Study On The Design Methods Of Stemless Hip Joint And The FE Analyse

The function of hip joint will lost because of the diseases or accident. The effective way at present is to use a custom made joint to replace the natural one if the medicine doesn't work. But the long-term stability of the artificial joint cannot turn up trumps, with the aseptic loosening, which lead to the failure of the operation. Many researchers consider that both the mechanics and the biology factors can cause the loosening, for example, the stress shielding and wearing chippings. So it has become a hot subject in the field of medicine and engineering that to solve the loosening, enhance the stability and prolong the life of the joint.This subject is rooted in the"national fund item". The author have done some research works toward the design of the custom made endoprosthesis, virtual hip replacement, analyse of the femur-stem contact using the finite element software, and stimulating the femur adaptation with the program in apdl. Plenty of data have gotten from these works, which are useful to the prosthesis optimization design. To sum up, the primart study content in this paper is described in the following:①According to the CT images of the femur, design the custom made prosthesis. Two methods which are nonanatomical stemless prosthesis, anatomical stemless prosthesis. After design the prosthesis, a virtual assembly has been finished to check the relation between the femur and the prosthesis.②Rebuild the femur material program using ANSYS parametric design language to make sure that the femur's finite element model is anisotropy and the finite element model and the entity model coexist.③Before analyze the femur-stem model, summarize the theory about the contact problem, moreover, simplify the contact problems with constraints equations. And then, constraints equations theory and settings are emphasized.④Start with the stress shielding, 27 models of two gaits have been compared, one is the femur before the replacement and the other are the femur-stem contact models of different design state, such as the shape of the prosthesis, material, design method and so on. Von Mises stress and strain of 10 differents measuring points of each model were compared. The result of the compare can be the guidance to the optimization design of the prosthesis.⑤According to the calculation results above, the paper carried out the fatigue...