Journal of neurosurgery. Spine最新文献

Objective: The objective of this study was to evaluate the impact of four-rod (4R) constructs and interbody cages (IBCs) on pseudarthrosis and rod breakage (PA/RB) in patients with adult spinal deformity (ASD) who had undergone surgery with pelvic fixation and Schwab grade 2 osteotomies, using a combined finite element model (FEM) and clinical data analysis.

Methods: A validated FEM simulated Schwab grade 2 osteotomies at the L4-5 level in two-rod and 4R configurations, with or without IBCs at L4-5 and L5-S1. Rod strain and range of motion were calculated under a 7.5-Nm moment. Clinical analysis was conducted on ASD patients with pelvic fixation and Schwab grade 2 osteotomies and ≥ 2 years of follow-up. Patients were classified into 2 groups depending on the presence or absence of PA/RB. Demographic, surgical, radiographic, and patient-reported outcome measure (PROM) data were compared.

Results: The FEM analysis revealed maximal rod strain of 399 MPa at the osteotomy site in flexion. The 4R constructs and IBCs reduced strain to 114 MPa at L4-5 and 80 MPa at L5-S1. Among the 213 patients included in the study, PA/RB occurred in 61 (28.6%). Multivariate analysis revealed the use of 4R constructs (OR 0.331, 95% CI 0.16-0.71, p = 0.004) and IBCs (OR 0.46, 95% CI 0.23-0.94, p = 0.033) as protective factors. Patients with PA/RB experienced more unplanned reinterventions, worse scores on PROMs, and greater loss of sagittal alignment at 2 years postoperatively.

Conclusions: Constructs with 4Rs and IBCs in ASD surgeries with pelvic fixation and Schwab grade 2 osteotomies significantly reduced rod strain and decreased the risk of PA/RB, leading to better scores on PROMs and decreasing unplanned reinterventions and loss of alignment.

Objective: The aim of this study was to review the management and outcomes of a consecutive cohort of patients with spinal myxopapillary ependymoma (MPE) treated at the authors' institution over a 23-year period.

Methods: A retrospective review of all patients treated surgically for spinal MPEs at a single institution between May 1998 and August 2021 was performed. Preoperative and postoperative clinical data, imaging, and/or radiology reports were reviewed to identify patient presentation and outcomes as well as tumor size, location, CSF dissemination, and other features. Method and extent of resection were characterized and related to preoperative tumor characteristics and outcomes.

Results: Fifty-six patients underwent 60 index surgical procedures at a single institution, including 4 surgeries for resection of a solitary drop sacral metastasis. The median postoperative follow-up was 126 months (range 22-304 months). En bloc gross-total resection (EGTR) was performed in 15 cases, marginal GTR (MGTR) in 17, piecemeal GTR (PGTR) in 6, piecemeal near-total resection (PNTR) in 9, and subtotal resection (STR) in 13 cases. Of the 55 primary filum terminale MPEs, 40 (73%) arose proximally, with their inferior tumor margin located at or above the L3 vertebral body. Nearly all patients who underwent EGTR (14/15) or MGTR (17/17) had MPEs that originated in the proximal filum terminale. In contrast, 10 of 13 patients who underwent STR had a distal MPE origin (below L3). CSF tumor dissemination, including drop metastases, was identified in 19.6% (11/56) of patients. Tumor size, especially width, significantly influenced the method of complete resection: the mean width of tumors resected with EGTR was 1.0 cm (range 0.4-1.7 cm) while the mean width of MGTR tumors was 1.5 cm (range 1.0-2.2 cm) (p < 0.001). Location, size, and marginal integrity of the tumor surface were important factors that influenced extent and quality of resection.

Conclusions: MPEs are benign tumors that arise predominantly from the filum terminale. Resection can be curative, especially for well-marginated tumors arising from the proximal filum terminale. Despite their benign nature, the tumors' lack of a capsule, friable tumor consistency, and frequent direct contact with the CSF and cauda equina create a propensity for local recurrence and CSF dissemination, especially for larger and distally originating tumors. Thus, long-term follow-up is recommended for all patients as is early surgical intervention for small, incidental MPEs.

