Asher, Anthony L.

Study Design: Prospective observational study, level of evidence 1 for prognostic investigations. Objectives: To evaluate the prevalence of sleep impairment and predictors of improved sleep quality 24 months postoperatively in cervical spondylotic myelopathy (CSM) using the quality outcomes database. Summary of Background Data: Sleep disturbances are a common yet understudied symptom in CSM. Materials and Methods: The quality outcomes database was queried for patients with CSM, and sleep quality was assessed through the neck disability index sleep component at baseline and 24 months postoperatively. Multivariable logistic regressions were performed to identify risk factors of failure to improve sleep impairment and symptoms causing lingering sleep dysfunction 24 months after surgery. Results: Among 1135 patients with CSM, 904 (79.5%) had some degree of sleep dysfunction at baseline. At 24 months postoperatively, 72.8% of the patients with baseline sleep symptoms experienced improvement, with 42.5% reporting complete resolution. Patients who did not improve were more like to be smokers [adjusted odds ratio (aOR): 1.85], have osteoarthritis (aOR: 1.72), report baseline radicular paresthesia (aOR: 1.51), and have neck pain of ≥4/10 on a numeric rating scale. Patients with improved sleep noted higher satisfaction with surgery (88.8% vs 72.9%, aOR: 1.66) independent of improvement in other functional areas. In a multivariable analysis including pain scores and several myelopathy-related symptoms, lingering sleep dysfunction at 24 months was associated with neck pain (aOR: 1.47) and upper (aOR: 1.45) and lower (aOR: 1.52) extremity paresthesias. Conclusion: The majority of patients presenting with CSM have associated sleep disturbances. Most patients experience sustained improvement after surgery, with almost half reporting complete resolution. Smoking, osteoarthritis, radicular paresthesia, and neck pain ≥4/10 numeric rating scale score are baseline risk factors of failure to improve sleep dysfunction. Improvement in sleep symptoms is a major driver of patient-reported satisfaction. Incomplete resolution of sleep impairment is likely due to neck pain and extremity paresthesia.

OBJECTIVE Patient-reported outcomes (PROs) have become the standard means to measure surgical outcomes. Insurers and policy makers are also increasingly utilizing PROs to assess the value of care and measure different aspects of a patient’s condition. For cervical myelopathy, it is currently unclear which outcome measure best reflects patient satisfaction. In this investigation, the authors evaluated patients treated for cervical myelopathy to determine which outcome questionnaires best correlate with patient satisfaction. METHODS The Quality Outcomes Database (QOD), a prospectively collected multi-institutional database, was used to retrospectively analyze patients undergoing surgery for cervical myelopathy. The North American Spine Society (NASS) satisfaction index, Neck Disability Index (NDI), numeric rating scales for neck pain (NP-NRS) and arm pain (AP-NRS), EQ-5D, and modified Japanese Orthopaedic Association (mJOA) scale were evaluated. RESULTS The analysis included 1141 patients diagnosed with myelopathy, of whom 1099 had an NASS satisfaction index recorded at any of the follow-up time points. Concomitant radiculopathy was an indication for surgery in 368 (33.5%) patients, and severe neck pain (NP-NRS ≥ 7) was present in 471 (42.8%) patients. At the 3-month follow-up, NASS patient satisfaction index scores were positively correlated with scores for the NP-NRS (r = 0.30), AP-NRS (r = 0.32), and NDI (r = 0.36) and negatively correlated with EQ-5D (r = −0.38) and mJOA (r = −0.29) scores (all p < 0.001). At the 12-month follow-up, scores for the NASS index were positively correlated with scores for the NP-NRS (r = 0.44), AP-NRS (r = 0.38), and NDI (r = 0.46) and negatively correlated with scores for the EQ-5D (r = −0.40) and mJOA (r = −0.36) (all p < 0.001). At the 24-month follow-up, NASS index scores were positively correlated with NP-NRS (r = 0.49), AP-NRS (r = 0.36), and NDI (r = 0.49) scores and negatively correlated with EQ-5D (r = −0.44) and mJOA (r = −0.38) scores (all p < 0.001). CONCLUSIONS Neck pain was highly prevalent in patients with myelopathy. Notably, improvement in neck pain–associated disability rather than improvement in myelopathy was the most prominent PRO factor for patients. This finding may reflect greater patient concern for active pain symptoms than for neurological symptoms caused by myelopathy. As commercial payers begin to examine novel remuneration strategies for surgical interventions, thoughtful analysis of PRO measurements will have increasing relevance.

