[show abstract][hide abstract] ABSTRACT: A prospective study was undertaken to assess the efficacy and financial cost of the use of an autologous blood transfusion device in the reduction of allogeneic blood requirements of patients undergoing primary unilateral total knee arthroplasty. Forty-nine consecutive patients received either the CellTrans blood salvage device (group A of 32 patients) or the Redivac high vacuum drainage system (group B of 17 patients). The preoperative and postoperative haemoglobin levels were recorded at 72 or 96 hours. Nine percent of group A patients received an allogeneic blood transfusion compared to 59% in group B. There was an average saving of 1.1 unit of allogeneic blood per patient in group A (p<0.001). The total cost per patient was about Euro 111 less for the group A patients. Autologous re-infusion was found in this study to be an effective method of reducing allogeneic blood requirements and to afford significant cost savings in primary unilateral knee arthroplasty.