Amine Zaoui, MD, Université René Descartes, Paris, France, presented data from a trial comparing the effect of femoral head material against conventional polyethylene (CPE) wear in total hip arthroplasty (THA). The results of the study demonstrated that the choice of a metal compared with a delta ceramic femoral head did not significantly influence creep or wear of a contemporary annealed polyethylene socket.

The study was conducted to examine the effect of femoral head material on CPE wear in a consecutive, prospective, randomized series of low friction THAs, said Dr Zaoui. Inclusion criteria included patients aged between 18 and 75 years with hip osteoarthritis. The study enrolled 110 patients (mean age, 60.6 years) from April 2007 to June 2008 who were randomized to receive either a 22.2-mm-diameter metal (n = 55) or delta ceramic (n = 55) femoral head (Figure 1). All patients received a polyethylene socket that was moderately cross-linked (3 Mrad of gamma radiation in nitrogen) and annealed at 130°C.

• Download figure
• Open in new tab
• Download powerpoint

Figure 1.

Flow Chart Illustrating Patient Randomization in the Study

Reproduced with permission from A Zaoui, MD.

The primary outcome of the study was femoral head penetration at a minimum of 4 years’ postoperative follow-up. This was evaluated using the Martell method, by an investigator who was blinded to the study’s randomization.

Complete data were available for 38 hips in the metal group at a median follow-up of 4.4 years, and in 42 hips in the delta ceramic group at a median follow-up of 4.0 years. Eight patients were lost to follow-up in each group, some patients in the metal and ceramic groups were removed from the final analysis due to sepsis (4 vs 1), and additional patients were excluded for other reasons (5 vs 4).

However, according to Dr Zaoui, at up to the 5-year follow-up, the results of this study showed no significant difference in CPE creep or wear using a metal femoral head compared with a delta ceramic head. The mean femoral head penetration was 0.14 vs 0.12 mm/y (P = .48), and the mean creep at the approximately 1-year follow-up was 0.27 vs 0.25 mm (P = .56). The mean steady-state penetration rate was 0.07 vs 0.06 mm/y (P = .48). There were no reports of ceramic femoral head fracture or periprosthetic osteolysis in either group.

Additional studies with longer-term follow-up will be required to further evaluate the potential clinical benefits of delta ceramic as the choice of femoral component in THA, concluded Dr Zaoui.