Socket wear in ceramic-on-polyethylene total hip arthroplasties: fixed versus rotating heads.

We measured radiographically the polyethylene socket wear in 34 hip prostheses with a 32 mm Al2O3-ceramic head with a rotating bearing and in 37 prostheses with a "fixed" ceramic head. The mean follow-up was 12 years in both groups. The mean annual linear wear of the polyethylene was 0.034 and 0.069 mm, respectively, (Mann-Whitney U-test p < 0.0001) in the "rotation" and the "fixed" group. A rotating bearing between the head and neck in a modular total hip system seems to reduce socket wear as compared to fixed taper junctions.