Efficacy of immediate postoperative intravenous iron supplementation after staged bilateral total knee arthroplasty

BACKGROUND: Approximately 26% of patients undergoing major orthopedic elective procedures have preoperative anemia. This study aimed to investigate the effect of intravenous (IV) iron supplementation on the hemoglobin (Hb) level after staged bilateral total knee arthroplasty (TKA) in patients with or without preoperative anemia. METHODS: We retrospectively analyzed 418 patients who underwent staged bilateral TKA (1 week interval). The iron group (n = 220) received IV iron isomaltoside immediately after each TKA. The no-iron group (n = 198) was recommended to receive transfusion if postoperative anemia was diagnosed between the first and second TKA. Preoperative anemia was present in 42 (21.2%) and 50 (22.7%) patients in the no-iron and iron groups, respectively. Demographic data, preoperative and postoperative Hb levels, Hb level change (preoperative minus postoperative 6-week Hb level), and blood drainage amount were compared between groups. RESULTS: The transfusion rate was lower in the iron group than in the no-iron group (96.5% vs. 58.6%, P < 0.001). Overall, the demographic data, preoperative and postoperative 6-week Hb levels, Hb level change, and blood drainage amount were not significantly different between the two groups. Among patients with preoperative anemia, the iron group showed lower Hb level change (0.6 ± 0.9 vs. 0.1 ± 1.1, P = 0.016). CONCLUSION: Patients with preoperative anemia treated with IV iron showed lower Hb level change than did those without IV iron treatment. Despite the lower transfusion rate, the iron group showed similar postoperative 6-week Hb level and Hb level change to the no-iron group.