The purpose of the study is to evaluate a product called Tranexamic Acid (TXA) and its best use in patients who are undergoing total knee replacement. The product is currently used to reduce bleeding during and after surgical procedures. This can lessen the chance of you needing a blood transfusion and may decrease pain, swelling and recovery time following the operation. Tranexamic Acid is already routinely used by surgeons for patients having joint replacements but there is currently no accurate information about the best dosing of the drug to achieve optimal patient outcomes. This study will assess whether different treatment durations will lead to better results for patients.