Spine

STUDY DESIGN:Retrospective observational study with prospectively collected data based on three national registries. OBJECTIVE:To investigate complications of lumbar spinal stenosis (LSS) surgery in Finland, clinically linked to complications, and their effects on functional outcomes, patient satisfaction, and risk of reoperation. SUMMARY OF BACKGROUND DATA:LSS surgeries continue to increase. Complication rates in previous studies vary greatly due to methodological differences, data quality, and the definition of complications. METHODS:Patients with a primary diagnosis of LSS identified from the Finnish Spine Register (FinSpine) were included in this study. Complications within 30 days of index operation were identified from FinSpine, the Finnish Care Register for Health Care (HILMO), and the Register of Primary Health Care Visits (AvoHILMO). The effect of complications on functional outcome was assessed using the Oswestry Disability Index (ODI) and by measuring patient satisfaction. Various factors including ASA grade and fusion surgery were analyzed as potential factors clinically linked to complications. The risk of reoperation at 1 year after the index operation was also assessed. RESULTS:The overall complication rate in LSS surgery was 16.8% (7.8% intraoperative, 4.6% in-hospital, and 4.4% later). The most common complications by group were dural tear, urinary retention, and wound infection. Older age, higher ASA grade, longer operative time, multilevel decompression, and fusion surgery increased complication risk. At 1-year follow-up, mean ODI was 28.1 and 24.3 with and without complications. Patients with complications of any type had significantly higher risk of reoperation 13.9% than patients without complications, which was further elevated by specific complications, spinal hematoma at 57.8% and wound infection 53.8%. CONCLUSION:By combining three national registries, a comprehensive overview of LSS surgery complications was obtained. Older age, higher ASA grade and multilevel decompression were identified as factors clinically linked to complications. Patients with and without complications achieved acceptable amelioration of disability. Complications increased the risk for reoperation within 1 month after index operation, and the risk remained higher up to 1 year than without complications. LEVEL OF EVIDENCE:Level III.

STUDY DESIGN:Multicenter, concurrently controlled Food and Drug Administration Investigational Device Exemption trial. OBJECTIVE:To test the hypothesis that decompression combined with a dynamic sagittal tether (D+DST) was a safe and effective noninferior alternative to decompression and transforaminal lumbar interbody fusion (D+TLIF) for patients with degenerative spondylolisthesis (DS) and stenosis. SUMMARY OF BACKGROUND DATA:Instability leading to symptom recurrence in patients undergoing decompression alone for DS is a concern, resulting in many patients receiving decompression and fusion. An alternative was developed incorporating decompression with stabilization using a dynamic sagittal tether to restore flexion stability and facet joint engagement, reducing segmental translation. METHODS:Patients with Grade I DS+stenosis amenable to decompression were recruited. Outcomes included composite clinical success (CCS), leg/hip and back pain, Oswestry Disability Index (ODI), reoperations, and radiographic measures. CCS was defined as: successful implantation, no reoperation at index or adjacent levels, minimum 15-point ODI improvement, no device failure, and no neurologic decline unless attributable to unrelated cause. A propensity score (PS) model was developed using 25 preoperative covariates to achieve balance and control for bias. RESULTS:287 patients were PS-selected (140 D+DST; 147 TLIF). D+DST demonstrated significantly lower operative time, blood loss, and hospital stay. CCS rates were 78.8% with D+DST and 61.2% with D+TLIF, with a PS-adjusted difference of +10.4% favoring D+DST, meeting the primary noninferiority endpoint. Leg/hip pain, back pain, and ODI scores significantly reduced in both groups. Angular motion and segmental translation were both reduced 24% after D+DST and by 68% and 77%, respectively, after D+TLIF. Angular and translational motion at the supradjacent level were significantly greater after D+TLIF, and statistically unchanged following D+DST. Index or adjacent level reoperation rates were 7.2% after D+DST and 9.8% after D+TLIF. CONCLUSIONS:D+DST was noninferior to D+TLIF at 2 years, supporting its effectiveness in treating Grade I DS+stenosis.

