Examination of intra-operative blood loss on the first side to perform simultaneous bilateral total hip arthroplasty without allogeneic blood transfusion

Simultaneous bilateral total hip arthroplasty (THA) offers benefits such as early rehabilitation and reduced medical costs but carries a risk of peri-operative bleeding necessitating post-operative blood transfusion. This study aimed to investigate factors associated with post-operative anemia in simultaneous bilateral THA using the direct anterior approach (DAA) and to identify criteria for limiting the surgery to one side. Patients who underwent simultaneous bilateral THA without allogeneic blood transfusion during surgery at Funabashi Orthopaedic Hospital (Chiba, Japan) between January 2022 and December 2022 were included. Multiple regression analysis was performed to identify factors associated with post-operative anemia. Receiver operating characteristic (ROC) analysis was performed using the results in multiple regression analysis to calculate cutoff values. In total, 161 patients (28 men and 133 women) were included, with a mean age of 61 years. Pre-operative hemoglobin levels and intra-operative blood loss on the first side were identified as factors associated with post-operative anemia. ROC analysis showed that the cutoff value of intra-operative blood loss on the first side was 9.2% of the patient blood volume (PBV) when the pre-operative hemoglobin level was <12 ​g/dL and 16.9% of the PBV when it was ≥12 ​g/dL. This study identified factors associated with post-operative anemia in simultaneous bilateral THA using DAA as well as the criteria for limiting surgery to the first side to prevent post-operative blood transfusion. • Decreased post-operative hemoglobin (Hb) in bilateral total hip arthroplasty (THA) was associated with pre-operative Hb. • Decreased post-operative Hb in bilateral THA was linked to blood loss on the first side. • Limit surgery if pre-operative Hb is ​< ​12 ​g/dL and blood loss is ​≥ ​9% of patient blood volume (PBV) on the first side. • Limit surgery if pre-operative Hb is ​≥ ​12 ​g/dL and blood loss is ​≥ ​16% PBV on the first side. • For prolonged surgeries, performing surgery on separate days may be safer.