Global Spine Journal

Literature review with clinical recommendation.

To provide the readers with a concise curation of the relevant spine literature regarding patient-specific alignment planning in patients with adult spinal deformity (ASD) and set out recommendations for how the practicing clinician should interpret and make use of this evidence.

Key articles on patient-specific alignment planning for ASD were reviewed to develop clinical recommendations by consensus. Recommendations are graded as strong or conditional, based on methodological quality and expert opinion.

Four articles were selected by the AO Spine Knowledge Forum Deformity and each evaluated for the strength of methodology and scientific evidence.

The 4 reviewed publications illustrate the progression from descriptive to proportional and finally continuous alignment concepts in adult spinal deformity surgery. The Roussouly morphotypes help clinicians understand native sagittal shape and compensatory patterns, the SRS–Schwab classification remains useful for standardized description and communication, the GAP Score introduces pelvic-incidence–based proportionality, the T4–L1–Hip axis offers continuous, directly modifiable angular targets. Used together, these models offer complementary perspectives that enhance preoperative planning and postoperative evaluation. Integrating their strengths, while considering patient-specific factors such as bone quality, physiologic reserve, and surgical goals, supports more individualized and durable alignment strategies.

Retrospective case–control study.

To identify risk factors for proximal junctional kyphosis (PJK) after long-segment fusion in adult degenerative scoliosis (ADS) and to develop a machine learning–based prediction model with external validation.

We retrospectively analyzed 142 ADS patients from two institutions undergoing posterior long-segment fusion with ≥24 months follow-up. Patients from center A (n = 105) formed the training cohort, and those from center B (n = 37) served as the external validation cohort. Demographic, radiographic, and surgical parameters were compared between patients with and without PJK. Independent predictors were determined with multivariate logistic regression. Least absolute shrinkage and selection operator (LASSO) regression identified key variables. Six supervised machine learning algorithms were trained using center A data and validated on center B data. Model interpretability was assessed using Local Interpretable Model-agnostic Explanations (LIME).

PJK occurred in 24 patients (16.9%). Logistic regression identified lower T-score, higher T1–pelvic angle, and female sex as independent predictors, with ASA grade III showing a marginal effect. LASSO retained five features: T score, ASA grade, T1PA, sacral slope, and pelvic incidence. Among algorithms, the back-propagation neural network with LASSO feature selection yielded the best discrimination (external validation AUC = 0.882). LIME analysis confirmed T score, T1PA, and PI as the most influential predictors.

Reduced bone density, impaired sagittal balance, and higher ASA grade increase PJK risk after long-segment fusion in ADS. A neural network combined with LASSO feature selection demonstrated superior predictive performance, supporting its potential for individualized preoperative risk assessment and surgical planning.

Pilot randomized controlled trial.

Iatrogenic nerve injury is a major complication in endoscopic spinal surgery, potentially causing serious neurological deficits. Near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) has shown promise for intraoperative nerve root identification. This study assessed the feasibility, optimal dosing, safety, and mechanism of ICG fluorescence for nerve root visualization, transitioning from preclinical to clinical phases.

In the preclinical phase, 36 rabbits were assigned to ICG dose groups (1.4, 2.8, or 5.5 mg/kg, corresponding to 0.5, 1, or 2 mg/kg in humans) and observation times (3, 6, 12, or 24 hours). Fluorescence signals in lumbar nerve roots were quantified by signal-to-background ratio (SBR) and mean fluorescence intensity (MFI). Histological analyses explored ICG retention mechanisms. In the clinical phase, 40 patients undergoing unilateral biportal endoscopic surgery for lumbar disc herniation were randomized into different ICG dose groups (0, 0.5, 1, or 2 mg/kg), administered 1.5 hours preoperatively. Intraoperative fluorescence parameters, nerve root identification time, and perioperative outcomes (VAS and ODI scores) were assessed.

In preclinical studies, the 2.8 and 5.5 mg/kg groups showed peak SBR and MFI at 3 hours post-injection. Histology revealed ICG accumulation in nerve root microvascular regions. In the clinical study, the 2 mg/kg group had the highest SBR and MFI, reducing nerve root identification time without significant adverse events.

ICG fluorescence imaging is a feasible and safe technique for intraoperative nerve root visualization, with ICG accumulation attributed to the enhanced permeability and retention effect.

Retrospective comparative study.

Neuromuscular scoliosis (NMS) is a complex deformity requiring individualized surgical strategies focused on improving sitting balance and quality of life. This study aimed to evaluate the clinical efficacy and safety of multilevel asymmetrical Ponte osteotomy (MAPO) in NMS patients, compared to conventional posterior fusion without osteotomy.

A retrospective review was conducted on 90 patients with NMS who underwent posterior spinal correction between 2015 and 2021. Patients were divided into a MAPO group (n = 52) and a control group (n = 38). Radiographic parameters and health-related quality of life (SRS-22) were assessed preoperatively, postoperatively, and at ≥2-year follow-up. Perioperative data, including operative time, blood loss, transfusion volume, and complications, were analyzed.

