Clinical evaluation of hip joint position sense in patients with hip resurfacing arthroplasty versus conventional total hip arthroplasty

The study aimed to compare the hip joint position sense (JPS) of patients undergoing conventional total hip arthroplasty (THA) or hip resurfacing arthroplasty (HRA). A total of 40 patients who underwent hip arthroplasty (20 THA and 20 HRA) for unilateral coxarthrosis in our department from January 2008 to July 2009 were reviewed. Both groups of patients were matched in age, gender, body-mass index, postoperative rehabilitation and clinical outcomes, and were followed up for > 3 years. The clinical assessments of hip JPS using Active-active method in supine position were performed at preoperatively, postoperative 6, 12, 24 and 36 months. Both groups of patients had similar absolute angle error preoperatively (P = 0.71) and decreased absolute angle error. The THA group had higher mean absolute angle error than that of HRA group at postoperative 6 month and 12 month (both P < 0.01), thereafter, both groups had similar absolute angle error. During the follow up, a tendency towards decreased absolute angle error from 6 month to 36 month was witnessed in both groups. Especially between 6 month and 12 month and between 12 month and 24 month, there were significant differences in absolute angle error (all P < 0.05). After one year, both group of patients had stable absolute angle error (all P > 0.05). Hip JPS after HRA and THA were similar in the long term. In short term, however, HRA was associated with a more improved hip JPS than THA.