Efficacy of Extramedullary Femoral Component Alignment Guide System for Blood Saving after Total Knee Arthroplasty

PURPOSE To compare the extramedullary femoral alignment guide system with the conventional intramedullary alignment guide system for bleeding and transfusion rate after total knee arthroplasty (TKA). MATERIALS AND METHODS Forty-nine female TKA patients were randomized into two groups: intramedullary (IM) group vs. extramedullary (EM) group. Drained volume of blood, hemoglobin concentration, hemoglobin drop, and transfusion rate were compared between the two groups. Wound problems, bleeding-related problems and thromboembolic complications were collected. RESULTS The mean drained volume via vacuum drainage was less in the EM group than that in the IM group (482.9 mL vs. 266.8 mL, p=0.001). Hemoglobin at 5 days after surgery was higher in the EM group (9.3 g/dL vs. 9.9 g/dL, p=0.002) than that in the IM group. The drop in hemoglobin after 5 days was smaller in the EM group (3.5 g/dL vs. 2.9 g/dL, p=0.003) than that in the IM group. The EM group had a lower prevalence of allogeneic transfusion (45.0% vs. 20.5%, p=0.026) than that in the IM group. No significant complications developed in either group. CONCLUSIONS The results suggest that the extramedullary femoral alignment guide technique is an advantageous method that can reduce the drained volume of blood and the allogeneic transfusion rate.