Baseline characteristics were comparable. The MAPO group achieved significantly greater correction in major curve angle (49.75% vs 46.34%, P = 0.031), pelvic obliquity (25.26% vs 20.81%, P = 0.048), and sagittal vertical axis (33.99% vs 30.08%, P = 0.045). Postoperative satisfaction (4.43 ± 0.55 vs 4.11 ± 0.57, P = 0.026) and function scores (4.39 ± 0.48 vs 4.10 ± 0.61, P = 0.040) were also significantly higher in the MAPO group. However, MAPO was associated with longer operative time (311 vs 229 min, P < 0.001), greater blood loss (685 vs 289 mL, P < 0.001), and a trend toward increased complications, including wound issues and CSF leaks.

MAPO offers improved deformity correction and higher patient satisfaction compared to non-osteotomy procedures in NMS, though with increased surgical complexity. It may serve as a valuable option for selected patients when balancing benefits and risks.

Retrospective cohort study.

This study aimed to compare the clinical efficacies of endoscopic surgery and nonsurgical treatment in patients with extruded or sequestered lumbar disc herniation (LDH).

613 patients with extruded or sequestrated LDH were included (endoscopic: n = 276; nonsurgical: n = 337).

Patients received either endoscopic discectomy or structured nonsurgical management. Longitudinal VAS and ODI trajectories were analyzed using linear mixed-effects models. Return to work (RTW) outcomes were evaluated using Kaplan–Meier survival curves and Cox proportional hazards models. Spearman correlation was used to assess the association between resorption and symptom improvement.

Both cohorts had comparable sex, BMI, and herniation levels (P > .05), but differed in age (P < .001), which did not influence outcomes after adjustment. VAS and ODI improved in both groups over time (P < .001). Endoscopic discectomy provided faster symptom relief within 6 months (P < .001), whereas mid to long-term outcomes were comparable between groups (P > .05). Disc resorption occurred in 58.2% of nonsurgical patients (median time 6.9 months). Resorption was correlated with greater improvements in ODI and VAS (P < .05). Surgical complications included transient neurological deficits (17.4%), dural tears (1.1%), and epidural hematomas (0.7%). Postoperative recurrence occurred in 8.3% of patients. RTW time was unaffected by treatment, sex, BMI, or herniation level (P > .05), but was influenced by age (HR = 0.948, P < .001) and occupational demands (HR = 0.697, P < .001).

Endoscopic discectomy provides faster early pain and functional improvement (≤6 months), while nonsurgical management achieves comparable outcomes thereafter. Disc resorption contributes to symptom recovery. RTW time is determined primarily by age and occupational demands.

Social determinants of health have been shown to influence various outcome measures after elective orthopaedic procedures, including spine surgery. However, there has been limited research investigating the influence between social determinants of health and healthcare resource utilization after elective spine surgery. The purpose of this study was to investigate the influence of social vulnerability on opioid use, healthcare utilization, and patient-report outcome measures (PROMs) after elective lumbar decompression procedures.

Patients undergoing elective 1- or 2- level lumbar decompression procedures between 2013 and 2018 at a single tertiary medical center were retrospectively identified. Various demographic variables, including the ZIP code of residence for each patient were reported. The Centers for Disease Control and Prevention (CDC) Social Vulnerability Index (SVI) scores were calculated for each patient. Social vulnerability was defined as combined socioeconomic and housing vulnerability scores in the upper quartile. Several outcome measures were compared between patients with or without social vulnerability. The outcomes of interest included healthcare utilization and patient-reported outcome measures – pain interference (PI) and physical function (PF) within 1 year postoperatively. Healthcare utilization metrics included opioid use, emergency department visits, urgent care visits, MRI studies, pain management referrals, and revision surgeries. The minimal clinically important difference (MCID) was defined as 8 for both PI and PF scores.

A total of 216 patients were included in the cohort −58 patients met criteria for social vulnerability. Patients with social vulnerability were more likely to be female and ASA class 2. Otherwise, patient demographics and medical comorbidities were similar between the 2 groups. Patients with social vulnerability were more likely to utilize the emergency department within 1-year postoperatively and to have persistent opioid use at both 6 months and 1 year postoperatively. On multivariate regression, SVI was independently associated with pre-operative opioid use, post-operative emergency department utilization, and persistent opioid use after surgery. Relative improvement in PI and PF scores and rates of MCID attainment were similar between groups.

Patients with social disparities were more likely to utilize the emergency department and have persistent opioid use at 6 months and 1 year postoperatively from elective lumbar decompression procedures.

Retrospective cohort study.

Prior studies have shown that adult spinal deformity (ASD) patients undergoing revision surgery due to mechanical complications had less radiographic improvement and worsening patient-reported outcomes scores. The combination of customized 3D planning and personalized implants has been shown to contribute to improved achievement of alignment goals. This study aimed to determine whether such improved correction also results in a correspondingly lower revision surgery rate due to mechanical complications.

Pre- and postoperative radiographic alignment measures, including lumbar lordosis (LL), distal lumbar lordosis (DLL), pelvic incidence (PI) – LL mismatch, and L1 pelvic angle (L1PA), as well as data on mechanical complications leading to reoperation were collected on 115 ASD patients with personalized interbody implants and minimum 2-year follow-up. This cohort was statistically compared to a multicenter dataset (ISSG) of 997 ASD patients treated using stock devices and using the same reoperation classifications.