STUDY DESIGN:Systematic review using Synthesis Without Meta-analysis (SWiM). OBJECTIVE:To synthesize evidence on osteoporosis and mechanical outcomes after fusion for degenerative lumbar scoliosis (DLS) and related adult spinal deformity (ASD), and appraise perioperative teriparatide or romosozumab. SUMMARY OF BACKGROUND DATA:DLS-specific long-fusion evidence is sparse; much literature comprises related ASD or indirect short-segment/mixed-fusion cohorts. METHODS:PubMed, Embase, CENTRAL, and Web of Science were searched through January 31, 2026, with a focused PubMed verification audit during revision. PROSPERO registration on April 22, 2026 followed the search; post-registration eligibility and analysis deviations are disclosed. Core DLS evidence required explicit long-segment fusion or ≥4 fused/instrumented levels; a stricter ≥5-vertebrae subset was examined. Adjusted estimates were reported per study without pooling. Risk of bias used QUIPS, RoB 2, or ROBINS-I; certainty used GRADE. RESULTS:Twenty-one index primary reports informed the synthesis; eight were core DLS long-fusion reports; one overlapping companion was linked to its index cohort. Of eight core reports, five showed adverse adjusted associations, one was adjusted-null, and two were mixed across bone measures. The strict ≥5-vertebrae subset contained three adverse reports. Direct estimates included osteoporosis OR 8.19 (95% CI, 2.40-27.97) for screw loosening, S1 VBQ OR 4.565 (1.430-14.568) for PJK, osteoporosis OR 6.713 (1.667-27.031) for mechanical complications, and lumbosacral HU OR 0.941 (0.906-0.977) for distal instrumentation problems. Two reports had internally inconsistent regression tables; unsafe numeric effects were not extracted. Cohort overlap, heterogeneous measures/endpoints, and indirect evidence precluded pooling; three anabolic studies did not establish a DLS-specific class effect. CONCLUSIONS:Most core DLS reports linked lower bone quality to mechanical complications, but retrospective design, probable cohort overlap, measure-dependent null findings, and reporting defects make certainty very low. No pooled DLS-specific magnitude is justified. Effects on final alignment and disability remain unresolved, and perioperative anabolic therapy is promising but not definitive. LEVEL OF EVIDENCE:3.

STUDY DESIGN:Prospective cohort study. OBJECTIVE:Our primary objective was to determine the effects of all classes of obesity (BMI ≥30) on patient-reported disability at one year of follow-up among patients undergoing surgery for degenerative lumbar conditions, with particular attention given to the effects of severe obesity (BMI ≥40). Secondary objectives were to determine effects on health-related quality of life, back pain, leg pain, and adverse events. SUMMARY OF BACKGROUND DATA:The importance of obesity among patients undergoing spine surgery has been well-established, but effects according to severity of obesity remain poorly understood. METHODS:Patients were prospectively enrolled in the Canadian Spine Outcomes and Research Network between 2015 and 2024. We used logistic regression and propensity score matching to compare outcomes while adjusting for potential confounders. RESULTS:Among 6,242 patients, 2309 (37%) had obesity including 1448 (23%) with Class I (BMI 30 to <35), 571 (9%) with Class II (BMI 35 to <40) and 290 (5%) with Class III (BMI ≥40, "severe" obesity). Patients with any class of obesity were significantly less likely to achieve the Minimum Clinically Important Difference (MCID) for the Oswestry Disability Index, and the effect most pronounced for those with Class III obesity (Odds Ratio (OR) 0.83, 95% CI 0.76 to 0.90, P<0.01). Rates of incidental durotomy (OR 1.20, 95% CI 1.05 to 1.38, P<0.01), surgical site infection (OR 1.49, 95% CI 1.25 to 1.78, P<0.01), and wound dehiscence (OR 2.21, 95% CI 1.59 to 3.07, P<0.01) were all significantly higher among patients with Class III obesity. CONCLUSIONS:Patients with obesity were less likely to experience improvement of disability after surgery for degenerative lumbar conditions and severe obesity was particularly associated with greater odds adverse events. These findings inform shared clinical decision-making and suggest that obesity management prior to surgery may be of benefit.

STUDY DESIGN:Systematic review and meta-analysis. OBJECTIVE:To determine whether perioperative anabolic osteoporosis pharmacotherapy is associated with lower rates of (1) proximal junctional kyphosis (PJK) and (2) reoperation for mechanical failure following adult spinal deformity surgery. SUMMARY OF BACKGROUND DATA:Mechanical complications occur in 15 to 40 percent of patients following adult spinal deformity surgery. Although poor bone quality has been associated with mechanical failure, no quantitative synthesis has tested whether perioperative pharmacotherapy alters these outcomes. METHODS:PubMed, Embase, Scopus, and Cochrane CENTRAL were searched through April 30, 2026 (PROSPERO CRD420261374961). Random-effects meta-analysis was performed for the primary and prespecified secondary outcomes. The primary pool comprised anabolic-exposed studies; a class-agnostic pool that additionally included a single antiresorptive-dominant, claims-based study was retained as a sensitivity analysis. RESULTS:Thirteen studies (one randomized controlled trial, twelve observational; 2,247 patients) met inclusion criteria. Teriparatide was the primary or sole study agent in nine of thirteen studies. Anabolic pharmacotherapy was associated with reduced odds of PJK (pooled OR 0.51, 95% CI 0.30 to 0.86, P=0.012; I2=0%, k=5) and of reoperation for mechanical failure (OR 0.36, 95% CI 0.14 to 0.88, P=0.025; I2=55%, k=4). A broadened-class sensitivity analysis including the antiresorptive-dominant study was directionally consistent (OR 0.63, 95% CI 0.42 to 0.94, P=0.024). Leave-one-out sensitivity analysis preserved the direction of the PJK effect across all iterations. CONCLUSIONS:Perioperative anabolic osteoporosis pharmacotherapy is associated with lower rates of proximal junctional kyphosis and reoperation following adult spinal deformity surgery, providing the first pooled evidence that the underlying bone-quality substrate may be pharmacologically modifiable. The certainty of this evidence is low; these findings support incorporating bone health optimization into perioperative planning as a modifiable target and prioritizing randomized trials of specific agents. LEVEL OF EVIDENCE:IILevel of Evidence: II: Systematic review of cohort studies with one randomized controlled trial.

