Glassman, Steven D.

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 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 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.

OBJECTIVE Reduction of Meyerding grade is often performed during fusion for spondylolisthesis. Although radiographic appearance may improve, correlation with patient-reported outcomes (PROs) is rarely reported. In this study, the authors’ aim was to assess the impact of spondylolisthesis reduction on 24-month PRO measures after decompression and fusion surgery for Meyerding grade I degenerative lumbar spondylolisthesis. METHODS The Quality Outcomes Database (QOD) was queried for patients undergoing posterior lumbar fusion for spondylolisthesis with a minimum 24-month follow-up, and quantitative correlation between Meyerding slippage reduction and PROs was performed. Baseline and 24-month PROs, including the Oswestry Disability Index (ODI), EQ-5D, Numeric Rating Scale (NRS)–back pain (NRS-BP), NRS-leg pain (NRS-LP), and satisfaction (North American Spine Society patient satisfaction questionnaire) scores were noted. Multivariable regression models were fitted for 24-month PROs and complications after adjusting for an array of preoperative and surgical variables. Data were analyzed for magnitude of slippage reduction and correlated with PROs. Patients were divided into two groups: < 3 mm reduction and ≥ 3 mm reduction. RESULTS Of 608 patients from 12 participating sites, 206 patients with complete data were identified in the QOD and included in this study. Baseline patient demographics, comorbidities, and clinical characteristics were similarly distributed between the cohorts except for depression, listhesis magnitude, and the proportion with dynamic listhesis (which were accounted for in the multivariable analysis). One hundred four (50.5%) patients underwent lumbar decompression and fusion with slippage reduction ≥ 3 mm (mean 5.19, range 3 to 11), and 102 (49.5%) patients underwent lumbar decompression and fusion with slippage reduction < 3 mm (mean 0.41, range 2 to −2). Patients in both groups (slippage reduction ≥ 3 mm, and slippage reduction < 3 mm) reported significant improvement in all primary patient reported outcomes (all p < 0.001). There was no significant difference with regard to the PROs between patients with or without intraoperative reduction of listhesis on univariate and multivariable analyses (ODI, EQ-5D, NRS-BP, NRS-LP, or satisfaction). There was no significant difference in complications between cohorts. CONCLUSIONS Significant improvement was found in terms of all PROs in patients undergoing decompression and fusion for lumbar spondylolisthesis. There was no correlation with clinical outcomes and magnitude of Meyerding slippage reduction.

Abstract BACKGROUND Trials of lumbar spondylolisthesis are difficult to compare because of the heterogeneity in the populations studied. OBJECTIVE To define patterns of clinical presentation. METHODS This is a study of the prospective Quality Outcomes Database spondylolisthesis registry, including patients who underwent single-segment surgery for grade 1 degenerative lumbar spondylolisthesis. Twenty-four-month patient-reported outcomes (PROs) were collected. A k-means clustering analysis—an unsupervised machine learning algorithm—was used to identify clinical presentation phenotypes. RESULTS Overall, 608 patients were identified, of which 507 (83.4%) had 24-mo follow-up. Clustering revealed 2 distinct cohorts. Cluster 1 (high disease burden) was younger, had higher body mass index (BMI) and American Society of Anesthesiologist (ASA) grades, and globally worse baseline PROs. Cluster 2 (intermediate disease burden) was older and had lower BMI and ASA grades, and intermediate baseline PROs. Baseline radiographic parameters were similar ( P > .05). Both clusters improved clinically ( P < .001 all 24-mo PROs). In multivariable adjusted analyses, mean 24-mo Oswestry Disability Index (ODI), Numeric Rating Scale Back Pain (NRS-BP), Numeric Rating Scale Leg Pain, and EuroQol-5D (EQ-5D) were markedly worse for the high-disease-burden cluster (adjusted- P < .001). However, the high-disease-burden cluster demonstrated greater 24-mo improvements for ODI, NRS-BP, and EQ-5D (adjusted- P < .05) and a higher proportion reaching ODI minimal clinically important difference (MCID) (adjusted- P = .001). High-disease-burden cluster had lower satisfaction (adjusted- P = .02). CONCLUSION We define 2 distinct phenotypes—those with high vs intermediate disease burden—operated for lumbar spondylolisthesis. Those with high disease burden were less satisfied, had a lower quality of life, and more disability, more back pain, and more leg pain than those with intermediate disease burden, but had greater magnitudes of improvement in disability, back pain, quality of life, and more often reached ODI MCID.

OBJECTIVE The ideal surgical management of grade I lumbar spondylolisthesis has not been determined despite extensive prior investigations. In this cohort study, the authors used data from the large, multicenter, prospectively collected Quality Outcomes Database to bridge the gap between the findings in previous randomized trials and those in a more heterogeneous population treated in a typical practice. The objective was to assess the difference in patient-reported outcomes among patients undergoing decompression alone or decompression plus fusion. METHODS The primary outcome measure was change in 24-month Oswestry Disability Index (ODI) scores. The minimal clinically important difference (MCID) in ODI score change and 30% change in ODI score at 24 months were also evaluated. After adjusting for patient-specific and clinical factors, multivariable linear and logistic regressions were employed to evaluate the impact of fusion on outcomes. To account for differences in age, sex, body mass index, and baseline listhesis, a sensitivity analysis was performed using propensity score analysis to match patients undergoing decompression only with those undergoing decompression and fusion. RESULTS In total, 608 patients who had grade I lumbar spondylolisthesis were identified (85.5% with at least 24 months of follow-up); 140 (23.0%) underwent decompression alone and 468 (77.0%) underwent decompression and fusion. The 24-month change in ODI score was significantly greater in the fusion plus decompression group than in the decompression-only group (−25.8 ± 20.0 vs −15.2 ± 19.8, p < 0.001). Fusion remained independently associated with 24-month ODI score change (B = −7.05, 95% CI −10.70 to −3.39, p ≤ 0.001) in multivariable regression analysis, as well as with achieving the MCID for the ODI score (OR 1.767, 95% CI 1.058–2.944, p = 0.029) and 30% change in ODI score (OR 2.371, 95% CI 1.286–4.371, p = 0.005). Propensity score analysis resulted in 94 patients in the decompression-only group matched 1 to 1 with 94 patients in the fusion group. The addition of fusion to decompression remained a significant predictor of 24-month change in the ODI score (B = 2.796, 95% CI 2.228–13.275, p = 0.006) and of achieving the 24-month MCID ODI score (OR 2.898, 95% CI 1.214–6.914, p = 0.016) and 24-month 30% change in ODI score (OR 2.300, 95% CI 1.014–5.216, p = 0.046). CONCLUSIONS These results suggest that decompression plus fusion in patients with grade I lumbar spondylolisthesis may be associated with superior outcomes at 24 months compared with decompression alone, both in reduction of disability and in achieving clinically meaningful improvement. Longer-term follow-up is warranted to assess whether this effect is sustained.

