- Discussion:
- refers to the portion of the posterior wall and column at the mid acetabulum lying above the ischial spine;
- screws placed in this one are at risk for joint penentration;
-
anatomic safe zone:
- entry point 2 cm medial to the lateral acetabular margin and angled medially 45 deg;
- this allows 5 mm between screw threads and subchondral bone;
- entry point 3 cm medial to the lateral acetabular margin and angled medially 15 deg;
- this allows 5 mm between screw threads and subchondral bone;
- angulations were determined from the perpendicular to the posterior column;
- note that the average total width of the posterior column is 4.8 cm;
-
flouroscopically assisted screw insertion:
- by showing the "end-on profile" of the lag screws, the surgeon can be relatively assured that the screws lie outside the joint;
Danger Zone of the Acetabulum.
NA Ebraheim, J. Waldrop, RA Yeasting, and WT Jackson. J. Orthop Trauma. Vol 6. No 2. pp 146-151.
Radiological diagnosis of screw penetration of hip joint in acetabular fracture reconstruction.
Ebraheim N. J. Orthop. Trauma. 3: 196-201. 1989.