Study Design. Retrospective single-center cohort study. Objective. To investigate whether postoperative T4-L1PA mismatch (T4 pelvic angle minus L1 pelvic angle) predicts mechanical revision within 5 years after multilevel fusion to the upper lumbar and lower thoracic spine, versus other alignment parameters. Summary of Background Data. T4-L1PA mismatch is an established predictor of mechanical failure after upper thoracic fusion to the sacropelvis. Its value in lower thoracic spine and upper lumbar constructs remains unclear. Methods. We retrospectively analyzed 204 patients who underwent posterior spinal fusion of 3 to 10 instrumented levels (upper instrumented vertebra [UIV] T8-L3) with distal fixation to the sacrum or ilium (2006-2024). Alignment was assessed preoperatively, at the first postoperative timepoint, and at 1 year: T4-L1PA mismatch, PI-LL mismatch, sagittal vertical axis, L1PA deviation, lordosis distribution index, and distal lordosis. The primary outcome was mechanical revision within 5 years. Cox regression, ROC, Kaplan-Meier, and combined-risk analyses were performed. Results. Thirty-three patients (16.2%) underwent mechanical revision within 5 years. On first postoperative radiographs, T4-L1PA mismatch predicted revision (hazard ratio [HR] 1.10, P =0.012), as did PI-LL (HR 1.03, P =0.027). Adjusted for PI-LL, age, and levels fused, T4-L1PA remained significant (HR 1.09, P =0.028) while PI-LL did not ( P =0.070). At 1 year (n=148, 16 events), T4-L1PA had an HR of 1.17 ( P =0.001; PI-LL P =0.171). Other parameters were non-significant. Five-year cumulative revision incidence rose from 6% with neither parameter malaligned to 19% with one and 39% with both (log-rank P =0.003). Conclusions. Postoperative T4-L1PA mismatch was the most consistent alignment predictor of mechanical revision over 5 years in thoracolumbar and upper lumbar fusions (UIV T8-L3) to the sacropelvis and remained independently prognostic at 1 year, with most revisions attributable to proximal junctional failure. PI-LL contributed early risk but weakened over time. Combined assessment identified a high-risk subgroup.

STUDY DESIGN:Retrospective study. SUMMARY OF BACKGROUND DATA:A considerable proportion of patients with degenerative lumbar scoliosis (DLS) have concomitant hip osteoarthritis (OA). However, the effect of hip OA on DLS patients remains unclarified. PURPOSE:To investigate the impact of concomitant hip OA on patient-reported outcome measures (PROMs) and global spinopelvic alignment in DLS. METHODS:Patients were divided into severe and low OA groups based on the Kellgren-Lawrence (KL) classification, with grades 0 to 2 classified as low OA and grades 3 or 4 classified as severe OA. Radiographic parameters and PROMs including the Visual Analog Scale (VAS), Scoliosis Research Society-22 (SRS-22), and Oswestry Disability Index (ODI) were compared among 3 groups: Bilateral severe, Unilateral severe, or Bilateral low. Multivariable regression analysis was performed to assess the effect of hip OA on pelvic decompensation and PROMs. RESULTS:A total of 134 patients were enrolled: 61 Bilateral severe, 25 Unilateral severe, and 48 Bilateral low. Bilateral severe hip OA was independently associated with pelvic decompensation (OR 1.37, 95% CI: 1.09-1.54, P=.016). At 2-year postoperatively, severe OA patients exhibited worse global sagittal malalignment and inferior clinical outcomes. Multivariate analysis showed that bilateral severe OA was significantly associated with worse baseline ODI (B=0.352, 95% CI: 0.082 to 0.622) and SRS-function (B=-0.405, 95% CI: -0.749 to -0.062), and 2-year VAS-back pain (B=0.223, 95% CI: 0.021 to 0.425), VAS-leg pain (B=0.365, 95% CI: 0.057 to 0.673), SRS-pain (B=-0.326,95% CI: -0.619 to -0.020 ), SRS-function (B=-0.337, 95% CI: -0.734 to -0.090) and ODI (B=0.323, 95% CI: 0.039 to 0.607). CONCLUSIONS:Severe hip OA was associated with pelvic decompensation and reduced hip extension. Patients with severe hip OA had worse baseline sagittal malalignment and inferior PROMs that persisted 2 year following surgery. These findings underscore the importance of evaluating hip OA during preoperative planning for DLS.

