Spine最新文献

Study design: A national retrospective observational cohort study was conducted using the Merative MarketScan database.

Objective: To evaluate whether preoperative ED use was predictive of postoperative readmission, reoperation, and increased overall cost in patients undergoing transforaminal lumbar interbody fusion (TLIF).

Summary of background data: Emergency department (ED) visits and unplanned readmissions after spine surgery are increasingly financially relevant, as the Centers for Medicare and Medicaid Services levies financial penalties for unplanned 30-day hospital readmission.

Methods: The dataset was queried for transforaminal lumbar interbody fusion (TLIF) performed between July 1, 2018 and June 30, 2023. The primary outcome was any postoperative ED visit. Secondary outcomes included 30-day readmissions, 90-day readmissions, major medical complications, any reoperation, and 30-day episode of care costs.

Results: A total of 25,203 patients underwent TLIF during the study period. Multivariate logistic regression demonstrated that at least one preoperative ED visit was predictive for any postoperative ED visit and was also predictive of 30-day complication, 90-day readmission, and 90-day reoperation. A diagnosis of CKD was the strongest predictor for 30-day complication. Multivariate linear regression for total 30-day episode-of-care cost demonstrated that a preoperative ED visit was associated with a $2,806.71 increase in total cost.

Conclusions: We found that any preoperative ED visit was associated with higher 30-day episode of care costs, increased postoperative ED visits, and higher 90-day readmissions and reoperations following TLIF. Preoperative ED visits may serve as an indicator for unnecessary postoperative 30-day-episode of care utilization. This represents an opportunity for preoperative counseling and intervention to close care gaps and decrease unnecessary healthcare expenditures.

Level of evidence: III.

Study design: A retrospective multicenter study.

Objective: To identify independent risk factors for Spinal Epidural Lipomatosis (SEL) and to develop and validate an interpretable machine learning-based predictive model.

Summary of background data: SEL is an underdiagnosed yet clinically significant cause of debilitating lumbar spinal stenosis. Robust tools for early identification and risk stratification of at-risk patients are currently lacking.

Methods: Using data from 774 patients with low back and leg pain who underwent lumbar MRI at five institutions, we applied LASSO regression for variable selection and developed a clinically accessible nomogram. The cohort was randomly divided into training (70%) and validation (30%) sets. Four machine learning models were constructed and evaluated based on discrimination (AUC), calibration, and clinical utility (decision curve analysis).

Results: Seven independent predictors were identified: elevated random blood glucose, blood type B, atherosclerosis index, body mass index, uric acid, obstructive sleep apnea, and age. The XGBoost model demonstrated superior predictive performance in the validation set (AUC: 0.726; 95% CI: 0.547-0.904), with satisfactory calibration and positive net clinical benefit. Interpretability analysis confirmed glucose, age, and uric acid as the most consistent contributors to individualized risk predictions.

Conclusions: We developed and validated an interpretable prediction model that integrates clinical risk factors with an XGBoost algorithm and provides an actionable nomogram. This tool demonstrates strong potential to assist clinicians in early SEL detection and risk-stratified management, potentially enabling more targeted interventions for this underdiagnosed condition.

Study design: Large multicenter prospective study.

Objective: We aimed to develop and validate a novel machine learning-based prognostic scoring system for spinal metastases.

Summary of background data: Spinal metastases, common complications in patients with advanced cancer, significantly affect neurological function, pain, and quality of life. Although surgery plays a crucial role in selected cases, the accurate prediction of patient prognosis remains challenging. Traditional scoring systems, developed for older treatment paradigms, do not fully reflect the impact of modern oncologic therapies.

Methods: This multicenter prospective study, conducted by the Japan Association of Spine Surgeons with Ambition, included 401 patients who underwent surgery for spinal metastases at 35 medical centers between 2018 and 2021. Patient demographics, tumor burden, performance status, and treatment history data were collected. Least Absolute Shrinkage and Selection Operator (LASSO) logistic regression was used to identify significant predictors of one-year survival, followed by stepwise variable selection. The model performance was assessed using the area under the receiver operating characteristic curve (AUROC) and calibration plots.

Results: Among the 401 patients, 67.1% survived for one year, whereas 32.9% did not. Survivors had better performance status, lower tumor burden, and lower opioid use than non-survivors. LASSO regression identified five key predictors of one-year survival: age ≥75 years, poor performance status (≥3), presence of other bone metastases, preoperative opioid use, and lower preoperative Vitality Index. The final model demonstrated a strong predictive performance (AUROC=0.762). Based on the key prognostic factors, a simplified risk stratification system was developed to classify patients into low- (one-year survival 82.2%), intermediate- (67.2%), and high-risk (34.2%) groups.

