Research On The Edge Loading Dynamics Parameters Simulation Of Hip Joint Prosthesis With Different Materials

Wear of the prosthesis due to edge contact is a major cause of jointprosthesis failure after hip replacement surgery.There are currently three types of hip prostheses commonly used in clinical practice: ceramic-to-ceramic,metal-to-metal,and metal-to-UHMWPE.These three prostheses have been confirmed to have contact between the femoral head and the edge of the cup during use problem.Although the predecessors used the hip joint simulator and the finite element method to study the wear problem caused by the edge contact of the prosthesis,they did not explore the duration of the edge contact and the magnitude of the edge contact force.In this paper,the edge contact mechanism of the above three hip prostheses under separation conditions was explored separately,and the factors that may affect the edge behavior of the prosthesis such as the diameter of the femoral head and the radial gap between the femoral head and the cup are discussed.Read related literature and combine 3D modeling software such as SolidWorks and Adams to construct a 3D dynamic model of hip prosthesis.The motion conditions of the prosthesis are consistent with the movement of the real human hip joint.A spring is added to the Adams software to achieve the separation condition between the center of the femoral head and the rotation center of the acetabular cup,so that the model can effectively simulate the contact between the edge of the femoral head and the acetabular cup.After verification,the validity of the model is proved,and the contact stiffness coefficients of the three prosthesis models are determined.Judging from the final dynamic separation curve,it is in line with the actual law.The parameter simulation study on the edge contact of the three materials of the acetabular prosthesis found that: the cup abduction angle,the separation distance of thefemoral head and the cup in the horizontal direction will have a serious impact on the edge loading of the acetabular prosthesis The smaller cup abduction angle and initial separation can effectively reduce the contact force generated when the edge contacts,and it has an important role in reducing the wear caused by the contact force.The influence of the change of femoral head size on the maximum contact force and volume wear measurement index produced by the hard-to-hard material hip prosthesis edge contact can be ignored.The small radial gap between the femoral head and the acetabular cup will increase the edge contact force of the metal on the polyethylene joint prosthesis and cause the wear of the prosthesis.This paper on the parameters of three hip joint prosthesis from the perspective of biomechanics.The results can be used to further study the wear of the prosthesis and provide theoretical guidance for clinical hip replacement surgery.