Drilling and length measurement
The type of drill used will depend on the diameter of screw chosen. The drill is observed using X-ray guidance as it is carefully advanced. Unless the bone is very hard, only the near cortex needs to be drilled, as the screw will advance through the cancellous bone by itself.
Multiple X-ray views are obtained intraoperatively to ensure that the screw does not penetrate the acetabulum and remains safely within the bone (inlet view, obturator oblique view).
The inlet view is used to ensure that the drill and later the screw do not penetrate the inner cortex of the ramus.