Fig. 2A–C.

(A) A CT slice tangential to the pedicle screw demonstrates the measurements for screw length and distance from the hip. (B) The distance from the skin to the tip of the pedicle screw, the tip of the pedicle screw to the bone, the maximal potential length of the screw in the bone, and the distance from the skin to the anterior aspect of the connecting bar are shown. (C) The distance from the connecting rod and pedicle screw to the external iliac bundle is demonstrated.