Is there a need for routine post-operative hemoglobin level estimation in total knee arthroplasty with tranexamic acid use?

Total knee arthroplasty (TKA) can result in significant blood loss, leading to a need for blood transfusion. The major indication of transfusion is post-operative hemoglobin (Hb) levels in association with symptomatic anemia. The aim of this study was to determine the possibility of eliminating routine post-operative Hb tests in patients undergoing TKA with intra-articular tranexamic acid (TXA) use based on the predictability of pre-operative factors.

We conducted a retrospective analysis of 487 patients who underwent TKA with intra-articular TXA use. Statistical analysis was done to predict the transfusion risk based on multiple pre-operative parameters.

Post-operative blood transfusions were required in 2.5% of all patients. Pre-operative-Hb was the only significant predictor of post-operative transfusion (p < 0.0001). Age, sex, weight, height and body mass index (BMI) were not related to post-operative transfusion risk. Transfusions were needed in 4.2% of patients with pre-operative Hb levels <14 g/dl. No patient with a pre-operative Hb >14 g/dl required a transfusion (p < 0.0001).

Pre-operative Hb is a strong predictor of post-operative blood transfusion risk. Patients who receive TXA in TKA, with a pre-operative Hb >14 g/dl do not require routine post-operative Hb evaluation.Level of evidence: IV