Journal of neurosurgery. Spine最新文献

Objective: Cervical spinal cord injury (SCI) and lower trunk brachial plexus injury (BPI) commonly result in hand paralysis. Although restoring hand function is complex and challenging to achieve, regaining volitional hand control drastically enhances functionality for these patients. The authors aimed to systematically review the outcomes of hand-opening function after supinator to posterior interosseous nerve (PIN) transfer.

Methods: A systematic literature review was performed according to the PRISMA guidelines.

Results: A total of 16 studies with 88 patients and 119 supinator to PIN transfers were included (87 transfers for SCI and 32 for BPI). In most studies, the time interval from injury to surgery was 6-12 months. Finger extension and thumb extension (Medical Research Council grade ≥ 3/5) recovered in 86.5% (103/119) and 78.1% (93/119) of cases, respectively, over a median follow-up of 19 months. The rates of recovery were similar for the SCI and BPI populations (finger extension, 87.3% in SCI and 84.3% in BPI; thumb extension, 75.8% in SCI and 84.3% in BPI). Type of injury (OR 1.05, 95% CI 0.17-6.4, p = 0.95), time from injury to surgery (OR 1.01, 95% CI 0.8-1.29, p = 0.88), and age (OR 0.97, 95% CI 0.90-1.06, p = 0.60) were not associated with odds of a successful outcome. Duration of follow-up was significantly associated with successful finger extension (OR 1.15, 95% CI 1.01-1.30, p = 0.026). No donor-associated supinator weakness was reported postoperatively given that patients had an intact bicep muscle preoperatively contributing to supination.

Conclusions: Supinator to PIN transfer is a safe and effective procedure that can achieve successful restoration of digital extension in the SCI and BPI population at similar rates. Duration of follow-up was associated with superior outcomes, which was expected.

Objective: The goal of this study was to compare rates of dysphagia and patient-reported outcomes (PROs) following long-segment (≥ 3 levels) anterior cervical spinal fusion (ACF) and posterior cervical spinal fusion (PCF) at 3 and 12 months postoperatively. PROs were also compared for patients with dysphagia versus those without dysphagia.

Methods: A prospectively collected quality improvement database was used to identify patients who had a long-segment cervical spinal fusion. Cohorts were divided into ACF and PCF groups. Eating Assessment Tool-10 scores and PROs were obtained for all patients preoperatively and at 3 and 12 months postoperatively to compare. Multivariate analysis was also performed to evaluate risk factors for dysphagia.

Results: A total of 132 patients met the inclusion criteria, 77 of whom had undergone ACF and 55 of whom had undergone PCF. Dysphagia rates between ACF and PCF cohorts were similar at baseline (13.0% vs 18.2%, p = 0.4). New-onset dysphagia rates were also comparable at 3-month follow-up (39.7% vs 23.1%, p = 0.08) and 12-month follow-up (32.6% vs 32.4%, p > 0.99). Patients who underwent PCF had worse Neck Disability Index (NDI) scores at 3 months than did patients with ACF (13.67 ± 9.49 vs 10.55 ± 6.24, respectively; p = 0.03). There were significantly higher NDI scores for patients with dysphagia at 3 months in both the ACF and PCF groups and at 12 months for those in the PCF group. Analogously, EuroQol-5 Dimensions scores were worse for patients with dysphagia; however, this was only significant for patients in the ACF group at 3 months. There were no significant risk factors for the development of dysphagia found on multivariate analysis.

Conclusions: Similar rates and severity of dysphagia were seen following ACF and PCF at 3- and 12-month follow-up. This suggests that long-term dysphagia following cervical fusion surgery may be due to structural changes from the fusion rather than the surgical approach. However, the ACF cohort was significantly younger, and this may have partially accounted for the findings. PROs were also compared for patients with and without dysphagia, demonstrating worsened outcomes in some domains for patients who presented with dysphagia at 3- and 12-month follow-up. This suggests that dysphagia may be associated with a decreased quality of life after cervical fusion.

Objective: When using the cortical bone trajectory (CBT) technique, two technical countermeasures are recommended to promote bone fusion: taking a long CBT screw path directed more anteriorly and improving the stability of the spinal construct by facet joint preservation, cross-link augmentation, and rigid anterior interbody reconstruction. However, there has been no report on how these surgical procedures, which are heavily dependent on the surgeon's preference, contribute to successful bone fusion. The aim of the present study was to investigate the progression of lumbar spinal fusion using the long CBT technique and identify factors contributing to the time taken to achieve bone fusion, with a particular focus on the involvement of surgical procedures.

