Retrospective, multi-surgeon cohort at a single academic center with ≥2-year follow-up. To identify dominant, modifiable drivers of intraoperative cost in lumbar interbody fusion and evaluate outcome profiles between graft types. Instrumentation and biologics are major cost contributors in lumbar fusion, yet prior reports often aggregate spending into broad categories, obscuring which specific supply decisions drive expenditure. Biologics such as bone morphogenic protein (BMP) and viable cellular allografts (VCA) have achieved high clinical utility, but their cost-effectiveness remains uncertain. Granular cost analyses are needed to clarify how graft selection influences expenditures and outcomes. Adults aged 18-89 years undergoing primary 1-2 level lumbar interbody fusion between March 2015 and July 2023 for degenerative pathology were included. Itemized procedural supplies were priced in 2023 USD, and operating room (OR) time was valued using standardized cost per minute. Pareto analysis summarized cost domains. Multivariable linear, logistic, and Cox regression models adjusted for demographics, diagnosis, surgeon, approach, level(s), fixation, laminectomy, and operative duration. Among 955 cases, 111 (11.6%) used iliac crest bone graft (ICBG), 257 (26.9%) local autograft, 263 (27.5%) VCA, and 324 (33.9%) BMP. OR time, interbody devices, grafts, and fixation accounted for 95% of total direct procedural cost. Grafting exhibited the widest interquartile cost range ($3,200). Median total procedural costs were significantly higher (adjusted P<0.001-0.005) for VCA (1 level: $16,949; 2 level: $24,424) and BMP ($14,654; $26,193) compared with ICBG ($14,093; $17,757) and local autograft ($11,962; $18,352). Inpatient opioid use, length of stay, 90-day complications, readmissions, revisions, and postoperative Oswestry Disability Index and EuroQol-5D scores were comparable across groups (adjusted P>0.05). Most direct procedural cost concentrated in OR time, interbody devices, and grafts. BMP and VCA markedly increased intraoperative expenditures without measurable improvement in outcomes. Autologous grafting demonstrated the most favorable cost-value profile. III.

Prospective cohort study. Determine whether epigenetic age (EA), calculated via DNA methylation analysis, is associated with early postoperative complications in adult spinal deformity (ASD) surgery. ASD is increasingly prevalent in the aging population, with postoperative complication rates ranging from 37% to 71%. While chronological age (CA) and frailty scores are known predictors of poor outcomes, they may not fully capture biological vulnerability. EA, derived from DNA methylation patterns, may better reflect a patient's physiological reserve and stress response capacity. Thirty patients undergoing ASD surgery were prospectively enrolled and provided peripheral blood samples on the day of surgery. DNA methylation of peripheral blood mononuclear cells (PBMCs) was analyzed using the Illumina EPIC v2.0 array. EA was computed using the Horvath DNAmAge algorithm. Associations between EA, CA, and the Edmonton Frailty Index (EFI) with postoperative complications at 30 days were assessed using appropriate parametric and non-parametric statistical tests. Differentially methylated positions (DMPs) were identified between complication and non-complication group. Of the 30 enrolled patients (mean CA: 68.4y, 21 female), 14 (47%) experienced postoperative complications. Sixty-three DMPs were found between the two groups, with 35 hypomethylated and 28 hypermethylated CpG sites in the complication group. Genes affected were linked to immune response, including LRBA and NFACT2. Regulators of EGFR and WNT pathways were also differentially methylated. Patients with EA greater than CA were significantly more likely to experience complications (86% vs. 14%, P=0.038). The difference between EA and CA was greater in the complication group (5.07 vs. 0.87y, P=0.029). No significant differences were found in mean CA, EA, or EFI alone between the groups. Postoperative complications in ASD patients were associated with epigenetic alterations and elevated EA relative to CA. These findings suggest EA may be a novel biomarker for preoperative risk stratification in ASD surgery.

