Does the Use of Tranexamic Acid in Patients Who Have Preoperative Coagulopathy Undergoing Total Joint Arthroplasty Normalize Their Risk of Complications? A Matched Equivalence Analysis

Introduction While patients who have a preoperative coagulopathy have an increased risk of perioperative blood loss, tranexamic acid (TXA) has been shown to decrease the risk of complications in this subset. However, a direct comparison of the use of TXA in coagulopathic and non-coagulopathic patients has not been performed. In addition to comparing differences in decreases in hemoglobin, transfusions, and complications, this study examined whether the use of TXA in coagulopathic patients normalized the risk of blood loss relative to matched non-coagulopathic patients. Methods We performed a retrospective review of 230 patients who had a preoperative coagulopathy and underwent primary total joint arthroplasty (127 hips, 103 knees) from 2012 to 2019 and received TXA. Coagulopathy was defined as international normalized ratio >1.2, partial thromboplastin time >35 seconds, or platelet count <150,000/milliliters (ml). A matched comparison group of 689 patients who did not have a coagulopathy and received TXA was identified. A two one-sided test (TOST) analysis was performed to test for equivalence. Assuming a clinically relevant difference of 1 g/dl in postoperative decrease in hemoglobin, the equivalence margin was set as ±1 g/dl between the groups. Results When comparing coagulopathic and non-coagulopathic patients, THA patients had no differences in hemoglobin, but had an increased reported estimated blood loss (243 vs 207 ml, P = 0.040) as well as an increased percent of patients requiring blood transfusions (11.8 vs 5.32%, P = 0.022). TKA patients had no differences in hemoglobin, estimated blood loss, or percent of patients requiring transfusion. There were no differences in medical or surgical complications for both groups for THA and TKA patients. Equivalence testing for both groups revealed statistical significance that THA and TKA coagulopathic patients receiving TXA had an equivalent risk of blood loss compared to non-coagulopathic patients receiving TXA. Discussion and Conclusion Coagulopathic patients receiving TXA and undergoing THA had an increased risk of receiving a transfusion; however, there were no differences in complications for both TKA and THA, as well as a normalized risk of blood loss when compared to non-coagulopathic patients.