Asian Spine Journal最新文献

Study design: Observational study.

Purpose: Cervical parameters play a vital role in maintaining global spinal sagittal alignment, but their correlation with spinopelvic parameters remains unclear. This study aimed to investigate potential direct correlations between cervical sagittal alignment and spinopelvic alignment in an asymptomatic population.

Overview of literature: Previous studies have demonstrated a direct relationship between pelvic parameters, lumbar lordosis (LL), and thoracic kyphosis (TK), as well as a direct correlation between cervical lordosis (CL) and TK. However, the direct influence of pelvic parameters and LL on cervical parameters remains unclear, warranting further research.

Methods: This study involved 104 asymptomatic adults (females 62 [59.6%]) aged 18-50 years. Whole-spine standing lateral radiographs were obtained, and the pelvic, lumbar, thoracic, cervicothoracic, and cervical parameters were studied. Pearson's correlation coefficient was used to assess correlations, with a significance threshold of p<0.05.

Results: The mean age of participants was 38.27±9.93 years. The pelvic incidence (PI) significantly correlated with C7 slope (r=-0.212, p=0.05). The pelvic tilt (PT) exhibited significant correlations with T1 slope-CL mismatch (r=-0.229, p=0.05) and C2 slope (r=-0.202, p=0.05). Furthermore, PI-LL mismatch showed a significant correlation with TIA (r=-0.197, p=0.05), T1 slope (r=-0.228, p=0.05), and C7 slope (r=-0.251, p=0.05).

Conclusions: This study reveals a significant correlation between cervical and spinopelvic parameters, emphasizing the interconnectedness of pelvic, lumbar, thoracic, and cervical spine parameters.

Numerous techniques for C2 screw fixation have been recently reported. However, concerns remain regarding the risk of spinal cord or vertebral artery injury and inadequate biomechanical stability. To our knowledge, the specific transforaminal "in-out-in" screw fixation technique has not been previously reported. This study aimed to investigate the feasibility and preliminary clinical outcomes of a transforaminal "in-out-in" multi-cortical purchase screw for posterior C2 screw fixation. Between October 2022 and March 2023, 10 patients underwent posterior atlantoaxial internal fixation. All patients had severe hypoplasia of the C2 pedicle on at least one side, precluding the use of standard C2 pedicle screws. A transforaminal "in-out-in" screw was used as an alternative. No spinal cord injury, vascular injury, or other major complications were observed. No implant failure was noted at the final follow-up. In conclusion, the transforaminal "in-out-in" screw may achieve rigid three-column fixation with multiple cortical purchases. It represents a safe and effective alternative for posterior C2 fixation in patients with severely narrow C2 pedicles where traditional pedicle screw placement is not feasible.

Study design: A retrospective study.

Purpose: To compare the predictive utility between Hounsfield unit (HU) values and vertebral bone quality (VBQ) scores for adjacent vertebral fracture (AVF) risk after balloon kyphoplasty (BKP) and to identify the appropriate measurement site.

Overview of literature: HU and VBQ have emerged as novel bone strength assessment methods. However, no study has compared the efficacy of these methods for evaluating AVF risk.

Methods: This single-center study included 130 patients with osteoporotic vertebral fractures who underwent BKP and preoperative computed tomography and magnetic resonance imaging. After propensity score matching for age; sex; body mass index; fracture level; use of steroids, teriparatide, or osteoporosis medication; and previous AVF, patients were classified into the AVF (-) and AVF (+) groups, each of which included 34 patients. Bone strength was assessed using the L1 HU, L1-4 HU (mean HU of L1-L4), L1 VBQ, and L1-4 VBQ. Group differences were analyzed, and the predictive accuracy for AVF was evaluated using area under the receiver operating characteristic curve (AUC).

Results: L1 HU was significantly lower in the AVF (+) group than in the AVF (-) group (92.1±29.4 vs. 71.6±21.4, p =0.013). No significant differences between the groups were observed for L1-4 HU, L1 VBQ, and L1-4 VBQ. L1 HU had the highest AUC (0.657), compared with those for L1-4 HU (0.625), L1 VBQ (0.524), and L1-4 VBQ (0.523). The predictive accuracy of L1 was superior to that of L1-4 for both HU and VBQ scores.

Conclusions: HU was superior to VBQ in predicting AVF risk after BKP, with L1 HU being the most effective indicator of bone strength and AVF risk.

Metastatic spine cancer (MSC), a common complication of advanced malignancies, poses significant challenges due to pain, neurological deficits, and mechanical instability. While radiation therapy is a cornerstone of treatment, the role of spine surgery is evolving, fueled by advances in surgical techniques and radiation modalities such as stereotactic body radiation therapy (SBRT). This review examines the evolving role of spine surgery in MSC management, focusing on separation surgery, surgical innovations, and future directions. The treatment paradigm for MSC shifted with the advent of SBRT, which delivers high-dose precision radiation, improving local control even in radioresistant tumors. This advancement enabled the adoption of separation surgery, a technique aimed at creating a safe margin between the tumor and neural structures without extensive tumor resection, followed by SBRT to achieve tumor regression. Separation surgery reduces morbidity, shortens operative times, and achieves comparable local control rates to traditional corpectomy procedures. Innovations like minimally invasive surgery, stereotactic navigation, and cement-augmented instrumentation have improved surgical safety and outcomes. Emerging technologies, such as machine learning for predictive modeling and augmented reality for surgical navigation, hold potential for improving decision-making and procedural accuracy. Spine surgery remains integral to MSC treatment, especially for high-grade metastatic epidural spinal cord compression and mechanical instability. Integrating advanced technologies and multidisciplinary collaboration is key to optimizing patient outcomes. Comprehensive, patient-centered strategies addressing both oncological and mechanical aspects can improve survival and quality of life for patients with MSC.

