TKA procedure and blood transfusion
All the TKAs were performed under general anaesthesia. All the operations were performed by the same senior surgeon in the same laminar air flow operation room. A midline skin incision, medial parapatellar approach, and a measured resection technique were performed in all the patients. Intramedullary guides were used for all the femoral preparations, and extramedullary guides were also used for the tibial preparations. All the patients received a cemented posterior-stabilized prosthetic with patellar resurfacing, and all the TKAs were conducted without a tourniquet. In addition, no blood salvage system or postoperative drain was used (13), and electrocautery and routine haemostasis were routinely performed during the surgery.
Blood transfusion was indicated for any patients with an Hb level of <70 g/L or an Hb level between 70 and 100 g/L and symptomatic anaemia (severe mental status changes, palpitations, and/or pallor)(14).