Wearable Augmented Reality Goggles Using 3D Computerized Tomography to Simulate Pedicle Screw Placement

Augmented reality has shown potential to enhance surgical navigation and visualization. Our objective was to demonstrate whether head-mounted display augmented reality (HMD-AR) technology projecting reconstructed 3D and 2D computerized tomography (CT) images can be accurately superimposed over a lumbar model and used to simulate placement of pedicle screws with no additional real-time fluoroscopy. CT imaging was obtained of a phantom composed of L1-L3 Sawbones vertebrae in opaque silicone. CT images and virtual trajectories of appropriate angle and depth were integrated into the Microsoft HoloLens using the Novarad OpenSight application allowing the user to view the virtual trajectory guides and CT images superimposed on the phantom in two- and three-dimensions. 22-gauge spinal needles were inserted following the virtual trajectories to the point of contact with bone. Repeat CT revealed actual needle trajectory, allowing comparison with preprocedural planning. Registration of AR hologram to phantom showed a roughly circular deviation with maximum average radius of 2.5 mm. Users averaged 200 seconds to place a needle. Extrapolation of needle trajectories into pedicles showed that of 36 needles placed, 35 (97%) would have remained within the pedicles. Compared to the edge of the bone, needles placed approximated a mean distance of 4.69 mm in the mediolateral direction and 4.48 mm in the craniocaudal direction. We effectively simulated pedicle screw placement using HMD-AR on a lumbar model with no additional fluoroscopy. This technology has potential to enhance safety and efficiency in selected surgical procedures