金属对金属人工髋关节的磨损预测

目的发展复杂动态载荷与瞬态运动条件下的球面共型接触硬对硬人工髋关节的磨损预测模型,并用于典型的金属对金属人工髋关节在复杂三维生理运动条件下的磨损预测研究。方法建立有限元模型用于接触力学问题求解,采用固定-跟踪法(fixed-tracked method)完成具有三维欧拉运动的人工髋关节双侧界面动态磨损几何再现及相应的接触与磨损问题模拟的数值交换。结果磨损预测表明,磨损导致金属对金属人工髋关节接触界面几何由球面向非球面过渡,接触区域随磨损周期而增大,接触压力变化趋于平缓、最大接触压力逐渐减小。结论本研究所发展的三维复杂动态、具有双侧界面几何磨损变化的人工髋关节磨损预测模型,能够很好地进行金属对金属髋关节磨损数值预测模拟实验,为认识人工髋关节磨损机理提供了新的方法。

Wear prediction for metal-on-metal hip joint replacements

Objective To develop a wear prediction model for hard-on-hard hip joint replacement under the condition of complex dynamic loading and time-dependent motion, and to apply it to the study on wear prediction of the typical metal-on-metal hip joint replacement in the complicated three-dimensional (3D) physiological motion condition. Methods The finite element model for contact mechanics was established and the fixed-tracked method was adopted to make the dynamic wear reappear on the bearing surface of artificial hip joint with 3D Euler transformation, and the data communication about the corresponding contact and wear for simulation was also made. Results The wear prediction test showed that the spherical bearing geometry of the artificial hip joint gradually became the non-spherical form due to the wear with time; meanwhile, the corresponding contact area was increased, the distribution of the contact pressure tended to be flattened, and the maximum contact pressure was decreased. Conclusions The wear prediction model developed here for metal-on-metal hip joint replacements with bilateral bearing surfaces under the condition of complex dynamic loading and motion could be used to carry out simulation test for the wear prediction of metal-on-metal artificial joint, which provides a new method to understand the wear mechanism of hip joint replacement.