Hip Resurfacing Versus Large-Diameter Head Total Hip Arthroplasty. A Prospective Comparative Cohort Study on Early Functional Outcomes

Abstract

Objective: There is no consensus whether hip resurfacing arthroplasty (HRA) performs better than a stem-type total hip arthroplasty (THA). Therefore, the aim of this prospective comparative matched-cohort study was to answer the following questions: 1) Do gait parameters differ between HRA and THA patients at 3, 6, and 12 months after surgery? 2) Are there differences in lower extremity muscle strength at the same time points? 3) Does the selfreported outcome using validated instruments improve similarly in both groups? Methods: One experienced senior surgeon implanted either Durom HRA or CLS Spotorno THA in 34 male patients matched for anthropometric characteristics, preoperative scores and comorbidities. Preoperatively and at 3, 6, and 12 months, gait parameters, hip and knee muscle strength, clinical data and standardized outcome scores were assessed and compared between the two groups. Results: No significant group differences were found for all gait and strength variables. Passive range of motion and mean scores for the SF-36, Harris Hip Score and UCLA activity scale improved significantly over time without differences between groups. At 12 months, more HRA than THA patients were reporting groin pain on impingement testing (20% versus 0%; P<0.05). Conclusions: Excellent early outcomes were achieved by both HRA and THA in terms of score values, lower extremity muscle strength and gait parameters. No clinically relevant differences could be observed between HRA and THA patients. Groin pain after HRA remains a concern that warrants future investigation.