Pedicle screw placement in the cervical vertebrae using augmented reality-head mounted displays: a cadaveric proof-of-concept study.

Abstract

The accurate and safe positioning of cervical pedicle screws is crucial. While augmented reality (AR) use in spine surgery has previously demonstrated clinical utility in the thoracolumbar spine, its technical feasibility in the cervical spine remains less explored. The objective of this study was to assess the precision and safety of AR-assisted pedicle screw placement in the cervical spine. In this experimental study, five cadaveric cervical spine models were instrumented from C3 to C7 by five different spine surgeons. The navigation accuracy and clinical screw accuracy were evaluated. Post-procedural CT scans were evaluated for clinical accuracy by two independent neuroradiologists using the Gertzbein-Robbins scale. Technical precision was assessed by calculating the angular trajectory (°) and linear screw tip (mm) deviations in the axial and sagittal planes from the virtual pedicle screw position as recorded by the AR-guided platform during the procedure compared to the actual pedicle screw position derived from post-procedural imaging. A total of forty-one pedicle screws were placed in five cervical cadavers, with each of the five surgeons navigating at least seven screws. Gertzbein-Robbins grade of A or B was achieved in 100% of cases. The mean values for tip and trajectory errors in the axial and sagittal planes between the virtual versus actual position of the screws was less than 3 mm and 30°, respectively (p<0.05). None of the cervical screws violated the cortex by more than 2 mm or displaced neurovascular structures. AR-assisted cervical pedicle screw placement in cadavers demonstrated clinical accuracy comparable to existing literature values for image-guided navigation methods for the cervical spine. This study provides technical and clinical accuracy data that supports clinical trialing of AR-assisted subaxial cervical pedicle screw placement.