Neurospine最新文献

Objective: Recent studies indicate that 3 morphological types of atlanto-occipital joint (AOJ) exist in the craniovertebral junction and are associated with type II basilar invagination (BI) and atlanto-occipital instability. However, the actual biomechanical effects remain unclear. This study aims to investigate biomechanical differences among AOJ types I, II, and III, and provide further evidence of atlanto-occipital instability in type II BI.

Methods: Models of bilateral AOJ containing various AOJ types were created, including I-I, I-II, II-II, II-III, and III-III models, with increasing AOJ dysplasia across models. Then, 1.5 Nm torque simulated cervical motions. The range of motion (ROM), ligament and joint stress, and basion-dental interval (BDI) were analyzed.

Results: The C0-1 ROM and accompanying rotational ROM increased progressively from model I-I to model III-III, with the ROM of model III-III showing increases between 27.3% and 123.8% indicating ultra-mobility and instability. In contrast, the C1-2 ROM changes were minimal. Meanwhile, the stress distribution pattern was disrupted; in particular, the C1 superior facet stress was concentrated centrally and decreased substantially across the models. The stress on the C0-1 capsule ligament decreased during cervical flexion and increased during bending and rotating loading. In addition, BDI gradually decreased across the models. Further analysis revealed that the dens showed an increase of 110.1% superiorly and 11.4% posteriorly, indicating an increased risk of spinal cord impingement.

Conclusion: Progressive AOJ incongruity critically disrupts supportive tissue loading, enabling incremental atlanto-occipital instability. AOJ dysplasia plays a key biomechanical role in the pathogenesis of type II BI.

Objective: Minimally invasive spine surgery (MISS) employs small incisions and advanced techniques to minimize tissue damage while achieving similar outcomes to open surgery. MISS offers benefits such as reduced blood loss, shorter hospital stays, and lower costs. This review analyzes complications associated with MISS over the last 10 years, highlighting common issues and the impact of technological advancements.

Methods: A systematic review following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines was conducted using PubMed, MEDLINE, Embase via OVID, and Cochrane databases, covering publications from January 2013 to March 2024. Keywords related to MISS and complications were used. Studies on adult patients undergoing MISS with tubular, uniportal, or biportal endoscopy, reporting intraoperative or postoperative complications, were included. Non-English publications, abstracts, and small case series were excluded. Data on MISS approach, patient demographics, and complications were extracted and reviewed by 2 independent researchers.

Results: The search identified 880 studies, with 137 included after screening and exclusions. Key complications in cervical MISS were hematomas, transient nerve root palsy, and dural tears. In thoracic MISS, complications included cerebrospinal fluid leaks and durotomy. In lumbar MISS, common complications were incidental dural injuries, postoperative neuropathic conditions, and disc herniation recurrences. Complications varied by surgical approach.

Conclusion: MISS offers reduced anatomical disruption compared to open surgery, potentially decreasing nerve injury risk. However, complications such as nerve injuries, durotomies, and hardware misplacement still occur. Intraoperative neuromonitoring and advanced technologies like navigation can help mitigate these risks. Despite variability in complication rates, MISS remains a safe, effective alternative with ongoing advancements enhancing its outcomes.

Objective: To explore the changes in coronal imbalance (CIB) in Lenke 5C adolescent idiopathic scoliosis (AIS) after posterior selective fusion surgery and determine their implications for surgical decision-making.

Methods: One hundred twenty patients were categorized according to the preoperative coronal pattern (type A, coronal balance distance [CBD]<20 mm; type B, CBD≥20 mm and coronal C7 plumbline [C7PL] shifted to the concave side of the curve; type C, CBD≥20 mm and C7PL shifted to the convex side of the curve). CIB group (CIB+) was defined as having a CBD≥20 mm at the 2-year follow-up.

Results: Compared to type A patients, the prevalence of postoperative CIB was higher in type C patients both immediately postoperative (22% vs. 38%, p<0.05) and at the final follow-up (5% vs. 29%, p<0.05), whereas type A patients showed a greater improvement in CBD (9 of 12 vs. 6 of 24, p<0.05) at the final follow-up. The majority of patients in all groups had recovered to type A at the final follow-up (96 of 120). The proximal Cobb-1 strategy reduced the incidence of postoperative CIB (1 of 38) at the 2-year follow-up, especially in preoperative type C patients. Multivariate logistic regression analysis revealed that type C and overcorrection of the thoracolumbar curve were risk factors for CIB at the 2-year follow-up (p=0.007 and p=0.026, respectively).

Conclusion: Patients with type C CIB in AIS exhibited unsatisfactory restoration, with 29% of them exhibiting CIB at the final follow-up. The selective fusion strategy of proximal Cobb-1 may reduce the risk of postoperative CIB especially when the preoperative coronal pattern is type C.

Objective: Biportal endoscopic transforaminal lumbar interbody fusion (BE-TLIF) is an emerging, minimally invasive technique performed under biportal endoscopic guidance. However, concerns regarding cage subsidence and sufficient fusion during BE-TLIF necessitate careful selection of an appropriate interbody cage to improve surgical outcomes. This study compared the fusion rate, subsidence, and other radiographic parameters according to the material and size of the cages used in BE-TLIF.