Study design: Retrospective study.

Purpose: To compare clinical and radiographic outcomes of patients undergoing anterior cervical decompression surgery with and without resecting the posterior longitudinal ligament (PLL).

Overview of literature: Resection of the PLL during anterior cervical decompression surgery is still a controversial topic among spine surgeons.

Methods: All patients undergoing anterior cervical decompression surgery from October 2018 to December 2023 were included in this cohort. The PLL was preserved in patients with cervical spondylosis with only axial neck pain, cervical spine injuries with an intact PLL and intervertebral disc, PLL ossification with double layer signs on magnetic resonance imaging studies, and cervical spine metastasis. Clinical outcomes were used to evaluate the visual analog scale for neck pain and a modified Japanese Orthopedic Association score. Radiographs were used to evaluate the device-level Cobb angle (CA), segmental CA, global CA, and sagittal vertical axis, and they were compared with postoperative measurements at 1 year.

Results: A total of 102 patients underwent surgical intervention. In 36 patients, PLL was preserved. The retractor time was shorter in the non-PLL resection group and was statistically significant (p=0.046). The non-PLL resection group had fewer complications, but this was not statistically significant (p=0.787). Both clinical and radiographic outcomes were improved after surgery, and there were no statistically significant outcome differences between the resection and non-resection groups.

Conclusions: Resecting the PLL in patients undergoing anterior cervical spine surgery may prolong retractor time and could potentially result in postoperative complications. However, it does not significantly affect radiographic outcomes regarding cervical spine alignment compared to patients where the PLL was not cut.

C5 palsy (C5P) is a common, yet poorly understood complication of cervical decompressive surgery, causing substantial disability and impacting postoperative quality of life. Despite extensive research, the actual incidence and distribution of C5P across different cervical surgical approaches over the past decade remain unclear. A comprehensive literature search was conducted on October 15, 2024, across Google Scholar, Embase, PubMed, Web of Science, and Cochrane Library databases. Studies reporting C5P incidence following surgery for degenerative cervical conditions, published until 2024, were included, excluding reviews, opinions, letters, and non-English manuscripts. Ninety-seven articles were included, encompassing 21,231 patients undergoing decompressive cervical surgery for degenerative cervical myelopathy. The overall incidence of postoperative C5P was 7% (95% confidence interval [CI], 4%-10%). The highest incidence was observed with circumferential fusion (combined anterior-posterior approach) at 16% (95% CI, 8%-24%), while the lowest was with anterior cervical decompression and fusion at 4% (95% CI, 3%-5%). Incidence rates following laminoplasty and laminectomy and fusion were 6% (95% CI, 5%-7%) and 10% (95% CI, 8%-12%), respectively. Recovery time ranged from 20.9 to 35 weeks, with 19.1%-33% of patients experiencing residual weakness. Significant risk factors included male sex, preoperative intervertebral foraminal stenosis, ossified posterior longitudinal ligament, open-door laminoplasty, laminectomy (with/without fusion), and excessive spinal cord shift. The role of C4-5 foraminotomy remains contested. Our meta-analysis identifies the posterior surgical approach as a significant risk factor for C5P. Circumferential fusion poses the highest risk, while laminoplasty can reduce the risk compared to laminectomy (alone or with instrumented fusion).

Study design: Retrospective cohort study.

Purpose: This study aimed to document the presentation, treatment, and clinical outcomes of surgically managed de novo C5 palsies.

Overview of literature: De novo C5 motor palsy-occurring without prior cervical spine intervention or trauma-presents with a unique constellation of symptoms. Unlike typical multilevel cervical radiculopathy, patients with de novo C5 palsy primarily experience motor deficits, most notably affecting the deltoid and biceps. The etiology of their symptoms may be attributed to intrinsic spinal pathologies, including foraminal stenosis and spinal cord compression.

Methods: A total of 31 C5 motor palsies in 26 patients were included in this case series. Patients underwent 16 anterior cervical discectomy and fusions, six laminoplasties, and four laminectomies with fusion procedures. Visual Analog Scale (VAS) pain scores, Neck Disability Index (NDI), and strength scores were recorded during pre- and postoperative follow-up visits. Statistical analysis was conducted using Fisher's exact test and a paired t-test with analysis of variance.

Results: The mean preoperative motor strength grades for the deltoid and biceps were 2.1 and 3.2, respectively. At final follow-up, mean deltoid and bicep motor grades had significantly improved compared to preoperative values (p <0.0001, p <0.0001, respectively). Significant improvements were also observed in NDI scores (39.3 to 26.7, p <0.05) and VAS pain scores (4.42 to 2, p <0.05) at final follow-up.

Conclusions: This study is the first to report outcomes of surgical management for spontaneous, de novo C5 motor palsies. Following surgical intervention, patients experienced favorable recovery of deltoid and bicep motor strength. Both anterior and posterior approaches resulted in successful motor recovery when appropriately selected based on preoperative imaging and surgical planning.