Improved Accuracy of Cervical Spinal Surgery With Robot-Assisted Screw Insertion

Abstract

STUDY DESIGN: Prospective, randomized, controlled trial. OBJECTIVE: To compare robot-assisted and conventional implantation techniques by evaluating the accuracy and safety of implanting screws in cervical vertebrae. SUMMARY OF BACKGROUND DATA: Cervical spinal surgery is difficult and dangerous as screw misplacement might lead not only to decreased stability but also neurological, vascular, and visceral injuries. A new robot-assisted surgical procedure has been introduced to improve the accuracy of implant screw positioning. METHODS: We randomly assigned 135 patients with newly diagnosed cervical spinal disease and who required screw fixation using either robot-assisted or conventional fluoroscopy-assisted cervical spinal surgery. The primary outcomes were the discrepancies between the planned trajectories and the actual screw positions. RESULTS: Altogether, 127 patients underwent the assigned intervention (61 robot-assisted and 66 conventional fluoroscopy-assisted). The baseline characteristics including the screw types, were similar in the two groups. Altogether, 390 screws were planed and placed in the cervical vertebrae, and 94.9% were acceptable. The robot-assisted group had a better screw placement accuracy than the conventional fluoroscopy-assisted group with associated P values <0.001 (0.83 [0.44, 1.29] vs. 1.79 [1.41, 2.50] mm). The Gertzbein and Robbins scales also showed a significant difference between the two groups (P < 0.001). Furthermore, the robot-assisted group experienced significantly less blood loss during surgery than the conventional fluoroscopy-assisted group (200 [50, 375] vs. 350 [100, 500] mL; P = 0.002) and shorter length of stay after surgery (P = 0.021). These two groups did not differ significantly regarding the duration of the operation (P = 0.525). Neurological injury occurred in one case in the conventional fluoroscopy-assisted group. CONCLUSION: The accuracy and clinical outcomes of cervical spinal surgery using the robot-assisted technique tended to be superior to those with the conventional fluoroscopy-assisted technique in this prospective, randomized, controlled trial. LEVEL OF EVIDENCE: 2.