正常膝关节和人工膝关节髌股关节高屈曲运动特性及其比较分析

目的　分析人体正常膝关节和人工膝关节高屈曲活动下髌股关节的运动, 为膝关节髌股关节运动特性研究提供参考。 方法　建立包括膝关节骨组织和主要软组织在内的正常膝关节以及人工膝关节的动态有限元模型，采用三束股四头肌肌力非同步变力加载的方式，对膝关节下蹲运动中髌股关节的运动特性进行研究，并与相关研究结果进行对比分析。 结果　通过有限元分析，获得高屈曲膝关节三维运动的相对运动参数。髌股关节在位移和旋转均呈现出相同的运动趋势，同时，存在局部的差异，在低屈曲时, 人工髌股关节表现出先外倾后内倾的运动趋势，而正常髌股关节表现出持续内倾的运动特性。 结论　通过仿真和对比分析，人体髌股关节的运动数据总体趋势近似，同时存在差异。 对于正常膝关节，差异的原因主要在于髌骨运动各个方向上和不同屈曲度时的约束程度的改变；对于人工膝关节，差异主要来源于膝关节型面和结构的改变，以及坐标系定义、在体和离体差异、负荷加载差异。

Characteristical analysis and comparison of the high flexion movement of human normal and artificial patellofemoral joints

Objective　The purpose of this work was to analyze the kinematics of the human normal and artificial patellofemoral joints during squat. Reference for the study of the patellofemoral joint kinematics of the knee was provided.　Method　Dynamic finite element (FE) models of knee before and after total knee arthroplasty (TKA), which included the bone tissues and main soft tissues were developed in this research, to simulate the kinematics of patellofemoral joint during squat by the way of three beams quadriceps femoris myodynamia being asynchronously loaded, and were compared with related researches.　Result　The dynamic 3D relative movement data of patellofemoral joint during deep flexion were obtained. The results showed that the relative motion of the nature knee were similar to that of the TKA knee. At the same time, there has partial difference, in low flexion the TKA knee showed lateral tilt and then medial tilt, but the normal knee showed continued medial tilt.　Conclusions　Through simulation and comparative analysis, in general, patellofemoral joint kinematics data were approximate. And there was a difference for the normal knee, and the main reason for the difference was the changes of the degree of restraint of the knee patella in each direction and different degrees of flexion; for the artificial knee, the main reasons for the difference were the change of the profile and structure of the knee, simultaneously, related to the difference of the definition of the coordinate system, in vivo and in vitro, and the way of load being loaded.