Do Oxidized Zirconium Femoral Heads Reduce Polyethylene Wear in Cemented THAs? A Blinded Randomized Clinical Trial

100 patients with osteoarthritis of the hip were randomized to cemented total hip arthroplasty (THA) with either an oxidized zirconium or a stainless steel femoral head, and either highly-crosslinked polyethylene (HXLPE) or ultra-high-molecular-weight polyethylene (UHMWPE). The purpose of the study was to determine whether there were differences in radiographic steady-state femoral head penetration rate between femoral head materials, as well as between different types of polyethylene. Follow-up was performed for a minimum of 4 years postoperatively. When paired with either HXLPE or UHMWPE, groups that received an oxidized zirconium femoral head demonstrated a significantly lower steady-state wear rate compared to stainless steel. In comparing wear rates between HXLPE and UHMWPE, a significantly lower steady-state wear rate was observed with HXLPE when paired with a stainless steel femoral head, though no significant difference between HXLPE and UHMWPE when paired with an oxidized zirconium head. Functional outcome through the Merl d'Aubigne score did not significantly differ between the four groups.