髋关节假体安装参数的计算机模拟研究

The simulation study on the orientation parameter of total hip cup components using computer-assisted model

目的研究不同颈干角股骨假体在前倾角变化时获得理想髋关节活动度所需要的髋臼安装参数。方法建立人工全髋关节三维计算机模型，髋臼杯假体采用半球形，臼杯直径480mm，颈干角分别为127°、131°和135°。股骨假体前倾角变化范围为0°-30°，臼杯假体俯倾角变化范围为30°-60°、前倾角变化范围为0°-40°。每变化5°重复一次髋关节在6个方向（屈曲、后伸、内收、外展、内旋、外旋）的活动，选出符合最佳髋关节活动度的假体安装参数。采用SAS 6．12统计学软件对数据进行分析。结果颈干角分别为127°、131°和135°的假体，其最佳的臼杯俯倾角安装位置分别为45°、40°和35°；在活动满足后伸〉40°、内收〉50°、外展〉50°、内旋〉80°、外旋〉40°的条件下，髋关节最大屈曲度分别为135．64°±3．45°、126．00°±3．57°和118．29°±3．29°；臼杯假体前倾角（Y）和股骨假体前倾角（X）的关系分别为Y＋0．69×X=36．93°，Y＋0．71×X=37．10°和Y＋0．64×X=36．79°。结论臼杯俯倾角最佳安装位置随着假体颈干角的变大而逐渐变小，髋关节在安全范围可以达到的最大屈髋度数随假体颈干角变大而逐渐减小，股骨假体前倾角度和臼杯前倾角度呈负相关。

Objective To study and obtain compliant position of the cup component for optimal range of motion during the changes in the anteversion of the femoral component with various collodiaphyseal angles. Methods A three-dimensional model of the total hip joint was created. In this model, the collodiaphyseal angles were 127°, 131° and 135° respectively, and the diameter of cup component was 480 mm. The range of the changes in the anteversion of the femoral component, the inclination and the anteversion of the cup component were 0°-30°, 30°-60° and 0°-40° respectively, and the motion of the hip joint was repeated in six directions （anteflexion, backward extension, abduction, adduction, internal and external rotation） every 5°. Then the orientation parameter of total hip components for optimal range of motion was selected. All data was analyzed using SAS 6.12 software. Results The optimal orientation in the inclination of the acetabulum of total hip components with stem-neck angle 127°, 131° and 135° were 45°, 40° and 35° respectively, however the potential maximum flexion degree of hip in the safety margin were 135.64°±3.45° ,126.00°± 3.57° and 118.29°±3.29° respectively. The relationships with the anteversion of the cup component （Y） and the anteversion of the femoral component （X） among these three total hip components were Y＋0.69×X= 36.93°, Y＋0.71×X=37.10° and Y＋0.64×X=36.79° respectively. Condusion The optimal orientation parameter in the inclination of the acetabulum was decreased gradually followed the increasing of the collodiaphyseal angles and the potential maximum flexion degree of hip in the safety margin was decreased gradually followed the increasing of stem-neck angle. The anteversion of the femoral component had negative relationship with the anteversion of the cup component.