Postoperatively achieved alignment measures correlated significantly with their respective preoperative alignment goals, with the following average offsets from plan: 2.4° LL, −0.2° DLL, −2.4° PI-LL, 0.3° L1PA. Compared to the ISSG cohort that utilized stock interbody implants, the cohort utilizing 3D preoperative planning and personalized interbody implants resulted in significantly fewer revisions for mechanical complications up to 2 years postoperatively: 5/115 (4.3%) vs 166/997 (16.6%), P < 0.001.

These findings suggest that achieving planned alignment targets with personalized interbody devices is associated with reduced revision surgery for mechanical complications, a result which may have positive implications for improved patient outcomes and reduced cost.

Prospective Cohort Study.

The rapidly evolving landscape of cancer care alters the prognostic accuracy of established scoring systems for metastatic spinal tumors. This study aimed to provide a contemporary assessment of patient survival and examine the independent and complementary roles of the new Katagiri score (a systemic prognostic tool) and the Spinal Instability Neoplastic Score (SINS, a mechanical instability tool) in predicting 6-month mortality, laying a foundation for future combined prognostic model development.

We prospectively analyzed 151 patients with metastatic spinal tumors treated between 2021 and 2023. Demographic, clinical, and treatment data, including the new Katagiri score and SINS, were collected. The primary endpoint was 6-month mortality, which was evaluated using trend tests, correlation, and multivariate logistic regression.

The 6-month mortality rate was 25.17%. Higher scores in both the new Katagiri score and the SINS were significantly associated with an increased risk of 6-month mortality. Notably, no significant correlation was observed between the total Katagiri score and the total SINS. Stratified analyses showed that prognostic factors for early mortality differed across new Katagiri score risk groups, with varying influences from specific Katagiri score items, SINS components, and spinal metastasis levels. SINS-related factors had a significant impact in the high-risk group.

The new Katagiri score and SINS independently predicted 6-month mortality in our cohort. Our findings suggest that considering both complementary measures may further refine prognostic assessment, providing a rationale for future prospective model development and validation.

Randomized Controlled Trial.

The Schroth method has emerged as a promising rehabilitation approach for Adolescent Idiopathic Scoliosis (AIS). This study compared the effects of Schroth and conventional exercise programs on spinal curvature, cortical thickness, and white matter pathways using structural MRI and Diffusion Tensor Imaging (DTI).

Thirty-six individuals with AIS were randomly assigned to a Schroth Exercise Group (SEG) or a Traditional Exercise Group (TEG). A healthy control group (n = 18) was also included. The sample size was calculated to provide 80% power (d = 0.60), and post hoc analysis indicated strong power (>0.99) for the observed treatment effect (d = 3.59). Both exercise groups completed supervised home-based programs for four months. Post-intervention MRI and DTI analyses were performed. The study was registered at ClinicalTrials.gov (NCT06410456).

After adjusting for baseline severity, the SEG showed a significantly greater improvement in Cobb angle compared to the TEG (adjusted mean difference = 8.07°, P < .001). Although the SEG achieved a significantly lower post-treatment Cobb angle compared to the TEG, residual curvature remained significantly different from the healthy controls (P < .001), reflecting the structural nature of scoliosis. Additionally, after adjusting for age and intracranial volume, cortical thickness in sensorimotor regions and tractography metrics of the right corticospinal tract in the SEG were comparable to controls and significantly different from the TEG.

Schroth exercises were associated with brain structural features suggestive of adaptive neuroplastic responses. These exploratory findings highlight potential neurobiological mechanisms and support further longitudinal research.

Post-hoc analysis of data from prospective multicenter observational study.

Adult spinal deformity (ASD) can have significant impact on various aspects of a patient’s social life. This study aims to examine the impact of ASD surgery on the social functioning among elderly patients.

Patients ≥60 years undergoing ≥5 levels of spinal fusion from 12 international centers were enrolled and followed up 2 years post-operatively. The outcome measures of interest in the current report were questions 14 and 18 of the Scoliosis Research Society-22r questionnaire (SRS-22r), and question 9 from the Oswestry Disability Index (ODI).

219 patients met the inclusion criteria, with a median age of 67.5 and 80.4% being female. More than a third were employed or homemakers, 60.3% were retired and 25.7% showed cognitive impairment. For the SRS-22r Q14, at baseline, 40.6% of patients felt their back condition moderately or severely affected their personal relationships compared to 14.7% at 2-years. For SRS-22r Q18, at baseline, 47.7% of patients felt their back often or very often limited them going out with friends/family compared to 17.1% at 2-years. For the ODI, Q9, 8.7% of patients felt that their social was normal and does not cause them extra pain pre-op compared to 44.1% of patients at 2-years.

While many factors can affect a patient’s social function, in this cohort ASD surgery had a positive impact on social function.

The ClinicalTrails.gov identifier: NCT02035280.

Vignette-based cross-sectional study.

Generative artificial intelligence (AI) programs such as large language models (LLMs) are reshaping treatment decision-making, yet applications in minimally invasive spine surgery (MISS) are still scarce. This study examines whether OpenAI’s ChatGPT-5 Pro and Google’s Gemini 2.5 Pro reproduce expert management categories from published MISS cases and measures agreement at procedural and binary triage levels.

