Higher doses of topical tranexamic acid safely improves immediate functional outcomes and reduces transfusion requirement in total knee arthroplasty

Background Topical administration of tranexamic acid (TXA) in patients undergoing total knee arthroplasty (TKA) is increasingly popular as it avoids the risks related with systemic absorption of the medication. Previous studies have established the efficacy of TXA in TKA, however here are limited direct comparison studies available and the dosing regimens vary. Hence, there is no consensus on an optimal dose. Our objective is to compare blood loss, transfusion requirement and immediate post-operative function between high (2 g) and low (1 g) dose tranexamic acid in patients undergoing TKA. Methods This is a retrospective cohort study of 104 patients undergoing total knee arthroplasty in a single institution under a single surgeon. In total, 61 and 43 patients receiving 1 g and 2 g of topical TXA respectively. Blood loss as estimated from the difference in haemoglobin (Hb) and haematocrit (HCT) levels post-surgery and number of blood transfusions required were compared between groups. Immediate post-operative function and complications were also measured. Results Patient characteristics were mostly similar between groups. The transfusion requirements were higher in 1 g group compared to the 2 g group (0.11 vs 0.00, p = 0.034). The mean post op day 1 (POD1) range of motion higher in the 1 g group vs 2 g group (72.1 vs 63.7, p = 0.035). The 2 g group had a lower POD1 pain score compared to the 1 g group (4.02 vs 5.43, p