Conclusion: We developed a clinically applicable prognostic scoring system for patients with spinal metastases using machine learning techniques to enhance predictive accuracy. This model provides a practical risk assessment tool to aid surgical decision-making and optimize postoperative management.

Level of evidence: 2.

Study design: Retrospective cohort study comparing sagittal spinopelvic alignment in patients with lumbar spinal stenosis (LSS) to age- and sex-matched normative data and evaluating postoperative changes following decompression surgery.

Objective: To determine whether LSS represents a distinct sagittal alignment phenotype beyond normal aging and to assess alignment changes up to two years after decompression surgery.

Summary of background data: Sagittal alignment in healthy populations and adult spinal deformity is has been widely studied. However, the sagittal alignment specific to LSS remains poorly researched.

Methods: Patients undergoing decompression without fusion for LSS between 2014 and 2022 at a single institution were included. Exclusion criteria were prior surgery, infection, tumor, scoliosis, or lack of radiographic data. Sagittal parameters were measured preoperatively and at two-year follow-up. We calculated normative value using a large population-based Japanese cohort. Comparison between LSS and controls were performed using one-sample t-tests.

Results: 448 patients were included for analysis. Compared to controls, LSS patients had significantly higher SVA and PT, and lower LL, SS, and TK. Postoperative alignment improved but did not normalize. Residual malalignment persisted across all age groups, indicating a distinct alignment phenotype in LSS.

Conclusion: LSS is associated with a unique sagittal alignment profile that exaggerates age-related changes. Decompression surgery partially improves sagittal alignment. These findings suggest intrinsic structural differences in LSS and highlight the need for individualized treatment and long-term follow-up.

Level of evidence: 3.

Study design: Retrospective case-control study.

Objective: To determine risk factors for recurrence of pediatric lumbar spondylolysis at L5 after return to sport in patients who achieved bone union with conservative treatment.

Summary of background data: Pediatric lumbar spondylolysis is a stress fracture commonly observed in adolescent athletes, particularly at the L5 vertebra. Because some patients experience a recurrence of spondylolysis after bone fusion with conservative treatment, identifying risk factors for recurrence may help athletes continue sports activities, maintain performance levels, and preserve mental health.

Materials and methods: Of the 375 pediatric patients (below 18 yr of age) who received conservative treatment for lumbar spondylolysis at L5 between 2015 and 2021, 296 patients who achieved bone fusion and returned to their original sports activities were analyzed. Recurrence rate, sports, pathologic stage of spondylolysis at initial examination, presence of spina bifida occulta (SBO), duration of conservative treatment for initial spondylolysis, and radiologic parameters including lumber lordosis, L5-S1 lordosis, and sacral slope were examined. Recurrence and nonrecurrence groups were compared using univariate and multivariate analyses to investigate risk factors for recurrence. A receiver operating characteristic (ROC) curve was drawn to determine cutoff values of the parameters to predict spondylolysis recurrence.

Results: Recurrence was observed in 52 of 296 patients (17.6%). Multivariate logistic regression analysis revealed that a large L5-S1 lordosis was a significant independent risk factor for recurrence. ROC analysis demonstrated a cutoff value of 24.5° for L5-S1 lordosis. Age, sex, SBO, and duration of conservative treatment for initial spondylolysis were not significant predictors of recurrence.

Conclusion: We identified large L5-S1 lordosis as an independent risk factor for recurrence of pediatric lumbar spondylolysis at L5 following conservative treatment. Intensive athletic rehabilitation to prevent recurrence and follow-up measures to monitor and detect recurrence are recommended for patients with large L5-S1 lordosis.

Study design: Retrospective cohort study.

Objective: Evaluate postoperative outcomes in lumbar fusion patients with preoperative iron deficiency anemia (IDA) on iron supplementation.

Background: IDA has been associated with impaired cognition, compromised immune response, and increased risk of morbidity and mortality after surgery. However, little is known about the relationship between IDA and postoperative complications among patients undergoing lumbar fusion, as well as about the impact of preoperative iron supplementation on these outcomes.

Methods: A national all-payer claims database was queried for adult patients who underwent lumbar spinal fusion between 2010 and 2022. Patients were initially stratified by a preoperative diagnosis of IDA and matched 1:1 based on age, sex, and medical comorbidities. IDA patients were further stratified by preoperative iron supplementation use and similarly matched. Postoperative complications and hospital costs were compared using χ 2 , t test, and multivariate logistic regressions.

Results: The matched cohorts consisted of 27,669 patients, with a mean age of 59 years and 89% female sex. IDA patients had higher rates of pulmonary embolism, acute kidney infection, deep venous thromboembolism, surgical site infection, urinary tract infection, blood transfusion, 90-day readmission rates, and hospital length of stay (all P <0.001). IDA patients on preoperative iron supplementation had lower rates of acute kidney injury, hematoma, pulmonary embolism, surgical site infection, urinary tract infection, stroke, 90-day readmission rates, and 90-day total hospital costs (all P <0.001). Non-IDA patients on preoperative iron supplementation similarly had lower rates of many of these complications as well.

