Intravenous Tranexamic Acid Safely and Effectively Reduces Transfusion Rates in Revision Total Knee Arthroplasties.

Background: The efficacy and safety of tranexamic acid (TXA) in primary total knee arthroplasty (TKA) have been well established. However, there have been limited data for revision TKAs. The primary aim was to assess the impact of intravenous TXA on transfusion rates and symptomatic venous thromboembolic events (VTEs) in a large revision TKA cohort with or without intravenous TXA utilization. Methods: A retrospective review of revision TKAs performed from 2005 to 2014 was performed, identifying 2,951 procedures (2,219 patients), in which TXA was utilized in 1,144 procedures (39%). The mean age was 65 years with 52% female patients in the TXA revision group and 67 years with 52% female patients in the non-TXA revision group. Transfusion rates and symptomatic VTEs were the primary outcomes assessed. Comparisons were performed between cohorts, utilizing a unique propensity model to mitigate bias, on the basis of TXA use and subsequently for aseptic or septic revision etiology. Results: Significant reductions in transfusion rates with use of TXA were identified in revision TKAs overall (13% compared with 39%; p < 0.001 [adjusted relative risk, 1.7]), including revisions for both aseptic etiology (6% with TXA compared with 28% without TXA; p < 0.001) and septic etiology (31% with TXA compared with 54% without TXA; p < 0.001). The risk of a postoperative symptomatic VTE was not significantly different (adjusted p = 0.63) with use of TXA at 11 events (1.0%) compared with 24 events (1.3%) in the non-TXA group). Conclusions: Intravenous TXA significantly reduced transfusion rates in revision TKAs by approximately twofold, including cohorts revised for aseptic and septic etiologies. There was a very low rate of VTEs (1.2%) with no significant difference in the number of VTEs between groups after adjusting risk utilizing propensity modeling.