(1) Background: The purpose of this study was to evaluate the efficacy and safety of intravenous (IV) ferric carboxymaltose (FCM) to treat acute postoperative anemia following same-day bilateral total knee arthroplasty (TKA). (2) Methods: A total of 118 patients who underwent same-day bilateral TKA were randomly assigned to two groups: an FCM group (FCM infusion, 58 patients) and a Control group (placebo with normal saline, 60 patients). The primary endpoint was the number of responders with a Hb increase of two or more points by the second postoperative week. The secondary endpoints were Hb level, iron metabolism variables and blood transfusion rate at 2, 6 and 12 weeks after surgery. (3) Results: The FCM group had more Hb responders than the Control group (62.1% vs. 31.6%, p < 0.001). The Hb level was significantly higher in the FCM group during 12 weeks after surgery (all p < 0.05). Ferritin, iron and transferrin saturation levels were significantly higher in the FCM group from 2 to 12 weeks postoperatively (all p < 0.05). There was no difference in transfusion rate after surgery (p > 0.05). (4) Conclusion: In patients with postoperative anemia after same-day bilateral TKA, IV FCM infusion significantly improved Hb response two weeks after surgery without severe adverse events compared to placebo. In contrast, transfusion rate and various parameters of quality of life assessment up to 12 weeks did not vary between these groups. Level of evidence: Level I.
Keywords: bilateral; ferric carboxymaltose; hemoglobin anemia; response; total knee arthroplasty.