The Accuracy of Robotic Subaxial Cervical Pedicle Screw Placement: A Cadaveric Study.
Academic Article
Overview
abstract
STUDY DESIGN: Biomechanical cadaveric study. OBJECTIVE: Assess the accuracy and precision of robotically placed cervical pedicle screws (CPS). SUMMARY OF BACKGROUND DATA: Posterior cervical fusion (PCF) can be performed using lateral mass screws or pedicle screws. Although pedicle screw trajectories are longer and allow for the placement of larger screws, these screws must be placed accurately as they traverse a narrow corridor bordered by critical neurovascular structures. Robotic technology may have the potential to improve the safety and accuracy of CPS, which could facilitate the routine use of these biomechanically favorable screws in PCF. METHODS: A cadaveric study was performed to assess the accuracy of subaxial CPS placement using robotic-assisted navigation in 3 cadavers. Computed tomography (CT) scans were performed preoperatively, and trajectories were planned in Mimics software. Intraoperative fluoroscopic registration was performed, and bilateral pedicle screws were drilled and placed through the robotic end-effector from C3-C7. Postoperative CT scans were performed. Accuracy was defined as the mean absolute error (MAE), precision was defined as 2 SD, and systematic error was defined as the signed mean error (SME) when comparing the planned versus placed pedicle screw positions. An automated computer vision algorithm that measures postoperative deviation from the preoperative plan was used to assess the final tip, tail, and mid-pedicle screw position in 3 dimensions. RESULTS: A total of 30 screws were successfully placed without registration failures. When compared with the planned screw trajectory, the accuracy/deviation of the tail in the ML and SI dimensions was 1.76 mm and 1.53 mm, respectively. Accuracy of the mid-pedicle position in the ML and SI dimensions was 1.06 and 1.17. Accuracy of the tip in the ML and SI dimensions was 0.67 and 0.87 mm, respectively. Angular deviation was 3.50 degrees. CONCLUSIONS: Robotic-assisted posterior cervical pedicle screw placement is highly accurate.
