82 patients requiring a total hip replacement were randomized to receive a resurfacing hip arthroplasty or a conventional uncemented metal-on-metal total hip arthroplasty. The objective of this trial was to compare both functional outcomes and cobalt and chromium blood levels. The results indicate that patients who underwent resurfacing arthroplasty had higher chromium concentrations for up to 24 months post-surgery. Additionally, cobalt concentrations were higher in the blood for 6 months. Both groups demonstrated improvements in functional outcome measurements 24 month postoperatively.