Spine最新文献

Study design: Observational cohort study.

Objective: To evaluate potential predictors of unsuccessful outcomes after surgery in patients with lumbar spinal stenosis (LSS).

Summary of background data: LSS is a common cause of disability in adults and the leading indication for spine surgery in Norway. Despite advances in surgical techniques, nearly one-third of patients report either minor or no improvement or worsening of symptoms after surgery. Identifying predictors of unsuccessful outcomes is essential for improving patient selection and shared decision-making.

Methods: This secondary analysis used data from the two NORwegian Degenerative spondylolisthesis and spinal STENosis (NORDSTEN) randomized trials, which included 704 surgically treated patients with LSS, with (n=267) or without (n=437) degenerative spondylolisthesis. The Oswestry Disability Index (ODI) was the primary outcome measure. A reduction in ODI score of less than 30% from baseline to two years postoperatively was defined as an unsuccessful outcome. Multivariable logistic regression analysis was used to evaluate whether carefully selected baseline variables were associated with an unsuccessful outcome at two-year follow-up.

Results: Longer duration of radiating pain (>12 mo; OR=2.58, 95% CI 1.54-4.29), psychological distress (HSCL-25 ≥1.75; OR=1.60, 95% CI 1.01-2.53), and advanced disc degeneration (Pfirrmann grades 4-5; OR=1.98, 95% CI 1.26-3.12) were independently associated with an unsuccessful outcome. Commonly discussed factors such as age, BMI, smoking, ASA grade, and predominant back pain did not reach statistical significance for association with the outcome.

Conclusion: Among patients undergoing surgery for LSS, longer symptom duration, psychological distress, and advanced disc degeneration were associated with a higher risk of unsuccessful postoperative outcomes.

Study design: A two-sample Mendelian randomization (MR) analysis.

Objective: To evaluate the association between insulin-like growth factor-1 (IGF-1) and adolescent idiopathic scoliosis (AIS).

Summary of background data: The IGF-1/growth hormone axis has been implicated in AIS development, yet discordant findings exist regarding an association between serum IGF-1 and AIS.

Methods: Summary statistics were retrieved from two genome-wide association studies; one investigating IGF-1 (389,525 patients) the other investigating AIS (7,956 patients). MR analysis was performed leveraging complementary methods including inverse variance weighting (IVW), MR Egger, simple mode, weighted median, and weighted mode. Sensitivity analyses included Cochran Q test, MR-Egger regression and leave-one-out analyses.

Results: 316 instrumental variables (IVs) were included with a total proportion of variance of 7.53% and a mean F-statistic of 94.08. The random-effects model of the inverse-weighted method demonstrated that for every 1-standard deviation decrease in IGF-1, the estimated risk of AIS increases by 37% (OR=0.73, 95% CI 0.62-0.86, P<0.001). The weighted median method provided a consistent estimate of this association (OR=0.74, 95% CI 0.58-0.95, P=0.016). MR-Egger regression demonstrated no evidence of directional pleiotropy (MR‑Egger intercept = -0.00091, P=0.84). While Cochran's Q statistic demonstrated heterogeneity among IVs for both IVW (Q=345.69, P=0.039) and MR-Egger (Q=345.64, P=0.036), the calculated I² was 12.9%, indicating modest heterogeneity. Leave‑one‑out analysis demonstrated robustness against individual single nucleotide polymorphisms disproportionately influencing the overall association.

Conclusion: A decrease of one standard deviation (estimated mean: 22 nmol/L [SD:5]) in circulating IGF-1 increases the risk of AIS by 37%. The putative causal association between serum IGF-1 levels and AIS warrants further study into the role of IGF-1 in AIS pathogenesis. Patients with short-stature syndromes and other disorders with IGF-1 dysregulation such as growth hormone deficiency should be routinely screened for AIS, and further research is required to assess whether IGF-1 can serve as a serum biomarker for AIS screening at the primary care level.

Study design: Retrospective review of a prospective cervical deformity (CD) database.

Objective: Determining when shorter fusions can be successful in CD surgery to reduce the extent of the surgical procedure while mitigating complications.

Summary of background data: Multicenter outcomes database of CD patients.

Methods: CD patients were stratified as short fusions (SF: ≤4 levels fused, cervical LIV) or long fusions (LF: >4 levels fused, LIV caudal to C7). Groups were compared in terms of demographics, baseline and 1-year alignment, patient-reported outcome measures (PROMs), and surgical parameters. The data were then reanalyzed after controlling for baseline cervical Sagittal Vertical Axis (cSVA) using propensity score matching. Decision trees were used to identify baseline factors associated with postop alignment failure (1-year cSVA>4 mm or C2S>20°) among SF patients.

