Ninety-six patients with moderate/severe knee osteoarthritis (OA) were randomized to receive an intra-articular injection of tranexamic acid (TXA) plus knee and hip flexion for 4 hours after total knee arthroplasty (TKA; n=48) or control (saline injection with limb fully extended post-operation; n=48). The primary outcome of interest was the change in hemoglobin levels measured at 6 hours and 1, 2, and 3 days post-surgery. Secondary outcomes of interest included pain evaluated on the Visual Analogue Scale (VAS), range of motion (ROM) at 6 days post-surgery, calculated blood loss, visible blood loss, hidden blood loss, incidence of transfusion, knee circumference increment at 6 days post-operation, and the incidence of adverse events (i.e. deep vein thrombosis [DVT], wound infection, and fever). Results of this trial revealed that all outcomes were statistically significantly in favour of the TXA group compared to the control (p<0.05 for all). Cases of DVT or wound infection were not observed in both groups; yet, the 2 patients in the control had a fever.