We constructed 90 clinical vignettes from published case reports and prompted each LLM to assign 1 or more of ten predefined categories with two-sentence rationales. Agreement with reference was assessed using Jensen–Shannon divergence (JSD), Stuart–Maxwell tests, Cohen’s κ, and McNemar’s test for surgical vs non-surgical triage.

Divergence from reference was small, with Jensen–Shannon divergence 0.115 (ChatGPT-5 Pro) and 0.112 (Gemini 2.5 Pro), and smaller between models at 0.073. Paired multinomial tests found differences from the reference (Stuart–Maxwell χ²(9) = 24.8 and 26.0; P = 0.007 and 0.006) but not between models (14.4; P = 0.108). Case-level agreement was slight for ChatGPT-5 Pro and fair for Gemini 2.5 Pro (κ = 0.146 and 0.245). Collapsing categories to surgical vs non-surgical improved agreement (κ = 0.415 and 0.587 vs reference; 0.692 between models) with no bias in rates (P ≥ 0.401).

LLMs may differentiate between surgical and non-surgical triage, but procedure selection should remain expert-led until systems mature. These findings establish a baseline for integrating LLMs into surgical triage workflows and highlight promise and limitations of generative AI in precision spine care.

Prospective Cohort Study.

This prospective observational study aimed to compare differences in the incidence of Cutibacterium acnes isolation in intervertebral discs from patients undergoing surgery for degenerative vs non-degenerative spinal pathology, and to assess differences in Modic changes and Pfirrmann grades between culture-positive and culture-negative discs.

Intervertebral disc tissue was obtained from patients undergoing discectomy or interbody fusion for degenerative pathology, or from traumatic or oncological indications without degenerative pathology. Samples were cultured for Cutibacterium acnes. MRI scans were assessed for Modic changes and Pfirrmann grades.

There were 92 samples (91.1%) collected from 60 patients with degenerative pathology, while nine samples were obtained from seven patients with non-degenerative pathology. Cutibacterium acnes was cultured in 10/92 (10.87%) degenerative and 2/9 (22.22%) non-degenerative samples (P = 0.338). Samples from the cervical spine had a significantly higher incidence of Cutibacterium acnes culture (25.71% vs 4.76, P = 0.002). No significant differences were observed in Modic changes and Pfirrmann grades between culture-positive and culture-negative samples in either group. Higher Pfirrmann grades were observed in the degenerative pathology patient group (P < 0.001).

The lack of significant differences in Cutibacterium acnes isolation between patient groups suggests that the presence of Cutibacterium acnes cultured from disc tissues is likely from contamination. This finding adds to the growing body of work examining the role of Cutibacterium acnes in degenerative disc disease, although the study is underpowered to draw firm conclusions. Further investigation involving larger patient groups is needed to build on these preliminary observations.

Retrospective Cohort Study.

Adolescent idiopathic scoliosis (AIS) with a concomitant pars defect poses the surgical challenge of balancing stress avoidance at the lytic segment, deformity correction, and mobility preservation. Data on lowest instrumented vertebra (LIV) selection are limited. This study aimed to identify a safe LIV in posterior spinal fusion (PSF) to minimize pain and slip progression.

Retrospective review of AIS patients (10-18 years) with spondylolysis or spondylolisthesis who underwent PSF (2016-2023) with ≥ 2-year follow-up. Variables included demographics, curve characteristics, Meyerding grade, LIV selection, and mobile segments between LIV and lytic level. Primary outcome was back pain (VAS). Secondary outcomes included slip progression, subjacent curve, mechanical complications, and revision. Between-group comparisons used Mann–Whitney U; regression assessed effects of mobility preservation and subjacent curvature on pain.

Of 462 AIS patients, 29 met inclusion criteria (mean age 15.5 ± 1.5 years; 24% spondylolisthesis). Fusion ended at or above L3 in 76% and below in 24%. Follow-up VAS pain was higher in patients with <3 mobile segments between LIV and lytic level (4.5 ± 1.4 vs 2.8 ± 1.5; P = .003) and in fusions extending below L3 (5.0 ± 1.3 vs 3.0 ± 1.4; P = .004). Regression showed each additional mobile segment decreased pain (β = −0.77, P = .001), while greater subjacent curvature increased pain (per 10°, β = 0.92, P = .043). Two patients progressed to grade 1 slip; three were indicated for revision with distal junctional failure or persistent pain.

In AIS with coexisting spondylolysis, selecting LIV proximal to L3 minimizes pain while preserving mobile segments, without excessive slip progression.

A prospective nonrandomized observational cohort study.

To compare the clinical efficacy of arthroscopic-assisted uniportal spinal surgery combined with unilateral laminotomy bilateral decompression (AUSS-ULBD) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of single-segment stable degenerative lumbar spondylolisthesis (DLS).

A total of 168 patients (AUSS-ULBD n = 86, MIS-TLIF n = 82) with single-segment stable DLS were included. The patients were followed up for at least 2 years. The primary outcome was Oswestry disability index (ODI). Other perioperative indicators, clinical, and radiological outcomes were also compared.

