Although the incidence of failures resulting from wear-related osteolysis and associated severe bone defects are expected to diminish with important advances in polyethylene manufacturing and processing, alternative bearing surfaces, implant design, and revision techniques, current failures still reflect concerns regarding earlier ultra-high-molecular-weight polyethylene sterilization and degradation. Clinical experience before the year 2000 included rates of wear and osteolysis from 10% to as high as 70% at 7- to 14-year follow-up. With recent advances, early clinical results are encouraging, demonstrating 50% to 81% decreases in radiographic wear rates. These improvements should eventually reduce the burden of future revision hip and knee surgery. However, the long-term in vivo durability of total hip arthroplasties using these alternative materials and bearing couples has not yet been well established, and considerably fewer clinical data are available for other types of joint arthroplasties, such as total knee arthroplasty.