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.