Robotic-assisted percutaneous iliac screw fixation for destructive lumbosacral metastatic lesions: an early single-institution experience

Background Robotic-assisted surgery is becoming more widely applied in surgical subspecialties due to its intraoperative and postoperative advantages such as minimally invasive approach, reduced blood loss, shorter hospital stay, and decreased incidence of postoperative complications. However, robotic devices were only recently introduced in the field of spinal surgery. Specifically, percutaneous approaches involving computer-assisted image guidance are relatively new in iliac screw fixation. Previous methods focused on the use of S2-alar-iliac (S2AI) screw fixation which allows for pelvic fixation without a need for side connectors. However, for patients with destructive lesions of the sacrum, placement of these S2AI screws may not be feasible. The purpose of this technical note is to illustrate the implementation of robotic-assisted percutaneous iliac screw fixation in two cases which allows for minimally invasive attachment to the proximal lumbar screws without a side connector and eliminates a potential source of instrumentation failure. Methods Robotic-assisted percutaneous iliac screw fixation was performed on two patients. The robotics system was used to merge the fluoroscopic images with intraoperative computed tomography (CT) images to plan the trajectories for placement of bilateral pedicle and iliac screws. Intraoperative CT scan was again performed to confirm proper placement of all screws. Rods were then engaged bilaterally with the pedicle and iliac screws without the use of side connectors. Results The patients did not experience immediate postoperative complications and had stable hardware at one-month follow-up. Our cases demonstrate the surgical efficiency of robotic-assisted lumbo-iliac instrumentation which obviates the need to use a side connector, which is commonly used in iliac fixation. This eliminates a step, which can reduce the possibility of instrumentation failure. Conclusion Robotic-assisted percutaneous iliac screw fixation is a safe and feasible technique to improve operative and clinical outcomes in complex spinal instrumentation surgeries.