P4A051: Intraoperative and Short-term Postoperative Complication Rates for Robotic-assisted Placement of over 1,500 Pedicle Screws in Pediatric Posterior Spinal Fusion

Background: Few studies characterize the complications associated with robotic-assisted spine surgery in pediatric patients undergoing posterior spinal fusion (PSF). This study assesses complication rates associated with over 1,500 consecutive robotically placed pedicle screws in pediatric patients undergoing posterior spinal fusion (PSF) for idiopathic scoliosis (IS) or Scheuermann’s kyphosis (SK).

Methods: We conducted a retrospective review of 93 patients (ages 10-22) with IS or SK who underwent PSF with robotic navigation from 2020-2022. Operative data included the number of screws placed with and without robotic assistance, intraoperative neuromonitoring changes and robotic complications. Robotic screw position was verified intraoperatively with a ball tip probe, fluoroscopy, and full-length AP/lateral spine x-rays.

Results: Of the 93 patients, 71.0% were female and the average age was 14.8 years, with a median of 13 fused levels (range 5-15). 1,653 (74.4%) of 2,221 pedicle screws were navigated robotically. Patients had a minimum follow-up time of six months. Forty-three (2.6%) robotically placed screws had unintentional breach (34 medial, 7 lateral, 1 inferior, and 1 combination), all of which were identified intraoperatively and redirected or removed. Breach rates were shown to decrease over time with continued robotic experience in PSF. In the first quartile of surgeries, there were 13 (4.2%) robotic breaches of the 311 pedicle screws placed, and by the fourth quartile there were only 7 (1.3%) out of 541 screws (Figure 1). There was 1 durotomy due to screw placement with no associated neurological changes, 2 neuromonitoring alerts remote to the surgical field that resolved with patient repositioning, 10 clamp/bridge strikes precluding screw placement at that level, 3 instances of inability to register the intraoperative fluoroscopy to the preoperative CT scan, and 1 loss of registration due to patient shifting (Table 1). There were 0 cases of postoperative infection or reoperation, and 2 (2.2%) cases of nonunion/delayed union.

Conclusion: Robotic navigation is a safe and effective method for pedicle screw fixation in pediatric spinal deformity. Error rates and unintentional breach rates decrease in frequency with user experience.