Efficacy of 1g Versus 2g Intra-auricular Tranexamic Acid in Postoperative Bleeding After Total Knee Arthroplasty

Total knee arthroplasty (TKA) is widely used as an effective treatment for end-stage osteoarthritis and other joint diseases of the knee and it improvements in surgical materials and techniques have greatly increased its effectiveness. However, TKA is an orthopaedic surgical method that has a substantial perioperative blood loss.

Classical methods for reducing blood loss and transfusion rate include the use of a pneumatic tourniquet, intraoperative cell saver, hypotensive anesthesia, application of erythropoietin, autologous blood transfusion, plugging of the femoral canal, cementing, drain clamping, navigation and minimally invasive surgery.

Tranexamic acid (TXA) an antifibrinolytic that develops its anti-haemorrhagic action by inhibiting fibrinolytic activities of plasmin has been used as an adjuvant to such measure and many studies with a level of evidence confirms its effectiveness in decreasing blood loss.

Fibrinolysis is stimulated by surgical trauma blood loss and TKA may be related to increased fibrinolytic activity. TXA inhibits fibrinolysis by blocking the lysine-binding sites of plasminogen to fibrin. Plasmin, bound to tranexamic acid, has a considerably diminished activity with respect to fibrin compared to that of free plasmin. Also, it appears from various studies that, in vivo, tranexamic acid at high doses exerts a braking activity on the activation of the complement system. So, TXA reduces bleeding in the TKA and its functional repercussion has also been confirmed in assays for various dosages and routes of administration.

In the literature, efficacy of intra-articular TXA has also been confirmed, but what is the right dosage is now unclear.