100 patients undergoing total knee arthroplasty (TKA) were randomized to receive either intra-articular tranexamic acid (TXA) plus dilute epinephrine, or tranexamic acid alone in surgery. The purpose of this study was to determine if the use of dilute epinephrine in combination with TXA reduces peri-operative blood loss associated with total knee arthroplasty, compared to TXA alone. Secondary outcomes included clinical examinations of rehabilitation, hemodynamic changes, and recovery complications. Results demonstrated a significant decrease in blood loss with the use of TXA plus dilute epinephrine compared to TXA alone, as well as a smaller drop in hemoglobin level. No significant effects were observed on surgery recovery or rehabilitation.