Do Patients with Borderline Anemia Need Treatment before Total Hip Arthroplasty? A Propensity Score-Matched Cohort Study

Objective: Preoperative anemia has been identified as a modifiable risk factor for multiple adverse outcomes. In real clinical practice, considering treatment of anemia would increase costs and delay surgery. Patients undergoing total hip arthroplasty (THA) with mild anemia are usually neglected and still underdiagnosed or inadequately treated. This study investigated the effects of preoperative borderline anemia and anemia intervention before THA on perioperative outcomes.Methods: We screened 706 patients from those receiving THA at our hospital from January 2020 to January 2022, with 112 in the borderline anemia group and 594 in the non-anemia group. The cohort for this retrospective study was created by using propensity score matching (PSM) and subgroup analysis. The primary outcome was perioperative blood loss, while secondary outcomes were the rate of allogeneic blood transfusion and human serum albumin transfusion, perioperative laboratory indicators, postoperative length of stay, and complications. The independent sample t test and the Mann-Whitney U -test were used to analyze continuous data, and the Pearson x2-test or the Fisher exact test was used to analyze categorical variables.Results: After PSM, there was no significant difference in perioperative blood loss between patients in the borderline anemia group and the non-anemia group. The primary outcomes of hidden (p = 0.004) and total (p = 0.005) blood loss were significantly lower in the intervention group than in the control group. No statistical differences were found in allogeneic blood transfusion, human serum albumin transfusion, postoperative length of stay, or complications (p > 0.05).Conclusions: Anemia treatments for patients with borderline anemia before THA significantly reduced hidden blood loss and total blood loss in the perioperative period and decreased the drop of hemoglobin and hematocrit without increasing postoperative complications.