Methods: A total of 167 consecutive patients with L4 degenerative spondylolisthesis who underwent single-level posterior lumbar interbody fusion at L4-5 using the long CBT technique were included (mean follow-up 42.8 months). Bone fusion was assessed to identify factors contributing to the time to achieve bone fusion. Investigated factors were 1) age, 2) sex, 3) BMI, 4) bone mineral density, 5) intervertebral mobility, 6) screw depth in the vertebra, 7) extent of facetectomy, 8) cross-link augmentation, 9) cage material, 10) cage design, 11) number of cages, and 12) contact area of cages with the vertebral endplate.

Results: The bone fusion rate was 89.2% at 2 years postoperatively and 95.8% at the last follow-up, with a mean period to bone fusion of 16.6 ± 9.6 months. Multivariate regression analysis revealed that age (standardized regression coefficient [β] = 0.25, p = 0.002), female sex (β = -0.22, p = 0.004), and BMI (β = 0.15, p = 0.045) were significant independent factors affecting the time to achieve bone fusion. There was no significant effect of surgical procedures (p ≥ 0.364).

Conclusions: This is the first study to investigate the progression of lumbar spinal fusion using the long CBT technique and identify factors contributing to the time taken to achieve bone fusion. Patient factors such as age, sex, and BMI affected the progression of bone fusion, and surgical factors had only weak effects.

Objective: Prior studies investigating the use of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for treatment of degenerative lumbar conditions and concomitant sagittal deformity have not stratified patients by preoperative pelvic incidence (PI)-lumbar lordosis (LL) mismatch, which is the earliest parameter to deteriorate in mild sagittal deformity. Thus, the aim of the present study was to determine the impact of preoperative PI-LL mismatch on clinical outcomes and sagittal balance restoration among patients undergoing MI-TLIF for degenerative spondylolisthesis (DS).

Methods: Consecutive adult patients undergoing primary 1-level MI-TLIF between April 2017 and April 2022 for DS with ≥ 6 months radiographic follow-up were included. Patient-reported outcome measures (PROMs) included the Oswestry Disability Index, visual analog scale (VAS), 12-Item Short-Form Health Survey (SF-12), and Patient-Reported Outcomes Measurement Information System at preoperative, early postoperative (< 6 months), and late postoperative (≥ 6 months) time points. The minimal clinically important difference (MCID) for PROMs was also evaluated. Radiographic parameters included PI, LL, pelvic tilt (PT), and sagittal vertical axis (SVA). Patients were categorized into balanced and unbalanced groups based on preoperative PI-LL mismatch according to age-adjusted alignment goals. Changes in radiographic parameters and PROMs were evaluated.

Results: Eighty patients were included (L4-5 82.5%, grade I spondylolisthesis 82.5%, unbalanced 58.8%). Mean clinical and radiographic follow-up were 17.0 and 8.3 months, respectively. The average preoperative PI-LL was 18.8° in the unbalanced group and -3.3° in the balanced group. Patients with preoperative PI-LL mismatch had significantly worse preoperative PT (26.2° vs 16.4°, p < 0.001) and SVA (53.2 vs 9.0 mm, p = 0.001) compared with balanced patients. Patients with preoperative PI-LL mismatch also showed significantly worse PI-LL (16.0° vs 0.54°, p < 0.001), PT (25.9° vs 18.7°, p < 0.001), and SVA (49.4 vs 22.8 mm, p = 0.013) at long-term follow-up. No significant radiographic improvement was observed among unbalanced patients. All patients demonstrated significant improvements in all PROMs (p < 0.05) except for SF-12 mental component score. Achievement of MCID for VAS back score was significantly greater among patients with preoperative PI-LL mismatch (85.7% vs 65.5%, p = 0.045).

Conclusions: Although 1-level MI-TLIF did not restore sagittal alignment in patients with preoperative PI-LL mismatch, patients presenting with DS can expect significant improvement in PROMs following 1-level MI-TLIF regardless of preoperative alignment or extent of correction. Thus, attaining good clinical outcomes in patients with mild sagittal imbalance may not require addressing imbalance directly.

Objective: Primary spinal cord glioblastoma (scGB) is a rare and aggressive spinal glioma, making up 7.5% of such cases. Whereas molecular profiles associated with improved overall survival (OS) are well studied for cranial glioblastoma (GB), the molecular characteristics of scGB are less documented. This review sought to document the molecular signatures of scGB, explore current treatment strategies, and evaluate clinical outcomes.

Methods: A systematic literature review following the PRISMA guidelines searched the PubMed, Embase, and CENTRAL databases (January 1, 2013, to October 14, 2023) using glioblastoma-, spine-, and genetics-related keywords. Inclusion criteria were English-language articles on humans with histologically confirmed primary scGB, excluding drop metastases. Data on demographic characteristics, treatments, molecular profile, and outcome were extracted.

