Aspects of geometry, fixation and materials in total hip arthroplasty: what have we learned?

This thesis investigated the long-term follow-up of different aspects of the geometry, fixation and materials used in total hip arthroplasty (THA). A THA consists of a femoral stem, acetabular component, insert bearing and a femoral head. The femoral stem and acetabular component can be fixed in to the bone with or without bone cement. In this thesis mainly the geometry of the cemented and cementless femoral stems were investigated. Besides the geometry of the femoral stems also the potential benefit of a type of material, Carbon-Fiber-Reinforced Poly-Ether-Ether-Ketone (CFR-PEEK), used as insert bearing was investigated. This thesis showed that small differences in geometry, of both the cemented and cementless femoral stems, influence the survival of the THA. Cemented femoral stems which can subside in the cement mantle showed less femoral loosening. CFR-PEEK used as insert bearing in THA is not recommended due to a high failure rate.