The impact of smoking on patient-reported outcomes following lumbar decompression: an analysis of the Quality Outcomes Database.

OBJECTIVE: Smoking has been shown to negatively impact spinal health, as well as the outcomes of spinal fusion. Published reports show conflicting data regarding whether smoking negatively impacts patient outcomes following lumbar decompression. The objective of this study was to investigate whether smoking affects the outcomes of patients undergoing lumbar decompression for spinal stenosis or herniated disc. METHODS: The Quality Outcomes Database was queried for patients with spinal stenosis or lumbar disc herniation who underwent one- or two-level lumbar decompression without fusion. All patients had preoperative and 12-month outcome measures and were divided into groups of nonsmokers and current smokers. Outcomes were compared between the two groups, as well as the percentage of patients reaching the minimal clinically important difference (MCID) threshold for numeric rating scale (NRS) back and leg pain scores and the Oswestry Disability Index (ODI). RESULTS: Of 17,271 patients, 14,233 were nonsmokers and 3038 were current smokers. Smokers had worse baseline NRS back and leg pain, ODI, and EQ-5D scores and experienced slightly less improvement in all measures following lumbar decompression (p ≤ 0.009), although changes were largely similar, and a high percentage of patients achieved the MCID thresholds for NRS back pain (78% nonsmokers vs 75% smokers), NRS leg pain (79% nonsmokers vs 73% smokers), and ODI (74% nonsmokers vs 68% smokers). Comparison of propensity-matched cohorts did not identify any difference in outcomes in smokers versus nonsmokers. CONCLUSIONS: In patients undergoing lumbar decompression for spinal stenosis or herniated disc, smokers demonstrated slightly less improvement in outcomes compared with nonsmokers, and a high proportion of both groups achieved meaningful improvement with surgery. While smoking cessation should be strongly encouraged in all patients, lumbar decompression procedures for spinal stenosis and herniated disc should not be denied to smokers.

Incidence of revision surgery and patient-reported outcomes within 5 years of the index procedure for grade 1 spondylolisthesis: an analysis from the Quality Outcomes Database spondylolisthesis data.

OBJECTIVE: Some patients treated surgically for grade 1 spondylolisthesis require revision surgery. Outcomes after revision surgery are not well studied. The objective of this study was to determine how revision surgery impacts patient-reported outcomes (PROs) in patients undergoing decompression only or decompression and fusion (D+F) for grade 1 spondylolisthesis within 5 years of the index surgery. METHODS: Patients in the 12 highest Quality Outcomes Database (QOD) enrolling sites with a diagnosis of grade 1 spondylolisthesis were identified and the incidence of revision surgery between the decompression-only and D+F patients were compared. PROs were compared between cohorts requiring revision surgery versus a single index procedure. RESULTS: Of 608 patients enrolled, 409 had complete 5-year data available for this study. Eleven (13.3%) of 83 patients underwent revision in the decompression-only group as well as 32 (9.8%) of 326 in the D+F group. For the entire cohort, patients requiring revision had significantly worse PROs at 5 years: Oswestry Disability Index (ODI) 27.4 versus 19.4, p = 0.008; numeric rating scale for back pain (NRS-BP) 4.1 versus 3.0, p = 0.013; and NRS for leg pain (NRS-LP) 3.4 versus 2.1, p = 0.029. In the decompression-only group, the change in 5-year PROs was not impacted by revision status: ODI 31.9 versus 24.2, p = 0.287; NRS-BP 1.9 versus 2.9, p = 0.325; and NRS-LP 6.2 versus 3.7, p = 0.011. In the D+F group, the change in 5-year PROs was diminished if patients required revision: ODI 19.1 versus 29.1, p = 0.001; NRS-BP 3.0 versus 4.0, p = 0.170; and NRS-LP 2.3 versus 4.6, p = 0.001. CONCLUSIONS: The most common reasons for reoperation within 5 years in the decompression-only group were repeat decompression and instability, whereas in the D+F group the most common reason was adjacent-segment disease. The need for revision resulted in modestly diminished benefit compared with patients with no revisions. These differences were greater in the fusion cohort compared with the decompression-only cohort. The mean PRO improvement still far exceeded minimal clinically important difference thresholds for all measures for patients who underwent a revision surgery.

Cost-effectiveness Improves for Operative vs Nonoperative Treatment of Adult Symptomatic Lumbar Scoliosis at Eight-Year Follow-up.

