Neurospine最新文献

Objective: This study evaluates surgical strategies based on preoperative computed tomography (CT) findings during unilateral biportal endoscopic (UBE) surgery for thoracic ossification of the ligamentum flavum (OLF) with dural ossification.

Methods: This retrospective study included patients undergoing posterior thoracic laminectomy via UBE surgery to treat symptomatic thoracic stenosis due to OLF. Clinical outcomes were assessed using visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) scores, alongside analyses of preoperative CT and intraoperative videos for dural ossification characteristics.

Results: A total of 34 patients participated, showing significant improvements in VAS and JOA scores postoperatively. All focal dural ossifications exhibiting the tram-track sign were effectively excised without significant dural defects. The circumferential floating technique was employed for cases with the bridge sign, whereas wide excision was warranted for those with the comma sign.

Conclusion: UBE surgery effectively manages progressive thoracic OLF associated with dural ossification. Preoperative CT imaging is essential for assessing dural involvement and guiding surgical techniques. Microscopic surgery is recommended for inexperienced surgeons requiring wide dural excision.

Objective: Cement augmentation is widely used to enhance pedicle screw fixation, particularly in osteoporotic patients. However, its effects on adjacent segment disease (ASD) and implant failure in multilevel lumbar interbody fusion remain unclear. This study aimed to assess the effectiveness of cement augmentation in preventing implant failure and its impact on ASD risk using finite element analysis (FEA).

Methods: A FEA of L2-S1 multilevel lumbar interbody fusion was performed to evaluate the biomechanical effects of cement augmentation. Three models were analyzed under normal and osteoporotic conditions: type 1 (no augmentation), type 2 (upper instrumented vertebra [UIV] augmentation), and type 3 (UIV and UIV+1 augmentation). Range of motion (ROM), intradiscal pressure (IDP), screw pull-out risk, and implant failure were assessed.

Results: Cement augmentation significantly reduced screw pull-out risk, particularly in osteoporotic conditions, where type 1 exhibited a failure rate of 91.5%, while type 2 and type 3 remained below 39%. Cement augmentation did not demonstrate a substantial impact on ASD development, as ROM and IDP changes remained within a minimal range in this FEA model. However, osteoporosis was associated with a substantial increase in IDP, with a result as high as 809%. Despite its benefits, augmentation at UIV+1 increased the risk of pedicle screw breakage and vertebral body fracture, with L1 (UIV+1) lower endplate fracture rate of 82.7% in type 3, compared to 56.6% in type 2 and 52.8% in type 1.

Conclusion: Cement augmentation effectively improves screw fixation and does not appear to significantly increase ASD risk based on this FEA study. Limiting cement augmentation to the UIV level in lumbar multilevel fusion may help reduce the risk of implant failure, though further clinical validation is required to confirm these biomechanical findings.

Objective: Intramedullary hemorrhage (IH) associated with cavernous malformation (CM) of the high cervical spine remains a significant challenge for neurosurgeons. This study aimed to evaluate the efficacy and safety of the posterolateral sulcus (PLS) approach in managing these complex cases.

Methods: This single-center retrospective study included 58 cases of spinal intramedullary tumors treated surgically over the past 4 years. The PLS approach on the side of the IH was applied for the removal of CM. Neurological function was assessed using the modified McCormick functional scale (MMCS) before surgery, one week after surgery, and at the most recent follow-up.

Results: Six patients with IH associated with CM above the C3 level were identified from the database. The mean age was 31.2 years, and 4 of the 6 patients were female. Symptom duration prior to surgery ranged from 0 to 48 months. Total removal of the CM was achieved in all 6 cases without any serious adverse events including respiratory complications. The average follow-up duration was 21.7 months. The mean MMCS score was 3.0 before surgery, maintained at 2.5 in the early postoperative period, and improved further to 2.2 at the most recent follow-up. One patient of ventral-type CM experienced recurrent hemorrhage at the same level 30 months after the initial surgery. This patient subsequently underwent a second surgery using the anterolateral sulcus approach, which was well tolerated.

Conclusion: The PLS approach enables safe removal of CM even in the high cervical spine. However, ventral-type CMs remain a major surgical concern.

