Methods

Twenty-nine patients (7 men and 22 women; 58 hips) were treated with one-stage bilateral THA. The mean age of subjects at the time of surgery was 60.6 years. The average body mass index for patients was 21.7 kg/m². The diagnoses were secondary osteoarthritis due to developmental dysplasia of the hip (n=25) and avascular necrosis (n=4). All patients had donated 800 ml of autologous blood in 2 stages preoperatively (1 to 4 weeks apart). All patients took iron supplements starting from 5 weeks preoperatively. For all patients, the procedure was performed under general anesthesia in the lateral decubitus position via a posterolateral approach. Intra-operative blood salvage was not used. Suction drains were inserted subfascially. As a general rule, pre-donated autologous blood was transfused back to the patients intra- or post-operatively. Allogenic blood transfusion was performed when clinical symptoms of anemia occurred (hypotension, low urinary output, tachycardia, etc.) rather than using a preset blood threshold (hemoglobin level <8 g/dl). To determine changes in blood pressure following surgery until the next morning, systolic and diastolic blood pressure were measured at 3-hr intervals.