Spine最新文献

Study design: Retrospective cohort study.

Objective: Anterior cervical discectomy and fusions (ACDF) have become a common and effective means of decompression and stabilization of the cervical spine. Anterior instrumentation with plates and screws (ACDF-P) are increasingly utilized to increase rates of union. However, concerns with plate-related risks have led to the evolution of stand-alone ACDF (ACDF-S) constructs in hopes of reducing adjacent segment degeneration from plate prominence though critics have pointed out potential for subsidence, instability, and nonunions. We sought to evaluate reoperation risk following ACDF-S compared with ACDF-P in a multicenter US-based cohort.

Summary of background data: Adult patients who underwent primary one to two-level ACDF between C3 and C7 for degenerative disc disease were identified using a health care system's spine registry (2009-2022). Three thousand nine hundred fifty-eight ACDF comprised the final study sample, 278 (7.0%) were ACDF-S. Procedures were performed by 59 surgeons at 16 hospitals.

Methods: Multivariable Cox proportional-hazards regression was used to evaluate ACDF-S versus ACDF-P and risk of reoperation for any cause with confounder adjustment. Reoperation for adjacent segment disease (ASD) or nonunion were also evaluated. Secondary analysis stratified by one and two-level ACDF procedures.

Results: In adjusted analyses, no differences in all-cause reoperation risk [hazard ratio (HR)=0.97, 95% CI=0.58-1.64] or reoperation for ASD (HR=1.11, 95% CI=0.61-1.99) was observed when comparing ACDF-S to ACDF-P. No differences in reoperation risks were also found when restricted to one-level procedures (all-cause: HR=0.92, 95% CI=0.50-1.68; ASD: HR=0.88, 95% CI=0.44-1.78). For two-level procedures, there were 49 ACDF-S and 1,886 ACDF-P. There were too few events observed for regression analysis.

Conclusions: In this large, comparative study including a cohort of nearly 4000 patients, differences in reoperation rates for ACDF-S compared with ACDF-P constructs were not observed. This information could be used to better inform surgeons, patients, administrators, and policy makers between the 2 ACDF options.

Study design: Retrospective cohort study.

Objective: To assess five-year bladder, bowel, and ambulatory function in patients receiving sacral tumor resection surgery.

Summary of background data: Sacral tumors are rare and slow-growing, often leading to late diagnoses and large tumor sizes. Surgical resection is the standard of care, and frequently involves nerve root sacrifice. These structures are important for bladder, bowel, and ambulatory function, and previous studies have limited follow-up. Hence, little is known regarding how sacral nerve function changes over time after sacrectomy surgery.

Methods: We conducted a retrospective analysis of 43 patients who received surgery at our institution. Patients were stratified into groups based on osteotomy level (intralesional, low, mid, and high). Descriptive statistics were calculated with point estimates. Kruskal-Wallis tests were used to compare oncologic, surgical, and functional outcomes across sacrectomy groups. Cumulative link mixed models (CLMMs) were used to assess functional trends over time.

Results: There were significant differences in preoperative and one-year bladder, bowel, and ambulatory function ( P <0.05). However, there were no significant differences between one-year and five-year bladder, bowel, and ambulatory function ( P =0.99, P =0.80, and P =0.72). At five years, bladder function was significantly better in the intralesional and low sacrectomy versus the mid sacrectomy group ( P =0.04 and P =0.002). At five years, bowel function was significantly better in the intralesional and low sacrectomy versus the mid sacrectomy group ( P =0.01 and P =0.01). At five years, the ambulatory function was significantly better in the low sacrectomy versus the high sacrectomy group ( P =0.006).

Conclusion: As expected, a higher osteotomy level was associated with poorer function. Bladder, bowel, and ambulatory function were shown to stabilize at one year postoperatively. This can serve as an assessment point for long-term function and can help set patient expectations after surgery.

Level of evidence: Level III, cohort study.

Study design: Retrospective cohort study.

Objective: To determine risks of reoperations for adjacent segment disease (ASD) and all-cause reoperations following cervical disc arthroplasty (CDA) versus anterior cervical discectomy with fusion (ACDF).

Summary of background data: To reduce the risk of ASD, CDA was developed to preserve mobility. While studies show CDA lowers ASD reoperation rates, few have included all-cause reoperation risks.

Methods: Using data from a National Spine Registry, patients (18-60 yr old) with cervical degenerative disc disease who underwent a primary one-level and two-level CDA or ACDF were selected. Patients with ACDF were 3:1 propensity-score matched to CDA patients. Cox Proportional-Hazards regression was used to evaluate reoperations for ASD and all-cause risks. Hazard ratios (HR) and 95% CIs were presented; P  < 0.05 was the significance threshold.

Results: The cohort consisted of 6318 patients with a mean follow-up of 6.9 years. Propensity score matching yielded 809 CDA patients and 2427 ACDF patients. In Cox Regression analysis, a lower risk of reoperation for ASD was observed for 1-level CDA compared with ACDF (HR=0.86, 95% CI=0.64-1.15, P  = 0.31) but without statically significance. For one-level and two-level, no difference in all-cause reoperation risks was found (HR=0.84, 95% CI=0.64-1.12, P  = 0.25) and (HR=0.67, 95% CI=0.33-1.37, P  = 0.27), respectively. Mean time to ASD reoperation was 3.9 years (SD=3.5) for CDA and 4.4 years (SD=3.1) for ACDF.

Conclusion: With nearly seven years of average follow-up, this large registry-based study showed that one-level CDA did not significantly reduce the risk of ASD or all-cause reoperations compared with ACDF. Similar results were only seen for all-cause reoperations in two-level CDA. Importantly, ASD reoperations occurred within four to five years on average, underscoring that while CDA preserves motion, the risk of subsequent surgery remains. These findings highlight the real-world performance of CDA and may reflect other factors that increase all-cause reoperations, which may have been underreported.

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: 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: 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.