膝关节假体设计的有限元分析  

Finite element analysis of the design in knee joint prosthesis

作　　者：赵志昕 侯丽丽 贾斌[1] 

机构地区：[1]北京德尔康尼骨科医院,北京100143 [2]北京纳通科技研究院,北京100094

出　　处：《中国矫形外科杂志》2015年第15期1415-1421,共7页Orthopedic Journal of China

基　　金：北京市科委资助项目(编号:Z111100059411060)

摘　　要：[目的]建立膝关节胫骨基座力学测试的有限元模型,并预测平台假体胫骨基座的疲劳特性和不同屈曲角度下聚乙烯衬垫的磨损。[方法]选用一款后稳定型（posterior stabilized,PS）固定平台膝关节假体,将模型设为连续、均匀和各项同性的材料,根据ISO 14879-1的要求,建立胫骨基座力学测试的有限元模型,试验测试基座在500万次载荷循环下的存活率。建立股骨假体和聚乙烯衬垫的三维有限元模型,测试不同屈曲角度下聚乙烯衬垫的磨损。[结果]胫骨基座的Von Mises应力峰值出现在基座固定柱和防旋翼的相接处,约为254.6 MPa。聚乙烯衬垫的接触面积在屈曲0°~60°时逐渐增加,屈曲60°~135°的过程中接触面积则开始迅速减少;而聚乙烯衬垫的平均接触应力则随着屈曲角度的增加而增加。[结论]有限元方法提供了一个可用于评估膝关节假体力学性能的虚拟平台,具有经济、可信度高的特点。本文建立的有限元模型能够快速、有效的预测膝关节假体的力学性能,为膝关节假体的设计改进奠定了基础。[Objective] To establish the finite element model of the knee tibial tray mechanics in order to determinate the endurance properties of tibial tray and predict the wear of polyethylene insert with different knee flexion angles. [Methods] A posterior stabilized fixed bearing knee prosthesis was chosen and the finite element model of the tibial tray mechanics was established according to the demand of ISO 14879- 1 to test the survival rate of tibial tray under 5 millions cyclic loading. The finite element model of the femoral prosthesis and polyethylene insert was established to determine the wear of polyethylene inserted with different knee flexion angles. [Results] The Von Mises peak stress of the tibial tray,which appeared at the connection between the fixed leg and anti rotor,was 254. 6MPa. The contact area of polyethylene insert increased gradually when the knee joint flexed from 0° to 60°,but began to decrease rapidly when the knee joint flexed from 60° to 135°. The average contact stress of polyethylene insert increased with augment of knee flexion angle. [Conclusion] The finite element method（ FEM） provided a virtual platform to evaluate knee prosthesis mechanics,which was considered to be economic and reliable. The finite element models established in this study can predict the knee prosthesis mechanics efficiently,which lay a good foundation for the improvement of knee prosthesis design.

关 键 词：膝关节假体 全膝关节置换术 有限元方法 

分 类 号：R687.4[医药卫生—骨科学]