Fig. 2.

Preoperative planning for iliosacral screw placement. a Identification of the entry point to the safe iliosacral corridor (solid red line) with regard to the lateral aspect of the sacral spine (dashed white line). b Lateral C-arm view showing the corresponding starting point posterior to the spinal canal. c CT scan revealing a regular screw position to S1. d To enhance stability, a second screw was inserted to S2