Ossification of posterior longitudinal ligament (OPLL) is a complex multifactorial spinal disorder characterized by ectopic bone formation within the ligament, leading to progressive spinal canal stenosis and neurological deficits. While its epidemiological and clinical profiles are well-established, the precise molecular pathogenesis remains incompletely understood. This review systematically synthesizes recent advances in understanding the mechanistic underpinnings of OPLL, highlighting the interplay of genetic predisposition, epigenetic regulation, metabolic disorders, and biomechanical stress. Pathological manifestations, anatomical features, and the dual-origin hypothesis of OPLL are elaborated, alongside its phenotypic overlaps with ankylosing spondylitis and the contribution of inflammatory signaling cascades. Susceptibility loci identified via genome-wide association studies and their functional relevance to key regulatory pathways are summarized. Epigenetic regulation, encompassing pre and posttranscriptional modifications, is highlighted with particular attention to the roles of long noncoding RNAs (lncRNAs) and microRNAs (miRNAs). Metabolic mechanisms implicated in OPLL, including diabetes, lipoprotein receptor-related protein 5 signaling, and lipid metabolism dysregulation, are discussed, as is the critical role of biomechanical stress in disease progression. By integrating insights across multiple disciplines, this review establishes a comprehensive pathophysiological framework for OPLL, with the goal of bridging basic science and clinical practice and identifying promising avenues for the development of targeted therapeutic strategies.

Mitochondrial respiratory chain dysfunction-induced chondrocyte senescence is a key contributor to the progression of osteoarthritis (OA), yet effective strategies for restoring mitochondrial respiratory homeostasis remain elusive. Herein, we develop a charge-guided micro/nano interpenetrating network hydrogel that targets cartilage and delivers a mitochondria-directed MnO2-based nanoparticles, in which the nanozyme catalyzes intracellular hydrogen peroxide to generate oxygen while releasing nicotinamide adenine dinucleotide (NAD+) precursor via particle degradation, thereby enabling synchronized electron donor and acceptor supply to fully reactivate the mitochondrial respiratory chain and alleviate chondrocyte senescence. Comprehensive evaluations reveal that this system enhances the activity of key antioxidant enzymes including superoxide dismutase, catalase, and glutathione peroxidase, elevates the intracellular nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide hydrogen (NAD+/NADH) ratio, and suppresses the secretion of senescence-associated secretory phenotype factors, thereby preserving cartilage matrix integrity. Collectively, these findings underscore the therapeutic potential of this dual-delivery platform to achieve full-length mitochondrial respiratory chain activation, offering a compelling strategy to mitigate chondrocyte senescence and impede OA progression.

Hematoma is a life-threatening complication of anterior surgery in cervical spondylosis patients. Herein, we report a cervical spondylosis patient complicated with Huntington’s disease, who developed unexpected neck hematoma after anterior cervical discectomy and fusion (ACDF) surgical treatment. During the debridement, we found no noticeable vessel lesions and concluded that the occurrence of postoperative hematoma might be due to the drainage displacement caused by excessive uncontrolled movements of the neck after the operation. The patient recovered well, and further literature review suggests that chorea secondary to Huntington’s disease likely increases mechanical stress on the cervical spine, indicating an internal relationship between degenerative cervical spondylosis and Huntington’s disease. Cervical spondylotic patients complicated with Huntington’s disease can be treated with surgical intervention but need to be immobilized and under close observation.

目的 探讨在颈椎前路椎间盘切除融合（ACDF）术中应用新型低切迹一体化融合器系统（Carmen）治疗单节段脊髓型颈椎病患者的临床效果。方法 对2018年1月至2020年1月于海军军医大学第二附属医院骨科颈椎外科行单节段ACDF治疗的脊髓型颈椎病患者136例的临床资料进行回顾性研究。依据所使用的内固定系统将全部患者分为两组：Carmen组38例，其中男20例，女18例，年龄（47.2±6.7）岁；零切迹内固定系统（Zero-P）组98例，其中男56例，女42例，年龄（48.7±7.3）岁。对两组患者手术时间、术中失血量和术后12个月融合率分别进行比较；对两组患者术前、术后6个月与术后12个月日本骨科协会评分（JOA）、疼痛视觉模拟评分（VAS）、颈椎C2-C7 Cobb角、手术节段局部Cobb角和颈椎活动范围（ROM）分别进行组内和组间比较。采用SPSS 18.0对数据进行统计学处理；P＜0.05为差异有统计学意义。结果 对所有患者完成12个月以上随访。两组患者手术时间、术中失血量和术后12个月融合率差异均无统计学意义（均P＞0.05）;两组患者术后JOA评分、颈部和上肢VAS评分、颈椎ROM较术前均有显著改善（均P＜0.05）,上述指标和手术相关并发症的发生率组间差异均无统计学意义（均P＞0.05）;Carmen组患者术后12个月颈椎C2-C7Cobb角及手术节段局部Cobb角均显著大于Zero-P组患者（均P＜0.05）。结论 在单节段脊髓型颈椎病患者ACDF术中使用Carmen融合器，其临床疗效与传统Zero-P系统相当，在纠正以及维持颈椎曲度方面较Zero-P系统更具优势。

