Accuracy of Robot-Assisted Percutaneous Pedicle Screw Placement Under Regional Anaesthesia: A Comparative Cohort Study

Abstract

Abstract Background: Robot-assisted pedicle screw placement is usually performed under general anaesthesia to keep the body still. The aim of this study was to compare the accuracy of the robot-assisted technique under regional anaesthesia with conventional fluoroscopy-guided percutaneous pedicle screw placement under general anaesthesia in minimally invasive lumbar fusion surgery. Methods: Patients who underwent robot-assisted percutaneous endoscopic lumbar interbody fusion (PELIF) or fluoroscopy-guided minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) from December 2017 to February 2020 in a single centre were included. Based on the method of percutaneous pedicle screw placement used, patients were divided into the robot-assisted under regional anaesthesia (group RE-RO) and fluoroscopy-guided under general anaesthesia (group GE-FLU) groups. The primary outcome measures were screw accuracy and the incidence of facet joint violation (FJV). Secondary outcome measures included X-ray exposure and intraoperative adverse events. Results: Eighteen patients were included in group RE-RO, and 23 patients were included in group GE-FLU. The percentages of clinically acceptable screws (Gertzbein and Robbins grades A and B) were 94.4% and 91.5%, respectively. There was no significant difference in the percentages of clinically acceptable screws ( p =0.44) or overall Gertzbein and Robbins screw accuracy grades ( p =0.35). Only the top screws were included in the analysis of FJVs. The percentages of FJV (Babu grades 1, 2 and 3) were 5.6% and 28.3%, respectively. This difference was statistically significant ( p =0.01). Overall, the FJV grades in group RE-RO were significantly better than those in group GE-FLU ( p =0.009). The mean fluoroscopy time for each screw in group RE-RO was significantly shorter than that in group GE-FLU (group RE-RO, 5.4±1.9 seconds, group GE-FLU, 6.8±2.0 seconds; P =0.03). The intraoperative adverse events included 1 case of registration failure and 1 case of guide-wire dislodgment in group RE-RO as well as 2 cases of screw misplacement in group GE-FLU. No complications related to anaesthesia were observed. Conclusion: Robot-assisted pedicle screw placement under regional anaesthesia can be performed effectively and safely. The accuracy is comparable to the conventional technique. Moreover, this technique has the advantage of fewer FJVs and a lower radiation time.