EXPERIMENTAL STUDY ON THE BEHAVIOR AND LOAD-BEARING CAPACITY OF THE PATELLOFEMORAL JOINT USING A SIMULATED KNEE JOINT

在本研究的早期阶段，对身体膝关节的形态、结构和尺寸进行了测量，并建立了数学模型，对其生物力学行为和承载能力进行了仿真分析。这一系列的研究不仅为模拟膝关节的设计提供了有用的数据，而且对膝关节生物力学的研究也有重要的意义。利用所设计的模拟膝关节对实验结果进行了选择。充分研究了各个伸肌在膝关节疾病中的插入和力量/弹性的影响，得到了对手术操作有指导意义的结果。还介绍了一些有用的参数作为膝关节屈曲角度的函数：髌股关节的接触力和滑动率。在模拟水平行走和爬下楼梯过程中膝关节屈曲角度和大腿肌力变化的情况下，测量了膝关节接触压力的变化。实验结果表明，在一个步态周期的站立阶段，膝关节股骨接触应力几乎始终不变，且各标本的应力峰值基本相同。实验结果表明，接触力大的部位产生的曲率较小。

In an early stage of this study, some measurements were performed subject to the cadaver knees with respect to morphology,structure and dimension.A mathematical model was also made and simulation analysis was performed to investigate a biomechanical behavior and load bearing capacity of the patellofemoral joint.A series of the study brought up not only useful data for designing a simulated knee but significant results on knee joint biomechanics. The following are the selections of the experimental results using the designed simulated-knee.The influence of both insertion and strength/elasticity of each extensor in patellofemoral disorders was fully investigated,obtaining the significant results for operative procedures in patellofemoral disorders.Some useful parameters that serve as a function of knee flexion angle were also introduced: contact force and slipping ratio of the patellofemoral joints.The variation of patellofemoral joint contact pressure was measured under the condition of simulating the variations of knee flexion angle and the thigh muscle forces during level walking and climbing and descending stairs,and the results were compared with those of the previous experimental studies in which the thigh muscle forces had been kept constant.The patellofemoral contact stress shows almost constant all the time of the stance phase of a gait cycle and also the peak values of stress are almost equal among specimens.The experimental results revealed that the contact portion where larger contact force occurs produces a smaller curvature.