Percutaneous screw fixation of the iliosacral joint: Optimal screw pathways are frequently not completely intraosseous

Secure and optimal placement of screws of at least 7 mm in diameter will be unfeasible in the majority of patients. Thoughtful preoperative planning of screw placement on CT scans is advisable to identify secure pathways with an optimal direction. For this purpose, the presented methodology of determining and transferring EPs and APs of corresponding pathways to the sagittal pelvic view using a coordinate system may be useful.