Dynamic Simulation Of The Contact Between The Ceramic Femoral Head And The Cup Rim

A hip joint replacement is a positive and effective surgical procedure to release joint pain and restore hip function.As the number of patients increases,and as the patients tend to be younger,the pursuit of the long-term lifespan of the joint in the body is even more urgent.To this end,ceramic hip joints due to its excellent biocompatibility and wear resistance are popular among physicians and patients of all ages.However,the high wear of the joints due to the contact of the femoral head with the rim of the cup hinder its long-term retention in the human body.Therefore,we have done the following aspects about the analysis and research on the dynamic contact mechanics of the femoral head against the cup rim of artificial hip joints :Combined with SolidWorks and ADAMS software,a dynamic simulation model was established to simulate the edge contact between ceramic femoral head and cup over a complete gait.This model completely achieved rotation of the hip prosthesis around the coronal,sagittal and vertical axes and effectively simulated the dynamic edge contact behavior of the femoral head and cup,especially the dynamic edge contact behavior caused by the initial separation distance of the femoral head and cup less than 1 mm.In the verification phase of the model,the contact between the femoral head and the cup edge was equivalent to the contact between the ball and the ring,and the contact deformation based on the Hertzian contact theory was compared with the deformation of the ADAMS simulation output.The rationality of the contact stiffness coefficient of the model was illustrated.when compared with the results of the hip joint simulator,through the analysis of the results of friction between the moving components of the model,it was better revealed that the maximum dynamic separation distance was small,but the maximum edge contact force was large in the experimental simulator results.All of the above results indicate thevalidity and accuracy of the edge contact simulation model.Using the above model of the edge contact of the femoral head with the acetabular cup,positional parameters and structural design parameters and the swing period load that affect the edge contact were studied.The above study can be drawn,45 ° acetabular abduction angle position can be used to avoid the edge contact which the separation distance,femoral head and acetabular,is less than 1mm.At the same time,reducing the damage to the surrounding tissues of the hip joint to increase the swinging load helps to avoid the adverse effects of the edge contact caused by the large initial separation distance.The above results are significant for the long-term survival of ceramic implants in the body.