Objective: To evaluate the correlation between lumbar degenerative spondylolisthesis (LDS) and facet joint orientation, and to examine the factors influencing facet joint orientation in patients with double-level LDS (dLDS).

Methods: A total of 40 patients with L3-5 dLDS (mean age, 64.1 years) and 106 patients with L4-5 single-level LDS (sLDS; mean age, 63.5 years) were included. Besides, 100 age-matched healthy participants were recruited as the control group. Facet joint angles at each level from L2-3 to L5-S1 were measured on axial computed tomogrpahy images. Slippage and spinopelvic sagittal parameters were measured using lateral full-spine x-rays.

Results: Both dLDS and sLDS groups had significantly larger facet joint angles from L2-3 to L5-S1 than those in the control group, except for left L5-S1. In patients with spondylolisthesis, the facet joint angles at the L2-3 and L3-4 levels in the dLDS group were significantly greater than those in the sLDS group, while the angles at the L4-5 and L5-S1 levels showed no significant differences. In contrast to the sLDS group, the dLDS group had significantly greater pelvic tilt, sagittal vertical axis, L3 slope, and L4 slope, as well as smaller sacral slope, lumbar lordosis, L3-4 disc height, L4-5 disc height, L4-5 slippage angle, and L3-S1 height. Age and dLDS were identified as independent factors influencing the changes in the L3-4 facet joint angles between the 2 LDS groups.

Conclusion: Spondylolisthesis and aging are associated with facet joint sagittalization. The present study provides evidence that the combined effects of preexisting degeneration and spondylolisthesis alter the morphology of the facet joints.

Objective: Idiopathic syringomyelia (IS) associated with occult arachnoid pathology is a relatively rare condition characterized by a subtle onset, atypical clinical manifestations, and significant diagnostic and therapeutic challenges. This study aims to evaluate the radiographic and clinicopathological features of IS to improve surgical management and patient outcomes.

Methods: In this study, clinical and radiologic data were retrospectively extracted from a single-center syringomyelia database (N=1,039) spanning December 2020 to March 2025. Among these, 15 patients diagnosed with IS underwent preoperative magnetic resonance imaging and myelography to identify the responsible spinal segments precisely. Comprehensive perioperative assessments and clinical outcomes were collected. During surgery, the subarachnoid space (SAS) was thoroughly explored, with complete removal of thickened and adherent arachnoid tissue to restore normal cerebrospinal fluid (CSF) circulation. Additionally, clinical data, pathological features, and surgical outcomes of IS were compared to those of posttraumatic delayed syringomyelia (PTDS) to evaluate potential differences.

Results: In this series, all patients underwent preoperative myelography, revealing varying degrees of SAS obstruction. For IS cases that received precise and comprehensive arachnoid lysis, overall postoperative outcomes were favorable. Intraoperative pathology confirmed that all IS cases were characterized by noninfectious, nonacute inflammation. The preoperative maximal syrinx/cord ratio averaged 0.70±0.07 (range, 0.54-0.88), while the syrinx resolution rate varied from 12.2% to 100%, with a mean improvement of 29.6%. Patients with PTDS exhibited a relatively higher incidence of hypesthesia and a greater syrinx tension index. However, no significant differences were observed between IS and PTDS in terms of syrinx length, deviation, or location. Notably, the IS group demonstrated significantly better postoperative syrinx resolution and improvement in syringomyelia-related symptoms compared to the PTDS group.

Conclusion: While both IS and PTDS share a common underlying mechanism of arachnoid adhesions, they differ significantly in pathological features, treatment approaches, and clinical outcomes. In cases of IS, thorough spinal arachnoid lysis at the affected segment could restore normal spinal cord pulsation and CSF circulation, leading to effective syrinx resolution and a favorable long-term prognosis.