OBJECTIVE Return to work (RTW) is an important surgical outcome for patients who are employed, yet a significant number of patients with cervical spondylotic myelopathy (CSM) who are employed undergo cervical spine surgery and fail to RTW. In this study, the authors investigated factors associated with failure to RTW in the CSM population who underwent cervical spine surgery and who were considered to have a good surgical outcome yet failed to RTW. METHODS This study retrospectively analyzed prospectively collected data from the cervical myelopathy module of a national spine registry, the Quality Outcomes Database. The CSM data set of the Quality Outcomes Database was queried for patients who were employed at the time of surgery and planned to RTW postoperatively. Distinct multivariable logistic regression models were fitted with 3-month RTW as an outcome for the overall population to identify risk factors for failure to RTW. Good outcomes were defined as patients who had no adverse events (readmissions or complications), who had achieved 30% improvement in Neck Disability Index score, and who were satisfied (North American Spine Society satisfaction score of 1 or 2) at 3 months postsurgery. RESULTS Of the 409 patients who underwent surgery, 80% (n = 327) did RTW at 3 months after surgery. At 3 months, 56.9% of patients met the criteria for a good surgical outcome, and patients with a good outcome were more likely to RTW (88.1% vs 69.2%, p < 0.01). Of patients with a good outcome, 11.9% failed to RTW at 3 months. Risk factors for failing to RTW despite a good outcome included preoperative short-term disability or leave status (OR 3.03 [95% CI 1.66–7.90], p = 0.02); a higher baseline Neck Disability Index score (OR 1.41 [95% CI 1.09–1.84], p < 0.01); and higher neck pain score at 3 months postoperatively (OR 0.81 [95% CI 0.66–0.99], p = 0.04). CONCLUSIONS Most patients with CSM who undergo spine surgery reenter the workforce within 3 months from surgery, with RTW rates being higher among patients who experience good outcomes. Among patients with good outcomes who were employed, failure to RTW was associated with being on preoperative short-term disability or leave status prior to surgery as well as higher neck pain scores at baseline and at 3 months postoperatively.

OBJECTIVE Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) has been used to treat degenerative lumbar spondylolisthesis and is associated with expedited recovery, reduced operative blood loss, and shorter hospitalizations compared to those with traditional open TLIF. However, the impact of MI-TLIF on long-term patient-reported outcomes (PROs) is less clear. Here, the authors compare the outcomes of MI-TLIF to those of traditional open TLIF for grade I degenerative lumbar spondylolisthesis at 60 months postoperatively. METHODS The authors utilized the prospective Quality Outcomes Database registry and queried for patients with grade I degenerative lumbar spondylolisthesis who had undergone single-segment surgery via an MI or open TLIF method. PROs were compared 60 months postoperatively. The primary outcome was the Oswestry Disability Index (ODI). The secondary outcomes included the numeric rating scale (NRS) for back pain (NRS-BP), NRS for leg pain (NRS-LP), EQ-5D, North American Spine Society (NASS) satisfaction, and cumulative reoperation rate. Multivariable models were constructed to assess the impact of MI-TLIF on PROs, adjusting for variables reaching p < 0.20 on univariable analyses and respective baseline PRO values. RESULTS The study included 297 patients, 72 (24.2%) of whom had undergone MI-TLIF and 225 (75.8%) of whom had undergone open TLIF. The 60-month follow-up rates were similar for the two cohorts (86.1% vs 75.6%, respectively; p = 0.06). Patients did not differ significantly at baseline for ODI, NRS-BP, NRS-LP, or EQ-5D (p > 0.05 for all). Perioperatively, MI-TLIF was associated with less blood loss (108.8 ± 85.6 vs 299.6 ± 242.2 ml, p < 0.001) and longer operations (228.2 ± 111.5 vs 189.6 ± 66.5 minutes, p < 0.001) but had similar lengths of hospitalizations (MI-TLIF 2.9 ± 1.8 vs open TLIF 3.3 ± 1.6 days, p = 0.08). Discharge disposition to home or home health was similar (MI-TLIF 93.1% vs open TLIF 91.1%, p = 0.60). Both cohorts improved significantly from baseline for the 60-month ODI, NRS-BP, NRS-LP, and EQ-5D (p < 0.001 for all comparisons). In adjusted analyses, MI-TLIF, compared to open TLIF, was associated with similar 60-month ODI, ODI change, odds of reaching ODI minimum clinically important difference, NRS-BP, NRS-BP change, NRS-LP, NRS-LP change, EQ-5D, EQ-5D change, and NASS satisfaction (adjusted p > 0.05 for all). The 60-month reoperation rates did not differ significantly (MI-TLIF 5.6% vs open TLIF 11.6%, p = 0.14). CONCLUSIONS For symptomatic, single-level grade I degenerative lumbar spondylolisthesis, MI-TLIF was associated with decreased blood loss perioperatively, but there was no difference in 60-month outcomes for disability, back pain, leg pain, quality of life, or satisfaction between MI and open TLIF. There was no difference in cumulative reoperation rates between the two procedures. These results suggest that in appropriately selected patients, either procedure may be employed depending on patient and surgeon preferences.

