Objective: Proximal junctional kyphosis (PJK) is a frequent postoperative complication following adult spinal deformity (ASD) surgery, whereas proximal junctional failure (PJF) is a less common but clinically more severe complication. Spinopelvic radiographic parameters have been associated with the development of these complications, yet existing studies have reported inconsistent results. This study aimed to investigate the association between spinopelvic parameters and proximal junctional complications (PJK/PJF), including analysis based on age-adjusted pelvic incidence (PI)–lumbar lordosis (LL) mismatch categories.Methods: This review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) 2020 guidelines. PubMed, Cochrane Library, and Embase were comprehensively searched from inception through March 2025. Adults (>18 years) who underwent surgery for ASD or long-segment (≥4 levels) spinal fusion were included. Studies were independently selected by 2 reviewers based on preset criteria. Random-effects model was used to calculate mean differences/standardized mean differences for continuous variables and odds ratios (ORs) for categorical outcomes.Results: A total of 47 retrospective studies were included in the meta-analysis. Preoperatively, the PJK group had lower LL and sacral slope (SS) but had higher pelvic tilt (PT), T1PA, and C7-sagittal vertical axis than the non-PJK group. Postoperatively, the PJK group showed significantly lower PI–LL mismatch values and SS and higher PT, thoracic kyphosis, thoracolumbar kyphosis, and T1 pelvic angle. When stratified by the age-adjusted PI–LL formula, overcorrection was associated with significantly higher odds of PJK (OR, 2.67; 95% confidence interval [CI], 1.61–4.42), whereas no significant association was observed for PJF. Using age-specific thresholds, overcorrection was significantly associated with higher odds of PJF (OR, 1.67; 95% CI, 1.10–2.52).Conclusion: Preoperative sagittal imbalance and postoperative spinopelvic differences were associated with proximal junctional complications, whereas associations for PJF were more limited. Age-adjusted overcorrection showed outcome-specific associations with proximal junctional complications, suggesting that age-tailored alignment may be clinically relevant. Given the retrospective aggregate evidence and limited age-adjusted data, future prospective studies with standardized radiographic timing and separate outcome assessment for PJK and PJF are needed to validate these findings.
Objective: To investigate explanatory factors associated with neck-related disability, headache, and neck and arm pain 2 years after anterior cervical decompression and fusion (ACDF) or posterior cervical foraminotomy (PCF) in individuals with cervical radiculopathy (CR) and neck-related headache.Methods: This registry-based cohort study used prospectively collected data with a 2-year follow-up from the Swedish Spine Registry. Individuals who underwent ACDF (n=1,866) or PCF (n=357) for CR between January 2016 and March 2021 and reported preoperative neck-related headache were included. Standard analysis of covariance models were used to identify explanatory factors for the absolute values of Neck Disability Index (NDI), NDI-headache, Numerical Rating Scale (NRS) neck pain, and NRS arm pain at the 2-year follow-up after ACDF or PCF.Results: Explanatory factors explained 33% and 32% of the neck-related disability, 20% and 35% of the headache, 21% and 13% of the neck pain, and 16% and 24% of the arm pain at 2-year follow-up after ACDF and PCF, respectively, in individuals with CR and neck-related headache. The preoperative value of these outcomes had the greatest impact, except for neck and arm pain after PCF, where neck-related disability had a greater impact.Conclusion: Neck-related disability, headache, and neck and arm pain after ACDF and PCF in individuals with CR and neck-related headache are associated with preoperative levels of these outcomes, as well as demographic, lifestyle, surgical factors and self-reported health, that should be considered before surgery. The models explained 13%–35% of the variance in the outcomes, indicating that a substantial proportion remains unexplained.