STUDY DESIGN: Secondary data analysis of the NIH sponsored study on Adult Symptomatic Lumbar Scoliosis (ASLS). OBJECTIVES: The purpose of this study is to perform a cost-effectiveness analysis comparing operative versus non-operative care for ASLS eight years after enrollment. SUMMARY OF BACKGROUND DATA: A prior cost-effectiveness analysis of the current cohort comparing operative to non-operative care at five years after enrollment showed and ICER of $44,033 in the As-Treated analysis and a ICER of $27,480 in the Intent-to-treat analysis. METHODS: Data was collected every three months for the first two years, then every six months for the remainder of the study. Data included use of non-operative modalities, medications and employment status. Costs for index and revision surgeries and non-operative modalities were determined using Medicare Allowable rates. Medication costs were determined using the RedBook and indirect costs were calculated based on reported employment status and income. Quality Adjusted Life Years (QALY) was determined using the SF6D. RESULTS: There were 101 cases in the Operative (Op) and 103 in the Non-operative (Non-Op) group with complete eight year data. Thirty-eight patients (37%) in the Non-Op group had surgery from 3 to 72 months after enrollment. An As-Treated analysis including only cases who never had surgery (N=65) or cases with complete eight-year post-operative data (N=101) showed that operative treatment was favored with an ICER of $20,569 per QALY gained which is within Willingness-to-Pay (WTP) thresholds. An Intent-to-Treat analysis demonstrated greater QALY gains and lower cost in the Op group (ICER = $-13,911). However, Intent-to-Treat analysis is influenced by Non-Op patients who crossed over to operative treatment at variable times during follow-up. CONCLUSION: Operative treatment was more cost-effective than non-operative treatment for ASLS at eight-year follow-up. The ICER continued to improve as compared to the five-year values ($20,569 vs. $44,033).

Does comorbid depression and anxiety portend poor long-term outcomes following surgery for lumbar spondylolisthesis? Five-year analysis of the Quality Outcomes Database.

OBJECTIVE: Depression and anxiety are associated with poor outcomes following spine surgery. However, the influence of these conditions on achieving a minimal clinically important difference (MCID) following lumbar spine surgery, as well as the potential compounding effects of comorbid depression and anxiety, is not well understood. This study explores the impact of comorbid depression and anxiety on long-term clinical outcomes following surgical treatment for degenerative lumbar spondylolisthesis. METHODS: This study was a retrospective analysis of the multicenter, prospectively collected Quality Outcomes Database (QOD). Patients with surgically treated grade 1 lumbar spondylolisthesis from 12 centers were included. Preoperative baseline characteristics and comorbidities were recorded, including self-reported depression and/or anxiety. Pre- and postoperative patient-reported outcomes (PROs) were recorded: the numeric rating scale (NRS) score for back pain (NRS-BP), NRS score for leg pain (NRS-LP), Oswestry Disability Index (ODI), and EQ-5D. Patients were grouped into 3 cohorts: no self-reported depression or anxiety (non-SRD/A), self-reported depression or anxiety (SRD/A), or presence of both comorbidities (SRD+A). Changes in PROs over time, satisfaction rates, and rates of MCID were compared. A multivariable regression analysis was performed to establish independent associations. RESULTS: Of the 608 patients, there were 452 (74.3%) with non-SRD/A, 81 (13.3%) with SRD/A, and 75 (12.3%) with SRD+A. Overall, 91.8% and 80.4% of patients had ≥ 24 and ≥ 60 months of follow-up, respectively. Baseline PROs were universally inferior for the SRD+A cohort. However, at 60-month follow-up, changes in all PROs were greatest for the SRD+A cohort, resulting in nonsignificant differences in absolute NRS-BP, NRS-LP, ODI, and EQ-5D across the 3 groups. MCID was achieved for the SRD+A cohort at similar rates to the non-SRD/A cohort. All groups achieved > 80% satisfaction rates with surgery without significant differences across the cohorts (p = 0.79). On multivariable regression, comorbid depression and anxiety were associated with worse baseline PROs, but they had no impact on 60-month PROs or 60-month achievement of MCIDs. CONCLUSIONS: Despite lower baseline PROs, patients with comorbid depression and anxiety achieved comparable rates of MCID and satisfaction after surgery for lumbar spondylolisthesis to those without either condition. This quality-of-life benefit was durable at 5-year follow-up. These data suggest that patients with self-reported comorbid depression and anxiety should not be excluded from consideration of surgical intervention and often substantially benefit from surgery.

Opioid Sparing Anesthesia for Adult Spinal Deformity Surgery Reduces Postoperative Pain, Length of Stay, Opioid Consumption, and Opioid-Related Complications: A Propensity-Matched Analysis.

STUDY DESIGN: This study was a retrospective propensity-matched study of patients receiving opioid sparing anesthesia (OSA) and those who did not receive an opioid sparing anesthesia regimen. OBJECTIVES: To determine whether patients undergoing spine fusion for deformity fared better with an OSA regimen than those not having an OSA regimen. SUMMARY OF BACKGROUND DATA: There has been a tremendous focus on opioid overuse. Accordingly, OSA regimens are being introduced to reduce narcotic use. However, OSA has not been studied in the adult spine deformity population. METHODS: 43 patients undergoing fusion of at least five levels in the thoracolumbar spine received OSA. They were matched to 43 patients who did receive an OSA regimen. We analyzed a number of metrics including blood loss, anesthesia time, post anesthesia care unit (PACU) pain scores, postoperative pain scores, complications, length of stay, and readmissions. RESULTS: The OSA group had significantly lower pain scores both before transfer to (4.6 vs. 7.6, P=0.000) and after transfer from (4.2 vs. 6.2 P=0.002) the PACU. Opioid use was significantly lower in the OSA group (454 vs. 241 MMEs by POD4, P=0.022). Fewer patients required blood transfusion in the OSA (1 vs. 28, P=0.000) group. Fewer patients in the OSA group had constipation and urinary retention (1 vs. 9, P=0.015). There was no difference in discharge home or to a facility. The lengths of hospital (4.33 vs. 6.19, P=0.009) and ICU (0.12 vs. 0.70 days, P=0.009) stay were significantly shorter in the OSA group. CONCLUSION: OSA regimens have numerous benefits in patients undergoing spinal deformity surgery including less opioid use, fewer postoperative complications, and a reduced length of stay.

