Background:Perioperative blood management in total hip arthroplasty (THA) has become a prime focus of research. Given the morbidity, delayed recovery, and prolonged hospital stay associated with postoperative anemia, various measures have been proposed to reduce perioperative blood loss (PBL). In this trial, we studied the efficacy of bone wax application on the distal cut surface of the femoral neck in reducing PBL during THA through the direct anterior approach.Methods:In a randomized controlled clinical trial, 152 patients underwent THA through the direct anterior approach with use of bone wax (n = 75) or without bone wax (control) (n = 77). The study was triple-blinded. The primary outcomes were apparent PBL (blood in sponges and suction canister) and total PBL on postoperative days (PODs) 3 and 5 (as calculated with the Good and Nadler methods). Transfusion and complications were the secondary outcomes.Results:No significant difference was found between the 2 groups in terms of age, sex, body mass index, American Society of Anesthesiologists score, etiology, preoperative hematologic/coagulation profile, anesthesia, intraoperative mean arterial pressure, or operative time. Apparent PBL, total PBL on POD3, and total PBL, in milliliters, on POD5 were significantly lower in the wax group, with median values of 200 (interquartile range [IQR]: 115 to 310) versus 370 (IQR: 195 to 513.7), 505.2 (IQR: 409.2 to 637.6) versus 747 (IQR: 494.6 to 955.4), and 536.7 (IQR: 430.9 to 689.3) versus 767.8 (IQR: 537.8 to 1,021.9) in the wax and control groups, respectively (p < 0.001). No significant differences in the rates of transfusion and complications were found.Conclusions:Bone wax on the cut surface of femoral neck can significantly reduce PBL during THA through the direct anterior approach. Bone wax is accessible and inexpensive and can be considered a routine part of the surgical technique in THA through the direct anterior approach. This intervention has no impact on complication or transfusion rates.Level of Evidence:Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.