Study Design. Systematic review using Synthesis Without Meta-analysis (SWiM). Objective. To synthesize evidence on osteoporosis and mechanical outcomes after fusion for degenerative lumbar scoliosis (DLS) and related adult spinal deformity (ASD), and appraise perioperative teriparatide or romosozumab. Summary of Background Data. DLS-specific long-fusion evidence is sparse; much literature comprises related ASD or indirect short-segment/mixed-fusion cohorts. Methods. PubMed, Embase, CENTRAL, and Web of Science were searched through January 31, 2026, with a focused PubMed verification audit during revision. PROSPERO registration on April 22, 2026 followed the search; post-registration eligibility and analysis deviations are disclosed. Core DLS evidence required explicit long-segment fusion or ≥4 fused/instrumented levels; a stricter ≥5-vertebrae subset was examined. Adjusted estimates were reported per study without pooling. Risk of bias used QUIPS, RoB 2, or ROBINS-I; certainty used GRADE. Results. Twenty-one index primary reports informed the synthesis; eight were core DLS long-fusion reports; one overlapping companion was linked to its index cohort. Of eight core reports, five showed adverse adjusted associations, one was adjusted-null, and two were mixed across bone measures. The strict ≥5-vertebrae subset contained three adverse reports. Direct estimates included osteoporosis OR 8.19 (95% CI, 2.40–27.97) for screw loosening, S1 VBQ OR 4.565 (1.430–14.568) for PJK, osteoporosis OR 6.713 (1.667–27.031) for mechanical complications, and lumbosacral HU OR 0.941 (0.906–0.977) for distal instrumentation problems. Two reports had internally inconsistent regression tables; unsafe numeric effects were not extracted. Cohort overlap, heterogeneous measures/endpoints, and indirect evidence precluded pooling; three anabolic studies did not establish a DLS-specific class effect. Conclusions. Most core DLS reports linked lower bone quality to mechanical complications, but retrospective design, probable cohort overlap, measure-dependent null findings, and reporting defects make certainty very low. No pooled DLS-specific magnitude is justified. Effects on final alignment and disability remain unresolved, and perioperative anabolic therapy is promising but not definitive. Level of Evidence. 3

STUDY DESIGN:Retrospective cohort study. OBJECTIVE:To assess iatrogenic sagittal malalignment after short-segment lumbar fusions at L4-5, L5-S1, and L4-S1 using segmental alignment criteria and identify preoperative predictors. SUMMARY OF BACKGROUND DATA:PI-LL mismatch is commonly used to assess sagittal correction after lumbar fusion, but may mask segmental under-correction due to compensatory mechanisms, risking iatrogenic flatback deformity. METHODS:A multicenter database of patients undergoing fusion at L4-5, L5-S1, or L4-S1 was retrospectively analyzed. Global alignment was defined as PI-LL <10°, and segmental alignment as L4-5≥15°, L5-S1≥20°, or L4-S1≥35°. Alignment changes were categorized as preserved, restored, not corrected, or worsened. McNemar's test compared global versus segmental alignment proportions, and logistic regression identified predictors of postoperative segmental alignment. RESULTS:Of 516 patients analyzed (273 L4-5, 122 L5-S1, 121 L4-S1), segmental criteria classified far fewer patients as aligned than PI-LL at L5-S1 (42.3% vs. 82.7%) and L4-S1 (33.6% vs. 72.0%; both P<.001). Segmental assessment also revealed markedly higher worsening rates at L5-S1 (44.2% vs. 12.5%) and L4-S1 (55.1% vs. 22.4%; both P<.001), while rates were identical at L4-5 (20.2% vs. 20.2%, P=1.0). Anterior interbody approaches and greater preoperative segmental lordosis predicted restoration; baseline lumbar lordosis was the only independent predictor of preserved alignment at L5-S1 (OR 1.25, 95% CI 1.05-1.49, P=.01). CONCLUSION:Segmental assessment revealed substantially higher rates of malalignment and postoperative worsening than PI-LL alone, particularly in fusions including L5-S1. Anterior interbody techniques and greater preoperative lordosis were associated with improved correction. Surgeons should incorporate segmental alignment targets when planning distal lumbar fusions to avoid inadvertent flatback deformity.