Objective: Both minimally invasive (MI) and open surgical approaches can be effective for the treatment of degenerative lumbar spondylolisthesis (DLS). However, comparative effectiveness might be influenced by body mass index (BMI). The authors aimed to determine if there is a differential impact of open versus MI approaches on patient outcomes based on BMI.

Methods: The authors performed a retrospective analysis of the prospective Quality Outcomes Database, identifying patients surgically treated for grade 1 DLS between July 2014 and June 2016. BMI was dichotomized into 2 groups: nonobese (BMI < 30 kg/m2) and obese (BMI ≥ 30 kg/m2) in accordance with the Centers for Disease Control and Prevention definition. The primary outcome was a minimal clinically important difference (MCID) in the Oswestry Disability Index (ODI). Secondary outcomes included an MCID in the EQ-5D, the North American Spine Society patient satisfaction index, an MCID in the numeric rating scale for leg pain (NRS-LP) and back pain (NRS-BP), surgical complications, discharge disposition, and reoperation. These variables were compared between surgical approaches and after subgrouping by BMI group. A nonroutine discharge was defined as discharge to any location other than home.

Results: Six hundred eight patients with grade 1 DLS were identified. Five hundred seventeen (85%) had 2-year follow-up for the primary outcome. There were 285 nonobese and 232 obese patients, and 216 patients underwent an MI approach and 301 underwent an open approach. Four hundred two patients (77.8%) underwent instrumented fusion, whereas 115 (22.2%) underwent decompression alone. Instrumented fusion was performed more frequently in the open group (81.7% vs 72.2%, χ2 = 6.03, p = 0.014) and in obese patients (83.6% vs 73.0%, χ2 = 7.76, p < 0.01). Regardless of surgical approach or BMI, 2-year (2Y) ODI (mean difference [MD] -23.4 ± 20.38, p < 0.001), NRS-LP scores (MD -3.81 ± 3.82, p < 0.001), and NRS-BP scores (MD -3.32 ± 3.43, p < 0.0001), and EQ-5D scores (MD 0.21 ± 0.24, p < 0.0001) improved from baseline. Among obese patients, the proportion attaining an MCID in 2Y ODI (73.3% vs 56.34%, χ2 = 6.11, p = 0.013) and EQ-5D (53.33% vs 37.32%, χ2 = 4.32, p = 0.038) was larger after MI than after open surgery; however, no differences were seen between MI and open surgery in the nonobese patients. There were no differences between MI and open approaches in either BMI group for the remaining secondary outcomes.

Conclusions: Regardless of approach, patients improved following surgery for grade 1 DLS. Patients with BMI ≥ 30 kg/m2 had better long-term outcomes when treated with an MI surgical approach versus open surgery. This difference in outcomes between MI and open surgery was not observed among patients with BMI < 30 kg/m2.

Objective: Adolescent idiopathic scoliosis (AIS) presents with complex 3D spinal deformities frequently accompanied by pelvic asymmetry. Sacral obliquity (SO), reflecting sacral tilt on the coronal plane, is one of the relevant parameters with clinical significance. There are several methods for measuring SO, but no standardized approach has been established. The aim of this study was to determine the most appropriate method for measuring SO by analyzing the relationship between sacral vertebral morphology and SO across different spinal curve patterns.

Methods: Consecutive patients with AIS who underwent corrective surgery from 2013 to 2023 at a single institution were assessed. Cobb angles of the major curve and thoracolumbar/lumbar (TL/L) curve, L4 tilt, C7 plumb line to center sacral vertebral line, leg length discrepancy, SO, and iliac obliquity (IO) were measured as radiographic parameters. The S1 angle, S2 angle, and S1 base angle were measured as sacral morphological parameters on multiplanar reconstructed CT. The S1 and S2 angles were defined using the respective vertebral endplates, while the S1 base angle was defined using the transition point of the sacral wing and the superior articular process of the S1 vertebra as anatomical landmarks. Patients were classified into two groups according to Lenke classification: those with TL/L major curves (TL/L+, Lenke types 4-6) and those without TL/L major curves (TL/L-, Lenke types 1-3).