Comparison of Complication Rates Between Transforaminal Interbody Fusion and Anteroposterior Fusion for One- or Two-Level Degenerative Lumbar Spine Surgery: A Propensity Score Matched Analysis.

Introduction Although transforaminal interbody fusion (TLIF) and anterior lumbar interbody fusion (ALIF) combined with posterior fusion (AP) have similar fusion rates, it is unclear if choice of approach has an impact on post-operative complications. Research question Is the incidence of residual leg and/or back pain requiring additional treatment after one- or two-level TLIF and AP similar? Material and methods Adult patients who underwent one- or two-level TLIF or AP for degenerative pathology were identified and matched using age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA), insurance status, smoking status, revision and number of levels fused. The incidence of radicular leg and back pain requiring emergency department visit/readmission or same level surgical intervention was compared between the two groups. Results Of the 319 TLIF and 288 AP cases, 119 cases in each cohort were matched. TLIF patients had shorter operative times (203 min vs 258 min, P<0.001) and hospital stays than the AP patients (3.76 days vs 4.98 days, P<0.001). The incidence of residual leg pain (7 vs 5, P=0.769) and back pain (13 vs 15, P=0.841) was similar between the two groups. Except for constipation, which was more common in the AP group, the incidence of complications was similar between the two groups. Conclusions Patients undergoing one- or two-level TLIF showed shorter operative time and hospital stay compared with those undergoing AP. The incidence of leg radiculopathy and back pain was similar between the two groups. Surgeons should consider these findings as part of the decision-making process regarding which approach to use in patients requiring a lumbar interbody fusion.

Do obese patients undergoing surgery for grade 1 spondylolisthesis have worse outcomes at 5 years' follow-up? A QOD study.

OBJECTIVE: The long-term effects of increased body mass index (BMI) on surgical outcomes are unknown for patients who undergo surgery for low-grade lumbar spondylolisthesis. The goal of this study was to assess long-term outcomes in obese versus nonobese patients after surgery for grade 1 spondylolisthesis. METHODS: Patients who underwent surgery for grade 1 spondylolisthesis at the Quality Outcomes Database's 12 highest enrolling sites (SpineCORe group) were identified. Long-term (5-year) outcomes were compared for patients with BMI ≥ 35 versus BMI < 35. RESULTS: In total, 608 patients (57.6% female) were included. Follow-up was 81% (excluding patients who had died) at 5 years. The BMI ≥ 35 cohort (130 patients, 21.4%) was compared to the BMI < 35 cohort (478 patients, 78.6%). At baseline, patients with BMI ≥ 35 were more likely to be younger (58.5 ± 11.4 vs 63.2 ± 12.0 years old, p < 0.001), to present with both back and leg pain (53.8% vs 37.0%, p = 0.002), and to require ambulation assistance (20.8% vs 9.2%, p < 0.001). Furthermore, the cohort with BMI ≥ 35 had worse baseline patient-reported outcomes including visual analog scale (VAS) back (7.6 ± 2.3 vs 6.5 ± 2.8, p < 0.001) and leg (7.1 ± 2.6 vs 6.4 ± 2.9, p = 0.031) pain, disability measured by the Oswestry Disability Index (ODI) (53.7 ± 15.7 vs 44.8 ± 17.0, p < 0.001), and quality of life on EuroQol-5D (EQ-5D) questionnaire (0.47 ± 0.22 vs 0.56 ± 0.22, p < 0.001). Patients with BMI ≥ 35 were more likely to undergo fusion (85.4% vs 74.7%, p = 0.01). There were no significant differences in 30- and 90-day readmission rates (p > 0.05). Five years postoperatively, there were no differences in reoperation rates or the development of adjacent-segment disease for patients in either BMI < 35 or ≥ 35 cohorts who underwent fusion (p > 0.05). On multivariate analysis, BMI ≥ 35 was a significant risk factor for not achieving minimal clinically important differences (MCIDs) for VAS leg pain (OR 0.429, 95% CI 0.209-0.876, p = 0.020), but BMI ≥ 35 was not a predictor for achieving MCID for VAS back pain, ODI, or EQ-5D at 5 years postoperatively. CONCLUSIONS: Both obese and nonobese patients benefit from surgery for grade 1 spondylolisthesis. At the 5-year time point, patients with BMI ≥ 35 have similarly low reoperation rates and achieve rates of satisfaction and MCID for back pain (but not leg pain), disability (ODI), and quality of life (EQ-5D) that are similar to those in patients with a BMI < 35.