Retrospective cohort study. To determine whether preoperative D-dimer predicts perioperative venous thromboembolism (VTE) risk in spine tumor patients. Venous thromboembolism (VTE) is a common perioperative complication in spine surgery. Though oncologic spine patients are at particularly high risk, few studies have investigated risk factors and screening measures for predicting VTE risk in this population. Medical records of adult surgical spine tumor patients from January 2021-September 2024 were retrospectively reviewed. Preoperative D-dimer was compared between patients who did and did not develop VTE. Age, sex, tumor type, spinal level, comorbid diabetes, and ambulatory status were assessed as risk factors. Differences between groups were tested using chi-square or Fisher's exact tests for categorical and t-test or Mann-Whitney for continuous variables. Multi-group comparisons by tumor type included adjusted pairwise analyses. Receiver operating characteristic (ROC) curves and area under the curve (AUC) evaluated the diagnostic performance of D-dimer, with optimal threshold determined by Youden Index. Results are presented as means  SD. Among the 134 patients, deep vein thrombosis (DVT) and pulmonary embolism (PE) incidences were 6.7% and 9.0% respectively. Patients who developed PE had higher D-dimer levels (2,088±2,114ng/mL) than those who did not (1,222±1,743ng/mL) (P=0.025). D-dimer was not significantly associated with DVT development. Preoperative D-dimer predicted VTE risk with sensitivity 0.88, negative predictive value 0.97, and AUC 0.67 (95% CI 0.55-0.78). Age, sex, tumor type, spinal level, ambulatory status, and diabetes were not associated with VTE risk. Preoperative D-dimer is a sensitive but non-specific tool for predicting VTE in spine tumor patients. It may be more useful in predicting PE than DVT and may help guide anticoagulation prophylaxis.

Level III Retrospective observational cohort study. To identify independent risk factors for postoperative ileus (POI) after elective lumbar spine surgery and evaluate its association with postoperative outcomes including complications, length of stay, discharge disposition, and patient-reported outcomes (PROs). Postoperative ileus is an uncommon but clinically significant complication after lumbar spine surgery. Prior studies have been limited by small sample sizes and inadequate adjustment for confounding factors such as surgical approach, open technique, and operative duration. Data from the Michigan Spine Surgery Improvement Collaborative (MSSIC) registry (2018-2023) were analyzed for elective lumbar procedures. Multivariable generalized estimating equation (GEE) models identified independent predictors of POI and adjusted associations with outcomes. Models included demographic, clinical, and procedural factors, including surgical approach, open status, and operative time. A 2020-2023 subset further adjusted for total morphine milligram equivalents (MME) at discharge. Among 41,164 patients, 447 (1.1%) developed POI. Independent risk factors included older age (RR 1.02 per year), male sex (RR 2.01), Black race (RR 1.79), multilevel procedures (2-level RR 1.36; 3-level RR 1.41), anterior fusion (RR 10.82), other fusion approaches (RR 3.28), and longer operative duration (RR 1.10 per hour). Preoperative independent ambulation (RR 0.81) and ambulation within 8 hours postoperatively (RR 0.69) were protective. After adjustment, POI was associated with higher complication rates (RR 1.51), increased readmissions (RR 1.40), lower discharge-to-home likelihood (RR 0.93), and longer hospital stay (+2.74d; all P<0.05). Findings persisted in the MME-adjusted subset (n=25,273). POI occurred in around 1% of elective lumbar spine surgeries and was associated with longer hospitalization, greater morbidity, and reduced home discharge. Surgical invasiveness and anterior exposure were key risk factors, while early ambulation was protective, underscoring its value in enhanced recovery protocols.

Systematic review and meta-analysis. To explore the impact of preoperative cannabis use on perioperative outcomes of spinal fusion procedures. of background data: Opioid use disorder is a growing problem, especially in the United States. Cannabis use is increasingly being adopted as an alternative method of pain management. However, it remains unclear how a history of preoperative cannabis use impacts opioid consumption, length of hospitalization, or perioperative complications in spinal fusion procedures. The Authors searched PubMed, Scopus, Web of Science, and Cochrane Library for studies where outcomes of spinal fusion were compared between patients preoperatively exposed and non-exposed to active cannabis use. A total of 7 retrospective studies and 1,920 patients (386 cannabis users) were included. Significant increase in in-hospital opioid use (MD 58.84 MME; 95% CI 29.75 to 87.93; P<0.01), readmission (OR 1.70; 95% CI 1.01 to 2.87; P=0.045), and reoperation (OR 3.78; 95% CI 2.06 to 6.94; P<0.001) was observed in the cannabis group. Studies showed no significant increase in surgical complications. A history of preoperative cannabis use may be associated with poorer surgical outcomes, including increased perioperative opioid utilization and a higher rate of postoperative hospital readmissions. Patients should be informed in detail about these risks, and clinicians should screen for them. Counsel patients to cease or at least reduce the use of cannabis before a spinal fusion procedure, in order to minimize surgical complications.