Objective: To establish an adult-lifespan segment-specific normative atlas of cervical spinal cord morphometry as a physiologically adjusted reference and to explore its application in degenerative cervical myelopathy (DCM).Methods: We included 829 healthy volunteers and 210 surgically treated DCM patients undergoing cervical magnetic resonance imaging (MRI) from 2019 to 2023. Follow-up MRI was obtained in a stratified random sample of 207 healthy volunteers and 42 patients. Axial T2-weighted images at C2–3 to C6–7 were segmented semiautomatically. Cross-sectional area (CSA) was the primary morphometric measure; right-left and anteroposterior diameters (APDs) were complementary measures. In healthy volunteers, sex-stratified, level-specific models including age, age², magnetic field strength, and scanner manufacturer were used to construct the atlas and compute z-scores. In DCM, z-scores were summarized as CompMinZ and NonCompMinZ and explored in relation to clinical outcomes.Results: In healthy volunteers, CSA showed a nonlinear pattern, with smaller values at older ages. Longitudinal changes were age dependent: CSA, right-left diameter, and APD increased in younger adults, were stable in midlife, and declined in older adults. In DCM, z-scores were most negative at compressed levels, while noncompressed segments also frequently fell below the normative mean. Z-score metrics showed exploratory associations with neurological status and postoperative outcomes. In the postoperative subset, CompMinZ showed the strongest association with recovery rate, whereas maximum spinal cord compression was not significantly associated with recovery rate.Conclusion: An adult-lifespan, segment-specific normative atlas of cervical spinal cord morphometry provides a physiologically adjusted reference for interpreting cervical cord morphologic variation and deviation, with exploratory application in surgically treated DCM.
Objective: Parkinson disease (PD) is frequently characterized by a forward-bent posture that increases biomechanical stress on the lumbar spine, which increases the rate of subsequent lumbar surgeries after spinal fusions. This study aimed to evaluate the rates of additional lumbar surgeries following spinal fusion in patients with PD.Methods: Data from the Health Insurance Review and Assessment Service of the Republic of Korea were retrospectively analyzed. PD was identified using the International Classification of Diseases, 10th Revision code G20. Patients with PD were matched with those without PD in a 3:1 ratio based on sex, age, and Charlson Comorbidity Index using the greedy nearest neighbor matching method. The primary outcome was the rate of subsequent lumbar surgeries following spinal fusion within the 7-year follow-up period. The timing of these reoperations was also assessed.Results: A total of 2,287 patients with PD and 6,861 matched patients without PD were included in this study. The prevalence of PD among patients undergoing lumbar fusion surgery remained stable throughout the study period. Patients with PD had 1.6-fold higher odds to undergo reoperation compared with the non-PD cohort. No significant difference was observed in the timing of additional surgeries between the groups.Conclusion: Patients with PD faced 1.6-fold higher odds of subsequent lumbar surgeries following spinal fusion compared to those without the disease. This finding suggests the need for a cautious treatment approach and thorough preoperative optimization when considering lumbar fusion in this population.
Objective: To compare perioperative burden, hardware outcomes, and oncologic control between sagittal vertebral resection (SVR) and total vertebral resection (TVR) for thoracolumbar tumors, and to propose a practical framework for SVR surgical decision making.Methods: Clinical data, operative parameters, and follow-up outcomes were retrospectively analyzed. To address baseline imbalances in tumor volume and preoperative embolization, a 1:1 propensity score matching was performed based on 5 critical covariates, resulting in a matched cohort of 78 patients (39 per group). Groups were compared using Student t-test or Mann-Whitney U-test for continuous variables and chi-square/Fisher exact test for categorical variables.Results: In the total cohort (39 SVR vs. 84 TVR), SVR significantly reduced blood loss (median 1,200 mL vs. 1,500 mL, p=0.016), transfusion (800 mL vs. 1,200 mL, p<0.001), complication rate (51.3% vs. 77.4%, p=0.004), and hospital stay (13.7 days vs. 19.0 days, p=0.012). Bilateral nerve root sacrifice was less frequent in SVR (41.0% vs. 69.0%, p<0.001). Negative surgical margins (71.8% vs. 73.8%, p=0.814) and local recurrence (12.8% vs. 13.1%, p=0.965) were comparable. Postmatching analysis (n=78) confirmed that even after balancing for tumor volume and embolization, the SVR group maintained significant advantages in blood loss (p=0.035) and operation time (p=0.041). Hardware failure occurred in 3 TVR patients (3.6%) but in none after SVR.Conclusion: SVR significantly reduces perioperative morbidity while maintaining comparable oncologic outcomes relative to TVR. The superiority of SVR remains robust after propensity score adjustment for tumor complexity. By formalizing a type-based surgical decision-making framework, this study provides practical guidance for when and how SVR may be safely adopted as a standardized alternative to TVR in appropriately selected thoracolumbar tumors.
