Evaluation of Fluoroscopic and Imageless Navigation Systems for Acetabular Component Positioning in Direct Anterior Approach Total Hip Arthroplasty.

Abstract

Background: Malpositioning of the acetabular component in total hip arthroplasty (THA) is a critical factor contributing to complications such as instability, impingement, and the need for revision surgery. This study aimed to compare the accuracy of acetabular component positioning in the direct anterior approach (DAA) using three techniques: conventional fluoroscopy, fluoroscopic image-dependent navigation, and imageless navigation.

Methods: A retrospective cohort study was conducted with 150 patients undergoing primary THA using the DAA. Patients were grouped based on the technique used (50 patients per group). Intraoperative cup inclination and anteversion were recorded, and postoperative measurements were obtained using 6-week antero-posterior radiographs. The primary outcomes included deviations in anteversion and inclination between intraoperative and postoperative measurements. The secondary outcomes included operative time and 60-day postoperative complications.

Results: A total of 150 patients undergoing DAA-THA were included, with 50 patients in each group: conventional fluoroscopy, fluoroscopic image-dependent navigation, and imageless navigation. The imageless group had significantly longer operative time (75.5 ± 10.8 minutes) than conventional fluoroscopy (65.8 ± 8.5 minutes) and image-dependent (68.9 ± 10.7 minutes), P < 0.0001. Radiographic analysis indicated that image-dependent navigation provided the highest accuracy, with 83 and 69% of cups placed within the target zones for the two surgeons, outperforming conventional and imageless methods. The imageless system showed improved accuracy over conventional fluoroscopy and image-dependent navigation when comparing intraoperative and postoperative inclination and anteversion. Postoperative anteversion (P = 0.08) and inclination (P = 0.94) showed no significant differences among groups. Complication rates, including dislocations and infections, were similar, though one periprosthetic joint infection was noted in both the conventional and image-dependent navigation groups, with no PJIs reported in the imageless group.

Conclusions: Navigation systems, particularly fluoroscopic image-dependent navigation, enhance acetabular component positioning accuracy over conventional methods in DAA-THA. However, imageless navigation requires optimization to reduce operative time and improve anteversion accuracy.