OBJECTIVE Patients who undergo surgery for cervical spondylotic myelopathy (CSM) will occasionally develop postoperative neck pain that was not present preoperatively, yet the incidence of this phenomenon is unclear. The authors aimed to elucidate patient and surgical factors associated with new-onset sustained pain after CSM surgery. METHODS The authors reviewed data from the Quality Outcomes Database (QOD) CSM module. The presence of neck pain was defined using the neck pain numeric rating scale (NRS). Patients with no neck pain at baseline (neck NRS score ≤ 1) were then stratified based on the presence of new postoperative pain development (neck NRS score ≥ 2) at 12 and 24 months postoperatively. RESULTS Of 1141 patients in the CSM QOD, 224 (19.6%) reported no neck pain at baseline. Among 170 patients with no baseline neck pain and available 12-month follow-up, 46 (27.1%) reported new postoperative pain. Among 184 patients with no baseline neck pain and available 24-month follow-up, 53 (28.8%) reported new postoperative pain. The mean differences in neck NRS scores were 4.3 for those with new postoperative pain compared with those without at 12 months (4.4 ± 2.2 vs 0.1 ± 0.3, p < 0.001) and 3.9 at 24 months (4.1 ± 2.4 vs 0.2 ± 0.4, p < 0.001). The majority of patients reporting new-onset neck pain reported being satisfied with surgery, but their satisfaction was significantly lower compared with patients without pain at the 12-month (66.7% vs 94.3%, p < 0.001) and 24-month (65.4% vs 90.8%, p < 0.001) follow-ups. The baseline Neck Disability Index (NDI) was an independent predictor of new postoperative neck pain at both the 12-month and 24-month time points (adjusted OR [aOR] 1.04, 95% CI 1.01–1.06; p = 0.002; and aOR 1.03, 95% CI 1.01–1.05; p = 0.026, respectively). The total number of levels treated was associated with new-onset neck pain at 12 months (aOR 1.34, 95% CI 1.09–1.64; p = 0.005), and duration of symptoms more than 3 months was a predictor of 24-month neck pain (aOR 3.22, 95% CI 1.01–10.22; p = 0.048). CONCLUSIONS Increased NDI at baseline, number of levels treated surgically, and duration of symptoms longer than 3 months preoperatively correlate positively with the risk of new-onset neck pain following CSM surgery. The majority of patients with new-onset neck pain still report satisfaction from surgery, suggesting that the risk of new-onset neck pain should not hinder indicated operations from being performed.

OBJECTIVE Prior studies have revealed that a body mass index (BMI) ≥ 30 is associated with worse outcomes following surgical intervention in grade 1 lumbar spondylolisthesis. Using a machine learning approach, this study aimed to leverage the prospective Quality Outcomes Database (QOD) to identify a BMI threshold for patients undergoing surgical intervention for grade 1 lumbar spondylolisthesis and thus reliably identify optimal surgical candidates among obese patients. METHODS Patients with grade 1 lumbar spondylolisthesis and preoperative BMI ≥ 30 from the prospectively collected QOD lumbar spondylolisthesis module were included in this study. A 12-month composite outcome was generated by performing principal components analysis and k-means clustering on four validated measures of surgical outcomes in patients with spondylolisthesis. Random forests were generated to determine the most important preoperative patient characteristics in predicting the composite outcome. Recursive partitioning was used to extract a BMI threshold associated with optimal outcomes. RESULTS The average BMI was 35.7, with 282 (46.4%) of the 608 patients from the QOD data set having a BMI ≥ 30. Principal components analysis revealed that the first principal component accounted for 99.2% of the variance in the four outcome measures. Two clusters were identified corresponding to patients with suboptimal outcomes (severe back pain, increased disability, impaired quality of life, and low satisfaction) and to those with optimal outcomes. Recursive partitioning established a BMI threshold of 37.5 after pruning via cross-validation. CONCLUSIONS In this multicenter study, the authors found that a BMI ≤ 37.5 was associated with improved patient outcomes following surgical intervention. These findings may help augment predictive analytics to deliver precision medicine and improve prehabilitation strategies.

