0. Iliosacral Screws: Radiographs & Anatomy
4/21/2017 5:56 PM
Iliosacral Screws: Radiographs & Anatomy V4

1. Iliosacral Screw “Safe Zone”
Sacral Ala (L5)
S1 Foramen
Upper Sacral Nerve Root Tunnel (S1)
Spinal Canal (cauda)
From Posterior Pelvic-Ring Disruptions: Iliosacral Screws, M.L Chip Routt, Jr. M.D. and Peter T. Simonian, M.D. in Master Techniques in Orthopaedic Surgery: Fractures. Lippincott Williams & Wilkins, 1998.

2. Imaging
All patients have different anatomy Varying amounts of lordosis Varying sacral slope Views determined by anatomy Not textbook (40-40)

3. Inlet Radiograph
Superimposed S1 And S2 Bodies (Inlet)

4. Spinal Canal
Wollinsky & Lee, JOT 2007

5. Outlet Radiograph
Sacral Foramina En Face; S2 ~ superior rami

6. Sacral Ala = 3D structure; Inlet/Outlet insufficient to r/o breach
From Posterior Pelvic-Ring Disruptions: Iliosacral Screws, M.L Chip Routt, Jr. M.D. and Peter T. Simonian, M.D. in Master Techniques in Orthopaedic Surgery: Fractures. Lippincott Williams & Wilkins, 1998.

7. Perfect Lateral of Sacrum
Need REDUCED pelvis!
Superimposition Of AICD or Greater Notches
Parallax makes both difficult
Farrell JOT 2009

8. Farrell JOT 2009

9. Traction & Fluoroscopy Set Up
Anterior/Caudad Traction Vector Appropriate For Most Fracture Displacements
From Posterior Pelvic-Ring Disruptions: Iliosacral Screws, M.L Chip Routt, Jr. M.D. and Peter T. Simonian, M.D. in Master Techniques in Orthopaedic Surgery: Fractures. Lippincott Williams & Wilkins, 1998.

10. Iliosacral Screw Inlet (Anterior / Posterior)
Make Translations / Rotation In Relation To Beam (Perpendicular)

11. Iliosacral Screw Outlet (Cephalad / Caudad)
Make Translations / Rotation In Relation To Beam (Perpendicular)

12. ***Inlet-Outlet Orthogonal ??***
Not always

13. Iliosacral Screw Placement: Case 1
30 year old Hispanic male
Fall from scaffolding
Injury films obtained in binder
Hemodynamically unstable
Bladder injury

14. Iliosacral Screw Placement: Case 1
Immediate concerns?
Unstable pelvic ring with hemodynamic instability
Binder vs ex-fix
Angiography?

15. Iliosacral Screw Placement: Case 1
Converted from binder to external fixator
Anterior ring injury more apparent out of binder
Bladder neck injury treated with foley catheter
Pelvic angiography

16. Iliosacral Screw Placement: Case 1
Definitive treatment?

17. Iliosacral Screw Placement: Case 1
Planned open reduction of anterior sacrum and SI joint IS screw fixation of central fracture Continued external fixation of anterior ring injury Issues?

18. Iliosacral Screw Placement: Case 1
Anterior sacral fragment and SI joint reduced Central sacral fracture badly malreduced IS screw a little anterior

19. Iliosacral Screw Placement: Case 1
Solution?
Anterior sacral ORIF revised
ORIF of symphysis performed
Bladder injury repaired
Improved central sacral reduction
IS screw removed
Postop CT to assess reduction

20. Iliosacral Screw Placement: Case 1

21. Iliosacral Screw Placement: Case 1