180 patients undergoing total knee arthroplasty were randomized to either have their operated knee placed in 120 degrees passive flexion for the first 6 hours postoperatively followed by flexion by placing over a pillow, or to full passive knee extension. The purpose was to determine the impact of keeping the knee in flexion postoperatively on blood loss and transfusion requirements. The results indicated that the flexion group experienced significantly lower blood loss and reduced transfusion requirements relative to those who had their knees in extension.