For ODI, the adjusted mean differences (AUSS-ULBD minus MIS-TLIF) were 1.20 (95% CI −0.85 to 3.25) at 3 months, −1.74 (−3.65 to 0.17) at 12 months, and −0.68 (−2.79 to 1.43) at 24 months. The excellent and good rates of efficacy for the AUSS-ULBD and MIS-TLIF groups were 90.7% and 93.9%, respectively. AUSS-ULBD group had a higher reoperation rate than MIS-TLIF group (difference 4.7%, 95% CI −2.7% to 11.4%, P > .05). The operation time, blood loss, incision length, and hospital stay in the AUSS-ULBD group were lower than those in the MIS-TLIF group (P < .001). At 24 months, lumbar lordosis and slippage improved significantly after MIS-TLIF (P < .05), but not after AUSS-ULBD (P > .05).

In single-level, stable DLS, AUSS-ULBD offered advantages in operative morbidity, while achieving 2-year improvements in pain and disability that were comparable to those of MIS-TLIF. By contrast, MIS-TLIF showed better radiographic correction and lower reoperation rate that did not reach statistical significance.

Retrospective Database Study.

Anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) are common procedures performed for cervical spondylosis. Sparse data exists comparing the utilization and reimbursement rates associated with these procedures. This study seeks to compare Medicare utilization of single- and multilevel ACDF to CDA between 2011 and 2021. Additionally, this study evaluates Medicare reimbursement rate changes for ACDF with structural allograft, ACDF with cage, and CDA between the years 2016 and 2021.

This study used the publicly available Medicare National Summary Data Files to aggregate annual utilization and reimbursement rates for ACDF procedures as well as CDA procedures based on Current Procedural Terminology codes. Reimbursement rates were adjusted for inflation through use of the U.S. Bureau of Labor Statistics’ 2021 Consumer Price Index. Changes in reimbursement rates and utilization were calculated and compared between procedures.

In 2011, 27 974 single-level ACDF procedures were performed on Medicare Part B patients compared to 34 683 performed in 2021. This represents a growth in procedure utilization of 24% over the study period. Over the course of the same study period CDA procedures grew by 1087.3%, from 118 in 2011 to 1401 in 2021. Throughout the reimbursement study period, Medicare reimbursements per case for single-level CDAs had an average annual percent change of 9.96%, rising from $1636 in 2016 to $2779 in 2021. Reimbursement per case for single-level ACDF with allograft had an average annual change of −1.25%, falling from $3408 in 2016 to $3206 in 2021. Medicare reimbursement per case for single-level ACDF with cage had an average annual change of 1.19%, from $3379 in 2017 to $3547 in 2021.

All procedures saw an increase in utilization throughout the study period, with CDAs showing significant growth within the Medicare population. While the reimbursement for ACDFs remained relatively constant, the reimbursement for CDAs demonstrated a moderate increase.

Prospective Cohort Study of 108 cases.

Prone Transpsoas (PTP) fusion is a minimally invasive surgical technique using a single-position prone lateral approach to augment the anterior column of the lumbar spine. Degenerative spondylolisthesis (DS) is a common pathology where anterior-posterior access can be advantageous. This study aimed to evaluate operative, radiological and functional outcomes of PTP fusion in the management of symptomatic DS.

A multi-centre cohort study was conducted, involving 108 consecutive patients who underwent PTP fusion for low-grade (Grade I–II) DS. Descriptive statistical analysis was used to evaluate clinical, radiological and functional outcomes.

In all 108 cases, anterior column fusion was combined with posterior percutaneous pedicle screw fixation to optimise spinal realignment. The cohort’s average operative time was 115 minutes, and the psoas retraction time was 14 minutes. The cohort had an average slip of 5.9 mm, which was reduced to 0.8 mm (P < 0.001) postoperatively. Statistically significant radiological improvements were observed in lumbar lordosis (Δ5°), segmental lordosis (Δ4°), anterior disc height (Δ 4.2 mm) and posterior disc height (Δ 2.1 mm). No major vascular or visceral complications were encountered. The sustained neurological complication rate was 1.9%, and patients maintained improved functional outcomes through the 1-year follow-up.

PTP is a safe approach for managing low-grade DS, showing significant postoperative correction of spinal alignment. These results support the use of PTP fusion for treating spondylolisthesis and add to the growing evidence of its safety and efficacy as a minimally invasive technique.

Prospective multicenter cohort study.

To determine the incidence and risk factors for postoperative complications following cervical spine surgery and to explore their association with long-term clinical outcomes.

A total of 1482 patients with degenerative cervical disorders who underwent surgery at 10 high-volume institutions in Japan were prospectively enrolled. Perioperative complications were defined as events occurring within 30 days postoperatively. Risk factors were analyzed using univariate and logistic regression analyses. Clinical outcomes were assessed using the cervical Japanese Orthopaedic Association (JOA) score and the Physical Component Summary (PCS) of the SF-36 at baseline and 2 years postoperatively.

Perioperative complications occurred in 5.5% of patients: segmental motor paralysis (2.3%), neurological deficit (0.6%), dural tear (0.5%), CSF leakage (0.3%), epidural hematoma (0.9%), and surgical site infection (0.8%). Male sex (OR 3.049; 95% CI 1.045-8.929) and posterior fusion (OR 4.016; 95% CI, 1.518-10.620) were significant risk factors for segmental motor paralysis, while respiratory disease (OR 5.500; 95% CI, 1.462-20.694) was associated with surgical site infection. At 2 years, patients with complications showed variable neurological recovery, with many failing to reach the minimum clinically important difference.

