髋关节发育不良髋臼假体位置与稳定的三维有限元分析

目的利用三维有限元仿真的方法，研究全髋关节置换术治疗成人髋关节发育不良时3 种不同髋臼假体位置与髋臼 假体初始稳定的相关性，为临床手术操作提供参考依据。方法采用专门的生物力学有限元网格划分器，从髋关节发育不良的CT 扫描数据中，建立高度仿真的个性化髋骨三维有限元模型，并模拟在真臼位置安放髋臼假体的解剖位重建、将髋臼内壁打磨穿透内移的中心化重建、和在真性髋臼上方假臼高位重建3种常见的临床手术方案，模拟不同臼杯假体位置对全髋关节置换术后髋臼假体稳定的影响。结果髋臼假体在真臼位置安放的解剖重建，出现应力集中和大剪切应力的可能性最小，穿透内移安放的模拟应力分布略高于真臼重建，而在假体上移高位安放的模拟则出现预测应力大幅增加。结论成人髋关节发育不良全髋关节置换术中应尽可能在真臼位置重建和安放臼杯假体，以达到最优的应力分布和稳定性。

Relation between position and stability of acetabular cup in ip of developmental dysplasia : three dimensional finite element simulation

Objective To investigate the relation between position and stability of acetabular cup in uncemented total hip arthroplasty with the hip of developmental dysplasia simulated by three-dimensional finite element method. Methods Using a specially designed biomechanical semi-automatic mesh generator, a high quality specific three-dimensional finite element model of the pelvis was generated fromthe CT scan data of a patient with dysplastic hip. Three reconstruction positions were simulated: the acetabular component was integrated at the true acetabular position, at the medialization position, and at the higher position of the true acetabulum. The influence of different positions on the stability of acetabular cup for total hip arthroplasty was investigated.Finally, all models were simulated under same loading conditions. Results The model with acetabular cup placed at the true acetabular position provided the optimal simulation result, with smallest principal stresses and sheer stresses. The model with medilizational position resulted in some larger stresses than the true acetabular position, while the model with position above the true acetabular resulted in much larger stresses. Conclusion The acetabular cup for the total hip arthroplasty should be placed at the true acetabular position if possible, to provide the optimal stresses distribution and functional repair.