STUDY DESIGN:Multicenter prospective cohort study. OBJECTIVE:To evaluate the impact of preoperative intramedullary T2 signal intensity (SI) changes on surgical outcomes in patients with cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA:Intramedullary SI on T2-weighted MRI has been considered a predictor of poor outcomes in CSM; however, its prognostic value remains controversial. METHODS:We prospectively analyzed 721 patients with CSM who underwent surgical decompression at 10 institutions between 2019 and 2022. Patients were classified into SI (+) and SI (-) groups based on preoperative T2-weighted MRI. Outcomes were assessed preoperatively and at 2 years using the Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS), JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and Short Form-36 (SF-36). Multivariable analyses were adjusted for age, sex, symptom duration, preoperative C2-7 angle, cervical range of motion, diabetes mellitus, and smoking history. RESULTS:Of the 721 patients, 554 (76.8%) were SI (+) and 167 (23.2%) were SI (-). Although preoperative upper extremity pain/numbness on VAS was significantly higher in the SI (+) group (64.7 vs. 58.9, P=0.037), this difference was not significant at 2 years. No significant between-group differences were found in preoperative or postoperative JOA score, JOA recovery rate, ΔJOA, SF-36, JOACMEQ effectiveness rates, or perioperative complications. SI was not independently associated with improvement in any JOACMEQ domain. Only the preoperative C2-7 angle was independently associated with the presence of SI (odds ratio, 1.02; P=0.023). CONCLUSION:Preoperative intramedullary T2 SI was associated with greater preoperative upper extremity pain/numbness, and with a greater preoperative C2-7 angle. However, after adjustment for confounders, the binary presence of intramedullary T2 SI was not statistically significantly associated with worse 2-year neurological, functional, or patient-reported outcomes. LEVEL OF EVIDENCE:Level II.

STUDY DESIGN:Retrospective database study. OBJECTIVE:To evaluate national and regional trends in lumbar laminectomy (Current Procedural Terminology (CPT) 63047) reimbursement, utilization, and patient population characteristics among Medicare fee-for-service beneficiaries from 2013 to 2023. SUMMARY OF BACKGROUND DATA:Lumbar laminectomy is among the most commonly performed spinal decompression procedures in the United States. Despite its prevalence in the Medicare population, national trends in surgeon reimbursement, utilization, and patient characteristics across geography and surgeon specialty have not been comprehensively characterized over the recent decade. METHODS:The CMS "Medicare Physician & Other Practitioners" database was queried for all billing episodes of lumbar laminectomy (CPT 63047) from 2013 to 2023 among neurosurgeons and orthopaedic surgeons. Population-based utilization rates were calculated using CMS Monthly Enrollment data. Inflation-adjusted reimbursement, procedural volume, and patient characteristics were extracted and stratified by US Census region and rural-urban commuting area (RUCA) codes. Kruskal-Wallis tests, Wilcoxon rank-sum tests, and linear regression analyses were performed. As this analysis was restricted to fee-for-service (FFS) claims, the reported trends reflect changes within the FFS-billed population and do not capture procedures performed on Medicare Advantage beneficiaries, whose enrollment grew substantially over the study period. RESULTS:Population-based utilization declined 18.1% (24.14 to 19.78 per 10,000 Medicare fee-for-service (FFS) beneficiaries) and inflation-adjusted surgeon reimbursement declined 17.0% ($783 to $649). The number of performing surgeons declined 16.6% (3,184 to 2,657). Between 2019 and 2020, national lumbar laminectomy volume fell 21.1%, reflecting the impact of the COVID-19 pandemic. In 2023, the South demonstrated the highest utilization (21.48 per 10,000 FFS beneficiaries) and reimbursement did not significantly differ across Census regions (P=.067) or RUCA categories (P=.531). Orthopaedic surgeons performed the majority of procedures by 2023 (51.5%), having increased their share from 46.0% in 2013. Surgeon specialty was the only significant predictor of reimbursement on regression analysis (P=.021). CONCLUSION:Lumbar laminectomy utilization and surgeon reimbursement declined substantially among Medicare FFS beneficiaries from 2013 to 2023 and geographic disparities in utilization persisted throughout the study period. These findings highlight ongoing workforce and access concerns in lumbar spine surgery. However, these findings reflect trends specific to the fee-for-service Medicare population and should not be interpreted as a decline in lumbar decompression access across all Medicare beneficiaries, given the concurrent expansion of Medicare Advantage enrollment during the study period. LEVEL OF EVIDENCE:Level III; Retrospective Database Study.