BACKGROUND: The modified Japanese Orthopedic Association (mJOA) score is a widely used and validated metric for assessing severity of myelopathy. Its relationship to functional and quality-of-life outcomes after surgery has not been fully described. OBJECTIVE: To quantify the association of the mJOA with the Neck Disability Index (NDI) and EuroQol-5 Dimension (EQ-5D) after surgery for degenerative cervical myelopathy. METHODS: The cervical module of the prospectively enrolled Quality Outcomes Database was queried retrospectively for adult patients who underwent single-stage degenerative cervical myelopathy surgery. The mJOA score, NDI, and EQ-5D were assessed preoperatively and 3 and 12 months postoperatively. Improvement in mJOA was used as the independent variable in univariate and multivariable linear and logistic regression models. RESULTS: Across 14 centers, 1121 patients were identified, mean age 60.6 ± 11.8 years, and 52.5% male. Anterior-only operations were performed in 772 patients (68.9%). By univariate linear regression, improvements in mJOA were associated with improvements in NDI and EQ-5D at 3 and 12 months postoperatively (all P < .0001) and with improvements in the 10 NDI items individually. These findings were similar in multivariable regression incorporating potential confounders. The Pearson correlation coefficients for changes in mJOA with changes in NDI were −0.31 and −0.38 at 3 and 12 months postoperatively. The Pearson correlation coefficients for changes in mJOA with changes in EQ-5D were 0.29 and 0.34 at 3 and 12 months. CONCLUSION: Improvements in mJOA correlated weakly with improvements in NDI and EQ-5D, suggesting that changes in mJOA may not be a suitable proxy for functional and quality-of-life outcomes.

OBJECTIVE The aim of this study was to determine whether multilevel anterior cervical discectomy and fusion (ACDF) or posterior cervical laminectomy and fusion (PCLF) is superior for patients with cervical spondylotic myelopathy (CSM) and high preoperative neck pain. METHODS This was a retrospective study of prospectively collected data using the Quality Outcomes Database (QOD) CSM module. Patients who received a subaxial fusion of 3 or 4 segments and had a visual analog scale (VAS) neck pain score of 7 or greater at baseline were included. The 3-, 12-, and 24-month outcomes were compared for patients undergoing ACDF with those undergoing PCLF. RESULTS Overall, 1141 patients with CSM were included in the database. Of these, 495 (43.4%) presented with severe neck pain (VAS score > 6). After applying inclusion and exclusion criteria, we compared 65 patients (54.6%) undergoing 3- and 4-level ACDF and 54 patients (45.4%) undergoing 3- and 4-level PCLF. Patients undergoing ACDF had worse Neck Disability Index scores at baseline (52.5 ± 15.9 vs 45.9 ± 16.8, p = 0.03) but similar neck pain (p > 0.05). Otherwise, the groups were well matched for the remaining baseline patient-reported outcomes. The rates of 24-month follow-up for ACDF and PCLF were similar (86.2% and 83.3%, respectively). At the 24-month follow-up, both groups demonstrated mean improvements in all outcomes, including neck pain (p < 0.05). In multivariable analyses, there was no significant difference in the degree of neck pain change, rate of neck pain improvement, rate of pain-free achievement, and rate of reaching minimal clinically important difference (MCID) in neck pain between the two groups (adjusted p > 0.05). However, ACDF was associated with a higher 24-month modified Japanese Orthopaedic Association scale (mJOA) score (β = 1.5 [95% CI 0.5–2.6], adjusted p = 0.01), higher EQ-5D score (β = 0.1 [95% CI 0.01–0.2], adjusted p = 0.04), and higher likelihood for return to baseline activities (OR 1.2 [95% CI 1.1–1.4], adjusted p = 0.002). CONCLUSIONS Severe neck pain is prevalent among patients undergoing surgery for CSM, affecting more than 40% of patients. Both ACDF and PCLF achieved comparable postoperative neck pain improvement 3, 12, and 24 months following 3- or 4-segment surgery for patients with CSM and severe neck pain. However, multilevel ACDF was associated with superior functional status, quality of life, and return to baseline activities at 24 months in multivariable adjusted analyses.

