Robotic assistance for upper cervical instrumentation: report on accuracy and safety

This study aims to evaluate the accuracy and safety of C1 lateral mass and upper cervical pedicle screw placement assisted by the TiRobot II system.

Ten patients who underwent cervical spine surgery assisted by the TiRobot II system were included. Screw accuracy was assessed using the Gertzbein-Robbins scale and by comparing the final screw positions with pre-planned trajectories. Deviations in screw tip, tail, and angle were recorded. Clinical data, including symptoms, surgical outcomes, and postoperative follow-up, were collected. Neurological improvement was evaluated using pre- and post-operative mJOA scores, with recovery rates calculated by Hirabayashi's method to assess outcomes 3 months after surgery.

A total of 30 screws were placed in 10 patients. All screws (30/30) were within the clinically acceptable range, with 93.33% (28 screws) classified as Grade A and 6.67% (2 screws) as Grade B. In the sagittal plane, the average tip deviation was 1.82 ± 0.79 mm, tail deviation 1.64 ± 0.60 mm, and angular deviation 1.92 ± 1.39°. In the axial plane, tip deviation was 1.96 ± 0.87 mm, tail deviation 1.92 ± 0.65 mm, and angular deviation 2.01 ± 1.07°. The average surgery time was 318.80 ± 66.07 min, with a mean EBL of 205.00 ± 55.03 mL. Postoperative mJOA scores significantly improved from 8.10 ± 1.97 to 12.60 ± 1.78 (p < 0.05), with a 52 ± 14% recovery rate. All patients showed significant symptom improvement.

The TiRobot II system demonstrates the capability to precisely execute pre-planned trajectories and improves the accuracy and safety of C1 lateral mass and upper cervical screw placement.