In the 1980s, the focus of the joint-replacement industry was on fixation of the implants, and progress has been made both with devices that are inserted with cement and with those that are inserted without cement. As has always been the case in the history of joint replacement, each advance has unmasked another limitation. More durable fixation allows for more frequent, more intense, and more variable use of the joint, and the indications for the procedure have gradually been expanded to include younger and more active patients. With greater anticipated longevity for both patients and devices, there are justified concerns about long-term skeletal remodeling, but this has not yet been demonstrated to be a widespread clinical problem. The current problem is osteolysis, which most commonly occurs in association with polyethylene wear particles.