The technological advances in orthopaedic surgery continue at an unprecedented rate. Many new designs and biomaterials represent not only practical improvements but also possible new problems. Current issues with regard to total joint arthroplasty relate to such topics as which biomaterial should be used in a particular situation, the systemic and remote-site effects of the various biomaterials that are used, and the local response (such as osteolysis) to orthopaedic biomaterials. Despite considerable success in the clinical application of biomaterials, many problems remain unsolved. Clinical and basic research continues in an effort to explore new methods for the enhancement of the bone-prosthesis interface and of long-term implant fixation.