Effect of knee flexion position and combined application of tranexamic acid on blood loss following primary total knee arthroplasty: a prospective randomized controlled trial

Abstract

Purpose: The aim of this study was to demonstrate the association between tranexamic acid (TXA)-combined application and knee flexion in the first 24 hour post-operatively that could reduce total blood loss and transfusion need in patients undergoing total knee arthroplasty (TKA), without sacrificing safety.

Methods: Ninety TKA patients were divided into three groups randomly: the flexion group: the knee was in 90° flexion position for the first 12 hour post-surgery and kept at 60°for the next 12 hour, combined with 1 g TXA topical and 1 g TXA intravenous application. The extension group: the knee was in fully extension position post-operatively, combined with topical and intravenous TXA application. The controlled group: the knee was in fully extension position post-operatively combined with single intravenous TXA application. The primary outcomes included blood loss variables and transfusion values. The secondary outcomes included post-operative hospital stay, knee flexion degree, complication rate, and hospital charge.

Results: The total blood loss and transfusion needs in the flexion group were significantly reduced in comparison with that in the extension group and controlled group. The post-operative knee flexion motion was significant higher in the flexion group than the other two groups. There was no difference among the three groups with regard to the rates of complications.

Conclusions: Keeping the knee in flexion position combined with topical and intravenous TXA application in patients undergoing primary unilateral TKA significantly reduced post-operative bleeding and the transfusion rate compared with what was found after treatment with extension knee position or single intravenous TXA application.

Level of evidence: Therapeutic Level I.

Keywords: Blood loss; Knee flexion position; Total knee arthroplasty; Tranexamic acid; Venous thromboembolism.