Results: 127 patients were analyzed with 100 LF and 27 SF patients. SF had significantly less EBL (131 vs. 1001 mL) and shorter operative time (223min vs. 435 min). At baseline, LF had worse cervical alignment (cSVA=42.6 vs. 23.0 mm) and were more disabled by Neck Disability Index (NDI, 50 vs. 38). After matching by cSVA, the mean baseline cSVA decreased from 42.6 mm to 27.6 mm in the LF group and increased from 23.0 mm to 27.2 mm in the SF group. 71% (n=15) of SF achieved the MCID for NDI vs. 52% (n=11) of LF pts. SF patients with a BL C2S>26° (n=13) were 12.4 times as likely as SF patients with C2S≤26° (n=13) to have post-operative alignment failure (85% vs. 31%, P<.01) and 5.1 times as likely to have a post-operative complication (69% vs. 31%, P<.05).

Conclusions: Although short fusions can result in excellent outcomes with less extensive surgeries, those with more severe deformities may require longer fusions. SF should be avoided in patients with a BL C2S>26° due to the increased risk of complications and realignment failure.

Study design: Retrospective analysis.

Objective: This study will compare post-operative pelvic incidence (PI) modification by types of pelvic-fixation.

Background: In adult spinal deformity (ASD), restoring sagittal spinal alignment which is usually based on PI is essential to improve the patient's quality of life. While PI was postulated to be a constant value, recent literature reported that the latter can change with pelvic fixation after ASD surgery.

Methods: This is a retrospective multicenter study of 423 patients who have undergone ASD surgery between 2012 and 2022. These patients were divided into four groups, based on the type of pelvic fixation they received being either S2-Alar-Iliac screws (S2AI), Iliac screws (IS), Iliosacral screws (ISS), and no pelvic-fixation. Post-operative PI change was defined by an absolute difference of ≥6° between pre- and post-operative values.

Results: Patients with S2AI had the higher rate of post-operative PI change (80%) followed by patients with ISS (39.6%) and patients with IS (15.3%).). In addition, patients with a low pre-operative PI had an increased post-operative PI (33.3° pre-operatively to 42.1° post-operatively) while patients with a high pre-operative PI had a lower post-operative PI (69.9° pre-operatively to 66.5° post-operatively). A logistic-regression model controlling for gender, pre-operative PI groups, the change in lumbar lordosis, pelvic tilt, sacral slope, and pelvic fixation showed that only the latter predicted the post-operative change in PI with an adjusted odd-ratio of 6.4. However, pelvic fixation was not a predictor of PI modification when we selected only patients with IS.

Conclusion: Pelvic fixation was found to be an independent risk factor for PI change with an adjusted Odds-ratio of 6.4. When stratifying by pelvic fixation type, S2AI screws had the greatest impact on post-operative PI change (Odds-ratio=25.3) followed by ISS (Odds-ratio=5.9) with IS having no impact on post-operative PI change.

Study design: Multicenter retrospective cohort.

Objective: To compare complications, patient-reported outcomes, and radiographic measures between patients treated for early-onset scoliosis (EOS) with magnetically controlled growing rods (MCGRs) according to whether they had definitive fusion, retention of implants, or implant removal alone.

Background data: For patients with EOS, MCGRs enable noninvasive spinal distraction until skeletal maturity, when most undergo definitive fusion. Because MCGR expansions are more frequent than with traditional growing rods, the incidence of autofusion may differ. The long-term safety and effectiveness of implant retention is unknown.

Methods: We included 240 patients with EOS (mean age at index surgery, 8.8 y) who completed treatment with MCGRs and had ≥2-year follow-up after definitive management. Patients were grouped by definitive management: fusion (n=225), implant retention without fusion (n=12), or implant removal alone (n=3). Demographics, radiographic parameters, Early Onset Scoliosis Questionnaire (EOSQ-24) scores, and complication rates were analyzed. P<.05 was considered significant.

Results: Two years after definitive treatment, mean Cobb angle improved in the fusion group (54° to 42°, P<.0001), remained stable in the retention group (60°, P=.89), and worsened in the removal group (61° to 78°, P=.03). At 5 y after definitive treatment, 6 patients with retained implants maintained Cobb angle (54°) and spinal height (338 mm). At 2 years, mean T1-S1 height did not differ between fusion and retention groups (P=.61). Two years after "graduation," EOSQ-24 scores were similar across groups, except pulmonary function, which was highest in the fusion group. Chronic pain was most frequent in the removal group (2 of 3, P=.005). No patients with retained implants experienced implant-related complications.

