Similar complications and outcomes with simultaneous versus staged bilateral total hip arthroplasty with the direct anterior approach: A comparative study

Introduction: Simultaneous bilateral total hip arthroplasty (THA) has demonstrated similar clinical outcomes to staged bilateral THA. However, there is scarce data regarding the early postoperative complications. This study compares simultaneous to staged bilateral THA with the direct anterior approach (DAA) regarding early complications and revision surgeries. Methods: This retrospective case-control study included all bilateral THAs, performed by DAA between 2013 and 2021 with a minimum follow-up of 6 months. A total of 264 THAs (132 patients) were identified [simultaneous group (1T): 58 patients; staged group (2T): 74] with a mean follow-up of 54 months. Complications and revisions, clinical outcomes, and days off work were assessed at the last follow-up. Moreover, blood loss was evaluated by the modified method of Mercuriali and Inghilleri. Results: Blood loss was higher in the 1T group (1003 mL 1T vs. 740 mL 2T; p < 0.001) but there was no significant difference in transfusion rates (5% 1T vs. 3% 2T; p = 0.4). There were no complications in 1T, while the complication rate was 5.2% (n = 6) in 2T (p = 0.012). There were 5 revisions in the 2T group, including 2 debridements with polyethylene exchange and implant retention for early infections, 2 revisions for aseptic loosening in the same patient, and 1 revision due to fracture. Postoperative pain on D3 was equivalent in both groups (4.2 1T vs. 4.3 2T; p = 0.79). The improvement in function according to the HHS at 2 months was better in the 1T group, but not significant (36.8 1T vs. 32.9 2T; p = 0.05). The total number of days off work was significantly higher in the 2T group (82.6 days vs. 178.8; p = 0.025). Discussion: Simultaneous bilateral THA with the DAA seems to be a safe procedure, with no risk of increased early postoperative complications when compared to the staged procedure with similar functional outcomes and significantly fewer complications and days off work.