Comparison of alumina-alumina to metal-polyethylene bearing surfaces in THA: a randomized study with 4- to 9-years follow-up.

We report the clinical and radiological results of 140 primary THAs, randomized to receive metal-polyethylene or alumina-alumina bearing surfaces. At last follow-up (average 79 months), no significant difference was found on clinical scores (WOMAC and Merle D'Aubigné) between the two groups. However, linear wear of 1 mm or more of the liner was observed in 89% (50/56) of polyethylene cases, whereas no measurable wear was noted in the alumima-on-alumina group. Calcar resorption was noted in 34% (19/56) of cases in the polyethylene group versus 6% (3/51) in the alumina group. Although no aseptic loosening was present in either group, 2 hips in the polyethylene group underwent revision for severe liner wear, and 2 more are pending. No specific complication was associated with alumina components. This study is in line with other reports indicating that alumina-alumina bearing surfaces have better wear properties than metal-on standard polyethylene and should be considered for THA in young and active patients.