Results: Over 10 years, 71 patients with adult primary scGB were reported in 31 papers. Most patients were located in Asia (53%) and the United States (23%). The median (range) age was 32 (24-47) years, with 61% of patients male. Tumors occurred primarily in the thoracic region (42%). Clinical presentation included motor deficits (92%), sensory deficits (86%), neck/back pain (68%), and bowel/bladder dysfunction (59%). Patients underwent subtotal resection (51%), gross-total resection (GTR) (23%), and biopsy (26%). Postoperative adjuvant treatment included concomitant external beam radiation therapy (XRT) and temozolomide (TMZ) in the majority of cases (66%), as well as palliative care without adjuvant treatment (17%). The molecular signature of scGB was similar to its cranial counterpart in terms of MGMT-promoter methylation (40% increased methylation) and higher for mutant TERT (50%) but decreased for wild-type tumor protein p53 (41% decreased mutation). Median (range) OS was 10 (6-18) months, and median progression-free survival (PFS) was 7 (3-10) months. PFS was significantly higher in patients treated with XRT/TMZ: median 15 months vs 4.5 months (95% CI -1.32 to 22.56, p < 0.05).

Conclusions: Primary scGB remains a rare disease with notable variations in treatment, potentially influenced by geographical availability. The observed molecular profile, when compared to that of cranial GB, emphasizes the need for further genomic validation and data collection. Surgical advancements to overcome the challenges of accomplishing GTR may contribute to improved OS.

Objective: Primary rod fracture after surgery for adult spinal deformity (ASD) is a leading cause of revision, with recent prospective multicenter fracture rates reported at 11%-14% by 2 years. Consequently, the addition of supplemental rods has been explored to reduce fractures. Here the authors describe their experience with a novel iliac accessory rod technique in which each accessory rod anchors to an independent iliac bolt caudally via lateral connector, and attaches to the primary rod rostrally via side-to-side connector.

Methods: This retrospective, single-center case series included patients who underwent thoracolumbar/lumbar fusion for ASD between March 2019 and August 2023. Data on baseline demographics, radiographic parameters, surgical characteristics, complications, rod fracture, and revision rates were collected. Paired, 2-tailed t-tests were used to compare pre- and postoperative radiographic outcomes. Rod fracture rates were compared to prior investigations via chi-square goodness of fit testing. The technique for iliac accessory rod placement is described.

Results: The study consisted of 82 patients (mean age 66 years, 51% female, 26% with prior fusion) with a median follow-up of 2 years (IQR 28-104 weeks). A total of 50 patients (61%) had ≥ 2-year follow-up. Each surgery involved an average of 4 posterior column osteotomies and 8 segments. Iliac accessory rods were cobalt chromium and were placed bilaterally in 87% of constructs. Postoperative alignment improved significantly in the following parameters: maximum coronal Cobb angle, fractional curve, sagittal vertical axis, lumbar lordosis, thoracic kyphosis, and pelvic incidence to lumbar lordosis mismatch (p < 0.001 for all comparisons). Of 50 patients with ≥ 2-year follow-up, rod fracture occurred in 1 (2.0%), which was incidentally found and required no intervention. The present rod fracture rate was significantly lower than the authors' historically reported institutional rate of 21% for traditional dual-rod constructs, and the 11%-14% reported in recent prospective multicenter studies that used traditional and supplemental rod constructs (p < 0.05 for all comparisons). Reoperation occurred in 12 patients (14.6%); 7 (8.5%) for proximal junctional kyphosis and 5 (6.1%) for wound complication.

Conclusions: Here the authors describe their experience with a novel iliac accessory rod technique to prevent rod fracture in patients undergoing surgery for ASD. The 2-year rod fracture rate (2.0%) in this study is significantly lower than the authors' historical dual-rod fracture rate, and other prospective multicenter investigations. Future studies with longer follow-up are needed to determine the durability of this technique.

Objective: A major shortcoming in optimizing care for patients with cervical spondylotic myelopathy (CSM) is the lack of robust quantitative imaging tools offered by conventional MRI. Advanced MRI modalities, such as diffusion MRI (dMRI), including diffusion tensor imaging (DTI) and diffusion basis spectrum imaging (DBSI), may help address this limitation by providing granular evaluations of spinal cord microstructure.

Methods: Forty-seven patients with CSM underwent comprehensive clinical assessments and dMRI, followed by DTI and DBSI modeling. Conventional MRI metrics included 10 total qualitative and quantitative assessments of spinal cord compression in both the sagittal and axial planes. The dMRI metrics included 12 unique measures including anisotropic tensors, reflecting axonal diffusion, and isotropic tensors, describing extraaxonal diffusion. The primary outcome was the modified Japanese Orthopaedic Association (mJOA) score measured at 2 years postoperatively. Extreme gradient boosting-supervised classification algorithms were used to classify patients into disease groups and to prognosticate surgical outcomes at 2-year follow-up.