STUDY DESIGN:A mixed-methods study. OBJECTIVE:To develop and perform the initial validation of the Lumbar Surgery Quality of Life (LSQoL), a multidimensional patient-reported outcome measure for patients with lumbar degenerative diseases. SUMMARY OF BACKGROUND DATA:Patient-reported outcome measures (PROMs) are widely used to evaluate outcomes in lumbar degenerative diseases but are often applied in combination, with each instrument capturing only specific aspects of patient status. Consequently, improvement in traditional measures such as the Oswestry Disability Index (ODI) does not always correspond to patient-perceived recovery or satisfaction, highlighting the need for multidimensional tools that better reflect patient experience. METHODS:The LSQoL was developed using a multistage mixed-method approach, including literature review, patient interviews, expert consensus through the Delphi method, and weighting via the Analytic Hierarchy Process (AHP). The instrument was validated in 1,996 patients with lumbar degenerative diseases. Internal consistency, test-retest reliability, construct validity, and correlations with established PROMs and patient-reported recovery and satisfaction were evaluated. RESULTS:The LSQoL consists of 21 items across five dimensions: pain, neurological function, activities of daily living, emotional status, and working ability. Internal consistency was acceptable to good (Cronbach's α: 0.744-0.805), and test-retest reliability was strong (ICC: 0.759-0.906). Factor analyses supported a stable multidimensional structure. The LSQoL demonstrated moderate correlations with established PROMs and stronger correlations with patient-reported recovery and satisfaction. CONCLUSION:The LSQoL is a reliable and valid PROM that provides a comprehensive assessment of quality of life in patients with lumbar degenerative diseases. It is suitable for evaluating patient-reported outcomes both before and after lumbar surgery.

STUDY DESIGN:Retrospective Cohort Study. OBJECTIVES:To develop and externally validate an explainable machine-learning framework for perioperative risk stratification of radiographic adjacent segment degeneration (ASDeg) after short-segment lumbar fusion. SUMMARY OF BACKGROUND DATA:Radiographic ASDeg is frequently observed after lumbar fusion and may represent an early structural phenotype preceding symptomatic adjacent segment disease (ASDis) in some patients. However, existing risk assessment approaches are limited by heterogeneous risk factors, insufficient model interpretability, and limited external validation. Machine-learning methods may improve perioperative risk stratification by integrating clinical, radiographic, surgical, and functional variables. METHODS:Clinical data were retrospectively collected from two hospitals. The internal cohort included 570 patients who underwent posterior short-segment lumbar fusion for lumbar degenerative disease, and an independent cohort of 150 patients from another institution was used for external validation. The internal cohort was randomly divided into training and internal test sets at a 7:3 ratio using stratified sampling according to ASDeg status. Feature selection was performed exclusively in the training set using least absolute shrinkage and selection operator regression (LASSO), random forest-recursive feature elimination (RE-RFE), and Boruta. Five algorithms were developed and compared: logistic regression, random forest (RF), extreme gradient boosting (XGBoost), Light Gradient Boosting Machine(LightGBM), and multilayer perceptron (MLP). Model performance was evaluated using discrimination, calibration, precision-recall (P-R) analysis, and decision-curve analysis(DCA). Shapley Additive Explanations (SHAP) were used for model interpretation. RESULTS:Radiographic ASDeg occurred in 212 of 570 patients in the internal cohort. Five perioperative variables were retained for model construction: preoperative intervertebral space height (ISH), postoperative pelvic incidence-lumbar lordosis (PI-LL) mismatch, frailty, Coflex implantation, and preoperative Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)-defined lower-extremity dysfunction. Among the candidate algorithms, the RF model showed the highest discriminative performance, with an AUROC of 0.782 in the internal test set and 0.749 in the external validation cohort. SHAP analysis identified preoperative ISH as the strongest contributor to model output. CONCLUSIONS:This externally validated RF-based model provides a structured and interpretable framework for postoperative radiographic ASDeg risk stratification after short-segment lumbar fusion. By integrating clinically accessible perioperative variables, the model may support individualized imaging follow-up and provide a preliminary basis for future studies using symptomatic adjacent segment disease or revision surgery as clinically oriented endpoints.

