Posterior column fixation
An axial posterior column screw provides interfragmentary compression across the posterior part of the fracture. This is inserted from distal to proximal.
A 7.3 mm partially threaded cannulated screw is inserted through a separate stab incision in the buttock crease over a guide wire.
The start point is at the ischial tuberosity, and a finger in the greater sciatic notch is used to guide the wire and screw up the posterior column, exiting at the pelvic brim.
Care is taken to protect the sciatic nerve at the level of the ischial tuberosity.
The use of a screw aids the placement of the posterior wall plate as it increases the freedom of placement of the wall plate.
This is commonly referred to as the “butt screw”.