Male sex, posterior fusion, and respiratory disease were identified as significant risk factors for major complications. Awareness of these factors may support improved surgical planning and perioperative management. However, interpretation of long-term outcomes should be made with caution because of the limited number of cases and potential selection bias associated with incomplete follow-up.

Retrospective multicenter cohort study.

Treatment of subaxial cervical spine injuries (SCSI) carries high risks of surgical adverse events (SAEs) and revision surgery. While anterior approaches are widely applied, large-scale trauma-specific data remain limited. This study assessed the incidence and predictors of SAEs and revisions after anterior stabilization of SCSI.

Adult patients with acute fractures of C3–C7 treated with single-stage anterior stabilization between 2017-2022 were identified in the German Spine Registry. Demographic, injury, and surgical variables were analyzed using univariate tests and multivariable logistic regression for SAEs and revisions. Model performance was evaluated with ROC curves.

A total of 1486 patients were included. SAEs occurred in 8.5%, most often motor (1.5%) or sensory dysfunctions (1.2%). Revision surgery was required in 4.5%, mainly instrumentation reimplantation (1.9%). Independent predictors of SAEs were male sex (OR 1.69), higher age (OR 1.02/year), AO type C fractures (OR 1.73), and spinal degeneration (OR 1.57). Revision was predicted by fracture type C (OR 2.31). ROC AUCs were 0.65 (SAEs) and 0.70 (revisions). Fracture type C was also linked to neurological deterioration, infection, and implant failure, while age and degeneration predicted implant failure.

Anterior surgery for SCSI carries notable complication risks. Fracture type C, age, male sex, and degeneration predicted SAEs, while fracture type C independently predicted revisions. Given its association with implant failure, anterior-only stabilization of type C injuries should be considered cautiously. Although individual SAE types were rare, findings underscore the need for vigilant postoperative management in specialized centers.

Retrospective Cohort Study.

To evaluate the prognostic value of preoperative increased signal intensity (ISI) grade on T2-weighted magnetic resonance imaging (MRI) and to identify risk factors associated with poor neurological recovery after surgery in adult cervical spinal cord injury without radiographic evidence of trauma (SCIWORET).

A total of 128 consecutive SCIWORET patients who underwent surgical treatment between January 2016 and June 2023 were retrospectively analyzed. Patients were classified into 3 groups (Grade 0, 1, and 2) according to ISI grade on preoperative MRI. Neurological function was assessed using the Japanese Orthopaedic Association (JOA) score and recovery rate (RR). Multivariate logistic regression analysis identified predictors of poor RR (< 50%), and receiver operating characteristic (ROC) analysis determined the optimal age cutoff for prognosis.

Signal intensity alterations were observed in 111 patients (86.7%). Higher ISI grades correlated with lower preoperative JOA scores (r = −0.303, P < 0.001) but not with postoperative RR (r = −0.067, P = 0.450). Multivariate analysis identified age as the only independent predictor of poor RR (OR = 1.10, 95% CI: 1.04-1.16, P < 0.001). ROC curve analysis yielded an optimal age cutoff of 58.5 years.

Preoperative ISI grade reflected the severity of spinal cord injury but did not predict postoperative neurological recovery. Older age (> 58.5 years) independently predicted poorer outcomes, highlighting the importance of integrating patient age into prognostic counseling and individualized surgical decision-making in SCIWORET.

Prospective multicentric study.

Thoracolumbar fractures without neurologic deficit are challenging situations in terms of treatment decision making. We aimed to analyze the occurrence of adverse events (AEs) after surgical and nonsurgical treatment and its impact on functional outcomes.

198 patients from a prospective multicentric database were included. The occurrence of adverse events and treatment failure within 2 years of follow up were recorded. ODI was compared between patients with and without adverse events at six months, 1 year and 2 years follow up. Multivariable regression analysis was conducted to assess the association between post-treatment adverse events and ODI at 1-year follow-up.

46 adverse events were recorded (23.2%). Higher categories of the Charlson Comorbidity Index (CCI) (P = 0.006), unemployment or retirement (P = 0.027), and current smoking (P = 0.008) were significantly associated with the occurrence of adverse events whereas no significant differences were observed in terms of treatment decision (conservative vs surgical). ODI values were significantly higher in patients with adverse events at the 6-month and 1-year follow-up visits without significant differences at 2 years follow up. Treatment failure was observed in only 5 patients.

We found association between the occurrence of AE and higher ODI at 6-months and one-year follow up. Additionally, a higher CCI and smoking status were associated with higher likelihood to develop adverse events in our cohort.

Retrospective Cohort Study.

Mental health disorders like depression and psychoses are increasingly recognized in surgical populations and may adversely affect outcomes. This study aimed to: (1) evaluate the prevalence of these disorders among patients undergoing single-level lumbar fusion, (2) compare perioperative complications, costs, and discharge disposition; and (3) determine whether psychotic disorders confer greater risk than depression.

