Flattening the learning curve - Early experience of robotic-assisted pedicle screw placement in spine surgery.

Aims and objectives: To determine accuracy of pedicle screws placed by freehand, fluoroscopy-assistance and robotic-assistance with intraoperative image acquisition, and determine the presence of learning curve in robotic spine surgery in a prospective single centre study. Materials and methods: In a prospective study, a total of 1120 pedicle screws were placed in Freehand group (n = 175), 1250 screws were placed in fluoroscopy-assisted group (n = 172), and 1225 screws were inserted in Robotic-assisted group(n = 180). Surgical parameters and screw accuracy were analyzed between the three groups. The preoperative plan was overlapped with post operative O-arm scan to determine if the screws were executed as planned. Results: The frequency of clinically acceptable screw placement (Gertzbein and Robbins grade A, B) in the Freehand, Fluoroscopy-assisted, and Robotic-assisted groups were 97.7 %, 98.6 %, and 99.34 % respectively. Higher pedicle screw accuracy, and lower blood loss were seen with robotic assistance. There was no significant difference in these parameters between surgeries commencing before and after 2 p.m. We found no statistically significant differences between the planned and executed screw trajectories in robotic assisted group irrespective of surgical experience. Conclusion: The third-generation robotic-assisted pedicle screw placement system, used in conjunction with intraoperative 3D O-arm imaging, consistently lowered blood loss and increased accuracy of pedicle screw placement in the thoracolumbar spine. It also has easy adaptability into spine practice with minimal learning curve.