不同运动状态下国产人工膝关节接触压力分布有限元分析

为研究力轴一致时不同运动对人工膝关节各组件接触压力的影响，拍摄下蹲、上楼梯和步行运动过程并解析得到运动学数据，基于国内厂家提供的图纸，建立人工膝关节的三维有限元模型，对其施加运动和载荷进行计算分析．结果表明：双腿直立时各组件上的接触压力峰值最小，而下蹲90°时股骨组件最大，下蹲120°时胫骨垫组件最大，上楼梯时各组件峰值介于下蹲90°和120°之间；步行过程中，单腿支撑、脚趾离地和脚跟着地时各组件的压力峰值依次降低．这表明该国产人工膝关节符合国人膝关节的解剖结构，内、外侧接触压力峰值适中且具有较大的接触面积，可以满足临床上的要求．

Finite element analysis of contact pressure distribution for domestic artificial knee joint under different movements

To study the effect of different movements on the contact pressure of various components of artificial knee joint in aligned mechanical axis, the processes of different movements are photographed including squatting, climbing stairs and walking, and then the kinematic data are analyzed in every motion state. Based on the drawings provided by domestic manufacturers, a 3D finite element model of artificial knee joint is built and calculated by applying movements and load on it. The results show that, for the contact pressure peak value, all the components are the minimum while double legs are standing, the femoral component is the largest while squatting 90°, the tibial cushion component is the largest while squatting 120°, and all the components are between the peak values in squatting 90° and 120°while climbing stairs; in walking process, the peak values for every component decrease successively in the motions of single leg standing, toe off and heel strike. It shows that the domestic artificial knee joint is in accord with the anatomical structure of Chinese knee joint, the peak values of contact pressure on medial and lateral sides are moderate and the contact area is larger, and the artificial knee joint can meet the clinical requirements.