Does 1000 mg ferric carboxymaltose have an additional benefit on the hemoglobin recovery post total knee arthroplasty? – A comparison with 500 mg of ferric carboxymaltose

Introduction: The aim of this study is to study the additional effect of 1000 mg of ferric carboxymaltose (FCM) on hemoglobin (Hb) recovery post total knee arthroplasty (TKA) as compared to 500 mg of FCM. Methods: We prospectively recruited 168 unilateral primary TKA who received 1000 mg of FCM on the first postoperative day in the study group. Our control group consisted of 157 TKA from our previous study receiving 500 mg of FCM. We compared the Hb levels preoperatively (Preop-Hb), on the third postoperative day (day 3-Hb), and at 5(+1) weeks postoperatively (week 5-Hb). We also compared the number of Hb responders (rise in Hb ≥2 g/dl from day 3-Hb to week 5-Hb) in each group. We used Student’s t -test and Fisher’s exact probability test for statistical analysis. Results: The rise in Hb from day 3-Hb to week 5-Hb was higher ( P < 0.001) in the study group, whereas the difference in preoperative Hb and week 5-Hb was lower ( P < 0.001) in the study group. There was a higher number of Hb responders in the study group (61.31%) as compared to the control group (33.76%). ( P < 0.001); no major complications were recorded in either group. Conclusion: 1000 mg of intravenous (IV) FCM administered on the first postoperative day post-TKA further hastens the Hb recovery as compared to 500 mg of FCM. More than twice the number of patients are able to achieve preoperative Hb values by 5 weeks post-TKA, with more than 60% patients showing ≥2 g/dl rise in Hb from the immediate postoperative status. Routine administration of 1000 mg of IV FCM in all patients undergoing primary unilateral TKA can further hasten the Hb recovery.