发育性髋脱位髋关节结构病理改变与细胞凋亡的动态实验研究

There were many pathological changes which the femoral head does not match the acetabular morphology and head and acetabulum non-relationship of the "concentric circles"and the femoral neck-shaft angle and anteversion angle increased and dysplasia of the hip cartilage in developmental dislocation of the hip (DDH), the extent and scope has been increasing over time ,that were key factors which resulting in hip osteoarthritis with a high incidence when DDH patient were adult. The study of apoptosis had become the focus of the medical in recent years. The hip dysplasia in DDH may be associated with abnormal apoptosis of the corresponding structure was suggested. The study intended to dynamic observation that if there were abnormal cells apoptosis in acetabulum and femoral head articular cartilage and the femoral head secondary ossification centers and epiphyseal plate cells through animal models.Using the TUNEL method and transmission electron microscopy to detect cell apoptosis,at the same time alassay Bcl-2 , Bax , Caspase-3 , caspase-8 and NF-κB expression which were related factors of apoptosis ,in multiple time points when the hip was dislocation and closed reduction . To investigate the mechanism of abnormalities hip and the possible way to regulate in DDH, and to clarify the exact location of the pathological changes occur and What is the relationship with the the deformity duration and interventions, so as to provide the theoretical basis for the clinical treatment of DDH.

发育性髋脱位（DDH）髋关节结构内存在股骨头和髋臼不匹配、头臼非"同心圆"对位、关节软骨发育不良、股骨近端颈干角和前倾角增大等病理变化，程度和范围随时间推移逐渐加重，是导致DDH成年后较早出现骨关节炎的重要因素。近年来，细胞凋亡成为医学界关注的热点。推测DDH髋关节病理改变与对应结构的异常细胞凋亡是否存在关联。本项目拟动态观察DDH模型中髋臼和股骨头关节软骨、股骨头二次骨化中心以及股骨近端骺板细胞中是否存在异常的细胞调亡为切入点，通过DDH动物模型，在髋关节脱位和闭合复位后的多个对应时间点，利用TUNEL法和透射电镜观察髋关节结构内细胞调亡情况，同时检测凋亡相关因子Bcl-2、Bax、Caspase-3、caspase-8以及NF-κB的表达情况，探讨DDH髋关节病理改变可能的发生机制和调控方式，澄清病理改变发生的确切位置以及与畸形持续时间和干预措施有何关联，为临床治疗DDH提供理论基础。

发育性髋关节脱位（DDH）的髋关节结构内存在股骨头和髋臼不匹配、头臼非"同心圆"对位、关节软骨发育不良、股骨近端颈干角和前倾角增大等病理变化，程度和范围会随时间推移逐渐加重，是导致DDH成年后较早出现骨关节炎的重要因素。近年来，细胞凋亡成为医学界关注的热点。推测是否DDH髋关节病理改变与对应结构的异常细胞凋亡之间可能存在关联。.本项目是动态观察DDH模型中，在髋关节脱位后的髋臼和股骨头关节软骨、股骨头二次骨化中心以及股骨近端骺板细胞中是否存在异常的细胞调亡为切入点，通过出生4W的新西兰大耳白兔采用后肢屈髋伸膝管型石膏固定制作DDH模型，右后肢固定作为实验侧，左后肢不作处理为对照侧。在髋关节脱位和闭合复位后的多个对应时间点，利用TUNEL法和透射电镜观察髋关节结构内细胞调亡情况，同时检测凋亡相关因子Bcl-2、Bax、Caspase-3、caspase-8以及NF-κB的表达情况。结果显示：实验侧髋关节X线显示髋臼指数较对照侧明显增大（P＜0.05）。持续髋脱位侧髋臼和股骨头关节软骨、股骨头二次骨化中心以及股骨近端骺板细胞软骨细胞稀疏，排列混乱，细胞凋亡率高于对照侧（P＜0.05），Bcl-2/Bax灰度比值、Caspase-3、caspase-8以及NF-κB的表达与软骨细胞凋亡率呈正相关，电镜下细胞染色质边集，核形不规整。经过闭合复位的髋关节脱位侧髋臼和股骨头关节软骨、股骨头二次骨化中心以及股骨近端骺板细胞软骨细胞凋亡率亦高于对照侧（P＜0.05），Bcl-2/Bax灰度比值、Caspase-3、caspase-8以及NF-κB的表达与软骨细胞凋亡率呈正相关。综合以上实验结果分析，DDH髋脱位后的髋臼和股骨头关节软骨、股骨头二次骨化中心以及股骨近端骺板细胞软骨细胞发育不良可能与软骨组织内过度细胞凋亡和凋亡因子表达异常有关，持续的髋脱位可造成软骨内过度细胞凋亡，但不会持续推高细胞凋亡率，对髋脱位的干预措施不能完全降低髋臼和股骨头关节软骨、股骨头二次骨化中心以及股骨近端骺板细胞软骨内过度细胞凋亡。实验结果证实，DDH髋脱位后，软骨内细胞凋亡变化与干预措施具有相关性。