Background Although ACDF has been widely used in treating cervical spondylosis and related diseases, the complications along with this anterior surgical technique have hindered its application and affected the postoperative outcome of the patients. Here, we investigated the clinical and radiological outcomes of a new integrated low-profile anterior plate and cage system for anterior cervical discectomy and fusion (ACDF) in treating cervical spondylosis. Methods A total of 96 cervical spondylosis patients who underwent single-level ACDF between 2018 to 2020 in our institute were enrolled. There were 28 patients using the new implants and 68 patients using the zero-profile (Zero-P) implants. The Japanese Orthopedic Association (JOA) score and the visual analog scale (VAS) were used to evaluate the clinical outcomes. The cervical and segmental Cobb angle and range of motion (ROM) were used to assessed the radiological outcomes. Incidence of complications were also recorded. All data were recorded at pre-operation, 6-month and 12-month post-operation. Results All patients were followed-up for at least 1-year, the mean follow-up time was over one year. The fusion rate was similar in the two groups. There was no significant difference in the postoperative JOA score recovery rate, postoperative VAS score of neck and arm pain, postoperative ROM, and incidence of complications between two groups ( P > 0.05). However, postoperative cervical and segmental Cobb angle were better maintained in the new low-profile implant group compared to Zero-P group. Conclusions The clinical outcomes of the new low-profile implant were satisfactory and comparable to that of zero-profile system. It may have advantages in improving and maintaining the cervical lordosis, and can be an alternative device for single-level cervical spondylosis treated with ACDF.

BACKGROUND CONTEXT:Laminoplasty is a common surgical method used to treat patients with cervical ossification of the posterior longitudinal ligament (OPLL). Although laminoplasty is preferred over traditional laminectomy, the factors affecting the complications and outcomes are unclear. Recently, sagittal balance indexes have been revealed to be predictors of clinical outcomes in patients with cervical degenerative diseases, but their relationships with laminoplasty-treated OPLL outcomes remains unknown. PURPOSE:The purpose of this study is to evaluate the relationship of preoperative cervical sagittal balance indexes and clinical outcome in laminoplasty treated OPLL patients. STUDY DESIGN:This is a retrospective case study. PATIENT POPULATION:Between January 2015 and January 2017, 181 consecutively included patients who underwent cervical laminoplasty for OPLL were enrolled (male:female ratio=126:75; mean age=60.2 years). Cervical spine lateral radiographs in neutral, flexion, and extension positions were taken before and 2 years after the surgery. OUTCOME MEASURES:The C2-C7 Cobb angle, T1 slope, C1-C7 sagittal vertical axis (SVA), C2-C7 SVA, CGH (center of gravity of the head)-C7 SVA, cervical JOA (Japanese Orthopedic Association) score, and neck VAS (visual analogue scale) score were measured preoperatively and postoperatively at the 2-year follow-up. METHODS:The patients were divided into two groups according to changes in the lordotic angle or the recovery rate of the JOA score. The relationships between the postoperative lordosis loss or the clinical outcome and the preoperative variables, including the patient's age, JOA score, C2-C7 Cobb angle, T1 slope, C1-C7 SVA, C2-C7 SVA, and CGH-C7 SVA, were investigated. RESULTS:The patients were divided into two groups according to the postoperative change in the C2-C7 Cobb angle. There were no differences in the age, preoperative C2-C7 Cobb angle, C1-C7 SVA, or C2-C7 SVA; there was only a difference in the preoperative CGH-C7 SVA and T1 slope level (p=.038, p=.042). The postoperative JOA and JOA recovery rate were related to the postoperative lordosis loss in cervical alignment (p=.048, p=.031). We again divided the patients into two groups according to the JOA recovery rate and found that only the preoperative CGH-C7 SVA and C1-C7 SVA were related to the neurological outcome (p=.011, p=.047). According to the multivariate logistic regression analysis, higher preoperative CGH-C7 SVA levels were significantly associated with decreases in the lordosis angle postoperatively and the clinical outcome (p=.018, OR=1.225; p=.034, OR=1.654). The ROC (receiver operating characteristic) analysis revealed that the proper cutoff value of preoperative CGH-C7 SVA for predicting the postoperative loss of lordosis and clinical outcomes is 3.8 cm. CONCLUSION:Preoperative cervical sagittal balance indexes are related to the outcomes of OPLL patients after laminoplasty. Patients with high preoperative CGH-C7 SVA levels have a high probability of developing sagittal imbalances and neurological symptoms of the cervical spine, and this measurement can be used as a predictor of outcomes in laminoplasty-treated cervical OPLL patients.

