Robot-Assisted Pedicle Screw Placement: Learning Curve Experience

To describe the learning curve of pedicle screw placement using robot-assisted spine surgery of an experienced neurosurgeon and 2 supervised neurosurgical fellows.

The first 120 cases of robot-assisted spine surgery at our institution were assessed. Patient variables included age, body mass index, and indication for surgery. Intraoperative variables included the vertebral level of screw placement, number of screws placed by each operator, intraoperative blood loss, and operative time. Postoperative variables included length of stay, discharge disposition, 30-day readmissions, wound complications, and hardware revisions. Screw accuracy was determined with image overlay analysis comparing planned screw trajectory on the navigation software with the intraoperative computed tomography scan with final screw placement. Two-dimensional accuracy was determined for the tip of the screw, tail of the screw, and angle at the screw was placed. The supervising physician and first fellow began utilizing the robot concurrently upon its arrival, and the second fellow began using the robot after the system had been in place for 7 months.

Both experienced surgeon and first fellow displayed a learning curve and achieved statistically significant improvement of accuracy after 30 screws. The second fellow had significantly better accuracy than the experienced surgeon in his first 30 screws. There were no complications from hardware placement in either group. There were no returns to the operating room for hardware issues.

Robot-assisted spine surgery is a safe, accurate method of pedicle screw instrumentation. Our data show similar learning adaptation rates for the first fellow and the experienced surgeon. Techniques learned by the attending surgeon were immediately transferable to a new learner, who was able to achieve a faster learning curve than both the first fellow and the experienced surgeon.