Neurospine最新文献

Objective: Spinal fusion surgery is effective for treating various adult spinal deformities. However, spinal fusion surgery is associated with the risk of adjacent segment disease (ASD; 5%-30%), particularly proximal junctional kyphosis (PJK) and proximal junctional failure (PJF). Proximal junctional tethering (PJT) has become a popular technique owing to increasing evidence that it can decrease the rate of PJK or PJF.

Methods: A literature search was conducted using PubMed, Embase, and Cochrane Library. Twelve eligible studies were identified. These studies were predominantly retrospective in nature and compared the incidence of PJK or PJF in adults undergoing spinal fusion surgery with or without PJT. Risk of bias was assessed using the Newcastle-Ottawa scale. All outcomes were analyzed using R software (ver. 4.4.1).

Results: We included 8 retrospective cohort studies and 3 propensity-score-matched analyses; these studies comprised 1,424 patients. PJT was associated with a significant decrease in the odds of development of PJK (odds ratio [OR], 0.44; 95% confidence interval [CI], 0.27-0.71) and PJF (OR, 0.36; 95% CI, 0.19-0.69) compared with control. Subgroup analysis results revealed no significant difference in ASD rates between geographical locations, between tethering with and without crosslinks, and between specific tethering techniques.

Conclusion: PJT significantly reduces the odds of both PJK and PJF in adults undergoing spinal fusion surgery.

Objective: Motor-evoked potential (MEP) loss during intramedullary (IM) spinal cord tumor surgery impairs the ability to monitor further neural injury. Direct wave (D-wave) monitoring may allow continued assessment of corticospinal tract integrity after MEP loss. This study evaluates the role of D-wave-guided surgery in preserving function and enabling safe resection after MEP loss.

Methods: A retrospective study was conducted in adult patients with ependymoma (EPN), cavernous angioma (CA) or subependymoma who experienced MEP loss during IM tumor resection between January 2012 and May 2025. Patients who underwent continued resection under D-wave guidance after MEP loss were compared with those who did not.

Results: Among 37 eligible patients, 9 underwent D-wave-guided surgery and 28 did not. Functional improvement at the last follow-up was more frequent in the D-wave-guided surgery group (66.7% vs. 17.9%, p=0.011). This trend remained significant in EPN patients (74.4% vs. 9.1%, p=0.003), but not in CA patients. Immediate postoperative motor grade ≤3 was more common in the D-wave-guided surgery group (66.7% vs. 39.3%), although this difference was not statistically significant (p=0.251). By last follow-up, the proportions of patients self-ambulatory without external aids (88.9% vs. 89.3%, p=1.000) were similar between groups. Extent of resection, complications, and recurrence rates showed no significant differences.

Conclusion: D-wave-guided surgery may enable safe continuation of tumor resection after MEP loss without increasing morbidity. It offers a viable intraoperative strategy to preserve long-term motor function by extending monitoring beyond MEP limitations.

Objective: Retro-odontoid pseudotumor (ROP) is a nonneoplastic mass associated with atlantoaxial instability (AAI). This study compared ROP-positive and ROP-negative AAI patients and evaluated cystic versus granulation-type ROP regarding regression patterns and surgical outcomes.

Methods: We retrospectively analyzed 112 AAI patients who underwent pre- and postoperative imaging and clinical evaluations. Patients were classified as ROP-positive or ROP-negative, with ROP-positive cases further categorized as cystic or granulation-type. Imaging parameters-including atlantodental interval (ADI), ΔADI, and cervical range of motion (ROM) were compared along with regression time and postoperative outcomes.

Results: Among 112 patients, 57 (50.9%) had ROP. The ROP-positive group was older (67.37±13.13 years vs. 56.90±15.15 years, p<0.001) and had lower ADI (5.63±2.77 mm vs. 6.99±2.33 mm, p=0.034), ΔADI (3.01±2.27 mm vs. 3.89±2.07 mm, p=0.006), and C2-7 ROM (30.78°±15.45° vs. 41.73°±16.58°, p<0.001). In ROP subgroups, the cystic group had greater C1-2 ROM (15.69°±6.34° vs. 10.00°±7.72°, p=0.013) and ADI (6.98±2.68 mm vs. 5.14±2.66 mm, p=0.042). Immediate postoperative ROP thickness remained greater in the cystic group (6.85±2.49 vs. 5.21±1.82 mm, p=0.042), while ROP thickness at 3 months and 1 year showed no significant differences. JOA recovery rates were similar.

Conclusion: This study demonstrates that ROP-positive AAI patients exhibit distinct radiological characteristics, with reduced cervical mobility. Furthermore, cystic ROP shows delayed regression following posterior fusion. These findings underscore the importance of ROP subtypes in surgical planning, requiring closer monitoring and possibly earlier intervention.

Objective: To develop a pedicle screw for posterior spinal fixation using this long fiber carbon fiber reinforced plastic (CFRP) technology and evaluate its strength and radiolucency compared with titanium (Ti)-alloy screws.

Methods: In this preclinical study, the shear strength, torsional strength, loosening resistance, and image evaluation of long fiber type CFRP pedicle screws and Ti-alloy screws were compared. A series of tests was conducted for future clinical-use approval.

Results: The long fiber type CFRP pedicle screw (mean±standard deviation: 11,377.7±245.1 N) had superior shear strength compared to the Ti-alloy pedicle screw (10,300.3±249.7 N). The long fiber type CFRP pedicle screw (4.4±0.5 Nm) had inferior torsional strength compared to the Ti-alloy pedicle screw (22.4±0.6 Nm), although it could withstand twice the maximum load applied during surgery, suggesting that this will not be a clinical concern. In terms of loosening resistance, maximum torque values of the long fiber type CFRP pedicle screw and Ti-alloy pedicle screw were 0.99±0.08 and 0.75±0.05 Nm, respectively. The long fiber type CFRP pedicle screw was significantly more resistant to loosening than the Ti-alloy pedicle screw. Moreover, artifacts in the radiographic images were smaller than those observed for the Ti alloy. Biosafety and magnetic resonance safety tests also yielded satisfactory results, supporting approval of the long fiber CFRP pedicle screws for clinical use.

Conclusion: Compared to existing Ti-alloy screws, the long fiber type CFRP pedicle screw with innovative manufacturing technology has sufficient performance for clinical use, and its use may make spinal surgery safer and more effective.