Results: After exclusions, 128 patients (122 females, mean age 16.9 ± 4.0 years) were included in this analysis, with 35 in the TL/L+ group and 93 in the TL/L- group. The S1 angle was significantly greater than both the S1 base angle and S2 angle (mean 2.8° ± 2.5° vs 1.4° ± 1.5° and 1.4° ± 1.2°, respectively; p < 0.001). The TL/L+ group had a significantly greater mean S1 angle (4.6° ± 3.2° vs 2.1° ± 1.7°, p < 0.001), whereas no significant differences were observed in the S1 base angle and S2 angle. Multivariable analysis confirmed TL/L curve presence, TL/L Cobb angle, SO, S1 base angle, and S2 angle as independent determinants of an increased S1 angle.

Conclusions: The S1 endplate was the most reliable landmark for evaluating SO, particularly in patients with AIS with TL/L major curves. Given the presence of asymmetry within the S1 vertebra, use of the S1 base angle might underestimate the true degree of SO. These findings support the standardized use of the S1 endplate to enhance accuracy of SO assessment and improve precision in surgical planning and bracing strategies.

Objective: Spinal cord cavernous hemangioma (CH) is a rare intramedullary vascular lesion with a risk of hemorrhage and progressive neurological deterioration. While resection is the standard treatment for symptomatic CH, the optimal timing for surgery remains uncertain. This study aimed to examine surgical outcomes, find prognostic factors of functional independence, and suggest the optimal surgical timing in functionally dependent patients.

Methods: A retrospective analysis was conducted on the medical records of 40 patients who underwent resection for CH at a tertiary medical institution between January 2002 and December 2023. The modified McCormick (MMC) scale was used, and the scores were defined as follows: MMC scores 1 and 2 indicated functional independence, and MMC scores 3-5 indicated functional dependence. The clinical outcomes of all patients were analyzed, and factors associated with functional independence at the last follow-up were identified. Additionally, in the initially functionally dependent group, the optimal surgical timing was determined by identifying the symptom duration that maximized the number of patients achieving MMC score improvement.

Results: The mean follow-up duration was 48.4 ± 46.8 months (range 7.2-208.6 months). At the last follow-up, 62.5% of patients were functionally independent, and 18 patients showed improvement in their MMC score. Initial functional independence was the strongest factor (OR 8.41, 95% CI 1.73-40.86; p = 0.008), followed by location of CH at the cervical level (OR 5.42, 95% CI 1.01-29.23; p = 0.049). The functionally dependent group had a significantly shorter surgical time since symptom onset (0.4 vs 8.8 months, p = 0.002). An optimal surgical timing threshold of 8.2 months was identified for functionally dependent patients (p = 0.002).

Conclusions: Initial functional independence and cervical lesion location were key predictors of postoperative functional independence at the last follow-up. Among patients with initial functional dependence, surgical treatment within 8.2 months was identified as optimal timing. Larger studies are needed to refine patient selection and surgical timing for CH.

Objective: The objective was to evaluate percutaneous endoscopic lumbar discectomy (PELD) combined with periradicular ozone injection for lumbar disc herniation (LDH) and to investigate ferroptosis roles in pain relief.

Methods: Sixty LDH patients were randomly assigned to groups A (PELD only), B (PELD + 20 µg/ml ozone), and C (PELD + 30 µg/ml ozone), with 20 patients per group. Outcomes included visual analog scale (VAS), Oswestry Disability Index (ODI), and Tampa Scale for Kinesiophobia-11 (TSK-11) scores at 1, 4, and 12 weeks postoperatively; pre- and postoperative serum levels of Nrf2, GPX4, and glutathione (GSH); and efficacy based on the modified Macnab criteria. Receiver operating characteristic (ROC) analysis assessed the predictive value of biomarkers.

Results: All groups improved postoperatively (p < 0.05). Groups B and C showed lower VAS, ODI, and TSK-11 scores versus group A at 1 and 4 weeks (p < 0.05), with group C outperforming group B early (p < 0.05). No significant differences were observed among the groups in either Macnab outcome evaluation or adverse events. Group C exhibited greater Nrf2, GPX4, and GSH elevation (p < 0.05). ROC curves confirmed Nrf2 (area under the curve [AUC] 0.76), GPX4 (0.75), and GSH (0.75) as significant predictors (p < 0.05).