Predictors of Delayed Clinical Benefit Following Surgical Treatment for Low Grade Spondylolisthesis.

STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: To investigate what factors predict delayed improvement after surgical treatment of low grade spondylolisthesis. SUMMARY OF BACKGROUND DATA: Lumbar surgery leads to clinical improvement in the majority of patients with low grade spondylolisthesis. Most patients improve rapidly after surgery, but some patients demonstrate a delayed clinical course. METHODS: The Quality and Outcomes Database (QOD) was queried for grade 1 spondylolisthesis patients who underwent surgery who had patient reported outcome measures (PROMs) collected at baseline, 3-, 6- and 12-months, including back and leg pain numeric rating scale (NRS), Oswestry Disability Index (ODI), and EuroQol-5D (EQ-5D). Patients were stratified as "Early responders" reaching MCID at 3 months and maintaining improvement through 12 months and "Delayed responders" not reaching MCID at 3 months but ultimately reaching MCID at 12 months. These two groups were compared with respect to factors which predicted delayed improvement. RESULTS: Of 608 patients enrolled, 436 (72%) met inclusion criteria for this study. Overall, 317 patients (72.7%) reached MCID for ODI at 12 months following surgery. Of these patients, 249 (78.5%) exhibited a rapid clinical improvement trajectory and had achieved ODI MCID threshold by the 3-month postop follow-up. 68 patients (21.4%) showed a delayed trajectory, and had not achieved ODI MCID threshold at 3 months, but did ultimately reach MCID at 12-month follow-up. Factors associated with delayed improvement included impaired preoperative ambulatory status, better baseline back and leg pain scores, and worse 3-month leg pain scores (P<0.01). CONCLUSIONS: The majority of patients undergoing surgery for low grade spondylolisthesis reach ODI MCID threshold rapidly, within the first three months after surgery. Factors associated with a delayed clinical course include impaired preoperative ambulation status, relatively better preoperative back and leg pain, and persistent leg pain at 3 months.

Predictors of patient satisfaction after surgery for grade 1 degenerative spondylolisthesis: a 5-year analysis of the Quality Outcomes Database.

OBJECTIVE: Lumbar decompression and/or fusion surgery is a common operation for symptomatic lumbar spondylolisthesis refractory to conservative management. Multiyear follow-up of patient outcomes can be difficult to obtain but allows for identification of preoperative patient characteristics associated with durable pain relief, improved functional outcome, and higher patient satisfaction. METHODS: A query of the Quality Outcomes Database (QOD) low-grade spondylolisthesis module for patients who underwent surgery for grade 1 lumbar spondylolisthesis (from July 2014 to June 2016 at the 12 highest-enrolling sites) was used to identify patient satisfaction, as measured with the North American Spine Society (NASS) questionnaire, which uses a scale of 1-4. Patients were considered satisfied if they had a score ≤ 2. Multivariable logistic regression was performed to identify baseline demographic and clinical predictors of long-term satisfaction 5 years after surgery. RESULTS: Of 573 eligible patients from a cohort of 608, patient satisfaction data were available for 81.2%. Satisfaction (NASS score of 1 or 2) was reported by 389 patients (83.7%) at 5-year follow-up. Satisfied patients were predominantly White and ambulation independent and had lower baseline BMI, lower back pain levels, lower Oswestry Disability Index (ODI) scores, and greater EQ-5D index scores at baseline when compared to the unsatisfied group. No significant differences in reoperation rates between groups were reported at 5 years. On multivariate analysis, patients who were independently ambulating at baseline had greater odds of long-term satisfaction (OR 1.12, p = 0.04). Patients who had higher 5-year ODI scores (OR 0.99, p < 0.01) and were uninsured (OR 0.43, p = 0.01) were less likely to report long-term satisfaction. CONCLUSIONS: Lumbar surgery for the treatment of grade 1 spondylolisthesis can provide lasting pain relief with high patient satisfaction. Baseline independent ambulation is associated with a higher long-term satisfaction rate after surgery. Higher ODI scores at 5-year follow-up and uninsured status are associated with lower postoperative long-term satisfaction.

Cost-effectiveness of posterior lumbar interbody fusion and/or transforaminal lumbar interbody fusion for grade 1 lumbar spondylolisthesis: a 5-year Quality Outcomes Database study.

