A meta-analysis on RCTs of direct anterior and conventional approaches in total hip arthroplasty

To conduct a systematic review and meta-analyses on short-term outcomes between total hip arthroplasty (THA) through direct anterior approach (DAA) compared to THA through conventional approaches (CAs) in treatment of hip diseases and fractures. We performed a systematic literature search up to March 1, 2021 to identify RCTs, comparing THA through DAA with THA through CAs. We calculated mean differences (MDs) with 95% confidence intervals (CIs) for continuous outcomes, using the DerSimonian and Laird method and a random effects model. We calculated odds ratios (ORs) with 95% CIs for dichotomous outcomes, using the Mantel-Haenszel method and a random effects model. Ten RCTs met the criteria for final meta-analysis, involving 1053 patients. Four studies were blinded RCTs with a level I evidence, the other 6 studies were non-blinded RCTs with a level II evidence. DAA had a longer operation time than CAs (MD = 17.8, 95% CI  4.8 to 30.8); DAA had similar results compared to CAs for incision length (MD = - 1.1, 95% CI - 4.1 to 1.8), for intraoperative blood loss (MD = 67.2, 95% CI - 34.8 to 169.1), for HHS 3 months postoperatively (MD = 2.4, 95% CI - 0.7 to 5.5), for HHS 6 months postoperatively (MD = 0.8, 95% CI - 1.9 to 3.5), for HHS 12 months postoperatively (MD = 0.9, 95% CI - 0.7 to 2.5), for pain VAS 1 day postoperatively (MD = - 0.9, 95% CI - 2.0 to 0.15), for acetabular cup anteversion angle (MD = - 4.3, 95% CI - 5.2 to - 3.5), for acetabular cup inclination angle (MD = - 0.5, 95% CI - 2.1 to 1.1) and for postoperative complications (OR = 2.4, 95% CI 0.5 to 12.4). Considering the overall results of our meta-analysis, we can conclude that THA through DAA showed similar short-term surgical, functional, radiological outcomes and postoperative complications compared to THA through CAs.