Resurfacing matched to standard total hip arthroplasty by preoperative activity levels - a comparison of postoperative outcomes.

BACKGROUND Some studies have suggested that resurfacing patients are generally more active postoperatively than their conventional total hip arthroplasty (THA)counterparts, but controversy remains over whether this is a reflection of preferential use of resurfacing for younger and higher-activity patients. We hypothesized that, when controlling for preoperative activity levels, in addition to relevant clinical and demographic factors, resurfacing provides similar results to conventional hip arthroplasty. MATERIALS AND METHODS The specific question asked was whether resurfacing patients had differences in postoperative activity level, clinical outcomes, or rate of revisions, as compared to a matched cohort of patients treated with conventional THA. Thirty-three patients (23 men and 10 women) who were treated with resurfacing arthroplasties were matched to a cohort of patients who underwent conventional hip arthroplasty by gender, age, body mass index (BMI), and preoperative activity level. Mean preoperative Harris hip scores and length of follow-up were similar for the two groups. Postoperative weighted activity scores, Harris hip scores, patient satisfaction score, pain scores, and revision rates were evaluated at a mean final follow-up of 42 months (range, 25 to 68 months) for the resurfacing group and 45 months (range, 24 to 67 months) for the conventional hip group, and analyzed for differences. RESULTS At final follow-up, activity levels were significantly higher in the resurfacing group, with a mean weighted activity score of 10.0 points (range, 1.0 to 27.5 points), as compared to a mean score of 5.3 points (range, 0 to 12.0 points) in the THA group. Mean Harris hip scores, patients satisfaction scores, and pain scores were similar for both groups. There were no revisions in either group. CONCLUSIONS The results of this study suggest that patients treated with hip resurfacing arthroplasty have a significantly higher postoperative activity level, as compared to those treated with conventional THA, when controlled for preoperative factors.