Simultaneous bilateral total knee arthroplasty (TKA) can lead to greater blood loss and higher risk of venous thromboembolism. The effectiveness and safety of tranexamic acid (TXA) in simultaneous bilateral TKAs have not been clearly defined. We presumed that a fixed dose of TXA may be a preferable alternative for ease of administration in patients undergoing simultaneous bilateral TKAs.
We prospectively randomized 120 primary simultaneous bilateral TKAs to a fixed dose of TXA or equivalent volume of normal saline intravenously. The primary outcome measure was total blood loss. The secondary outcome measures were blood transfusion rate, transfusion units, intraoperative blood loss, drainage volumes, hidden blood loss, maximum decline of hemoglobin, and postoperative suprapatellar girth increment.
There were statistically significant lower total blood loss, blood transfusion rate, drainage volumes, transfusion units, and maximum decline of hemoglobin in the TXA group than in the control group (P < .05), without increasing incidence of asymptomatic and symptomatic venous thromboembolism. However, TXA did not significantly reduce the hidden blood loss (P = .123). No differences were observed in suprapatellar girth increments between both groups on postoperative day 5 and week 6 (P = .251 and .299).
Fixed dose of TXA for patients undergoing simultaneous bilateral TKAs was effective and safe in reducing total blood loss and allogeneic blood transfusion needs without any additional thromboembolic risk. However, TXA administered intravenously did not significantly reduce the hidden blood loss.