Complications and mid to long term outcomes for hip resurfacing versus total hip replacement: a systematic review and meta-analysis.

INTRODUCTION: The long-term results of total hip replacement (THR) are excellent; however, it has higher failure rates in young and active patients. Hip resurfacing arthroplasty (HRA) is an alternative in such patients and gaining popularity. This review was done to compare complications and outcomes between HRA and THA by assessing the latest level 1 studies comparing the two from the past 10 years. METHOD: A systematic review and meta-analysis was conducted using three databases (PubMed, EMBASE and SCOPUS) to compare the complications between THR and HRA in medium to long term follow up. The primary outcome of interest included the complication and revision rate between the two techniques. Functional outcomes and ionic levels at follow up were also compared as secondary outcomes. Risk of bias assessment was done using the Cochrane risk of bias tool. RESULT: The present review included 6 level 1 studies. These included 308 THR and 304 HRA. On meta-analysis, overall complications rates were significantly lower in HRA compared to the THA group with an Odds ratio (OR) of 2.17 (95% CI 1.21, 3.88; p = 0.009). No difference was seen between the two groups in terms of revision rate (OR 1.06 95% CI 0.57, 1.99; p = 0.85). Functional outcomes in both the groups were satisfactory but the Harris Hip Score was found to be significantly better in the resurfacing group (MD 2.99 95% CI - 4.01, - 1.96, p < 0.00001). There were increased cobalt and chromium ions in the resurfacing group but no detrimental effect was seen in terms of reported poisoning. CONCLUSION: Despite similar function and revision rates, HRA was seen to have lesser associated complications and ionic levels may not be a detrimental issue. Hip resurfacing provides relative ease during revisions, especially in younger patients and it may be an alternative to THR in the younger population.