Conclusions: Targeted periradicular ozone injection is a safe and effective adjunct to PELD, enhancing outcomes in LDH patients. A concentration of 30 µg/ml ozone yielded superior early recovery. The authors' findings suggest that pain relief is mediated through ferroptosis suppression, unveiling a novel therapeutic mechanism for ozone therapy.

Objective: Previous studies reported that 58%-88% of patients undergoing operations for degenerative cervical radiculopathy (DCR) have concomitant headache, but the prospects of experiencing a minimal important change (MIC) in the headache after surgery are unknown. This study aimed to assess the prevalence of concomitant headache prior to DCR surgery, establish the MIC for headache, and determine the proportion of patients achieving this level of improvement at 12 months follow-up.

Methods: In this population-based study, 6234 cases operated on for DCR were prospectively enrolled in the Norwegian Registry for Spine Surgery and followed for 12 months. The Global Perceived Effect scale was used as an external criterion and receiver operating characteristic (ROC) curve analyses to assess MIC values of the numeric rating scale for headache (NRS-HA) change score and the corresponding percentage change scores.

Results: At admission for surgery, 4689 (75.2%) of 6234 cases reported concomitant headache. A percentage change in the NRS-HA of 23.6% was the most accurate and acceptable MIC cutoff value (area under the ROC curve = 0.75, 95% confidence interval 0.73-0.78). At the 12-month follow-up evaluation, 63% of the cases with headache achieved improvement equal to or greater than the MIC value.

Conclusions: Patients undergoing operations for DCR who have concurrent headache can be informed that empirically at least 60% will have a noticeable improvement of their headache 12 months after surgery.

Objective: Correcting sagittal alignment is important in surgery for adult spinal deformity (ASD) surgery. T1 slope (TS) is a key parameter for evaluating whole spine alignment. Many patients with a large TS have thoracolumbar and cervical spine deformities. The aim of this study was to compare alignment changes before and after ASD surgery in two groups categorized by a preoperative TS of ≥ 40° or < 40°.

Methods: The authors included patients aged ≥ 40 years who underwent spinal correction surgery for ASD between 2010 and 2019 and had at least 5 years of follow-up. The patients were divided into two groups: the high TS group (group H, TS ≥ 40°) and the low TS group (group L, TS < 40°). Radiographic parameters and patient-reported outcome measures (PROMs) such as the Scoliosis Research Society-22 and Oswestry Disability Index were assessed preoperatively, postoperatively, and at the 2- and 5-year follow-ups.

Results: There were 57 patients in group H and 161 in group L. Patients in group H had a higher upper instrumented vertebra (mean 8.1 vs 9.8, p < 0.001). Postoperative TS was reduced in both groups (mean 32.7° vs 24.2°). The sagittal vertical axis (SVA) improved in both groups immediately after surgery (51.9 mm vs 37.3 mm) but was higher in group H at 5 years (mean 85.3 mm vs 62.2 mm, p < 0.001). Thoracic kyphosis (TK) increased in both groups but remained significantly higher in group H (mean 38.2° to 46.2°) than in group L (mean 32.8° to 39.4°) (p < 0.001). The C2-7 SVA worsened in group H (18.5 mm to 31.4 mm) compared with group L (14.4 mm to 20.1 mm) (p < 0.001). Proximal junctional kyphosis (PJK) was more frequent in group H (36.8% vs 18.0%, p = 0.0058).

Conclusions: In ASD patients with TS ≥ 40°, initial alignment improvement was followed by significant deterioration in nonfused segments at 5 years. While PROMs showed no differences between the groups, higher PJK incidence warrants careful monitoring.

Objective: This study characterizes biomechanical complications reported across 9 Food and Drug Administration (FDA)-approved cervical disc arthroplasty (CDA) devices, stratified by fixation strategy.

Methods: Data from the FDA's Manufacturer and User Facility Device Experience (MAUDE) database were reviewed to characterize revision surgical procedures involving 4 primary cervical disc fixation strategies: spike based (PCM, Mobi-C, and Discover), keel based (Prodisc-C, Secure-C, and Prestige-LP), spike-keel combination (M6-C and Simplify), and press-fit (Bryan). Biomechanical complications included migration, heterotopic ossification (HO), subsidence, and osteolysis. Revision surgical procedures were further categorized on the basis of whether cases necessitated repeat arthroplasty or conversion to fusion.

