This cadaveric and clinical study examined how upper sacral morphology varies and whether the true lateral sacral fluoroscopic view can guide safer percutaneous iliosacral screw placement. It evaluated 10 cadaveric pelvises with wire markers and 80 consecutive patients with unstable pelvic fractures treated by a single surgeon. The central question: can preoperative imaging and intraoperative lateral fluoroscopy prevent the malposition errors that inlet and outlet views alone cannot detect?
The complication this paper targets is silent neurovascular injury: a screw that looks perfect on inlet and outlet fluoroscopy but is actually extraosseous, violating the alar cortex and threatening the L5 or S1 nerve root.
The practical rule from this paper: every iliosacral screw case requires three intraoperative fluoroscopic views — inlet, outlet, and true lateral sacral. The lateral view is obtained by superimposing the greater sciatic notches. The ICD on that view marks the anterior boundary of your safe zone; the guide pin tip must sit caudal to it before you advance.
Before every case, review the outlet and lateral sacral plain films and the CT for the six signs of dysplasia. If S1 is dysplastic, plan for S2 fixation from the start. Do not attempt to make a dangerous corridor work.
This paper directly enabled subsequent work specifying starting points for S1 iliosacral screws in the dysmorphic sacrum (JBJS 2024, 2025), and the three-view fluoroscopic protocol it established remains the minimum standard taught in pelvic trauma fellowships today.
This cadaveric and clinical study examined how upper sacral morphology varies and whether the true lateral sacral fluoroscopic view can guide safer percutaneous iliosacral screw placement. It evaluated 10 cadaveric pelvises with wire markers and 80 consecutive patients with unstable pelvic fractures treated by a single surgeon. The central question: can preoperative imaging and intraoperative lateral fluoroscopy prevent the malposition errors that inlet and outlet views alone cannot detect?
The complication this paper targets is silent neurovascular injury: a screw that looks perfect on inlet and outlet fluoroscopy but is actually extraosseous, violating the alar cortex and threatening the L5 or S1 nerve root.
The practical rule from this paper: every iliosacral screw case requires three intraoperative fluoroscopic views — inlet, outlet, and true lateral sacral. The lateral view is obtained by superimposing the greater sciatic notches. The ICD on that view marks the anterior boundary of your safe zone; the guide pin tip must sit caudal to it before you advance.
Before every case, review the outlet and lateral sacral plain films and the CT for the six signs of dysplasia. If S1 is dysplastic, plan for S2 fixation from the start. Do not attempt to make a dangerous corridor work.
This paper directly enabled subsequent work specifying starting points for S1 iliosacral screws in the dysmorphic sacrum (JBJS 2024, 2025), and the three-view fluoroscopic protocol it established remains the minimum standard taught in pelvic trauma fellowships today.