In Vivo Study of Local Tranexamic Acid Concentrations Following Intra-Articular Administration in Total Knee Arthroplasty

The goal of this observational study is to measure local tranexamic acid (TXA) concentrations following intra-articular administration in patients undergoing total knee arthroplasty. By evaluating its pharmacokinetic profile in the periarticular hematoma, the study will also assess the safety of topically administered TXA considering its cytotoxicity in healthy periarticular tissue. The main questions it aims to answer are: * How does TXA concentration in periarticular hematoma change over time following intra-articular administration after TKA? * Do local TXA concentrations after standard intra-articular dose of 2 g exceed the proposed cytotoxic levels, and for how long? Participants will: * Receive standard 2 g of TXA intra-articularly at the end of surgery as per the estabished hospital protocol * Undergo intra-articular hematoma fluid sampling via a drainage catheter at 0.5, 1.5, 3, 6, and 9 hours postoperatively