[Endoprostheses in the elderly : Biomaterials, implant selection and fixation technique].

The replacement of hip and knee joints is one of the greatest success stories in orthopedics. Due to continuous improvement of biomaterials and implant design, patient-associated problems are now mostly multifactorial and only rarely caused by the implant. Abrasion was significantly reduced by the introduction of highly cross-linked polyethylene (PE), antioxidant stabilized PE, new ceramics and the development of ceramic and protective surfaces. It is assumed that further reduction of frictional resistance will not lead to a significantly better clinical result: however, the problem of periprosthetic infections and implant-related incompatibility is still unsolved and remains challenging for biomaterial research. For the knee joint PE will be irreplaceable for joint articulation even in the future due to the contact situation. Mobile bearings and fixed bearings are two established successful philosophies, which have shown comparably good clinical results. For the hip joint, it is forecasted that ceramic-on-ceramic will be the system of the future if the correct positioning and mounting of the components can be solved so that the problems, such as development of noise and breakage can be reduced to a minimum. An in-depth understanding and detailed knowledge of the biomaterials by the surgeon can prevent implant-related problems. For elderly patients it is assumed that the economic burden on the public healthcare system will have the strongest impact on implant selection.