Total knee arthroplasty (TKA), the definitive treatment of osteoarthritis, is often associated with excessive postoperative bleeding due to increased fibrinolysis. Hence, the objective of the proposed study is to determine the role of topical application of tranexamic acid (TA), an anti-fibrinolytic agent, into the knee joint just before closure during TKA to reduce perioperative bleeding. The investigators' hypothesis is that in patients undergoing unilateral primary TKA, intraoperative application of 1.5 g or 3.0g topical TA into the knee joint before closure reduces perioperative bleeding as depicted by a decrement in the maximal drop in hemoglobin concentration following surgery. This proposal describes a randomized, double-blinded, placebo-controlled clinical trial with three arms. The primary outcome is the extent of the postoperative reduction in hemoglobin levels. Secondary outcomes will include transfusion requirements, hospital stay, joint functionality, quality of life and safety of using topical TA. Topical application of TA is a novel intraoperative approach that has not been used or studied in TKA. However if it is effective, it will directly reduce postoperative intra-articular bleeding without subsequent systemic absorption and thromboembolism. In addition, the reduction in microvascular intra-articular bleeding will lead to less pain and infection rates as well as improved surgical functional outcomes.