椎间盘退行性变（IDD）是脊柱外科常见病和多发病,会引起一系列临床症状,是下腰痛及颈肩痛的主要原因,严重影响患者生活质量。IDD是一个多因素过程,包括基因因素、代谢和生物力学损伤等。发生退行性变的椎间盘会通过应力失衡、血供障碍、免疫反应、炎性因子介导等相关因素进一步导致相应症状及疾病的发生,而这些过程都

Objective To fabricate amino cationic polymer on the surface of titanium alloys and evaluate its antibacterial property. Methods Amine cationic polymer was deposited on the surface of titanium rod with plasma polymerization technique by introducing allyl amine. The surface topography and wettability of the samples were observed with scanning electron microscope(SEM) and contact angle. Surface element contents were analyzed by X-ray photoelectron spectroscopy(XPS). The antibacterial activity was measured by bacteria counting of Staphylococcus aureus and Escherichia coli in vitro. Antibacterial experiment in vivo in rabbit was conducted and histological analysis performed. Results Diffused distribution of spherical particles was observed under SEM on the surface. Water contact angle reduced from 100.3°±3.4° to 13.6°±3.0°,which was of a statistical significance(P<0.05). XPS results showed the content of N element increased from 2.75% to 11.8%. Bacteriostasis rate of Staphylococcus aureus was (86.1±3.8)% and that of Escherichia coli was (75.5±2.6)% in plasma group,which has a statistical significance in difference copmpared with the control group(P<0.05). In vivo,histological analysis demonstrated that decrease of neutrophils was observed around the implant and bone in plasma group. Conclusion Plasma polymerization technique can acquire amino cationic polymer on titanium surface successfully,and the polymer shows good antibacterial activity,thus providing the basis for future experiments.

BACKGROUND:Hoffa fractures, coronal-plane fractures involving the distal femoral condyles, are unstable, intra-articular fractures. The aim of this study was to define the location and frequency of fracture lines and comminution zones in Hoffa fractures using computed tomography (CT) mapping in both 2-dimensional and 3-dimensional contexts. METHODS:Seventy-five Hoffa fractures (OTA/AO types 33B3.2 and 33B3.3) were retrospectively reviewed. The directions of fracture lines were characterized in the axial and sagittal CT planes. CT images for all fractures were superimposed on one another and oriented to fit a standard template. Mapping of fracture lines and comminution zones in both the axial and sagittal planes was performed. A 3-dimensional map was created by reducing reconstructed fracture fragments to fit to a model of the distal aspect of the femur. RESULTS:This study included 1 bicondylar and 74 unicondylar (26 medial and 48 lateral) Hoffa fractures. Comminuted fractures accounted for 35.5% of all fractures and 44.9% of lateral fractures. Axial fracture mapping demonstrated that fracture lines were concentrated in the middle-third area of the lateral condyle but were less concentrated and with greater variation in the medial condyle. The mean angle of fracture lines with respect to the posterior condylar axis was 34.4° and 29.0° in the lateral and medial femoral condyles, respectively. Sagittal fracture mapping also demonstrated that fracture lines were concentrated in the middle third of the lateral condyle but were less concentrated in the medial condyle. The mean angle of fracture lines with respect to the posterior cortex of the distal femoral shaft was 23.1° and 19.3° in the lateral and medial condyles, respectively. Three-dimensional mapping demonstrated comminution zones commonly occurring in the weight-bearing zone of the lateral condylar articular surface. CONCLUSIONS:Hoffa fractures occurred more frequently in the lateral femoral condyle. In the axial plane, fractures commonly extended from anterolateral to posteromedial in the lateral condyle and from anteromedial to posterolateral in the medial femoral condyle. In the sagittal plane, fractures traversed from anteroinferior to posterosuperior. Articular comminution was more commonly seen in lateral condylar fractures and concentrated in the weight-bearing zone of the articular surface. CLINICAL RELEVANCE:Research in this area is imperative for optimal preoperative planning, such as for the selection of surgical approach and fixation constructs. Our findings lend insight into fracture morphology, which can assist with fracture classification and the design of biomechanical studies, ultimately aiding in treatment.