Results: Forty-seven patients with CSM, including 24 (51%) with a mild mJOA score, 12 (26%) with a moderate mJOA score, and 11 (23%) with a severe mJOA score, as well as 21 control subjects were included. In the classification task, the traditional MRI metrics correctly assigned patients to healthy control versus mild CSM versus moderate/severe CSM cohorts, with an accuracy of 0.647 (95% CI 0.64-0.65). In comparison, the DTI model performed with an accuracy of 0.52 (95% CI 0.51-0.52) and the DBSI model's accuracy was 0.81 (95% CI 0.808-0.814). In the prognostication task, the traditional MRI metrics correctly predicted patients with CSM who improved at 2-year follow-up on the basis of change in mJOA, with an accuracy of 0.58 (95% CI 0.57-0.58). In comparison, the DTI model performed with an accuracy of 0.62 (95% CI 0.61-0.62) and the DBSI model had an accuracy of 0.72 (95% CI 0.718-0.73).

Conclusions: Conventional MRI is a powerful tool to assess structural abnormality in CSM but is inherently limited in its ability to characterize spinal cord tissue injury. The results of this study demonstrate that advanced imaging techniques, namely DBSI-derived metrics from dMRI, provide granular assessments of spinal cord microstructure that can offer better diagnostic and prognostic utility.

Objective: Nonunion and significant subsidence after anterior cervical discectomy and fusion (ACDF) are associated with poor clinical outcomes, which occasionally lead to revision surgery. Allograft and polyetheretherketone (PEEK) cages are the two most commonly used interbody spacer devices for ACDF. Although studies have been conducted to compare the efficacies of these two interbody materials, the question remains regarding the superiority of one over the other. Therefore, the authors conducted a systematic review and meta-analysis to compare nonunion, subsidence, and reoperation rates after ACDF using allograft and PEEK cages as interbody devices.

Methods: In this systematic review and meta-analysis, the authors systematically searched the MEDLINE, EMBASE, and Cochrane Library databases for studies published prior to November 2023 that compared the efficacy and safety of allograft and PEEK cages for ACDF. A pooled analysis was designed to identify differences in nonunion, subsidence, and reoperation rates between the two interbody devices.

Results: Ten studies involving 1462 patients (allograft, 852 patients; PEEK cage, 610 patients) were included. The pooled analysis demonstrated that allograft had a significantly lower rate of nonunion compared to that of PEEK cages (OR 0.33, 95% CI 0.14-0.79; p = 0.01). Furthermore, the reoperation rate due to nonunion was significantly higher with PEEK cages compared to that with allograft (OR 0.28, 95% CI 0.11-0.71; p < 0.01), whereas the reoperation rate due to overall causes did not display significant results (OR 0.38, 95% CI 0.11-1.29; p = 0.12). The incidence of significant subsidence (OR 0.66, 95% CI 0.28-1.55; p = 0.34) and the mean amount of subsidence (standard mean difference 0.03, 95% CI -0.42 to 0.47; p = 0.90) did not demonstrate significant differences between allograft and PEEK cages.

Conclusions: Overall, the current meta-analysis suggests the advantages of allograft over PEEK cages used for ACDF, due to an enhanced fusion rate and minimized revision risk, with no increase in the risk of subsidence.

Objective: The aim of this study was to assess the correlation between patient-perceived changes in health and commonly utilized patient-reported outcome measures (PROMs) in lumbar spine surgery.

Methods: This was a retrospective review of prospectively collected data on consecutive patients who underwent lumbar microdiscectomy, lumbar decompression, or lumbar fusion at a single academic institution from 2017 to 2023. Correlation between the global rating of change (GRC) questionnaire, a 5-item Likert scale (much better, slightly better, about the same, slightly worse, and much worse), and PROMs (Oswestry Disability Index, visual analog scale for back and leg pain, 12-Item Short Form Health Survey Physical Component Summary and Mental Component Summary, and PROMIS physical function) was assessed using Spearman's rank correlation coefficients.

Results: A total of 1871 patients (397 microdiscectomies, 965 decompressions, and 509 fusions) were included. A majority of patients in each group rated their lumbar condition as much better at each postoperative time point compared with preoperatively and reported improved health status at each postoperative time point compared with the previous follow-up visit. Statistically significant but weak to moderate correlations were found between GRC and change in PROM scores from the preoperative time point. Correlation between GRC and change in PROM scores from the prior visit showed some statistically significant correlations, but the strengths ranged from very weak to weak.

Conclusions: A majority of patients undergoing lumbar microdiscectomy, decompression, or fusion endorsed notable improvements in health status in the early postoperative period and continued to improve at late follow-up. However, commonly used PROMs demonstrated very weak to moderate correlations with patient-perceived changes in overall lumbar spine-related health status as determined by GRC. Therefore, currently used PROMs may not be as sensitive at detecting these changes or may not be adequately reflecting changes in health conditions that are meaningful to patients undergoing lumbar spine surgery.