Conclusions: Retention of MCGRs may be considered in some high-risk patients with acceptable alignment who are poor candidates for fusion. Although short-term outcomes were promising, retention should be regarded as an exception. Long-term risks warrant further study.

Level of evidence: III.

Study design: Retrospective cohort study.

Objectives: In patients undergoing adult spinal deformity (ASD) surgery, we sought to: (1) describe mechanisms of Proximal junctional kyphosis/failure (PJK/F), and (2) compare time-to-diagnosis, proximal junctional angle (PJA), reoperation, and neurologic deficit between PJK/F mechanisms.

Summary of background data: PJK/F includes several different failure mechanisms.

Methods: ASD patients (2009-21) with ≥5-level fusion, sagittal/coronal deformity, and 2-year follow-up were included. Primary outcome was mechanism of PJK/F, defined as a PJA≥10° and ≥10° change from preoperative. PJK/F mechanisms were: screw pullout, UIV fracture, UIV+1 fracture, screw lucency, fracture dislocation, supradjacent disc-degeneration with/without listhesis, and radiographic kyphosis only. Descriptive and bivariate statistics were performed.

Results: Among 238 patients, 113(47.5%) developed PJK/F: screw pullout (7.1%), UIV fracture (15.0%), UIV+1 fracture (8.0%), screw lucency (12.4%), fracture dislocation (11.5%), supradjacent disc-degeneration with/without listhesis (31.0%), and radiographic kyphosis only (15.0%). One mechanism was seen in 91(80.5%) patients, and 2+ mechanisms in 22(19.5%). Median time-to-PJK/F diagnosis was 5.3 (IQR: 1.4-17.7) months: screw pullout (8.3m, PJA=19.9°), UIV fracture (3.8m, 25.6°), UIV+1 fracture (11.8m, 28.0°), screw lucency (12.8m, 19.0°), fracture dislocation (1.6m, 27.9°), disc-degeneration (4.5m, 25.6°), and radiographic kyphosis only (6.1m, 19.5°) (P=0.986, P<0.001). Reoperation occurred in 45(39.8%) patients: 6/8(75.0%) screw pullout, 6/17(35.2%) UIV fracture, 4/9(44.4%) UIV+1 fracture, 9/14(64.3%) screw lucency, 6/13(46.1%) fracture dislocation, 9/35(25.2%) disc-degeneration, and 5/17(29.4%) radiographic kyphosis only (P=0.068). Neurologic Deficits occurred in 15(13.3%) patients: UIV fracture 3(17.6%), UIV+1 fracture 2(22.2%), screw lucency 5(35.7%), fracture dislocation 2(15.4%), disc-degeneration 2(5.7%), kyphosis only 1(5.9%) (P=0.093).

Conclusion: Supradjacent disc-degeneration was the most common PJK mechanism. Fracture dislocation presented earliest and with greatest kyphosis. Reoperation was most frequent with screw pullout, lucency, and UIV+1 fracture, while neurologic deficits were most common with lucency and UIV+1 fracture. These results demonstrate that PJK/F occurs in many different forms and ideally should be analyzed independently to further improve our treatment of this vexing complication.

Study design/setting: Retrospective, multi-surgeon cohort at a single academic center with ≥2-year follow-up.

Objective: To identify dominant, modifiable drivers of intraoperative cost in lumbar interbody fusion and evaluate outcome profiles between graft types.

Summary of background data: 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.

Methods: 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.

Results: 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).

Conclusions: 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.

Level of evidence: III.

Study design: Prospective cohort study.

Objective: Determine whether epigenetic age (EA), calculated via DNA methylation analysis, is associated with early postoperative complications in adult spinal deformity (ASD) surgery.

Background: 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.

Methods: 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.

Results: Of the 30 enrolled patients (mean CA: 68.4 y, 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. 0.87 y, P=0.029). No significant differences were found in mean CA, EA, or EFI alone between the groups.

Conclusion: 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.

Study design: Level III Retrospective observational cohort study.

Objective: 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).

Summary of background data: 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.

Methods: 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.

Results: 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 (+2.74 d; all P<0.05). Findings persisted in the MME-adjusted subset (n=25,273).

Conclusion: 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.

Study design: Systematic review and meta-analysis.

Objective: To explore the impact of preoperative cannabis use on perioperative outcomes of spinal fusion procedures.

Summary: 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.

Methods: 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.

Results: 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.

Conclusion: 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.