Impact of tranexamic acid and autologous blood transfusion on postoperative complications after primary total knee arthroplasty: a retrospective comparative study

Background: Blood loss during total knee replacement is a major concern for the operating surgeon as well as the patients. Various techniques have been adopted to reduce the blood loss and its consequent complications during the intra-operative and post-operative period. Of the various methods, tranexamic acid and autologous blood transfusions are widely used. There is however a paucity of data comparing the impact of these two techniques on post-operative complications and also the advantages of the combined use of two techniques. Methods: A retrospective study on postoperative blood management of TKA was done in 392 patients (279 female, 113 male). All the patients were divided into 4 groups. The first group comprised of patients who had received neither autologous transfusion nor tranexamic acid (Group A); the second group received autologous blood transfusion only (Group B); the third group received a combined management with tranexamic acid injection and autologous blood transfusion (Group C); the fourth group received tranexamic acid without any auto transfusion (Group D). Through routine blood tests, the blood loss was calculated by the Gross formula. Allogeneic blood transfusion amounts were also recorded. Knee swelling was evaluated by measuring the circumference of the knee. After surgery, suspicious deep vein thrombosis was excluded by B-ultrasound. During the first follow-up, we checked whether skin edge necrosis was present and examined range of motion. Results: After primary TKA surgery, intravenous injection of tranexamic acid could decrease the drainage amount (268.4 mL vs 318.7 mL, P<0.01), hidden blood loss (668.8 mL vs 762.1 mL, P<0.01), and allogenic blood transfusion rate (3.17% vs 5.74%). The use of VAC auto transfusion equipment on the patient led to an increase in the drainage amount (368.1 mL vs 318.7 mL, P<0.01), although it reduced skin edge necrosis (1.83% vs 4.59%, P=0.409). It could also reduce the swelling (1.17 mL vs 1.21 mL, P=0.02) and accelerate the recovery of ROM (2.48 vs 2.69, P=0.023). The combined use of tranexamic acid and the auto transfusion VAC system resulted in an increase in the drainage amount (268.4 mL vs 311.6 mL, P<0.01) and also could not reduce hidden blood loss (716.6 mL vs 668.8 mL, P=0.023) or the allogenic blood transfusion rate (3.75% vs 3.17%). However, the combined use did result in a significant reduction in knee swelling in the post-operative period (1.15 vs 1.18, P=0.07). Conclusions: The use of tranexamic acid reduces both apparent and hidden blood loss in the post-operative period in knee replacement patients. The use of the autologous transfusion system reduces the incidence of wound necrosis, decreases knee swelling, and improves rehabilitation. The combined use did not result in a significant reduction in blood loss but did decrease knee swelling on post-operative evaluation.