Abstract: ObjectiveTo evaluate the efficacy of local injection of epinephrine, and a combination of tranexamic acid and epinephrine on reducing postoperative blood loss after unilateral total knee arthroplasty (TKA). MethodsA total of 90 patients who underwent primary unilateral TKA were enrolled into the current study. They were randomly divided into three groups (n=30). Group A was injected with 50 ml normal saline into the knee joint cavity. Group B was injected with 50 ml normal saline and 0.2 mg epinephrine. Group C was injected with 50 ml normal saline, 1 g tranexamic acid and 0.2 mg epinephrine. Comparisons were made among the three groups in the volume of drainage on Days 1 and 2 after surgery, the level of hemoglobin (Hb) and hematocrit (Hct) on Days 1 and 3 after surgery, and the incidence of deep vein thrombosis (DVT) and skin necrosis three months after surgery. ResultsCompared with Group A, Group B showed remarkable decreases in the volume of drainage on Days 1 and 2 after surgery and the changes of Hb and Hct on Days 1 and 3 after surgery (P<0.05). Compared with Group B, Group C showed remarkable decreases in the volume of drainage on Days 1 and 2 after surgery and the changes of Hb and Hct on Days 1 and 3 after surgery (P<0.05). No incidence of skin necrosis and DVT was observed during follow-up visits within postoperative three months. ConclusionsLocal application of epinephrine can effectively reduce blood loss after TKA. The combined use of tranexamic acid and epinephrine is more effective on reducing postoperative blood loss, and does not increase the incidence of DVT and skin necrosis.