What Should Define Preoperative Anemia in Primary THA?

Area of Science:

• Orthopedic Surgery
• Anesthesiology
• Hematology

Background:

• Tranexamic acid (TXA) reduces but does not eliminate transfusion needs in total hip arthroplasty (THA).
• Postoperative transfusion is linked to increased complication risks.
• Preoperative anemia is a key predictor, but optimal hemoglobin (Hgb) thresholds for transfusion risk in THA are not well-defined.

Purpose of the Study:

• Identify preoperative factors associated with postoperative transfusion in THA patients using TXA.
• Determine optimal preoperative Hgb cutoff values to predict transfusion risk after THA.

Main Methods:

• Retrospective analysis of 558 primary THAs (2013-2015).
• Multivariable logistic regression identified transfusion predictors.
• Area Under the Curve (AUC) determined best preoperative Hgb cutoff values.

Main Results:

• Lower preoperative Hgb, female sex, and topical/no TXA use independently predicted transfusion.
• Preoperative Hgb showed the strongest association with transfusion (AUC=0.876).
• A Hgb cutoff of 12.6 g/dL maximized predictive accuracy (sensitivity 83%, specificity 84%) across all patients.

Conclusions:

• Current WHO anemia definitions (<13 g/dL men, <12 g/dL women) may underestimate THA transfusion risk.
• A preoperative Hgb cutoff of 12.6 g/dL is recommended for predicting transfusion.
• Further research on preoperative anemia treatment and blood conservation referral is warranted.