outcomes. This is the first study to assess MIS-TLIF outcomes using the minimal clinically important difference (MCID) criterion. METHODS: The outcomes of 56 patients treated by a single surgeon, including the Oswestry disability index (ODI), neurogenic symptom score, short-form 36 questionnaire (SF-36), and visual analog scale (VAS) scores for back pain (BP), and leg pain (LP), were collected prospectively for up to 5 years postoperatively. Radiological outcomes included adjacent segment degeneration, fusion, cage subsidence, and screw loosening rates. RESULTS: Our patients were predominantly female (71.4%) and had a mean age of 53.7±11.3 years and mean body mass index of 25.7±3.7 kg/m2. The mean operative time, blood loss, time to ambulation, and hospitalization were 167±49 minutes, 126±107 mL, 1.2±0.4 days, and 2.8±1.1 days, respectively. The mean fluoroscopic time was 58.4±33 seconds, and the mean postoperative intravenous morphine dose was 8±2 mg. Regarding outcomes, postoperative scores improved relative to preoperative scores, and this was sustained across various time points for up to 5 years (p<0.001). Improvements in ODI, SF-36, VAS-BP, and VAS-LP all met the MCID criterion. Notably, 5.4% of our patients developed clinically significant adjacent segment disease during follow-up, and 7 minor complications were reported. CONCLUSIONS: Single-level instrumented MIS-TLIF is suitable for patients with neurogenic symptoms secondary to lumbar spondylolisthesis and is associated with an acceptable complication rate. Both clinical and radiological outcomes were sustained up to 5 years postoperatively, with many patients achieving an MCID.