Objective: This study aimed to investigate the role of the STAT3/POSTN/GSTP1/JNK axis in ferroptosis and extracellular matrix (ECM) metabolic imbalance in nucleus pulposus cells (NPCs) during intervertebral disc degeneration (IDD) and to explore therapeutic strategies targeting this axis.Methods: Using integrated multiomics sequencing, transcriptional regulation assays (chromatin immunoprecipitation, dual‑luciferase reporter), protein interaction analysis (CoIP), and other molecular biology approaches, we systematically elucidated the regulatory role of the STAT3/POSTN/GSTP1/JNK axis in ferroptosis of NPCs during IDD. Functional validation was performed in POSTN‑edited cell and rat models as well as in a needle‑puncture‑induced rat IDD model. A small‑molecule candidate targeting this axis was identified through virtual screening, molecular docking, and molecular dynamics simulations.Results: Periostin (POSTN) expression increased during ferroptosis and induced ferroptosis and ECM metabolic imbalance in NPCs in a concentration- and time-dependent manner. STAT3 was identified as a transcriptional regulator of POSTN and functionally coupled with POSTN to form a self-amplifying positive feedback loop, accelerating ferroptosis progression. Furthermore, POSTN impaired the binding of the GSTP1/JNK complex, leading to the depletion of cellular glutathione. Chemical screening identified pristimerin (PN) as a potential GSTP1-targeting compound, targeting the STAT3/POSTN/GSTP1/JNK axis and delaying IDD progression.Conclusion: This study identified the important role of the STAT3/POSTN/GSTP1/JNK axis in regulating ferroptosis and ECM metabolism in NPCs and highlighted PN as a promising candidate therapeutic agent for IDD. These findings provide new insights into the molecular mechanisms underlying IDD and offer new targeted therapeutic avenues for IDD.
Objective: Endoscopic spine surgery (ESS) has expanded rapidly, but existing spine registries do not consistently capture ESS-specific technical variables, ultra-early recovery trajectories, selective imaging validation, or dissemination-related learning-curve effects. This review synthesizes established spine registry models, contemporary consensus initiatives, and digital follow-up approaches to propose a candidate ESS-specific registry framework and preliminary Minimum Data Set (MDS) for future validation.Methods: A structured narrative review was conducted on national and multinational spine registries, relevant consensus initiatives, and digital follow-up models. Sources were reviewed with emphasis on governance, data architecture, workflow design, patient-reported outcome measures (PROMs) integration, follow-up structure, data linkage, validation strategies, and implementation feasibility.Results: Established registries provide a methodological foundation for benchmarking, complication surveillance, longitudinal PROM capture, and real-world evidence generation. However, ESS requires modular augmentation of existing registry infrastructures to capture approach-specific operative details, early recovery, selective imaging phenotypes, and governance-controlled maturity indicators. The proposed candidate MDS is organized into 4 domains: (1) baseline case-mix and phenotyping, (2) procedure-specific technical and perioperative variables, (3) selective quantitative imaging and morphometric validation, and (4) structured longitudinal outcome surveillance. The framework prioritizes an essential core dataset while separating recommended, optional, research-oriented, and governance-controlled modules, including digitally enabled early follow-up, opioid-related outcomes, radiation exposure, advanced imaging, and learning-curve variables.Conclusion: A candidate ESS-specific registry framework may support harmonized data capture, real-world evidence generation, quality feedback, and future registry-based research. Formal Delphi consensus, multicenter feasibility testing, and staged integration into existing spine registry infrastructures are required before broader implementation.
