The Effect of Autotransfusion System in Minimally Invasive Total Knee Arthroplasty

PURPOSE To evaluate the effect of autotransfusion system in minimally invasive total knee arthroplasty (TKA). MATERIALS AND METHODS Seventy-one patients who underwent unilateral minimally invasive TKA between October 2009 and June 2010 were selected. The first group included 36 patients who received standard vacuum drainage and the second group, 35 patients who underwent autologous retransfusion drainage. In the first group, allogeneic blood transfusion was performed if the postoperative hemoglobin level was <7.0 g/dL or 7.0-8.0 g/dL with the presence of a medical complication and an anemic symptom. The second group received autotransfusion and allogeneic transfusion additionally according to the same criteria. Changes in the pre- and postoperative hemoglobin level, amount of auto- or allotransfusion, and frequency of allogeneic transfusion were assessed. RESULTS Allogeneic transfusion was required in 13 patients (36.1%) in the first group and four patients (11.4%) in the second group. The mean allogeneic transfusion volume was significantly low in the second group compared to the first group (64.4 mL vs. 278.9 mL; p<0.05). The hemoglobin level on the 1st postoperative day compared to the preoperative level decreased by 22.6% in the first group and 11.7% in the second group. The postoperative hemoglobin level was higher in the second group (p<0.05). CONCLUSIONS Minimally invasive unilateral TKA with an autotransfusion system can be beneficial in patients with no medical complications because of the decreased allogeneic transfusion.