Background Tranexamic acid (TXA) has been widely applied in total knee arthroplasty (TKA) to significantly reduce perioperative blood loss and improve knee function recovery in patients after surgery. The choice of antithrombotic agents for venous thromboembolism (VTE) prevention after TKA is controversial. Therefore, this study aimed to compare the effects of different antithrombotic agents on patients after primary unilateral TKA in the context of applied TXA. Methods A total of 180 patients undergoing primary unilateral TKA from October 2020 to December 2021 were included in this study. All patients were given an intraoperative drip of 60 mg/kg TXA. Thereafter, patients were divided into three groups (n = 60 each). Baseline data were comparable among the three groups. The average follow-up time was 3.02 ± 0.09 months. Group 1 enrolled patients receiving oral rivaroxaban (RA) at 10 mg, Group 2 included patients who received subcutaneous Dalteparin sodium at 2500 IU, while Group 3 included patients taking oral aspirin (ASA) at 100 mg. Patients in all the three groups received treatment once a day for 30 days at 12 h postoperatively. The primary outcomes in this study were post-treatment drainage volume and thrombotic complication rate. The secondary outcomes included hematologic parameters, transfusion rate, intraoperative blood loss, total blood loss (TBL), and bleeding complication rate. Results The average drainage volume after treatment was significantly lower in Group 3 than in Group 1 and Group 2 (205.2 ± 69.0 vs 243.4 ± 72.5 vs 295.4 ± 72.5 ml, P < 0.001), and there was a significant difference between Group 1 and Group 2 (243.4 ± 72.5 mL vs 295.4 ± 72.5 mL, P < 0.001). The blood transfusion rate of Group 2 dramatically increased compared with Group 1 and Group 3 (20.0% vs 6.7% vs 5.0%, P = 0.01). The bleeding complication rate in Group 1 apparently increased relative to Group 2 and Group 3 (26.7% vs 10.0% vs 8.3%, P = 0.008). Besides, there was no significant difference in the thrombotic complication rate among the three groups. Conclusion Under the background of TXA application, ASA, RA, and Dalteparin sodium were all effective on preventing VTE after TKA. In addition, ASA effectively reduced post-treatment Hemoglobin (Hb) loss, drainage volume, TBL, transfusion rate, and bleeding complications compared with RA and Dalteparin sodium. Trial registration The trial was registered at the Chinese Clinical Trial Registry (ChiCTR2200060169). Date of Registration: 21/05/2022.

Background: To observe the effect of tranexamic acid (TXA) in combination with different antithrombotic agents in patients after initial unilateral total knee arthroplasty (TKA). Methods: One hundred and eighty patients with initial unilateral TKA from October 2020 to December 2021 were selected, all of whom were given intraoperative intravenous 60 mg/kg TXA and were divided into the rivaroxaban group, the dalteparin sodium group, and the aspirin group according to the application of antithrombotic drugs, with 60 cases each. The rivaroxaban group received 10 mg of oral Rivaroxaban 12 h after surgery, the dalteparin sodium group received 2500 U of subcutaneous dalteparin sodium, and the aspirin group received 100 mg of oral aspirin once daily for four weeks. The incidence of various hematological indices, transfusion rate, blood loss, and complications (bleeding complications and thrombotic complications) were observed in the three groups before and after treatment. Results: The hemoglobin levels were significantly lower in the Rivaroxaban, dalteparin sodium, and aspirin groups on days 1, 3, and 5 after treatment compared with those before treatment (P<0.05). The hemoglobin level was higher in the aspirin group than in the rivaroxaban and dalteparin sodium groups on days 1, 3, and 5 after treatment (P<0.05) and in the rivaroxaban group than in the dalteparin sodium group (P<0.05). When comparing the transfusion rates of the three groups, the transfusion rate in the dalteparin sodium group (20.0%) was significantly higher than that in the rivaroxaban group (6.7%) and the aspirin group (5.0%), with P<0.05. When comparing the post-treatment drainage and total blood loss in the three groups, the post-treatment drainage and total blood loss in the aspirin group were significantly lower than those in the rivaroxaban and dalteparin sodium groups (P<0.05), and the post-treatment drainage and total blood loss in the rivaroxaban group were significantly lower than those in the rivaroxaban and dalteparin sodium groups (P<0.05). Total blood loss was significantly lower in the rivaroxaban group than in the dalteparin sodium group (P<0.05). The incidence of bleeding complications in the three groups was significantly higher in the rivaroxaban group (26.7%) than in the dalteparin sodium group (10.0%) and the aspirin group (8.3%), with P<0.05. There was no significant difference in the incidence of thrombotic complications between the three groups of patients (P>0.05). Conclusion: Aspirin, Rivaroxaban, and dalteparin sodium effectively prevent venous thromboembolism after total knee arthroplasty. The additional benefit of aspirin in reducing total blood loss, transfusion rates, and bleeding complication rates supports the use of aspirin as a suitable alternative to other anticoagulants to prevent thrombosis after total knee arthroplasty in low-risk patients. Trial registration: The trial was registered in the Chinese Clinical Trial Registry (ChiCTR2200060169). Registered date: 21/05/2022