Abstract: BACKGROUND: The use of tranexamic acid in total knee arthroplasty can reduce perioperative blood loss, but the optimal choice of tranexamic acid administration route and dose remains controversial.  
OBJECTIVE: To investigate the efficacy and safety of tranexamic acid in reducing perioperative blood loss in patients with total knee arthroplasty.
METHODS: 261 patients undergoing total knee arthroplasty in Fuyang Hospital Affiliated to Bengbu Medical College (Fuyang People’s Hospital) from January 2020 to December 2021 were enrolled, including 61 males and 200 females, at the age of (68.0±7.1) years. Among them, 85 cases received intravenous infusion of tranexamic acid 1 g before skin incision and when the incision was sutured (intravenous group); 115 cases received intravenous infusion of tranexamic acid 1 g before skin incision, and 1 g of tranexamic acid was given intravenously when the incision was sutured after surgery (combined group); 61 cases did not use tranexamic acid (blank group). Blood loss of the patients was recorded; blood laboratory data of the patients were collected after surgery; postoperative complications and blood transfusion were counted. All patients were followed up to 1 month after the operation.  
RESULTS AND CONCLUSION: (1) Compared with the blank group, the total blood loss and invisible blood loss during the perioperative period in the intravenous group and the combined group were significantly lower (P < 0.05). There was no significant difference in the total blood loss and invisible blood loss between the intravenous group and the combined group during the perioperative period (P > 0.05). (2) There was no significant difference in intraoperative blood loss and postoperative venous thrombosis incidence among the three groups (P > 0.05). The blood transfusion rate in the intravenous group and the combined group was lower than that in the blank group (P < 0.05). (3) The hemoglobin levels of patients in the intravenous group and the combined group were higher than those in the blank group on days 1 and 3 after operation (P < 0.05). The platelet counts in the intravenous group and the combined group were higher than those in the blank group on the first day after operation (P < 0.05). The leukocyte count of the intravenous group and the combined group on the first day after operation was lower than that of the blank group (P < 0.05). The leukocyte count in the intravenous group on the first day after operation was lower than that in the combined group (P < 0.05). The erythrocyte sedimentation rate and C-reactive protein level of the intravenous group and the combined group on the first day after operation were lower than those of the blank group (P < 0.05). The erythrocyte sedimentation rate and C-reactive protein level in the intravenous group on the first day after operation were lower than those in the combined group (P < 0.05). (4) These results have suggested that intravenous injection and intra-articular injection are both effective ways of using tranexamic acid, and intravenous injection and intra-articular injection have no synergistic effect.

Key words: total knee arthroplasty, tranexamic acid, knee osteoarthrosis, intravenous injection, local injection, blood loss, venous thrombosis, hemoglobin, inflammatory response