Predictors for Blood Transfusion Risk in Patients Undergoing Total Hip Arthroplasty for Femoral Neck Fracture: A Two-Center Retrospective Cohort Study.

BACKGROUND: Postoperative blood transfusion is common in older patients undergoing total hip arthroplasty (THA) for femoral neck fractures, but is associated with an increased risk for complications. This study aimed to identify relevant predictors and develop and validate a nomogram prediction model to guide perioperative blood management and reduce transfusion rates. METHODS: We retrospectively analyzed older patients who underwent THA for femoral neck fractures at two institutions between January 2017 and August 2023. Of the 391 patients, 80 (20.5%) required postoperative blood transfusion. A dataset with a smaller sample size was used for external validation. Patients' baseline characteristics, surgical data, and preoperative laboratory parameters were collected. We performed univariate and multivariate logistic regression analyses to identify independent predictors for postoperative blood transfusion and then constructed a nomogram based on those predictors. We assessed the model's performance using the area under the receiver operating characteristic curve (AUROC) and calibration curves and evaluated its clinical utility using decision curve analysis (DCA). RESULTS: Multivariate analysis identified four independent predictors: preoperative anticoagulant use, intraoperative tranexamic acid (TXA) use (protective factor), prolonged surgical duration (greater than 120 minutes), and lower preoperative hemoglobin. The nomogram demonstrated excellent discrimination (AUROC = 0.90) and good calibration. The DCA revealed a substantial net benefit of the nomogram across a wide range of threshold probabilities (10 to 85%) compared to the default strategy of transfusing all or no patients. CONCLUSIONS: Preoperative anticoagulant use, intraoperative TXA administration, surgical duration, and preoperative hemoglobin levels are key predictors for post-THA blood transfusion in older patients who have femoral neck fractures. Our nomogram should be considered a preliminary tool to be externally validated before clinical implementation. Nevertheless, optimizing modifiable intraoperative factors, especially TXA administration and surgical duration minimization, remains a crucial strategy to reduce unnecessary transfusions in this acute setting.