Data-driven preoperative hemoglobin thresholds in patients undergoing Bilateral simultaneous total Knee arthroplasty are similar to patients undergoing unilateral total Knee arthroplasty.

Introduction: Preoperative anemia is a risk factor for transfusions and complications following total knee arthroplasty (TKA). Bilateral TKA (bTKA) is more extensive compared to unilateral TKA (uTKA) and a higher preoperative hemoglobin threshold may be warranted. We hypothesized that the optimal hemoglobin cutoff value which predicts the need for postoperative transfusion would be higher for bTKA than uTKA.