Operative Technique

After stripping the muscle off the posterior sacrum, the first and second sacral dorsal foramen are identified. A, The starting point is made half way between these two foramen along an imaginary line on the lateral aspect of the foramen. The awl is then directed inferiorly 40 to 50 degrees relative to a horizontal line connecting the posterior superior iliac spine and 20 to 30 degrees caudal from a straight lateral projection. B, The awl is advanced under fluoroscopic guidance in the AP projection to ensure a true orthogonal view is being obtained. C, The awl should be directed so it is just lateral and anterior to the sciatic notch for optimum fixation. The AP view demonstrating a well-placed screw. D, A fluoroscopic view shooting straight down the screw demonstrates the screw between the inner and outer cortices of the ilium, and the teardrop is seen with the screw in the center.