OBJECTIVE: Posterior lumbar interbody fusion (PLIF) and/or transforaminal lumbar interbody fusion (TLIF), referred to as "PLIF/TLIF," is a commonly performed operation for lumbar spondylolisthesis. Its long-term cost-effectiveness has not been well described. The aim of this study was to determine the 5-year cost-effectiveness of PLIF/TLIF for grade 1 degenerative lumbar spondylolisthesis using prospective data collected from the multicenter Quality Outcomes Database (QOD). METHODS: Patients enrolled in the prospective, multicenter QOD grade 1 lumbar spondylolisthesis module were included if they underwent single-stage PLIF/TLIF. EQ-5D scores at baseline, 3 months, 12 months, 24 months, 36 months, and 60 months were used to calculate gains in quality-adjusted life years (QALYs) associated with surgery relative to preoperative baseline. Healthcare-related costs associated with the index surgery and related reoperations were calculated using Medicare reimbursement-based cost estimates and validated using price transparency diagnosis-related group (DRG) charges and Medicare charge-to-cost ratios (CCRs). Cost per QALY gained over 60 months postoperatively was assessed. RESULTS: Across 12 surgical centers, 385 patients were identified. The mean patient age was 60.2 (95% CI 59.1-61.3) years, and 38% of patients were male. The reoperation rate was 5.7%. DRG 460 cost estimates were stable between our Medicare reimbursement-based models and the CCR-based model, validating the focus on Medicare reimbursement. Across the entire cohort, the mean QALY gain at 60 months postoperatively was 1.07 (95% CI 0.97-1.18), and the mean cost of PLIF/TLIF was $31,634. PLIF/TLIF was associated with a mean 60-month cost per QALY gained of $29,511. Among patients who did not undergo reoperation (n = 363), the mean 60-month QALY gain was 1.10 (95% CI 0.99-1.20), and cost per QALY gained was $27,591. Among those who underwent reoperation (n = 22), the mean 60-month QALY gain was 0.68 (95% CI 0.21-1.15), and the cost per QALY gained was $80,580. CONCLUSIONS: PLIF/TLIF for degenerative grade 1 lumbar spondylolisthesis was associated with a mean 60-month cost per QALY gained of $29,511 with Medicare fees. This is far below the well-established societal willingness-to-pay threshold of $100,000, suggesting long-term cost-effectiveness. PLIF/TLIF remains cost-effective for patients who undergo reoperation.

Accuracy of Phantomless Calibration of Routine Computed Tomography Scans for Opportunistic Osteoporosis Screening in the Spine Clinic.

STUDY DESIGN: Diagnostic accuracy study. OBJECTIVE: To establish a simple method of phantomless bone mineral density (BMD) measurement by using preoperative lumbar Computed Tomography (CT) scans, and compare the accuracy of reference tissue combinations to diagnose low BMD against uncalibrated Hounsfield units (HUs). SUMMARY OF BACKGROUND DATA: HUs are used as a measure of BMD; however, associations between HU and T-scores vary widely. Quantitative CT (qCT) scans are more accurate, but they require density calibration with an object of known density (phantom), which limits feasibility. As an emerging technique, phantomless (internal) calibration of routine CT scans may provide a good opportunity for screening. METHODS: Patients who were scheduled to undergo lumbar surgery, with a preoperative CT scan, and a dual-energy x-ray absorptiometry (DXA) scan within six months were included. Four tissues were selected for calibration: subcutaneous adipose (A), erector spinae (ES), psoas (P) and aortic blood (AB). The HUs of these tissues were used in linear regression against ground-truth values. Calibrations were performed by using two different internal tissues at a time to maintain simplicity and in-office applicability.Volumetric bone mineral densities (vBMD) derived from internally calibrated CT scans were analyzed for new threshold values for low bone density. Areas under the curve (AUC) were calculated with 95% confidence intervals (CI). RESULTS: 45 patients were included (M/F=10/35, mean age:63.3). Calibrated vBMDs had stronger correlations with DXA T-scores when compared with HUs, with L2 exhibiting the highest coefficients. Calibration by using A and ES with the threshold of 162 mg/cm3 had a sensitivity of 90% in detecting low BMD (AUC=0.671). CONCLUSIONS: This novel method allows simple, in-office calibration of routine preoperative CT scans without the use of a phantom. Calibration using adipose and erector spinae with a threshold of 162 mg/cm3 is proposed for low bone density screening with high sensitivity (90%). LEVEL OF EVIDENCE: Level III.

Impact of educational background on preoperative disease severity and postoperative outcomes among patients with lumbar spondylolisthesis: a Quality Outcomes Database study.

