ABSTRACT
The highest points of the two iliac crests (intercristal plane) are at the level of the 4th lumbar vertebra and mark the level of the preferred site for lumbar puncture (the L4/ L5 intervertebral space is wide and allows access to the subarachnoid space below the termination of the spinal cord). The iliac crest is a common site for bone biopsy (Fig. 5.1, p. 75 and Fig. 8.1, p. 110), using the posterior superior spine as a landmark (it lies under the skin dimple, the ‘dimple of Venus’) to the medial side of the upper buttock. It is more prominent in females and lies at the level of S2. The ischium, an L-shaped bone, has a body and a ramus.
