定制化双动半膝关节假体的接触力学性能分析

Analyzing Contact Mechanics Performance of Customized Bipolar Hemi-knee Prosthesis

为满足青少年膝关节恶性骨肿瘤患者保肢治疗的需求,基于"双滑动"原理设计出一种定制化双动半膝关节假体,通过将膝关节多数运动转移至假体内部以减轻假体对对侧关节面的磨损。为验证假体减轻关节磨损的性能,采用有限元方法对假体关节在典型状态相下的接触力学性能进行分析,并以自然膝关节和定制化半膝假体关节作为对照组。结果表明,定制化双动半膝假体关节的最大接触应力除在站立相下(关节屈曲角度为0°)大于自然膝关节外,在其它典型状态相下均小于对照组。定制化双动关节半膝假体不仅能实现膝关节的运动功能,还能减轻关节面的磨损。

In order to meet young patients＇ needs of treating malignant bone tumor using limb salvage, the customized bipolar hemi-knee prosthesis is designed. With the design principle of ＂double gliding＂, the prosthesis can ease the wear of contralateral articular surface by transferring the major movement of the bipolar hemi-knee to the interior of the prosthesis. To verify the prosthesis＇ capability of easing the wear of articular surface, the contact mechanics performance in different typical states of the prosthesis is analyzed by using the finite element method and the natural knee and the customized hemi-knee prosthesis as contrast knees. The analysis results show that the maximum contact stress of the customized bipolar hemi-knee prosthesis is much smaller than that of the contrast knees in other typical states except in the standing state （the flection angle of the articular surface is 0 degree）. Therefore, the prosthesis can not only achieve the movement function of a knee but also ease the wear of the articular surface.