A retrospective study of the National Inpatient Sample (2016-2022) identified adults undergoing elective single-level lumbar fusion procedures. Patients were stratified into depression, psychoses, or control cohorts. Multivariable logistic regression was adjusted for demographic, hospital, and clinical covariates and used to assess associations with perioperative complications, non-home discharge, and inpatient mortality. Hospital costs were converted and inflation-adjusted to 2022 United States (U.S.) dollars.

Among 792 065 weighted admissions, 17.7% had depression and 2.6% had psychotic disorders. Depression was independently associated with increased odds of cardiovascular complications (OR 1.26), mechanical complications (OR 1.25), adverse events (OR 1.26), and non-home discharge (OR 1.17, all P < .001). Psychotic disorders had greater risk, with higher odds of cardiovascular (OR 1.41), mechanical (OR 1.45), any adverse event (OR 1.42), and non-home discharge (OR 1.59; all P < .001). Mean costs ($41 097 vs $39 256 vs $38,117; P < .001) and length of stay (3.72 vs 3.51 vs 3.19 days; P < .001) were greatest in psychoses.

Depression and psychotic disorders are common in patients undergoing lumbar fusion, and are independently associated with increases in perioperative morbidity, non-home discharge, and costs. Tailored perioperative planning may help mitigate these risks.

Retrospective Cohort Study.

To evaluate the prognostic utility of preoperative laboratory values (PLVs) in predicting 30-day postoperative outcomes among patients undergoing single-level vertebral fracture fixation.

The ACS-NSQIP database (2015-2020) was queried to identify adults who underwent single-level vertebral fracture fusion. Patients were stratified by PLV categories using clinically relevant hypo- and hyper-thresholds. Outcomes included 30-day mortality, major complications, Clavien-Dindo IV complications, non-home discharge (NHD), readmission, reoperation, and extended length of stay. Multivariate logistic regression adjusted for demographics and comorbidities was used to assess associations between PLVs and adverse outcomes.

A total of 4005 patients were identified. Hypoalbuminemia emerged as the strongest independent predictor of poor outcomes, including mortality (OR 4.05, 95% CI 2.14-7.69, P < 0.001), major complications (OR 1.94, 95% CI 1.46-2.57, P < 0.01), and NHD (OR 1.72, 95% CI 1.37-2.17, P < 0.001). Elevated creatinine and leukocytosis were significantly associated with increased mortality (P = 0.047) and Clavien-Dindo IV complications (P < 0.001), while preoperative anemia predicted prolonged hospitalization (P < 0.01).

Among patients undergoing single-level vertebral fixation for fracture, hypoalbuminemia is the most consistent predictor of adverse 30-day outcomes. Elevated creatinine, leukocytosis, and anemia also confer independent risks for specific complications. Incorporating PLVs into preoperative risk stratification may enhance patient counseling, optimize perioperative planning, and identify candidates for targeted prehabilitation.

Prospective Study.

Degenerative lumbar central spinal stenosis (DLCCS) commonly affects the elderly, causing back and leg pain that often necessitates surgical intervention. Perioperative tranexamic acid (TXA) effectively reduces blood loss in lumbar instrumented fusion surgeries. Its effectiveness in elderly patients undergoing posterolateral lumbar instrumented fusion and posterior decompression for DLCCS remains insufficiently investigated. This study aims to evaluate the potential benefits of TXA in these surgical interventions.

170 patients with DLCCS that underwent posterolateral lumbar instrumented fusion with posterior decompression at two consecutive vertebral levels were included. Patients were divided into two groups: Group A (87) without intravenous TXA and Group B (83) with intravenous TXA 30 minutes preoperatively. Outcomes included intraoperative blood loss, postoperative drainage, transfusion rates, surgical duration, initiation of mobilization and hospital stay.

No significant differences were found in patients’ baseline demographics. Surgical duration was significantly shorter in the TXA group (103.6 ± 9.8 min vs 128.6 ± 8.2 min, P < 0.001). Intraoperative blood loss was lower in the TXA group (462.7 ± 92.0 mL vs 864.4 ± 157.0 mL, P < 0.001), as was postoperative drainage (85.2 ± 47.6 mL vs 207.4 ± 153.5 mL, P < 0.001). Postoperative transfusion was required in 3 TXA patients vs 27 in the non-TXA group (P < 0.001). TXA patients mobilized earlier (7.4 ± 3.4 hours vs 12.1 ± 8.1 hours, P < 0.001) and had a shorter hospital stay (2.1 ± 0.4 days vs 2.6 ± 0.9 days, P < 0.001).

Preoperative TXA administration in this spinal surgery improved surgical and postoperative outcomes and should be considered more.

Retrospective cohort study.

Postoperative surgical site infections (SSI) remain a major cause of morbidity and cost in spine surgery. Existing risk calculators have limited applicability in this population. This study introduces a literature-informed, point-based SSI calculator designed to complement standard preoperative assessment. GPT-4 (OpenAI, San Francisco, CA) was used solely for structured literature synthesis and preliminary variable weighting.