Objective: Accurate segmentation of surgical instruments in endoscopic images is essential for developing computer-assisted surgical systems, yet creating annotated training datasets remains labor-intensive. This study aimed to evaluate the efficiency of point-based interactive segmentation using foundation models for surgical instrument annotation in spinal endoscopy.Methods: We conducted a retrospective study comparing point-based segmentation performance between Segment Anything Model (SAM) 2.0, SAM 2.1, and domain-adapted MedSAM 2.1 for surgical instrument segmentation in spinal endoscopy. A test set of 308 images from 10 patients undergoing full-endoscopic lumbar decompression/discectomy or biportal endoscopic decompression/discectomy was evaluated. Models were assessed using standardized point prompts placed at the ground truth mask centroid. Primary outcomes included Dice similarity coefficient at single-click and success rate (Dice≥0.85). Secondary analysis evaluated click-to-quality metrics across iterative refinement up to 10 clicks.Results: At single-click, MedSAM 2.1 achieved significantly higher Dice scores than SAM 2.1 (0.937±0.074 vs. 0.844±0.222, p<0.001; 95% confidence interval [CI] for difference, 0.070–0.116) and SAM 2.0 (0.937±0.074 vs. 0.824±0.236, p<0.001; 95% CI for difference, 0.088–0.138), with a 3-fold reduction in variability (standard deviation: 0.074 vs. 0.222). External validation on the publicly available Spine Endoscopic Atlas dataset (202 images from 10 patients) confirmed generalizability, with MedSAM 2.1 achieving Dice 0.918±0.083, compared to 0.724±0.281 for SAM 2.1 and 0.708±0.290 for SAM 2.0 (both p<0.001). Interrater agreement between 2 independent annotators demonstrated excellent reliability (intraclass correlation coefficient, 0.991; 95% CI, 0.986–0.994; mean pairwise Dice, 0.953±0.051). The MedSAM 2.1-assisted workflow reduced annotation time by 75.8% compared to manual polygon annotation (7.7±13.3 seconds vs. 31.8±18.2 seconds per image; p<0.001; 4.1-fold speedup). SAM 2.1 improved progressively with additional clicks (Dice 0.844 to 0.943 at 10 clicks), while MedSAM 2.1 showed nonmonotonic progression (0.937 to 0.947), indicating near-optimal first-click predictions.Conclusion: Domain-adapted MedSAM 2.1 improved single-click annotation accuracy and efficiency for surgical instruments in spinal endoscopy, suggesting that low-resource domain adaptation may facilitate institutional dataset construction for surgical artificial intelligence research.
Objective: Advanced age has been proposed as a risk factor for worse outcomes and higher complication rates after spinal surgery. We assessed whether decompression for central lumbar spinal stenosis (CLSS) provided meaningful improvement in patients aged 50–95 years.Methods: We evaluated preoperative and 1-year postoperative Numerical Rating Scale (NRS) leg and back pain, Oswestry Disability Index (ODI), and complications in 17,987 patients aged ≥50 years undergoing decompression without fusion for CLSS without spondylolisthesis from the Swespine register. Meaningful improvement was defined using minimal clinically important difference (MCID) thresholds for NRS leg/back pain and ODI. Across 5-year age groups, we assessed the proportions improving ≥MCID and odds ratios (ORs) with 95% confidence intervals (CIs), using ages 65–69 years as the reference group.Results: Across age groups, 71%–80% improved ≥MCID in ≥1 outcome. Compared with the reference group, ORs (95% CI) for ≥MCID improvement were lower in ages 70–74 (0.8; 0.7–1.0), 75–79 (0.7; 0.6–0.8), 80–84 (0.6; 0.5–0.7), and 85–89 (0.6; 0.5–0.8); no other age groups differed. 5%–12% experienced complications. Compared with the reference group, ORs (95% CI) for complications were higher in ages 75–79 (1.3; 1.1–1.6), 80–84 (1.7; 1.4–2.1), and 85–89 (2.0; 1.5–2.8), and lower in ages 55–59 (0.7; 0.5–0.9).Conclusion: 77% of patients aged 50–95 years improved ≥MCID after decompression without fusion for CLSS without spondylolisthesis. Although outcomes were slightly worse and complication rates higher in older than younger patients, decompression without fusion remains effective across this age range.
