To explore the hemostatic effect of intra-articular administration of tranexamic acid (TXA) combined with knee flexion in total knee arthroplasty (TKA).
This randomized controlled trial was conducted at the Third Affiliated Hospital of Southern Medical University (Guangzhou, China) from January 2017 to February 2018. The patients were randomized 1:1 to the TXA group (TXA 500 mg into the joint after closure, knee, and hip flexed at 45° for 4 h) or the control group (physiological saline, with limb fully extended). The primary endpoint was postoperative hemoglobin reduction. The postoperative levels of hemoglobin were measured at four time points: 6 h after operation, and on the first, second, and third postoperative days. Calculated blood loss (CBL) at 3 days, transfusion rate, range of motion (ROM), VAS pain score, and knee circumference increment were the secondary endpoints. Ninety-four (47/group) patients were analyzed.
Postoperatively, there were statistically significant differences between the TXA and control groups in CBL (791 ± 212 mL vs 1175 ± 273 mL, P < 0.05). Hemoglobin reduction was significantly lower in the TXA group (2.0 ± 0.9 g/dL vs 4.5 ± 0.7 g/dL, P < 0.05). Based on the transfusion criteria, 3 out of 47 (6.4%) patients in the TXA group and 13 out of 47 (27.6%) patients in the control group received blood transfusions (P = 0.006). ROM (90.8° ± 6.2° vs 87.6° ± 6.4°, P = 0.004), VAS pain score (4.1 ± 1.1 vs 4.8 ± 1.3, P = 0.004), and KCI (2.4 ± 0.9 cm vs 3.2 ± 1.0 cm, P = 0.01) were better in the TXA group compared with thecontrols. There was no deep venous thrombosis (DVT), wound infection or other adverse events in either group. In the control group, 2 patients had a fever after blood transfusion.
Intra-articular injection of TXA combined with knee and hip flexion at 45° can effectively attenuate CBL and hemoglobin reduction during primary TKA, without an additional adverse event.

© 2020 The Authors. Orthopaedic Surgery published by Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.