In this study we evaluate whether a single dose of intravenous Tranexamic acid on wound closure leads to a significant reduction in both blood loss and transfusion rates following primary total knee arthroplasty.

We recruited patients prospectively who were undergoing primary total knee replacement over an 11 month period from 1^st January to 12^th November 2009. Patients were divided into two groups. Group A were given a single 500mg dose of intravenous Tranexamic acid on wound closure and group B did not receive Tranexamic acid. 282 were eligible for the study, but 59 were excluded. There were 81 patients in group A and 142 patients in group B. The group populations were matched for age, sex, body mass index, ASA (American Society of Anaesthesiologists) grade, and pre-operative haemoglobin. The average post-operative haemoglobin drop was 1.76 g/dl in group A, compared with 2.37 g/dl in group B. The transfusion rate was 1.2% in group A, compared with 12% in group B.

After taking into account the possible confounding factors, post-operative haemoglobin drop (p< 0.001), transfusion rate (p=0.026) and length of hospital stay (p=0.014) were shown to have a significant difference between the two groups (using multiple linear, logistic or ordinal logistic regression). From our results, the use of 500mg of intravenous tranexamic acid during closure of the wound during total knee replacement significantly reduces the post-operative haemoglobin drop, reducing the need for transfusion, and may reduce the length of hospital stay.