Abstract
Introduction
The purpose of this prospective randomized study was to compare the 2-year follow-up penetration of Oxinium versus Metal on polyethylene in a consecutive series of low friction total hip arthroplasty.
Methods
Between July 2006 and May 2006, 50 patients (27 females and 23 males) with a mean age of 60.6 ± 11.4 years (21 to 75) were randomized to receive either Oxinium (25 hips) or Metal (25 hips) femoral head. Other parameters, including the femoral component and the all polyethylene socket (EtO sterilized), were identical in both groups. The primary criterion for evaluation was linear head penetration measurement using the Martell system.
Results
At the time of the 2-year follow-up evaluation, two patients were deceased, one was lost to follow-up, and radiographs were excluded by the software in three patients, leaving 44 hips (22 in each study group) with complete clinical and radiologic data available for analysis (median follow-up 2.01 years; 1.9 to 2.3). The median penetration rate was 0.16 mm/year in the Oxinium group versus 0.19 mm/year in the Metal group (Mann and Whitney test, p = 0.76). When using the one-year follow-up radiograph as the baseline (limiting the effect of creep), wear was 0.066mm/year in the Oxinium group versus 0.19 in the Metal group (Mann and Whitney test, p = 0.38).
Discussion and Conclusion
This study demonstrated a reduction in the yearly linear wear of EtO sterilized polyethylene when using an Oxinium femoral head when compared to metal. Although the difference was not statistically significant, longer follow-up is necessary to evaluate the clinical significance of such a reduction.