Results: A total of 393 revision cases with biomechanical complications were identified across 4 cervical disc fixation strategies. Migration was the most frequently observed complication (n = 160 [41%]), particularly in spike-based (n = 97 [60.6%]) and keel-based (n = 41 [25.6%]) fixations. Spike-keel hybrids showed 5 cases (3.1%) of migration but displayed the highest rate of osteolysis (n = 35 [77.8%]) and implant breakage over time (n = 17 [47.2%]). HO was particularly observed in spike-based (n = 22 [50%]) and keel-based (n = 15 [34.1%]) devices. Subsidence was also prominent in these groups, affecting 18 cases (41.9%) in spike-based and 20 cases (46.5%) in keel-based devices. Spike based was the only group where revision arthroplasty (n = 203 [76.6%]) exceeded conversion to fusion.

Conclusions: This study characterizes complication patterns across CDA devices with differing fixation strategies, noting variation in the types of biomechanical failures reported in revision cases. Spike- and keel-based devices accounted for the majority of reported cases involving migration, HO, and subsidence, whereas spike-keel hybrid designs may demonstrate improved primary stability and a tendency toward osteolysis. Spike-based fixation was the only method in which revision arthroplasty was more frequent than conversion to fusion, potentially due to reduced bone modification, which may better preserve endplate integrity and enhance the feasibility of arthroplasty reimplantation. These data underscore the importance for further biomechanical and clinical studies to better optimize fixation strategy and complication avoidance in CDA.

Objective: Lateral lumbar interbody fusion (LLIF) can be performed as a stand-alone procedure, with lateral plate and screw fixation, or with supplemental posterior instrumented fusion. In vitro biomechanical data suggest that lateral plate fixation limits segmental motion. The aim of this study was to evaluate the impact of lateral screw and plate fixation on the rate and grade of long-term radiographic implant subsidence after LLIF.

Methods: A review of patients who underwent LLIF for degenerative lumbar spondylosis from 2014 to 2022 at two quaternary referral centers was conducted. All patients underwent CT evaluation a minimum of 1 year after surgery. Patients with posterior instrumented fusion were excluded. Age, sex, BMI, smoking status, cage material, and the bone density of the operative level (in Hounsfield units) were collected. Postoperative implant subsidence at the long-term follow-up was graded according to Marchi criteria by two separate spine surgeons. A stepwise multivariate logistic regression analysis was performed.

Results: Overall, 146 patients (219 surgical levels; 85 female, mean age 67.9 years) met inclusion criteria. Sixty-five patients (45%) underwent LLIF with lateral plate and screw fixation, and 81 patients (55%) underwent stand-alone LLIF. No intraoperative subsidence was observed. In the univariate analysis, age, sex, smoking status, bone density at the operative level, and BMI were not significantly associated with radiographic subsidence on a per-level basis. Multivariable logistic regression analysis showed that a 3D-printed porous titanium cage was moderately associated with reduced subsidence (OR 0.401, 95% CI 0.202-1.069; p = 0.071). Lateral plate fixation was significantly associated with reduced subsidence (OR 0.484, 95% CI 0.099-0.652; p = 0.006). All 4 patients (4.9%) with grade II (severe) subsidence underwent stand-alone LLIF. One patient with lateral plating experienced delayed vertebral body fracture. All patients with lateral plates received 18-mm-wide interbody implants, while all but 2 patients who underwent stand-alone LLIF received 22-mm-wide implants.

Conclusions: LLIF with lateral plate and screw fixation was significantly associated with a lower rate of radiographic subsidence at the long-term follow-up compared with stand-alone LLIF. There was no significant difference in the reoperation rate between the two procedure groups. No cases of reoperation were identified in patients who received 3D-printed porous titanium cages, and there was a trend toward the superiority of 3D-printed porous titanium over PEEK cage material. The results of this study suggest that LLIF with lateral plate and screw fixation has potential to protect against severe (grade II or worse) radiographic subsidence.