Hip replacement versus resurfacing in patients with arthritis of the hip joint

This recent study compared the clinical benefits and cost-effectiveness of total hip arthroplasty with resurfacing arthroplasty in patients with severe arthritis of the hip. The authors used a single-centre, two-arm, parallel-group, assessor-blinded, randomised, controlled trial with 1:1 treatment allocation. Patients were drawn from one large teaching hospital in the UK.

A total of 126 patients older than 18 years with severe arthritis of the hip joint, suitable for resurfacing arthroplasty of the hip, participated. Patients were excluded if they were considered unable to adhere to trial procedures or complete questionnaires.

The interventions were total hip arthroplasty (replacement of entire femoral head and neck) or hip resurfacing arthroplasty (replacement of the articular surface of the femoral head only – femoral neck remains intact). Both procedures replaced the articular surface of the acetabulum.

The main outcome measures were hip function at 12 months after surgery, assessed using the Oxford hip score and Harris hip score. Secondary outcomes were quality of life, disability rating, physical activity level, complications and cost-effectiveness.

Sixty patients were randomly assigned to hip resurfacing arthroplasty and 66 to total hip arthroplasty. Intention-to-treat analysis showed no evidence for a difference in hip function between treatment groups at 12 months; 95% of follow-up data was available for analysis. Mean Oxford hip score was 40.4 in the resurfacing group and 38.2 in the total arthroplasty group (estimated treatment effect size 2.23 (−1.52 - 5.98)). Mean Harris hip score was 88.4 (84.4 - 92.4) in the resurfacing group and 82.3 (77.2 - 87.5) in the total arthroplasty group (6.04 (−0.51 - 12.58)). ‘Although we saw no evidence of a difference, we cannot definitively exclude clinically meaningful differences in hip function in the short term. Overall complication rates did not differ between treatment groups (p=0.291). However, we saw more wound complications in the total arthroplasty group (p=0.056) and more thromboembolic events in the resurfacing group (p=0.049),’ reported the authors.

No evidence of a difference in hip function was seen in patients with severe arthritis of the hip 1 year after receiving a total hip arthroplasty versus resurfacing arthroplasty. The long-term effects of these interventions remain uncertain.

Cost ML, et al. BMJ 2012;344:e2147.