Systematic review and meta-analysis. To compare perioperative, radiographic, and functional outcomes between open and percutaneous posterior fixation following anterior or lateral lumbar interbody fusion (ALIF/LLIF). Posterior fixation enhances construct stability after ALIF or LLIF, yet the optimal approach, open versus percutaneous, remains debated. While minimally invasive surgery (MIS) reduces tissue disruption, open fixation may offer superior sagittal correction, particularly in adult spinal deformity (ASD). Prior meta-analyses have not isolated ALIF/LLIF procedures. Following PRISMA guidelines, PubMed, Embase, and Google Scholar were searched (January 2000-January 2025). Comparative studies evaluating open versus percutaneous posterior fixation after ALIF/LLIF were included. Outcomes included sagittal parameters, perioperative variables, postoperative events and patient-reported outcomes. Meta-analyses were performed using random- or fixed-effects models depending on heterogeneity (I² >50%). Thirteen studies (912 patients; 454 open, 458 percutaneous) met inclusion criteria. For radiographic outcomes: No overall difference in Δ Lumbar Lordosis(LL), Δ Pelvic Incidence-LL, or Δ Sacral Slope; however, open fixation achieved greater sagittal correction in ASD (ΔLL=12.9° [95% CI 0.01 - 25.87, P=0.05] , PI-LL=-4.1° [95% CI -7.88 - -0.38, P=0.03] , SS=+2.5° [95% CI 0.38 - 4.58, P=0.02]). For perioperative outcomes, percutaneous fixation reduced EBL (-387mL [95% CI -575.72 - -197.71, P <0.0001]), OR time (-65 min [95% CI -93.90 - -15.82, P=0.006]), LOS (-1.7d [95% CI -2.42 -1.01, P < 0.00001]), and transfusion risk (OR 0.26 [95% CI 0.11 - 0.58, P=0.001]). For postoperative outcomes, no significant differences in reoperation, fusion, or adjacent segment disease incidence; percutaneous fixation improved pain-medication independence (OR 4.29 [95% CI 1.20 - 15.36, P=0.03]). For patient-reported outcomes, percutaneous fixation yielded superior ODI (-7.1 [95% CI -11.07 - -3.21, P=0.0004]) improvements early; at two years, it maintained minimally better VAS Back (-0.31 [95% CI -0.54 - -0.08, P=0.009]) and ODI (-2.9 [95% CI -5.04 - -0.68, P=0.01]) scores. Percutaneous posterior fixation after ALIF/LLIF offers clear perioperative advantages, reduced blood loss, operative time, LOS, and transfusion need, without compromising fusion or long-term outcomes. Open fixation remains preferable for ASD cases requiring extensive sagittal realignment. Surgical approach should therefore be individualized based on deformity rigidity and alignment goals.

Prospective multicenter cohort study. To comprehensively evaluate the impact of diabetes mellitus (DM) on surgical outcomes, perioperative complications, and patient-reported outcomes in patients undergoing surgery for degenerative cervical myelopathy (DCM). Both DM and DCM are age-related conditions, and their coexistence has become increasingly common with the aging population. DM is associated with microvascular and metabolic disturbances that may impair neurological recovery and wound healing. Previous studies have yielded inconsistent results, largely due to small sample sizes, retrospective designs, and inadequate adjustment for confounders. A total of 875 patients with DCM, including 200 with DM, were prospectively enrolled across ten high volume centers in Japan. Clinical outcomes, including the JOA score, SF 36, Neuropathic Pain Symptom Inventory, and JOA Cervical Myelopathy Evaluation Questionnaire, were evaluated before surgery and at two years after surgery. Perioperative complications were recorded within 30 days after surgery. Clinical and surgical outcomes were analyzed using multivariable statistical models adjusting for demographic and surgical confounders, and the association between preoperative HbA1c and outcomes was examined within the diabetic cohort. Patients with DM were older and had higher BMI than those without DM. After statistical adjustment, DM was not associated with significant differences in postoperative neurological recovery, quality of life, pain, or perioperative complications. Within the diabetic cohort, higher HbA1c levels were modestly associated with smaller improvements in JOA scores (β=-0.111, P=0.045), but no significant correlations were found with other outcomes or complication rates. DM did not adversely affect surgical or patient-reported outcomes in patients with DCM when perioperative glycemic control was appropriately maintained. These findings suggest that well-managed DM should not be considered a contraindication to surgical treatment for DCM and provide reassurance for clinicians and patients in shared decision-making.

