Validation of a Prototype Augmented Reality Navigation System for Total Hip Replacement

Assistive technologies are becoming more common in total hip replacement (THR) procedures, improving surgeons' abilities to achieve target implant orientations. These systems can be large, absorbing limited space in the operating theatre, and they can add complexity to surgery.We developed a small footprint prototype system that can assist in the accurate placement of implant components using augmented reality (AR) technology into preoperatively planned positions. This technology augments the 3D pelvis and the cup in its target position and displays the real-time position of instruments. The accuracy of the developed prototype system was assessed through a cadaveric study, comparing the achieved implant positions to the preoperative target. All cadavers received preoperative 3D planning to identify the target cup position and orientation. Cadaveric surgeries were completed using the AR system to achieve the target cup placement. Postoperative computed tomography (CT) was used to measure the achieved component position for each hip.The mean absolute deviation (range) from target acetabular placement to the achieved acetabular placement was 2.9° (-8.7 to 3.3°), 3.0° (-5.7 to 7°) and 1.6mm (-1.2 to 3.5mm) for inclination, anteversion, and depth, respectively. Sixty-six percent of results were within +/-5° of the preoperative target orientation.We present a cadaver validation study on a small footprint prototype system using augmented reality to enable accurate cup placement and provide additional information intraoperatively. Our results are comparable with reported results for image-based navigation from the literature.