Thirty-two polyethylene sockets and 22 femoral heads were retrieved because
of aseptic loosening more than 9 years after total hip arthroplasty. The v
olumetric wear rates of the retrieved polyethylene sockets were significant
ly greater in those coupled with an alumina head (P <0.05). The retrieved a
lumina heads showed significantly better surface roughness and roundness th
an heads of Co-Cr and of stainless steal (P <0.05). However, no significant
difference was found in polyethylene quality demonstrated as fusion defect
s among the three different groups. The present study suggests that maintai
ning better surface roughness and roundness of the femoral heads does not a
lways result in an in vivo reduction of polyethylene wear.