Adult patients undergoing spine surgery at a single academic center (2019-2025) were retrospectively reviewed. A 29-variable AI-assisted risk calculator integrating demographic, clinical, laboratory, and surgical factors was developed. SSI was defined using CDC/NHSN criteria with a 90-day window. Risk calculator performance was evaluated using receiver operating characteristics (ROC) curve analysis, bootstrap optimization correction, and calibration and decision curve analyses. A stratified analysis was performed comparing performance by procedure types and spinal regions.

A total of 338 patients were included (SSI: 177; controls: 161). Median risk scores were significantly higher in infected vs non-infected patients (18 vs 10; P < .001). Discrimination was strong (AUC 0.7978, 95% CI 0.7521-0.8427). The optimal threshold was 17 points, yielding 61.0% sensitivity, 84.2% specificity, and 72.1% accuracy. Bootstrap validation showed minimal optimism (corrected AUC 0.7974). Calibration was excellent (calibration-in-the-large <0.001; slope 1.045; Brier score 0.1833). At the study prevalence (52.3%), PPV was 0.8106 and NPV 0.6540, with expected PPV reduction at real-world prevalence. Patients with scores ≥17 had significantly higher infection risk (RR 2.42; OR 8.31; P < .001). Stratified analyses showed consistent performance across procedure types and spinal regions.

This internally validated, AI-assisted SSI calculator demonstrated strong discrimination and calibration. Prospective external validation is needed to determine clinical utility.

Narrative Review.

To summarize the scientific contributions generated from the AO Spine Knowledge Forum Tumor (AOSKFT) databases, focusing on primary spine tumors, and highlight key findings, research trends, and future directions.

Data from the Primary Tumor Retrospective (PT-Retro) and Primary Tumor Research Outcome Network (PTRON) registries were analyzed. The nineteen studies included were peer-reviewed manuscripts focused on primary spine tumors, excluding abstracts, book chapters, systematic reviews, and metastatic studies.

The PT-Retro registry compiled data from 1495 patients across 18 primary tumor histologies, offering insights into recurrence, survival, and treatment paradigms. Key findings emphasize the importance of Enneking-appropriate (EA) resection in improving survival and reducing recurrence in tumors such as chordoma, chondrosarcoma, and osteosarcoma. Genetic markers, including hTERT promoter mutations and rs2305089 SNP, were linked to prognosis in specific histologies. Benign tumors, such as giant cell tumors and aneurysmal bone cysts, demonstrated variable outcomes with different surgical approaches and selective arterial embolization.

The AOSKFT registries have significantly advanced knowledge in primary spine tumor management, emphasizing preoperative staging, surgical margins, and multidisciplinary approaches. International, multicentric registries are essential for studying rare diseases like primary spine tumors, enabling robust data collection, improved statistical power, and broader applicability of findings across diverse clinical settings. Ongoing prospective data collection through PTRON will further refine evidence-based care for these rare and challenging conditions.

Systematic review.

Intracardiac cement embolism (ICE), a rare but life-threatening complication of vertebral augmentation (VA), is poorly characterized. Our review summarizes the incidence, clinical characteristics, treatment and outcome of this complication.

Medline, Embase, and Cochrane databases were systematically searched from inception to April 1, 2025. References were cross-checked to identify additional relevant articles. Included publications underwent quality assessment using the Case Report (CARE) Guidelines and the Joanna Briggs Institute (JBI) Critical Appraisal Checklist, with pooled analysis of incidence, clinical characteristics, treatment, and outcomes.

4 case-series and 96 case reports (181 cases) were included. The overall reporting rate for each study was relatively high, but low reporting rates in 11 sub-items may introduce bias. Among 115 cases with epidemiological data, osteoporotic fractures predominated (n = 83), followed by other diseases (n = 32). The incidence was low, but the exact value was unclear. Common symptoms included dyspnea and chest pain, with onset typically within 48 h postoperatively, though delays of months to 5 years occurred. Diagnosis relied on chest imaging. Treatment was individualized, but most reports lacked objective evidence to guide decisions. Asymptomatic patients required monitoring, while symptomatic ones may need surgery intervention. The outcome was uneventful for all but 10 patients.

ICE was reported only in case report or case-series. A comparative analysis of pre- and postoperative chest X-ray is recommended for screening, while patients with chest discomfort after VA warrant immediate CT imaging. The simplified decision-making flowchart we have developed may provide valuable insights.

PROSPERO identifier CRD 42023455121

Systematic review.

To identify and classify intervertebral foraminal morphologies associated with failed indirect decompression (IND), with the goal of developing a preoperative classification system to assess candidacy for this procedure.

A systematic review of PubMed, EMBASE, and Google Scholar was conducted. All reported cases of failed indirect decompression secondary to abnormal foraminal morphology were included. Imaging findings were reviewed to identify distinct morphological patterns.

Thirteen studies describing 22 patients with failed indirect decompression due to abnormal foraminal morphology were identified. Four distinct imaging patterns were observed: (1) hypertrophic superior articular process variant, (2) prominent posterior inferior osteophyte variant, (3) osseous ring variant, and (4) foramen crowded by disco-ligamentous material variant.

We propose a simple, intuitive classification system for preoperative evaluation of the foramen in candidates for indirect decompression. Each variant is presented with supporting literature implicating it in failed indirect decompression. Future studies should aim to determine the prevalence, clinical significance, and failure rates associated with each morphology type.