Methods: In this retrospective cohort study, patients who underwent single-segment BE-TLIF between April 2019 and February 2023 were divided into 3 groups: group A, regular-sized three-dimensionally (3D)-printed titanium cages; group B, regular-sized polyetheretherketone cages; and group C, large-sized 3D-printed titanium cages. Radiographic parameters, including lumbar lordosis, segmental lordosis, anterior and posterior disc heights, disc angle, and foraminal height, were measured before and after surgery. The fusion rate and severity of cage subsidence were compared between the groups.

Results: No significant differences were noted in the demographic data or radiographic parameters between the groups. The fusion rate on 1-year postoperative computed tomography was comparable between the groups. The cage subsidence rate was significantly lower in group C than in group A (41.9% vs. 16.7%, p=0.044). The severity of cage subsidence was significantly lower in group C (0.93±0.83) than in groups A (2.20±1.84, p=0.004) and B (1.79±1.47, p=0.048).

Conclusion: Cage materials did not affect the 1-year postoperative outcomes of BE-TLIF; however, subsidence was markedly reduced in large cages. Larger cages may provide more stable postoperative segments.

Objective: Oblique lumbar interbody fusion (OLIF), performed using a retroperitoneal approach, can lead to complications related to the approach, such as lumbar sympathetic chain injury (LSCI). Although LSCI is a common complication of OLIF, its reported incidence varies across studies due to an absence of specific diagnostic criteria. Moreover, research on the risk factors of postoperative sympathetic chain injuries after OLIF remains limited. Therefore, this study aimed to describe the incidence, and identify independent risk factors for LSCI, in patients with degenerative lumbar spinal diseases who underwent OLIF.

Methods: Between October 2020 and August 2023, a retrospective review was conducted at our institute on 200 patients who underwent OLIF at 1 to 4 consecutive spinal levels (L1-5) for degenerative spinal diseases including spinal stenosis, spondylolisthesis, degenerative scoliosis. We excluded those with infections, trauma, tumors, and lower extremity edema/warmth due to other causes. The patients were categorized into 2 groups: those with and without LSCI symptoms. Demographic data, operative data, and pre- and postoperative parameters were evaluated for their association with LSCI using a univariate logistic regression model. Variables with a p-value <0.1 in the univariate analysis were included in a multivariate model to identify the independent risk factors.

Results: Thirty-five of 200 patients (17.5%) developed LSCI symptoms after OLIF. Multivariate logistic regression analysis indicated that prolonged retraction time, particularly exceeding 31.5 miniutes, remained an independent risk factor (adjusted odds ratio, 12.59; p<0.001).

Conclusion: This study demonstrated that prolonged retraction time was an independent risk factor for LSCI following OLIF, particularly when it exceeded 31.5 minutes. Protecting the lumbar sympathetic chain during surgery and minimizing retraction time are crucial to avoiding LSCI following OLIF.

This review aims to systematically evaluate the incidence, management strategies, and clinical outcomes of iatrogenic durotomy (ID) in endoscopic spine surgery and to propose a management flowchart based on the tear size and associated complications. A comprehensive literature search was conducted, focusing on studies involving endoscopic spinal procedures and incidental durotomy. The selected studies were analyzed for management techniques and outcomes, particularly in relation to the size of the dural tear and the presence of nerve root herniation. Based on these findings, a flowchart for intraoperative management was developed. A total of 14 studies were included, encompassing 68,546 patients. Varying incidences of ID, with management strategies largely dependent on the size of the dural tear, were found. Small tears (less than 5 mm) were often left untreated or managed with absorbable hemostatic agents, while medium (5-10 mm) and large tears (greater than 10 mm) required more complex approaches like endoscopic patch repair or open surgery. The presence of nerve root herniation necessitated immediate action, often influencing the decision to convert to open repair. Effective management of ID in endoscopic spine surgery requires a nuanced approach tailored to the size of the tear and specific intraoperative challenges, such as nerve root herniation. The proposed flowchart offers a structured approach to these complexities, potentially enhancing clinical outcomes and reducing complication rates. Future research with more rigorous methodologies is necessary to refine these management strategies further and broaden the applications of endoscopic spine surgery.

Objective: Chordoma, a rare malignant tumor originating from embryonal notochord remnants, exhibits high resistance to conventional treatments, making surgical resection imperative. However, the factors influencing prognosis specifically for cervical spine chordoma have not been clearly identified. We investigate the prognosis of cervical spine chordoma with factors influential in a nationwide multicenter retrospective study.

Methods: This study included all patients diagnosed with cervical spine chordoma at 7 tertiary referral centers from January 1998 to March 2023, excluding those with clivus and thoracic spine chordomas extending into the cervical spine. Local recurrence (LR) was identified through follow-up magnetic resonance imaging, either as reappearance in completely resected tumors or regrowth in residual tumors. The study assessed LR and overall survival, analyzing factors influencing LR and death.

Results: Forty-five patients with cervical spine chordoma had a mean age of 46.4 years. Over a median follow-up of 52 months, LR and distant metastasis were observed in 21 (46.7%) and 4 patients (8.9%), respectively, and 16 patients (36%) were confirmed dead. The 5-year and 10-year cumulative LR rates were 51.3% and 60%, respectively, while the 5-year and 10-year survival rates were 82% and 53%. Age was the only significant factor affecting mortality (hazard ratio, 1.04; 95% confidence interval, 1.04-1.07; p=0.015). Notably, the degree of resection and adjuvant therapy did not statistically significantly impact local tumor control and mortality.

Conclusion: This study, the largest multicenter retrospective analysis of cervical spine chordoma in Korea, identified age as the only factor significantly affecting patient survival.