Perioperative course and accuracy of screw positioning in conventional, open robotic-guided and percutaneous robotic-guided, pedicle screw placement

Abstract

Robotic-guided and percutaneous pedicle screw placement are emerging technologies. We here report a retrospective cohort analysis comparing conventional open to open robotic-guided and percutaneous robotic-guided pedicle screw placement. 112 patient records and CT scans were analyzed concerning the intraoperative and perioperative course. 35 patients underwent percutaneous, 20 open robotic-guided and 57 open conventional pedicle screw placement. 94.5% of robot-assisted and 91.4% of conventionally placed screws were found to be accurate. Percutaneous robotic and open robotic-guided subgroups did not differ obviously. Average X-ray exposure per screw was 34 s in robotic-guided compared to 77 s in conventional cases. Subgroup analysis indicates that percutaneously operated patients required less opioids, had a shorter hospitalization and lower rate of adverse events in the perioperative period. The use of robotic guidance significantly increased accuracy of screw positioning while reducing the X-ray exposure. Patients seem to have a better perioperative course following percutaneous procedures.

Fig. 1

Pictures a percutaneous robotic-guided procedure, as performed in 35 patients in this study. a1 shows the SpineAssist™ robot fixed to the spinous process by a clamp. The robot is already in the final position as planned by the surgeon on the planning-workstation. The arm which will guide drilling and guiding-wire insertion is being fixed to the robot. a2 shows placement of a guiding tube and marking of the skin at the planned entry point for pedicle screw placement. In a3 the skin has been incised at the marked spot and the guiding tube is inserted through the muscles to the entry point in the vertebral bone. a4 shows robotic-guided drilling of a transpedicular burr hole, a5 positioning of the guiding-wire and a6 percutaneous insertion of the screw. b shows a postoperative axial CT scan of the same screw and c displays the surgical wound postoperatively. The central incision was used for exposure of the spinous process and fixation of the robot and for placement of two PLIF cages. The four smaller incisions (two on each side) are the entry points of the percutaneously placed pedicle screws. The bar in the left lower corner of c is a cm scale

Fig. 2

a Shows the surgical scar (left image) and postoperative CT scan (one sagittal and two axial reconstructions) after a robotic-guided percutaneous procedure (instrumentation from L2 to L4 because of osteoporotic L3 fracture). b Shows the same for a similar case (L3–L5 because of osteoporotic L4 fracture) operated by conventional pedicle screw positioning via a midline incision. The bars in the left lower corners of the photographs are cm scales

Fig. 3

Displays the system applied in this study for grading of pedicle screw deviations