Design analysis of the bearing component of the hip joint prosthesis to improve distribution of forces and frictional wear.

This is a design analysis project aimed at reducing wear of the hip joint components by improvement of distribution of forces. Though there have been celebrated achievements in the total hip arthroplasty (THA) procedure that have brought much relief, challenges as- sociated with wear, hip joint stresses and adverse biological response have greatly affected the longevity of the implants. Prosthetic wear is a problem that has overshadowed the tremendous gains in the THA and has resulted in implants loosening so much that corrective revision surgeries were necessary. Previously THA has been known to be confined to the older patients but has recently crept downwards to include those in the twenties. This has increased demand and quality of the implants. The project analyses the forces that are active at the hip joint articular surfaces and by use of computer simulation, finite element analysis (FEA) was performed on the models where upon material and proposed design of the bearing were recommended. The finite element analysis was also compared to the Herztian contact method where it can be concluded that low stresses are achievable by maximising the contact area. This was followed by the model design optimization that gave the final specifications of the proposed design. The proposed design managed to lower contact stresses from a peak of 22 MPa which was equatorial contact to 3MPa over a considerable wide area due alterations in the geometry, diameters sizes and clearances. However the model still needs to be tested in vitro to ascertain the wear characteristics