OBJECTIVE: Deficiency in patient education has been correlated with increased disease-related morbidity and decreased access to care. However, the associations between educational level, preoperative disease severity, and postoperative outcomes in patients with lumbar spondylolisthesis have yet to be explored. METHODS: The spondylolisthesis dataset of the Quality Outcomes Database (QOD)-a cohort with prospectively collected data by the SpineCORe study team of the 12 highest enrolling sites with an 81% follow-up at 5 years -was utilized and stratified for educational level. Patients were classified into three categories (high school or less, graduate, or postgraduate). Patient-reported outcome measures (PROMs) documented at baseline and follow-up included Oswestry Disability Index (ODI) score, EQ-5D in quality-adjusted life years, and numeric rating scale (NRS) scores for back and leg pain. Disease severity was measured with PROMs. Postoperatively, patients also completed the North American Spine Society assessment to measure their satisfaction with surgery. Multivariable regression analysis was used to compare education level with disease severity and postoperative outcomes. RESULTS: A total of 608 patients underwent analysis, with 260 individuals (42.8%) at an educational level of high school or less. On univariate analysis, baseline disease severity was worse among patients with lower levels of education. On multivariable regression analysis, patients with postgraduate level of education had significantly lower ODI scores (ß = -3.75, 95% CI -7.31 to -0.2, p = 0.039) compared to graduates, while the other PROMs were not associated with significant differences at baseline. Five years postoperatively, patients from various educational backgrounds exhibited similar rates of minimal clinically important differences in PROMs. Nevertheless, patients with the lowest educational level had higher ODI scores (27.1, p < 0.01), lower EQ-5D scores (0.701, p < 0.01), and higher NRS leg pain (3.0, p < 0.01) and back pain (4.0, p < 0.01) scores compared to those with graduate or postgraduate levels of education. The odds for postoperative satisfaction were also comparable between cohorts at 5 years (reference, graduate level; high school or less, OR 0.87, 95% CI 0.46-1.64, p = 0.659; postgraduate, OR 1.6, 95% CI 0.7-3.65, p = 0.262). CONCLUSIONS: Lower patient education level was associated with a greater baseline disease severity in patients with lumbar spondylolisthesis. Surgery demonstrated similar benefits irrespective of educational background; however, individuals with lower educational level reported lower outcomes overall. This emphasizes the need for enhanced health literacy to mitigate disparities for reported outcomes.

Immediate Postoperative Change in the Upper Instrumented Screw-Vertebra Angle Is a Predictor for Proximal Junctional Kyphosis and Failure.

STUDY DESIGN: Retrospective review. OBJECTIVES: To determine if change in position of upper instrumented vertebral (UIV) screw between intraoperative prone and immediate postoperative standing radiographs is a predictor for proximal junctional kyphosis or failure (PJK/PJF). SUMMARY OF BACKGROUND DATA: Cranially directed UIV screws on post-operative radiographs have been found to be associated with PJK. Change in the screw position between intraoperative and immediate postoperative radiographs has not been studied. METHODS: Patients with posterior fusion ≥3 levels and UIV at or distal to T8, and minimum 2-year follow-up were identified from a single center database. Primary outcomes were radiographic PJK/PJF or revision for PJK/PJF. Demographic, surgical and radiographic variables, including intraoperative screw-vertebra (S-V) angle, change in S-V angle, direction of UIV screw (cranial-neutral-caudal) and rod-vertebra (R-V) angle were collected. RESULTS: 143 cases from 110 patients were included with a mean age of 62.9 years and a follow-up of 3.5 years. 54 (38%) cases developed PJK/PJF, of whom 30 required a revision. Mean S-V angle was -0.9°±5.5° intraoperative and -2.8°±5.5° postoperative. The group with PJK/PJF had a mean S-V angle change of -2.5°±2.4 while the rest had a change of -1.0°±1.6 (P=0.010). When the change in S-V angle was <5°, 33% developed PJK, this increased to 80% when it was ≥5° (P=0.001). Revision for PJK/PJF increased from 16% to 60% when S-V angle changed ≥5° (P=0.001). Regression analysis showed S-V angle change as a significant risk factor for PJK/PJF (P=0.047, OR=1.58) and for revision due to PJK/PJF (P=0.009, OR=2.21). CONCLUSIONS: Change in the S-V angle from intraop prone to immediate postop standing radiograph is a strong predictor for PJK/PJF and for revision. For each degree of S-V angle change, odds of revision for PJK/PJF increases by 2.2x. A change of 5° should alert the surgeon to the likely development of PJK/PJF requiring revision.

Comparison of No Tap (two-step) and tapping robotic assisted cortical bone trajectory screw insertion.

Workflow for cortical bone trajectory (CBT) screws includes tapping line-to-line or under tapping by 1 mm. We describe a non-tapping, two-step workflow for CBT screw placement, and compare the safety profile and time savings to the Tap (three-step) workflow. Patients undergoing robotic assisted 1-3 level posterior fusion with CBT screws for degenerative conditions were identified and separated into either a No-Tap or Tap workflow. Number of total screws, screw-related complications, estimated blood loss, operative time, robotic time, and return to the operating room were collected and analyzed. There were 91 cases (458 screws) in the No-Tap and 88 cases (466 screws) in the Tap groups, with no difference in demographics, revision status, ASA grade, approach, number of levels fused or diagnosis between cohorts. Total robotic time was lower in the No-Tap (26.7 min) versus the Tap group (30.3 min, p = 0.053). There was no difference in the number of malpositioned screws identified intraoperatively (10 vs 6, p = 0.427), screws converted to freehand (3 vs 3, p = 0.699), or screws abandoned (3 vs 2, p = 1.000). No pedicle/pars fracture or fixation failure was seen in the No-Tap cohort and one in the Tap cohort (p = 1.00). No patients in either cohort were returned to OR for malpositioned screws. This study showed that the No-Tap screw insertion workflow for robot-assisted CBT reduces robotic time without increasing complications.

Intra-Operative Hypotension is an Important Modifiable Risk Factor for Major Complications in Spinal Fusion Surgery.

