Accuracy and safety of acetabular cup placement in total hip arthroplasty using mixed-reality navigation: A prospective trial

Background: Safe and accurate placement of the acetabular component is critical in total hip arthroplasty (THA). Fluoroscopy helps with cup positioning in the direct anterior approach (DAA) but increases radiation exposure. Augmented and mixed-reality (MR) systems may improve precision while decreasing reliance on fluoroscopy. This study assessed the accuracy, safety, and impact on radiation exposure of MR navigation in anterior and posterior THA. Methods: From July 2023 to May 2024 at a single tertiary level institution, 33 patients underwent unilateral THA with MR by either the anterior (16) or posterior (17) approach. Operative time, patient demographics, pre-operative plan and post-operative positioning measures (center of rotation, leg length discrepancy, anteversion, and inclination) were compared between cohorts. Results: , p = 0.03) and reference air kerma (4.17 vs 2.60 mGy, p = 0.02) in the initial 20% of cases. While cup placement accuracy was comparable between groups for center of rotation, leg length discrepancy, and anteversion, inclination differed significantly (2.88 vs -6.71°, p = 0.0003). Within-group analyses showed significant deviations from the preoperative plan for all measured variables in both cohorts. Despite this, all patients met clinical thresholds for LLD (