Conclusion: IDA was associated with an increased risk of 90-day postoperative medical complications and hospital resource utilization. However, preoperative oral iron supplementation mitigated these risks. Further research is critical to understand how preoperative or perioperative iron supplementation can be used to optimize patients' hematologic status before lumbar fusion to maximize clinical outcomes.

Level of evidence: Level IV.

Study design: Retrospective cohort.

Objective: Investigate how home care (HC) services impact utilization of postoperative resources and outcomes after lumbar fusion.

Summary of background data: Utilization of spinal fusion has increased over the past decade-it has become important to coordinate postoperative discharge that maximizes rehabilitation and cost-effectiveness.

Methods: Bundled payment information of lumbar fusion episodes of care from a private payer (2019-2021) was reviewed to identify patients. Manual chart review was conducted to evaluate demographic/surgical details, complications, and readmissions. Insurance claims data were reviewed to identify HC utilization after discharge-disposition was designated as home with HC versus no HC.

Results: Seven hundred fifty-eight patients were included (13.6% HC, 86.4% no HC). Patients with HC were older (68.6±9.76 vs. 59.5±11.2; P <0.001), had higher BMI (31.1±6.17 vs. 30±5.9; P <0.001), and CCI (1.07±1.24 vs. 0.59±0.91; P =0.002), and longer operative time (211±86.7 vs. 178±78.9; P <0.001). HC was associated with 90-day reoperation (13.6% vs. 1.07%; P <0.001), and readmission (30-day: 7.77% vs. 1.98%; 90-day: 12.6% vs. 3.51%; P <0.001). HC was associated with reoperation for compressive fluid/dural repair (2.91% vs. 0.31%), and wound complication/infections (3.88% vs. 0%), and with medical readmissions (4.85% vs. 1.53%; P <0.001). On multivariate analysis, HC was an independent predictor of further health care utilization-office visits [incidence rate ratio (IRR): 1.14; P =0.049], phone calls (IRR: 1.38; P =0.02), and ED visits (IRR: 6.5; P <0.001). Despite similar preoperative physical function scores (SF-12 PCS), HC was associated with worse six-month ( P <0.001) and one-year scores ( P =0.05).

Conclusion: Patients receiving HC were older, sicker, and had longer surgeries. Patients with HC experienced more readmissions and reoperations particularly for wound and medical issues. HC independently predicted further postoperative health care utilization through office calls/visits and ED visits. These findings suggest that patients requiring HC are a particularly vulnerable population and that HC does not exert a protective effect against additional health care utilization. Further research is needed to identify proactive interventions that can decrease cost and improve outcomes.

Study design: Longitudinal cohort study.

Objective: To explore the association between preoperative lumbar paraspinal intramuscular fat (IMF) and recovery over a five-year period following surgical decompression for lumbar spinal stenosis (LSS)-related intermittent neurogenic claudication.

Summary of background data: The literature is inconclusive whether higher IMF concentrations on MRI are related to unfavorable outcomes following lumbar decompressive surgery for intermittent neurogenic claudication due to LSS.

Materials and methods: Patients (N=149) with LSS-related intermittent neurogenic claudication [52% male; mean (SD) age: 65.5 (9.1) yr; BMI: 27.9 (4.3)] were included for this study. Preoperative lumbar paraspinal IMF was quantified and categorized as nonsevere (<50%) and severe (≥50%) IMF for each muscle (left and right lumbar multifidus and erector spinae) from axial T 2 -weighted MRI scans using automated computer-vision models. Logistic regression was used to investigate the association between IMF and global perceived effect as well as surgical success. Linear mixed-effects models were used to assess the difference in the clinical course of leg and back pain and disability between the IMF groups. The models were corrected for potential confounders.

Results: Overall, participants with nonsevere IMF in the lumbar multifidus reported a higher percentage of successful recovery (53.7% vs. 37.5%) and surgical success (76.5% vs . 59.9%) compared with the severe IMF group. This association was not present for erector spinae IMF. After adjusting for the potential confounders, the associations between lumbar multifidus IMF and successful recovery and surgical success remained significant for most timepoints across the five-year follow-up (odds ratios: 2.26-7.32, P ≤0.049). Patients with nonsevere IMF in the right lumbar multifidus experienced less disability ( P =0.035). No between-group differences were found for the clinical course of leg and back pain ( P ≥0.143).

Conclusions: Preoperative levels of IMF in the lumbar multifidus, but not the erector spinae, were associated with five-year recovery and success following surgery for LSS-related intermittent neurogenic claudication.