Summary:Because of clinical success, total hip arthroplasty (THA) is being performed increasingly in a younger, more active population. Given the cumulative activity of these patients, the wear characteristics of the prosthetic components take on greater importance. Additionally, because the wear of components generates biologically active particles with an inflammatory potential, wear essentially determines the life span of total joint replacement devices. The solutions to this clinical problem thus depend on controlling the production and dissemination of particulate wear debris to the joint space and implant interfaces.