STUDY DESIGN: Retrospective observational cohort. OBJECTIVES: This study explores the impact of Intraoperative hypotension (IOH)on post-op complications for major thoracolumbar spine fusion procedures. SUMMARY OF BACKGROUND DATA: IOH with mean arterial pressure (MAP) < 65 mmHg is associated with post-op acute kidney injury (AKI) in general surgery. In spinal deformity surgery, IOH is a contributing factor to MEP changes and spinal cord dysfunction with deformity correction. METHODS: 539 thoracolumbar fusion cases, > 6 surgical levels and > 3 hours duration were identified. Anesthetic/surgical data included OR time, fluid volume, blood loss, blood product replacement and use of vasopressors. Arterial-line based MAP data was collected at 1 min intervals. Cummulative duration of MAP < 65 mmHg was recorded. IOH within the first hour of surgery vs. the entire case was determined. Post-op course and complications including SSI, GI complications, pulmonary complications, MI, DVT, PE, AKI and encephalopathy were noted. Cumulative complications were grouped as none, 1-2 complications, or >3 complications. RESULTS: There was a significant association between occurrence of complications and duration of IOH within the first hour of surgery (8.2 vs. 5.6 min, P<0.001) and across the entire procedure (28.1 vs. 19.3 min, P=0.008). This association persisted for individual major complications including SSI, acute respiratory failure, PE, ileus requiring NGT and post-operative cognitive dysfunction. Comparison of patients with 0 vs. 1-2 vs. 3 or more complications demonstrated that patients with 3 or more complications had a longer duration of IOH in the first hour of the surgery and that patients who had no complications received less vasopressor than patients who had 1-2 or 3 or more complications. CONCLUSION: This study identifies duration of IOH during the first hour of surgery as a previously unrecognized modifiable risk associated with major complications for multi-level lumbar fusion surgery.

Proximal Junctional Degeneration and Failure Modes: A Novel Classification and Clinical Implications.

STUDY DESIGN: Case-control study. OBJECTIVE: To introduce a classification system that will include the major types of degenerative changes and failures related to the proximal junction, and to determine the clinical course and characteristics for the different types of proximal junctional degeneration. BACKGROUND: Proximal junctional kyphosis and failures are well recognized after adult spinal fusion; however, a standardized classification is lacking. MATERIALS AND METHODS: The proposed system identified 4 different patterns of proximal junctional degeneration: (1) Type 1 (multilevel symmetrical collapse), (2) Type 2 (single adjacent level collapse), (3) Type 3 (fracture), and (4) Type 4 (spondylolisthesis). A single-center database was reviewed from 2018 to 2021. Patients 18 years or older of age, who underwent posterior spinal fusion of ≥3 levels with an upper instrumented vertebral level between T8 and L2, and a follow-up of ≥2 years were included. Radiographic measurements, revision surgery, and time to revision were the primary outcomes. RESULTS: One hundred fifty patients were included with a mean age of 65.1 (±9.8) years and a mean follow-up of 3.2 (±1) years. Sixty-nine patients (46%) developed significant degenerative changes in the proximal junction and were classified accordingly. Twenty (13%) were type 1, 17 (11%) were type 2, 22 (15%) were type 3, and 10 (7%) were type 4. Type 3 had a significantly shorter time to revision with a mean of 0.9 (±0.9) years. Types 3 and 4 had greater preoperative sagittal vertical axis, and types 1 and 3 had greater final follow-up lumbar lordosis. Bone density measured by Hounsfield units showed lower measurements for type 3. Types 1 and 4 had lower rates of developing proximal junctional kyphosis. Type 1 had the lowest revision rate with 40% (types 2, 3, and 4 were 77%, 73%, and 80%, respectively, P = 0.045). CONCLUSION: This novel classification system defines different modes of degeneration and failures at the proximal junction, and future studies with larger sample sizes are needed for validation. LEVEL OF EVIDENCE: Level III.

Comparing posterior cervical foraminotomy with anterior cervical discectomy and fusion in radiculopathic patients: an analysis from the Quality Outcomes Database.

