Retrospective study of complications following two-stage bilateral total hip arthroplasty: does inter-stage interval matter?

Introduction: This study analyzed complication rates in two-stage bilateral Total Hip Arthroplasty (THA) across three distinct inter-stage intervals to determine the optimal timing for minimizing risk. Methods: This was a retrospective, multicentre, analytic study. The three intervals evaluated were <2 weeks (Group A), 2–12 weeks (Group B), and >12 weeks (Group C). The primary outcomes were blood transfusions, thromboembolic events (TVE), and coronary events, and the secondary outcomes were hospital stay, respiratory complications, reintervention, and mortality. The associations between demographic characteristics and complications and the risk hazard of complications were determined. Results: A total of 331 patients were included: 86 in Group A, 47 in Group B, and 198 in Group C. Blood transfusions after the second THA were performed in 29.1%, 14.9%, and 7.6% of the time interval groups respectively (p = 0.000). One TVE (1.1%) was recorded in group A and 4 (2%) in group C (p = 0.613). Conclusions: Two-stage bilateral THA with a time interval between both surgeries of <2 weeks presented a significantly higher rate of blood transfusions than longer time intervals between surgeries, with an HR of 2.4 (CI: 95% 1.7–3.3, p = 0.000). The incidences of thromboembolic and coronary events were similar between the different timeintervals, demonstrating that two-stage bilateral THA is safe when performed with an interval of at least 2 weeks between both surgeries.