Wear

Bearing wear leads to osteolysis, aseptic loosening, and potential catastrophic failure, and the active athletic patient is at the greatest risk. Further, in the Swedish Registry a subgroup of active patients who were young heavy males had the highest historic incidence of THR failure [16]. Many of these concerns, however, arose because of the limitations of previously available bearing surfaces. Elevated levels of wear beyond 0.2 mm per year were a recognized problem with standard metal on polyethylene [17]. Enhanced alternative bearing

Fig. 3. Aseptic loosening of a cemented acetabulum developed 8 years after heavy athletic use in a 59-year-old professional tennis instructor.

surfaces promise a potential solution to activity-related wear. Although only long-term analysis will validate these claims, early-to-intermediate reports of ceramic on ceramic, metal on metal, and highly crosslinked polyethylene all show a significant reduction in annual wear rates [17,18]. With such a reduction in bearing wear, even the athletic patient is less likely to wear out the joint.

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