Does Intraoperative Fluoroscopy Improve Limb-Length Discrepancy and Acetabular Component Positioning During Direct Anterior Total Hip Arthroplasty?

Background: One potential benefit of the direct anterior approach (DAA) for total hip arthroplasty is the ability to use intraoperative fluoroscopy for acetabular cup positioning and limb-length evaluation. Previous studies comparing the use of fluoroscopy with an anterior approach to a posterior approach have reported conflicting results. To our knowledge, no prior study has compared acetabular cup position and limb-length discrepancy (LLD) using a DAA with and without fluoroscopy. Methods: We retrospectively reviewed the charts of 298 patients who underwent direct anterior total hip arthroplasty with or without intraoperative fluoroscopy. All procedures were performed by 2 surgeons who use DAA as their primary approach. Preoperative and 6-week postoperative low anteroposterior pelvis and cross-table lateral radiographs were reviewed by 3 independent surgeons. Acetabular cup inclination, anteversion, and LLD were measured and compared. Results: Thirty-three patients were excluded for inadequate imaging, leaving 125 patients in the fluoroscopy group and 140 patients in the nonfluoroscopy group. Mean inclination, anteversion, and LLD were 39.4 degrees (95% confidence interval [CI], 38.5 degrees-40.2 degrees), 30.2 degrees (95% CI, 29.2 degrees-31.2 degrees), and 1.1 mm (95% CI, 0.1 mm-2.2 mm) for the fluoroscopy group and 39.9 degrees (95% CI, 39.3 degrees-40.5 degrees), 31.1 degrees (95% CI, 30.0 degrees-32.2 degrees), and 0.8 mm (95% CI, -0.1 mm to 1.6 mm) for the nonfluoroscopy group. There was no significant difference in acetabular inclination (P = .35), anteversion (P = .22), or postoperative LLD (P = .64) between groups. Conclusion: This study found no clinically or statistically significant difference in acetabular inclination, anteversion, or LLD between the fluoroscopy and nonfluoroscopy groups. Both surgeons achieved a similar mean acetabular cup position and an equivalent mean LLD. (C) 2018 Elsevier Inc. All rights reserved.