OBJECTIVE Surgical treatment for degenerative spondylolisthesis has been proven to be clinically challenging and cost-effective. However, there is a range of thresholds that surgeons utilize for incorporating fusion in addition to decompressive laminectomy in these cases. This study investigates these surgeon- and site-specific factors by using the Quality Outcomes Database (QOD). METHODS The QOD was queried for all cases that had undergone surgery for grade 1 spondylolisthesis from database inception to February 2019. In addition to patient-specific covariates, surgeon-specific covariates included age, sex, race, years in practice (0–10, 11–20, 21–30, > 30 years), and fellowship training. Site-specific variables included hospital location (rural, suburban, urban), teaching versus nonteaching status, and hospital type (government, nonfederal; private, nonprofit; private, investor owned). Multivariable regression and predictor importance analyses were performed to identify predictors of the treatment performed (decompression alone vs decompression and fusion). The model was clustered by site to account for site-specific heterogeneity in treatment selection. RESULTS A total of 12,322 cases were included with 1988 (16.1%) that had undergone decompression alone. On multivariable regression analysis clustered by site, adjusting for patient-level clinical covariates, no surgeon-specific factors were found to be significantly associated with the odds of selecting decompression alone as the surgery performed. However, sites located in suburban areas (OR 2.32, 95% CI 1.09–4.84, p = 0.03) were more likely to perform decompression alone (reference = urban). Sites located in rural areas had higher odds of performing decompression alone than hospitals located in urban areas, although the results were not statistically significant (OR 1.33, 95% CI 0.59–2.61, p = 0.49). Nonteaching status was independently associated with lower odds of performing decompression alone (OR 0.40, 95% CI 0.19–0.97, p = 0.04). Predictor importance analysis revealed that the most important determinants of treatment selection were dominant symptom (Wald χ2 = 34.7, accounting for 13.6% of total χ2) and concurrent diagnosis of disc herniation (Wald χ2 = 31.7, accounting for 12.4% of total χ2). Hospital teaching status was also found to be relatively important (Wald χ2 = 4.2, accounting for 1.6% of total χ2) but less important than other patient-level predictors. CONCLUSIONS Nonteaching centers were more likely to perform decompressive laminectomy with supplemental fusion for spondylolisthesis. Suburban hospitals were more likely to perform decompression only. Surgeon characteristics were not found to influence treatment selection after adjustment for clinical covariates. Further large database registry experience from surgeons at high-volume academic centers at which surgically and medically complex patients are treated may provide additional insight into factors associated with treatment preference for degenerative spondylolisthesis.

Study Design. Retrospective analysis of a prospective registry. Objective. We utilized the Quality Outcomes Database (QOD) registry to investigate the “July Effect” at QOD spondylolisthesis module sites with residency trainees. Summary of Background Data. There is a paucity of investigation on the long-term outcomes following surgeries involving new trainees utilizing high-quality, prospectively collected data. Methods. This was an analysis of 608 patients who underwent single-segment surgery for grade 1 degenerative lumbar spondylolisthesis at 12 high-enrolling sites. Surgeries were classified as occurring in July or not in July (non-July). Outcomes collected included estimated blood loss, length of stay, operative time, discharge disposition, complications, reoperation and readmission rates, and patient-reported outcomes (Oswestry Disability Index [ODI], Numeric Rating Scale [NRS] Back Pain, NRS Leg Pain, EuroQol-5D [EQ-5D] and the North American Spine Society [NASS] Satisfaction Questionnaire). Propensity score-matched analyses were utilized to compare postoperative outcomes and complication rates between the July and non-July groups. Results. Three hundred seventy-one surgeries occurred at centers with a residency training program with 21 (5.7%) taking place in July. In propensity score-matched analyses, July surgeries were associated with longer operative times ( average treatment effect = 22.4 minutes longer, 95% confidence interval 0.9–449.0, P = 0.041). Otherwise, July surgeries were not associated with significantly different outcomes for the remaining perioperative parameters (estimated blood loss, length of stay, discharge disposition, postoperative complications), overall reoperation rates, 3-month readmission rates, and 24-month ODI, NRS back pain, NRS leg pain, EQ-5D, and NASS satisfaction score (P > 0.05, all comparisons). Conclusion. Although July surgeries were associated with longer operative times, there were no associations with other clinical outcomes compared to non-July surgeries following lumbar spondylolisthesis surgery. These findings may be due to the increased attending supervision and intraoperative education during the beginning of the academic year. There is no evidence that the influx of new trainees in July significantly affects long-term patient-centered outcomes. Level of Evidence: 3