Robotic-assisted ilio-sacral screws in vertically-unstable sacral fractures

Posterior pelvic stabilization with the iliosacral screw has long been a challenge due to the complex anatomy, proximity to vessels and nerves and narrow safe bony corridor for screw placement. Conventionally these screws were placed under fluoroscopic guidance, however the safe bony corridors are poorly represented on 2D imaging. The current generation of spine robots allow accurate drilling of trajectories while visualizing the 3D bony anatomy using intraoperatively acquired computed tomographic scans. The TiRobot (TINAVI Medical Technologies, Beijing, China) has been used to place percutaneous iliosacral screws in pelvic fractures, but no such workflow exists for the MazorX stealth edition (MXSE) (Medtronic, Dublin, Ireland). Two patients who underwent iliosacral screw fixation for vertically unstable sacral fractures using robotic assistance were included. The challenges faced and lessons learned were described in detail in this technical note. In each patient, two 6.5mm cannulated cancellous ilio-sacral screws were placed percutaneously through the ilium-S1/S2 bony corridor, using robotic assistance. The patients were allowed to sit with the leg hanging down on the first post operative day. Robotic assistance in surgery offers unique solutions to challenges, improves surgeon's understanding of the problem, and increases confidence in treating them unconventionally.