Efficacy of Low-dose Intra-articular Tranexamic Acid in Total Knee Replacement

Inclusion Criteria: * patients diagnosed as primary knee osteoarthritis and underwent unilateral primary cemented conventional total knee replacement * no risk of abnormal bleeding tendency or bleeding disorder (normal coagulogram, serum creatinine \< 2.0 mg/dL, stop nonsteroidal anti-inflammatory drugs and antiplatelet drugs more than 7 days * no contra-indication for tranexamic acid use (no active intravascular clotting process, no acquired defective colour vision, no subarachnoid hemorrhage, no hypersensitivity to TXA, and no any of history of serious adverse effects, thrombotic disorder and hematuria) Exclusion Criteria: * incomplete data collection, for example, malfunctioned drain or accidental drain removal.