The atlantoaxial (C1-2) junction is among the most technically demanding regions for cervical spine surgery owing to its complex osseoligamentous anatomy and proximity to critical neurovascular structures. Numerous posterior fixation constructs have been developed to optimize biomechanical rigidity and promote arthrodesis. Since Gallie's introduction of posterior wiring with autologous bone grafts in 1939, evolving techniques have focused on enhancing fusion rates while minimizing risk to adjacent structures. This paper outlines the historical evolution of C1-2 posterior instrumentation, current fixation strategies, bone fusion techniques, and reduction methods. A systematic literature search identified 61 relevant studies on C1-2 fusion. Additional references were manually reviewed to provide a comprehensive context. Of these, 41 studies were narratively summarized to outline the historical and conceptual evolution of C1-2 fusion techniques, while the remaining 20 post-2000 studies on contemporary surgical modifications were systematically reviewed and tabulated for technical details and clinical outcomes. C1-2 fusion techniques have evolved significantly over time. Early methods primarily involved posterior wiring with autologous bone grafts, but later transitioned to rigid segmental fixation using pedicle screw constructs, resulting in improved fusion rates and clinical outcomes. Interarticular fusion, when concurrently performed, enhances the biological fusion environment, contributing to favorable clinical results. C1 lateral mass, posterior arch, pedicle screws and C2 pedicle, lamina screws give us much stronger stability and higher fusion rates. Interarticular fusion using local bone also gives us technical easiness guaranteeing high fusion rate overcoming inconvenience of wiring and iliac bone harvest. Interarticular height reduction and interarticular fusion should be discriminated.

Objective: To investigate the correlation between paraspinal sarcopenia (PS) and sagittal imbalance (SI) in degenerative kyphosis (DK), and to explore the correlation between paraspinal muscle (PSM) function loss and morphology change in DK.

Methods: One hundred thirty-eight patients with DK and 204 with lumbar spinal stenosis (LSS) were enrolled. The spinopelvic parameters and sagittal vertical axis (SVA) were measured. Patients were divided into the sagittal balance (SB, SVA ≤ 5 cm, n = 61) and SI (SVA > 5 cm, n = 77) groups. Sagittal balanced LSS patients were served as control group. PSM function was evaluated by measuring the maximal voluntary exertion (MVE) and endurance time (ET). Magnetic resonance imaging-derived cross-sectional area (CSA) and fat infiltration rate (FI%) of PSM at T10-L5 were normalized to intervertebral disc CSA. Psoas CSA and FI% were calculated at L3-4 disc level. The correlation assessment using Spearman rank correlation coefficient and multiple linear regression. Logistic regression was used to identify the risk factors of SI.

Results: Significantly lower ET, MVE, relative CSA (rCSA) and higher rFI% was found in the SI group than in the SB and control. The PS were correlated with spinopelvic parameters and regional kyphosis, while lack of correlation was found between the rFI% and MVE. Logistic regression and Youden index analysis showed ET < 15.5 seconds, MVE < 1.3 N/kg, and rCSA (L1-5) atrophy to be potential risk factors for SI in DK.

Conclusion: DK patients with SI demonstrate acerbated PS that indicated by significant PSM dysfunction and morphological alterations. We highlight the significance of PSM combined evaluation and revealed that PS plays an indispensable role in the progression of SI, providing novel insights into the underlying sagittal compensatory mechanisms.

Metastatic spine disease represents a growing therapeutic challenge that demands a balance between incorporating emerging technologies while respecting the fundamental principles during clinical decision-making. Advances in adjuvant therapies, including stereotactic body radiotherapy (SBRT) and chemotherapy, have significantly improved long-term patient survival. Surgical decision-making should be guided by well-established frameworks such as the NOMS (neurologic, oncologic, mechanical, systemic) criteria, the ESCC (epidural spinal cord compression) scale, and the SINS (spinal instability neoplastic score), ensuring a structured and evidence-based approach to treatment. The integration of minimally invasive techniques, including percutaneous instrumentation, ablation techniques, and biportal endoscopic approaches, has reduced surgical morbidity and facilitated faster recovery. Additionally, carbon fiber implants are revolutionizing spinal stabilization by allowing better postoperative visualization of any local recurrence and easier radiation planning. SBRT has emerged as a critical modality, offering precise, high-dose radiation with minimal toxicity to the spinal cord, improving local tumor control and patient outcomes. A multidisciplinary approach remains paramount, requiring collaboration between spine surgeons, radiation oncologists, and medical oncologists. In this narrative review, we aim to provide a comprehensive overview of the current state of metastatic spine tumor management, focusing on: (1) fundamentals of metastatic spine care, (2) minimally invasive surgical techniques, (3) the use of carbon fiber screws, (4) SBRT, and (5) ways to maximize patient safety.