OBJECTIVE: The objective of this study was to compare clinical and patient-reported outcomes (PROs) between posterior foraminotomy and anterior cervical discectomy and fusion (ACDF) in patients presenting with cervical radiculopathy. METHODS: The Quality Outcomes Database was queried for patients who had undergone ACDF or posterior foraminotomy for radiculopathy. To create two highly homogeneous groups, optimal individual matching was performed at a 5:1 ratio between the two groups on 29 baseline variables (including demographic characteristics, comorbidities, symptoms, patient-reported scores, underlying pathologies, and levels treated). Outcomes of interest were length of stay, reoperations, patient-reported satisfaction, increase in EQ-5D score, and decrease in Neck Disability Index (NDI) scores for arm and neck pain as long as 1 year after surgery. Noninferiority analysis of achieving patient satisfaction and minimal clinically important difference (MCID) in PROs was performed with an accepted risk difference of 5%. RESULTS: A total of 7805 eligible patients were identified: 216 of these underwent posterior foraminotomy and were matched to 1080 patients who underwent ACDF. The patients who underwent ACDF had more underlying pathologies, lower EQ-5D scores, and higher NDI and neck pain scores at baseline. Posterior foraminotomy was associated with shorter hospitalization (0.5 vs 0.9 days, p < 0.001). Reoperations within 12 months were significantly more common among the posterior foraminotomy group (4.2% vs 1.9%, p = 0.04). The two groups performed similarly in PROs, with posterior foraminotomy being noninferior to ACDF in achieving MCID in EQ-5D and neck pain scores but also having lower rates of maximal satisfaction at 12 months (North American Spine Society score of 1 achieved by 65.2% posterior foraminotomy patients vs 74.6% of ACDF patients, p = 0.02). CONCLUSIONS: The two procedures were found to be offered to different populations, with ACDF being selected for patients with more complicated pathologies and symptoms. After individual matching, posterior foraminotomy was associated with a higher reoperation risk within 1 year after surgery compared to ACDF (4.2% vs 1.9%). In terms of 12-month PROs, posterior foraminotomy was noninferior to ACDF in improving quality of life and neck pain. The two procedures also performed similarly in improving NDI scores and arm pain, but ACDF patients had higher maximal satisfaction rates.

Cervical spondylotic myelopathy and driving abilities: defining the prevalence and long-term postoperative outcomes using the Quality Outcomes Database.

OBJECTIVE: Cervical spondylotic myelopathy (CSM) can cause significant difficulty with driving and a subsequent reduction in an individual's quality of life due to neurological deterioration. The positive impact of surgery on postoperative patient-reported driving capabilities has been seldom explored. METHODS: The CSM module of the Quality Outcomes Database was utilized. Patient-reported driving ability was assessed via the driving section of the Neck Disability Index (NDI) questionnaire. This is an ordinal scale in which 0 represents the absence of symptoms while driving and 5 represents a complete inability to drive due to symptoms. Patients were considered to have an impairment in their driving ability if they reported an NDI driving score of 3 or higher (signifying impairment in driving duration due to symptoms). Multivariable logistic regression models were fitted to evaluate mediators of baseline impairment and improvement at 24 months after surgery, which was defined as an NDI driving score < 3. RESULTS: A total of 1128 patients who underwent surgical intervention for CSM were included, of whom 354 (31.4%) had baseline driving impairment due to CSM. Moderate (OR 2.3) and severe (OR 6.3) neck pain, severe arm pain (OR 1.6), mild-moderate (OR 2.1) and severe (OR 2.5) impairment in hand/arm dexterity, severe impairment in leg use/walking (OR 1.9), and severe impairment of urinary function (OR 1.8) were associated with impaired driving ability at baseline. Of the 291 patients with baseline impairment and available 24-month follow-up data, 209 (71.8%) reported postoperative improvement in their driving ability. This improvement seemed to be mediated particularly through the achievement of the minimal clinically important difference (MCID) in neck pain and improvement in leg function/walking. Patients with improved driving at 24 months noted higher postoperative satisfaction (88.5% vs 62.2%, p < 0.01) and were more likely to achieve a clinically significant improvement in their quality of life (50.7% vs 37.8%, p < 0.01). CONCLUSIONS: Nearly one-third of patients with CSM report impaired driving ability at presentation. Seventy-two percent of these patients reported improvements in their driving ability within 24 months of surgery. Surgical management of CSM can significantly improve patients' driving abilities at 24 months and hence patients' quality of life.

Risk Factors for Medial Breach During Robotic-Assisted Cortical Bone Trajectory Screw Insertion.

OBJECTIVE: We describe the incidence of, and identify the risk factors for, a medial breach of the pedicle wall during robotic-assisted cortical bone trajectory (RA-CBT) screw insertion. METHODS: We analyzed a consecutive series of adult patients who underwent RA-CBT screw placement from January 2019 to July 2022. To assess the pedicle wall medial breach, postoperative computed tomography (CT) images were analyzed. Patient demographic data and screw data were compared between patients with and without a medial breach. The Hounsfield units (HUs) on the L1 midvertebral axial CT scan was used to evaluate bone quality. RESULTS: Of 784 CBT screws in 145 patients, 30 (3.8%) had a medial breach in 23 patients (15.9%). One screw was grade 2, and the others were grade 1. Patients with a medial breach had a lower HU value compared with the patients without a medial breach (123.3 vs. 150.5; P = 0.027). A medial breach was more common in the right than left side (5.5% vs. 2.0%; P = 0.014). More than one half of the screws with a medial breach were found in the upper instrumented vertebra (UIV) compared with the middle construct or lowest instrumented vertebra (6.7% vs. 1.3% vs. 2.7%; P = 0.003). Binary logistic regression showed that low HU values, right-sided screw placement, and UIV were associated with a medial breach. No patients returned to the operating room for screw malposition. No differences were found in the clinical outcomes between patients with and without a medial breach. CONCLUSIONS: The incidence of pedicle wall medial breach was 3.8% of RA-CBT screws in the postoperative CT images. A low HU value measured in the L1 axial image, right-sided screw placement, and UIV were associated with an increased risk of medial breach for RA-CBT screw placement.