Wear rates of ceramic-on-ceramic bearing surfaces in total hip implants - A 12-year follow-up study

A retrospective clinical and radiographic analysis was performed on 58 pati ents (60 hips; mean age at lime of surgery, 45.2 years) at a minimum of 10- year follow-up (mean, 12.7 years) after total hip replacement using a ceram ic-on-ceramic bearing total hip implant (Autophor, Smith and Nephew, Memphi s, TN). Mean wear rare at final follow-up was 0.21 mm, averaging 0.016 mm/y . There were no cases of periprosthetic osteolysis in the acetabulum or fem ur. For the unrevised components, there were 3 (5%) cases of protrusio acet abuli and 4 (7%) cases of acetabular component loosening. On the femoral si de, 78.3% had distal pedestal formation, and 83% had greater than 2 mm impl ant-bone radiolucencies in more than 5 Gruen zones as a result of gross mot ion of the stem. Despite radiographic evidence of implant loosening, this h ard bearing articulation functioned well in vivo for more than 12 years wit h remarkably low wear-approximately one tenth the rate reported for metal-o n-polyethylene total hip bearings.