Research On Human Nature And TKA Patellofemoral Biomechanical Characteristics Of Squat Movement

This research is supported by National Natural Science Foundation of China on research on high-flexion stability michanism of high-flexion artificial knee, studies the biomechanical characteristics of the patellofemoral joint during squat of nature knee and post total knee arthropcasty(TKA).Computer’s image processing technology was applied to process the obtained human knee-joint anatomical parameters, and a real structural three-dimensional(3-D)geometric anatomical model of nature knee including the bone tissue and main soft tissues such as ligament, cartilage and meniscus was constructed. The model is relatively comprehensive and higher comparability model for finite element analysis(FEA)of nature and post-TKA knee. Commonly adopted TKA components(Sigma PFC) were modeled in this research. The simulation resection and prosthesis assembly were carried out on the nature knee model in the CAD environment, thereby the 3-D geometric model of knee joint post TKA was established.A dynamic finite element model of natural knee flexion motion was established. In the simulation model, three quadriceps loading methods were adopted: performed quadriceps single beam load; the quadriceps were divided into three beams and performed simultaneous load; the quadriceps were divided into three beams and performed delay loading. The biomechanics parameters of natural patellofemoral joint were obtained under three quadriceps loading methods, and more reasonable loading method(delay loading) was obtained by compared with previous works. The biomechanics parameters and characteristics of natural patellofemoral joint on high-flexion condition were also obtained.An experimental device of knee squat simulation and patellofemoral joint(PFJ)biomechanics parameter measurement was designed according to the human anatomy parameters, load boundary conditions of the knee squat movement. The quadriceps can be divided into three beams simultaneously and lazy loading in this experimental device.The tibio-femoral and patello-femoral joints biomechanical parameters can be synchronal measured in this experimental device.Dynamic finite element model of knee post TKA was established. In the simulation model, the quadriceps was divided into three beams and performed delay loading. The biomechanics parameters and characteristics of knee post TKA were obtained, and then compared them with nature PFJ. Also this paper put forward some suggestions on how to improve the PFC prosthesis design and TKA surgery.The 3-D geometric anatomical model of nature knee was built in this research,which can be used to analysis the nature and post-TKA knee. the designed experimental device can obtain the tibio-femoral and patello-femoral joints biomechanical parameters.more reasonable loading method(delay loading) was obtained by use of finite element method for nature knee. In subsequent experiments and simulations, the delay loading method is capable of predicting the kinematics and the stress more accurately during knee flexion, and could be efficient tools for the analysis of TKA and knee prosthesis design. Results of this research could be references for the research of knee pathology,rehabilitation and prosthesis design.