STUDY DESIGN:Retrospective cohort study. OBJECTIVE:To evaluate the independent associations of operative extent and advanced age with postoperative dysphagia after anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA:Dysphagia is common after ACDF and may be especially consequential in octogenarians. The relative contributions of multi-level surgery and advanced age to dysphagia risk after adjustment for comorbidity remain unclear. METHODS:We performed a retrospective cohort study using the TriNetX Research Network to identify patients aged 80 to 89 years undergoing ACDF from 2015 to 2023. Single-level ACDF was defined as CPT 22551 without 22552 and multi-level ACDF as CPT 22551 plus 22552. Cohorts were propensity score matched 1:1 on demographics and comorbidities. The primary outcome was new onset dysphagia at 0 to 2 weeks, 6 to 24 weeks, and 1 to 2 years. Secondary outcomes included aspiration pneumonia, reoperation, readmission, and mortality. Additional matched analyses compared octogenarians with younger patients aged 50 to 69 years stratified by operative extent. RESULTS:After matching, 993 octogenarians remained in each operative extent cohort. Dysphagia was more frequent after multi-level versus single-level ACDF at 0 to 2 weeks (11.5% vs 8.0%; RR 1.44, 95% CI 1.10 to 1.90; P =0.008), but did not differ at later timepoints. Other major postoperative complications did not differ by operative extent. In age stratified analyses, octogenarians had higher dysphagia rates than younger patients at 0 to 2 weeks after both single-level ACDF (7.7% vs. 4.5%; RR 1.71, 95% CI 1.23 to 2.39; P =0.001) and multi-level ACDF (11.6% vs. 8.0%; RR 1.45, 95% CI 1.13 to 1.85; P =0.003), with differences resolving by 6 to 24 weeks. CONCLUSIONS:Multi-level ACDF in octogenarians is associated with higher acute dysphagia risk than single-level ACDF. Advanced age is associated with increased early dysphagia after both procedures, supporting focused counseling and early dysphagia mitigation strategies. LEVEL OF EVIDENCE:III.

Study Design. Retrospective cohort study. Objective. To evaluate the independent associations of operative extent and advanced age with postoperative dysphagia after anterior cervical discectomy and fusion (ACDF). Summary of Background Data. Dysphagia is common after ACDF and may be especially consequential in octogenarians. The relative contributions of multi-level surgery and advanced age to dysphagia risk after adjustment for comorbidity remain unclear. Methods. We performed a retrospective cohort study using the TriNetX Research Network to identify patients aged 80 to 89 years undergoing ACDF from 2015 to 2023. Single-level ACDF was defined as CPT 22551 without 22552 and multi-level ACDF as CPT 22551 plus 22552. Cohorts were propensity score matched 1:1 on demographics and comorbidities. The primary outcome was new onset dysphagia at 0 to 2 weeks, 6 to 24 weeks, and 1 to 2 years. Secondary outcomes included aspiration pneumonia, reoperation, readmission, and mortality. Additional matched analyses compared octogenarians with younger patients aged 50 to 69 years stratified by operative extent. Results. After matching, 993 octogenarians remained in each operative extent cohort. Dysphagia was more frequent after multi-level versus single-level ACDF at 0 to 2 weeks (11.5% vs 8.0%; RR 1.44, 95% CI 1.10 to 1.90; P =0.008), but did not differ at later timepoints. Other major postoperative complications did not differ by operative extent. In age stratified analyses, octogenarians had higher dysphagia rates than younger patients at 0 to 2 weeks after both single-level ACDF (7.7% vs. 4.5%; RR 1.71, 95% CI 1.23 to 2.39; P =0.001) and multi-level ACDF (11.6% vs. 8.0%; RR 1.45, 95% CI 1.13 to 1.85; P =0.003), with differences resolving by 6 to 24 weeks. Conclusions. Multi-level ACDF in octogenarians is associated with higher acute dysphagia risk than single-level ACDF. Advanced age is associated with increased early dysphagia after both procedures, supporting focused counseling and early dysphagia mitigation strategies. Level of Evidence. III

STUDY DESIGN:Systematic review and meta-analysis. OBJECTIVE:To provide an updated global estimate of adolescent idiopathic scoliosis (AIS) prevalence, and to investigate its association with socioeconomic and environmental factors. SUMMARY OF BACKGROUND DATA:AIS, a common spinal deformity in adolescents aged 10 to 19, with unclear aetiology, limits early diagnosis and prevention. Current global estimates of AIS prevalence require updating, and studies investigating the association with socioeconomic and environmental factors are limited. METHODS:We systematically searched PubMed, Embase, Scopus, CINAHL, and Web of Science from inception to March 2025, without language restrictions. We included studies with radiographically confirmed AIS in adolescents aged 10 to 19 years. Pooled prevalence estimates for Cobb angles ≥10° and ≥20° were calculated using random-effects meta-analysis. Multivariable meta-regression was employed to explore associated factors. RESULTS:From 57,701 records, 104 studies encompassing 5.4 million adolescents from 33 countries across six World Health Organization regions were included. The pooled prevalence was 1.26% (95% CI: 1.03 to 1.55) for Cobb angle ≥10°, and 0.28% (95% CI: 0.23 to 0.34) for Cobb angle ≥20°. For curves ≥20°, multivariable meta-regression revealed that higher annual mean surface air temperature (odds ratio [OR]=1.03; P=0.043), screening not involving orthopaedic surgeons (OR=2.04; P=0.003), and higher study quality (OR=1.40; P=0.010) were significantly associated with a higher prevalence. Using the forward bending test alone (OR=0.64; P=0.034) was associated with a lower prevalence. CONCLUSION:The updated global prevalence of clinically significant AIS (Cobb angle ≥20°) was 0.28%, associated with environmental (such as temperature) and methodological factors (screening personnel, technique). These findings highlight the complex, multifactorial nature of AIS, underscoring the need for epidemiological surveillance and further assessment of screening strategies to optimize early detection and treatment of AIS worldwide.

