gms | German Medical Science

Objective: Robotic-guidance is a relatively new technology for placement of pedicle screws. We evaluate a single-center’s experience with a newly introduced robotic system in patients who underwent percutaneous thoraco-lumbar fixation with pedicle screws.

Method: The medical records of consecutive patients operated with robotic-guidance were analyzed for screw accuracy, complications, intraoperative radiation exposure and re-operations. Screw position was rated grade 0-4 according to Wiesner et al.

Results: In total, 183 patients were operated at our department by 4 different surgeons. In 171 cases the robot was used for percutaneous robotic-guided implants and 163 patients had a post-operative CT scan for implant evaluation. Of 850 robot-guided percutaneously placed screws in 426 vertebrae from TH2 to S2, 713 (83.9%) were graded 0, 66 (7.7%) were graded 1, 39 (4.6%) were graded 2, 21 (2.5%) were graded 3, and 11 (1.3%) were graded 4. A total of 818 (96.2%) screws were defined as clinically acceptable (graded 0, 1 or 2). One screw was misplaced grade 4 and later necessitated a revision surgery (0.12%). The overall revision rate of implants was 5.8%, due to misplacement 0.58%, late loosening of screws 1.7% or dislocation 2.9%. Complications related to screw insertion were hemorrhage in 1 case and wound infections in 15 cases (8.7%), which in 11 patients (6.4%) required a surgical wound revision. The total average intra-operative exposure to radiation was 126 seconds per case or 24.1 seconds per screw.

Conclusions: In our series, accuracy of robotic-guidance compares favorably to published reports of accuracy in freehand percutaneous series. The low surgical complication rate is typical of a percutaneous surgical technique and the intra-operative radiation exposure levels are low compared to freehand percutaneous techniques. The revision rate is low and superior to other reported techniques.