Retrospective cohort study. To characterize the success rate of anti-osteoporosis treatment for patients with spine fracture that otherwise confers eligibility for treatment. We also evaluated factors associated with successful initiation of treatment. Thoracic and lumbar spine fractures in patients ≥50 years of age after low energy injuries confer a diagnosis of osteoporosis and indicate eligibility for bone health treatment. Despite this, there is little information available regarding the extent to which these patients receive appropriate treatment and underlying factors that influence this decision. We included patients ≥50 years of age treated at one of four medical centers within a single system for Type A thoracic or lumbar spine fractures from low energy trauma between 2015- 2021. Clinical, radiographic, sociodemographic, and medication data were abstracted from the medical record. Patients were noted to have successful treatment if they had de novo initiation of bone health treatment, addition of a new bone health agent to a prior osteoporosis regimen, or switched between anti-osteoporosis agents within 90 days (90d) of injury. Bivariate statistics and logistic multivariable regression were utilized to identify factors associated with successful osteoporosis treatment while adjusting for potential confounders. In total, 409 patients with complete data and 90d of follow-up were included. Only 41 (10%) patients had successful treatment initiation of bone health medications. In both bivariate and multivariable analyses, surgical intervention was the only factor significantly associated with bone health treatment. Patients treated with surgery demonstrated a more than 3-fold increase in the odds of receiving osteoporosis treatment (OR 3.35, 95%CI 1.42-7.58, P=0.003). Appropriate osteoporosis treatment after low energy spine fracture was uncommon in our cohort, occurring in just 10% of patients. Active engagement on the part of spine surgeons increased the likelihood of receipt of bone health medications. This may represent a scalable intervention that can improve patient care. Level III.

Retrospective study design on prospectively collected registry data. To compare clinical outcomes and complication rates between anterior cervical discectomy and fusion (ACDF) using iliac crest bone graft with plate or cage with plate. ACDF is an effective surgical treatment for cervical degenerative radiculopathy. Restoring the disk space with iliac crest bone graft yields good outcomes; however, it is associated with donor site pain and complications. The alternative, using an interbody cage, may delay bony union. Patients who underwent ACDF for cervical degenerative radiculopathy using either iliac crest bone graft with plate or cage with plate were identified in the Swedish Spine Registry. Patient-reported outcome measures (PROMs) included the Neck disability index (NDI), quality of life and numeric pain rating scale scores. PROM improvements after two years of follow-up as well as postoperative complications and reoperations, were compared between the iliac crest bone graft and cage groups. Multivariable mixed-effects regression analyses were used to analyze factors associated with NDI improvement, complications and reoperations while accounting for inter-facility variability. Included participants were 225 in the iliac crest group and 1,288 in the cage group. Both groups achieved comparable postoperative PROMs, with a median NDI improvement of -20 (iliac crest) and -18 (cage) points, respectively. The rate oflatereoperations (after 30d) was significantly lower in the cage group than in the iliac crest group (odds ratio: 0.19, 95% CI: 0.05-0.76, P =0.02). At two-years of follow-up, ACDF with a cage and plate achieved postoperative outcomes comparable to those of with an iliac crest bone graft and plate. Moreover, the study findings suggest that the cage represents a safer alternative to the iliac crest bone graft. Level 3.

Retrospective cohort study. To establish the maximal outcome improvement (MOI) threshold for moderate-to-severe spinal deformity. Interpretation of patient-reported outcome measures (PROMs) is often limited by ceiling effects and inadequate consideration of baseline status when determining clinically meaningful thresholds. One hundred and seven patients who underwent surgery for moderate-to-severe spinal deformity and completed ≥ 2-year follow-up were retrospectively included. The Scoliosis Research Society-22 revised (SRS-22r) was administered preoperatively and at ≥ 2-year follow-up to determine the MOI threshold using the anchor-based method. Anchor questions were derived from the SRS-22r satisfaction domain, with postoperative satisfaction defined as scores ≥ 4 on both questions. The MOI was calculated as the changes in SRS-22r scores relative to the total possible improvement. Receiver operating characteristic (ROC) curve analysis identified the optimal MOI threshold. Logistic regression analysis evaluated predictors associated with achieving the MOI threshold. Significant radiographic and clinical improvements were obtained at ≥ 2-year follow-up. Dissatisfied patients had lower postoperative SRS-22r satisfaction (3.1±0.4 vs. 4.5±0.4, P<0.001) and subtotal scores (3.7±0.4 vs. 4.0±0.3, P<0.001). The determined MOI threshold for the SRS-22r score was 43.5%. Adolescents demonstrated a significantly higher mean MOI percentage than adults (50.3% vs. 42.8%, P=0.001), although the proportion achieving the MOI threshold was comparable between groups (73.4% vs. 62.8%, P=0.242). Male sex (OR=0.8, P=0.022) and surgical complications (OR=0.7, P<0.001) significantly decreased the likelihood of achieving the MOI threshold. Conversely, preoperative neurological deficits were associated with increased odds of meeting this threshold (OR=1.6, P=0.041). The MOI threshold for the SRS-22r in moderate-to-severe spinal deformity was 43.5%. Male sex and perioperative complications were negative predictors, while preoperative neurological deficits increased the probability of achieving clinically meaningful improvement.