OBJECTIVETo evaluate the efficacy and safety of one dose tranexamic acid combined with temporary drain lamping in primary unilateral total knee arthroplasty.

METHODSTotal 160 patients undergoing unilateral primary total knee arthroplasty between January 2012 and December 2013 were randomly divided into four groups(40 cases in each group):group A (the drain was clamped for 2 hours after the operation and the patients received 20 ml physiological saline), group B(the drain was clamped for 2 hours after the operation and the patients received 10 ml tranexamic acid and 10 ml physiological saline), group C (the drain was clamped for 4 hours after the operation and the patients received 20 ml physiological saline) and group D(the drain was clamped for 4 hours after the operation and the patients received 10 ml tranexamic acid and 10 ml physiological saline). The postoperative hemoglobin level, maximum hemoglobin loss, wound drainage, blood loss, the volume of blood transfusion, the number of patients inquiring blood transfusion, venous thrombo embolism rate, and ecchymosis rate were recorded and compared among the four groups.

RESULTSThere was no incision infection, severe hypoxia, and symptomatic pulmonary embolism in these groups. There were significant differences in hemoglobin content one day after operation in each group(=12.26,=0.000), in the hemoglobin content 7 days after operation in each group(=20.74,=0.000), in postoperative drainage in each group(=38.71,=0.000);in the amount of invisible red blood cell loss in each group(=83.41,=0.000), and in total red blood cell loss in each group(=102.68,=0.000). Color Doppler ultrasound examination found that the total incidence of VTE was 3%(5/160) and there were no significant differences in each group(=0.892). There were no significant differences in postoperative subcutaneous ecchymosis area>1% incidence(=0.143).

CONCLUSIONSTopical tranexami acid treatment combined with temporary clamping of drain for 4 hours could reduce postoperative blood loss, blood transfusion, and ecchymosis rate without increasing the risk of thromboembolic event after total knee arthroplasty.