Study Design. Retrospective analysis on prospectively collected data. Objective. To determine the effectiveness of elective spine surgery in patients with Parkinson disease (PD). Background Context. PD has become increasingly prevalent in an aging population. While surgical treatment for degenerative spine pathology is often required in this population, previous literature has provided mixed results regarding its effectiveness. Methods. Data from the Quality Outcomes Database (QOD) was queried between April 2013 and January 2019. Three surgical groups were identified: (1) elective lumbar surgery, (2) elective cervical surgery for myelopathy, (3) elective cervical surgery for radiculopathy. Patients without PD were propensity matched against patients with PD in a 5:1 ratio without replacement based on American Society of Anesthesiology grade, arthrodesis, surgical approach, number of operated levels, age, and baseline Oswestry Disability Index, Numerical Rating Scale (NRS) extremity pain, NRS back pain, and EuroQol 5-Dimensions (EQ-5D). The mean difference was calculated for continuous outcomes (Oswestry Disability Index, NRS leg pain, NRS back pain, and EQ-5D at 3 and 12 mo after surgery) and the risk difference was calculated for binary outcomes (patient satisfaction, complications, readmission, reoperation, and mortality). Results. For the lumbar analysis, PD patients had a higher rate of reoperation at 12 months (risk difference=0.057, P=0.015) and lower mean EQ-5D score at 12 months (mean difference=−0.053, P=0.005) when compared with patients without PD. For the cervical myelopathy cohort, PD patients had lower NRS neck pain scores at 3 months (mean difference=−0.829, P=0.005) and lower patient satisfaction at 3 months (risk difference=−0.262, P=0.041) compared with patients without PD. For the cervical radiculopathy cohort, PD patients demonstrated a lower readmission rate at 3 months (risk difference=−0.045, P=0.014) compared with patients without PD. Conclusion. For the matched analysis, in general, patients with and without PD had similar patient-reported outcomes and complication, readmission, and reoperation rates. These results demonstrate that a diagnosis of PD alone should not represent a major contraindication to elective spine surgery.

OBJECTIVE While surgical decompression is an important treatment modality for cervical spondylotic myelopathy (CSM), it remains unclear if the severity of preoperative myelopathy status affects potential benefit from surgical intervention and when maximum postoperative improvement is expected. This investigation sought to determine if retrospective analysis of prospectively collected patient-reported outcomes (PROs) following surgery for CSM differed when stratified by preoperative myelopathy status. Secondary objectives included assessment of the minimal clinically important difference (MCID). METHODS A total of 1151 patients with CSM were prospectively enrolled from the Quality Outcomes Database at 14 US hospitals. Baseline demographics and PROs at baseline and 3 and 12 months were measured. These included the modified Japanese Orthopaedic Association (mJOA) score, Neck Disability Index (NDI), quality-adjusted life-years (QALYs) from the EQ-5D, and visual analog scale from the EQ-5D (EQ-VAS). Patients were stratified by preoperative myelopathy severity using criteria established by the AO Spine study group: mild (mJOA score 15–17), moderate (mJOA score 12–14), or severe (mJOA score < 12). Univariate analysis was used to identify demographic variables that significantly varied between myelopathy groups. Then, multivariate linear regression and linear mixed regression were used to model the effect of severity and time on PROs, respectively. RESULTS For NDI, EQ-VAS, and QALY, patients in all myelopathy cohorts achieved significant, maximal improvement at 3 months without further improvement at 12 months. For mJOA, moderate and severe myelopathy groups demonstrated significant, maximal improvement at 3 months, without further improvement at 12 months. The mild myelopathy group did not demonstrate significant change in mJOA score but did maintain and achieve higher PRO scores overall when compared with more advanced myelopathy cohorts. The MCID threshold was reached in all myelopathy cohorts at 3 months for mJOA, NDI, EQ-VAS, and QALY, with the only exception being mild myelopathy QALY at 3 months. CONCLUSIONS As assessed by statistical regression and MCID analysis, patients with cervical myelopathy experience maximal improvement in their quality of life, neck disability, myelopathy score, and overall health by 3 months after surgical decompression, regardless of their baseline myelopathy severity. An exception was seen for the mJOA score in the mild myelopathy cohort, improvement of which may have been limited by ceiling effect. The data presented here will aid surgeons in patient selection, preoperative counseling, and expected postoperative time courses.