Sacral slanting—defined as the oblique tilt of the upper sacral endplate measurable on standing anteroposterior whole-spine radiographs—is a distinctive and clinically underappreciated finding in adolescent idiopathic scoliosis (AIS). Its etiology is multifactorial and incidence among AIS patients reaches 40%. The direction and degree of sacral slanting interact with the distal lumbar curve type (L4-left vs. L4-right) to influence the pattern of postoperative radiographic changes at the distal spine and shoulder. In patients with L4-left curves and left-sided slanting, stopping fusion at L3 generally prevents coronal decompensation. Furthermore, 5-year data show that the disc wedge angle below the lowermost instrumented vertebra (LIV) does not progress when LIV is L3, and patient-reported outcomes are preserved without revision surgery. When fusion extends to L4 in patients with high sacral slanting, coronal decompensation is more frequent, yet functional outcomes remain comparable and no revision has been required in published series to date, indicating that the decompensation observed is radiographically significant but clinically tolerable within the medium term. In Lenke 1A patients with right-sided sacral slanting (L4-right type), the slanting lowers the last touching vertebra and may facilitate distal adding-on. In Lenke 2A patients with right-sided slanting, distal adding-on serves as a natural shoulder-rebalancing mechanism and may be reasonably monitored conservatively rather than reflexively treated, pending further validation in independent cohorts, unless progressive or symptomatic. Across all scenarios, the optimal distal fusion level remains an unresolved dilemma requiring further long-term prospective study. This review synthesizes the available literature to characterize sacral slanting as a promising radiographic parameter that may serve as a potentially useful adjunct in distal fusion level planning, while highlighting the need for prospective multicenter validation before its routine incorporation into surgical decision-making in AIS.
Objective: Adjacent segment disease (ASD) is a recognized long-term complication after anterior cervical discectomy and fusion (ACDF). Cervical disc arthroplasty (CDA) was introduced as a motion-preserving alternative, thought to reduce stress at adjacent levels and lower ASD risk. This study aimed to compare the risk of ASD requiring reoperation after ACDF and CDA and identify factors associated with ASD.Methods: This retrospective cohort study used prospectively collected data from the Swedish Spine Registry (Swespine) and included adult patients undergoing anterior cervical surgery for degenerative cervical disease between 2006 and 2026. ASD was defined as a secondary operation at an adjacent level ≥12 months after the index procedure. Cumulative incidence was estimated using Kaplan-Meier analysis, and associations with ASD were evaluated using multivariable Cox proportional hazards regression. Radiological or conservatively treated ASD were not assessed.Results: A total of 9,338 patients were included (ACDF, n=9,005; CDA, n=333). During 45,666 person-years follow-up, 509 ASD events occurred (incidence rate 11.1 per 1,000 person-years). Cumulative incidence was 4.9% at 5 years and 10.4% at 10 years. CDA was associated with lower ASD hazard than ACDF (hazard ratio [HR], 0.61) though this association was not significant after propensity score matching (HR, 0.88). Multilevel procedures (HR, 0.61), increasing age (HR, 0.96 per year), and radiculopathy were associated with lower risk, while myelopathy or stenosis was associated with higher risk (HR, 1.22).Conclusion: The long-term risk of ASD requiring reoperation was lower than previously reported. After adjustment, CDA was associated with lower ASD risk compared to ACDF, although the absolute difference was small, and the clinical significance remains uncertain.