STUDY DESIGN:Retrospective Cohort Study. OBJECTIVE:The objective of the present investigation is to evaluate the association between perioperative SGLT2i use and short-term postoperative complications and long-term outcomes following ACDF. SUMMARY OF BACKGROUND DATA:Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are a class of diabetic medications that provide cardiorenal benefits beyond glycemic control. Despite these benefits, SGLT2i use has been associated with a range of adverse effects. However, the literature remains limited regarding the impact of SGLT2i on perioperative recovery and complications in patients undergoing anterior cervical discectomy and fusion (ACDF). METHODS:A retrospective cohort study was conducted using the TriNetX database. Patients undergoing ACDF were identified and stratified by preoperative SGLT2i use. After 1:1 propensity score matching on demographics and comorbidities, 1,585 patients remained per cohort. Outcomes included postoperative events and long-term sequelae. Risk ratios (RR), 95% confidence intervals (CI), and P values were calculated; Kaplan-Meier curves were used to assess long-term event incidence. RESULTS:The SGLT2i cohort demonstrated lower rates of postoperative emergency department visits (1.3% vs. 2.2%; RR 0.59, 95% CI 0.34-0.99; P=0.047). At 1-year follow-up, patients receiving SGLT2i had lower rates of pseudoarthrosis (4.9% vs. 6.8%; RR 0.73, 95% CI 0.55-0.97; P=0.028). Reoperation rates at 5 years were also lower in the SGLT2i cohort (2.2% vs. 3.5%; RR 0.64, 95% CI 0.42-0.97; P=0.033). No significant differences were observed in ICU admission, surgical site infection, urinary tract infection, acute kidney injury, or readmission. CONCLUSION:Preoperative SGLT2 inhibitor use was associated with reduced postoperative emergency department utilization and lower rates of early pseudarthrosis following ACDF, without an increased risk of short-term complications. Recognition of these risks should inform preoperative counselling, postoperative surveillance, and multidisciplinary care planning for patients undergoing ACDF.

STUDY DESIGN:Retrospective cohort study of 42 patients with locally recurrent PST of the thoracic or lumbar spine after an EI resection performed by a referring institution. Patients were subsequently treated with gross total resection between 1995 and 2023. Outcome measures included local recurrence (LR), overall survival, mechanical complications, and functional outcomes. OBJECTIVE:To report the outcomes of revision resection for PST after prior Enneking inappropriate (EI) resection and to compare these outcomes with published controls for index en bloc resection. SUMMARY OF BACKGROUND DATA:En bloc resection is the preferred treatment for primary spine tumors (PST). This recommendation is supported by improvements in local control and overall survival in prior studies. Outcomes in the revision resection setting remain unclear. METHODS:Demographic, clinical, oncologic, and surgical variables were abstracted from medical records. Margin status was graded R0, R1, or R2 per pathology report. Overall survival and LR were estimated using the Kaplan Meier method. Between-group comparisons utilized Chi-square and Wilcoxon rank-sum testing. RESULTS:Local recurrence occurred in 50.0% of patients. Five-year overall survival was 66.7% and to-date overall survival was 54.8%. Surgical margin was the strongest predictor of outcome: local recurrence occurred in 37.5% of R0 resections, 50% of R1 resections, and 100% of R2 resections (P=0.20). R0 survival to-date was 21 of 29 patients (72.4%) and R1/R2 survival was 3 of 13 (23.1%) (P=0.04). The perioperative complication rate was 28.6% and the revision surgery rate was 40.5%. CONCLUSIONS:Patients undergoing resection for PST following local recurrence after prior EI surgery experienced higher local recurrence rates and inferior survival compared with published cohorts for index en bloc resection. Yet, a negative margin revision resection improves oncologic prognosis. These data support early referral to a comprehensive spine tumor program as the standard of care for PST.