Impact of Preoperative Anaemia on Blood Transfusion and Clinical Outcomes in Total Knee Arthroplasty: A Retrospective Observational Study

Preoperative anemia is a common, yet inadequately managed condition in patients undergoing total knee arthroplasty (TKA) and is associated with an increased need for perioperative blood transfusions. However, variability in physicians' transfusion practices remains understudied. This study investigated the influence of preoperative anaemia on transfusion rates and clinical outcomes and examined inter-physician variability in transfusion procedures.

This study included 265 patients who underwent TKA. Preoperative anaemia was defined as haemoglobin <13 g dL^-1. Demographic characteristics, perioperative variables, laboratory parameters, transfusion data, and postoperative outcomes were recorded. Transfusion rates, complications, and lengths of hospital stay were compared between anemic and non-anemic groups. Inter-physician variability in transfusion decisions was also analysed.

Preoperative anaemia was present in 43% of individuals. Transfusion rates were significantly higher in patients with anaemia (69.3% vs. 54.3%, P=0.013). When postoperative outcomes were analysed according to anaemia and transfusion status, anaemia was not independently associated with postoperative complications (P=0.072). Perioperative blood transfusion was associated with significantly higher complication rates (31.7% vs. 15.4%, P=0.003) and a prolonged hospital stay (P < 0.001). Receiver operating characteristic analysis showed modest discrimination for predicting transfusion (area under the receiver operating characteristic curve =0.61; cut-off =13.15 g dL^-1). Significant inter-physician variability was observed, independent of anaemia status (P < 0.05).

Preoperative anemia is common among TKA patients and has been associated with higher transfusion rates. Transfusion was associated with adverse clinical outcomes, including prolonged hospitalisation and higher complication rates. The substantial physician-related variability observed in transfusion practices underscores the need for standardised, evidence-based perioperative transfusion protocols.