Handheld Navigation for Direct Anterior Total Hip Arthroplasty Cup Placement

Introduction: Traditionally, acetabular component insertion in direct anterior approach (DAA) total hip arthroplasty (THA) has been performed using fluoroscopic guidance. We investigated the use of a new, accelerometer-based, handheld navigation system during DAA THA to compare it to traditional meansWe investigated the use of a new, accelerometer-based, handheld navigation system during DAA THA to compare it to traditional means.

Methods: Data was prospectively collected for 200 consecutive DAA THA procedures using a handheld navigation system (HipAlign, OrthoAlign, Aliso Viejo, CA) compared to a group that underwent the same procedure without use of the navigation system. All patients underwent a pre and post-operative AP pelvis radiograph.Acetabular component inclination and version were calculated post-operatively with Elin Bild Roentgen Analyse (EBRA) software. Targeted angles for all cases were 40° ±5 for inclination and 20° ±5 for anteversion. Intraoperative fluoroscopy exposure times were obtained from post-anesthesia care unit radiographs.

Results: There were no significant differences in mean postoperative acetabular inclination angles between the navigation group as compared to the non-navigation group (38.3° vs 40.2°) (p=0.072). There were no significant differences in mean postoperative acetabular anteversion angles between the navigation group as compared to the non-navigation group (20.1° vs 20.7°) (p=.133). Mean intraoperative fluoroscopy exposure times were significantly lower in the navigation group as compared to the non-navigation group (p<.0001).

Conclusion: The findings demonstrated that a new handheld navigation system was as accurate for cup positioning as fluoroscopically assisted DAA THA. Furthermore, there was a 45% reduction in fluoroscopy exposure time. Reduction in fluoroscopy time will lower radiation exposure for the surgeon and patients.