A comparison of total hip resurfacing and total hip arthroplasty - patients and outcomes.

A comparison of pertinent preoperative and postoperative data relative to total hip resurfacing versus total hip arthroplasty (THA) would assist in evaluating current perceptions in outcome. We compared 50 consecutive metal-metal resurfacing replacements in 50 patients with 44 consecutive conventional total hip arthroplasties in 35 patients, who were implanted during the same time period, by the same surgeon, and followed prospectively for 2 to 4 years. The patients undergoing hip resurfacing were 62% male, 9 years younger, and 3.2 inches taller, with a lower mean body mass index and American Society of Anesthesiologists (ASA) grade than patients undergoing total hip arthroplasty. Preoperatively, patients undergoing resurfacing had a lower Harris hip score (46 vs 52 points), more pain, higher UCLA (University of California at Los Angeles) activity scores (4.2 vs 3.6), and better range of motion. Surgical time for resurfacing was 18% longer, but there was less total blood loss and fewer transfusions. Postoperatively, there was no difference in Harris hip score (97 vs 96). Patients undergoing resurfacing had higher function, Short Form-12 physical activity scores, and UCLA activity scores, but also a higher incidence of slight or mild pain. There were no differences in postoperative range of motion or dislocation (one each). The preoperative characteristics and general health status of the average patient undergoing resurfacing are more favorable than that of the average patient undergoing conventional total hip arthroplasty. Caution should be applied in attributing differences in outcomes directly to the arthroplasty technology.