Wing of Ilium - Posterior Border of The Ala

Posterior Border of The Ala

The posterior border of the ala, shorter than the anterior, also presents two projections separated by a notch, the posterior superior iliac spine and the posterior inferior iliac spine.

The former serves for the attachment of the oblique portion of the posterior sacroiliac ligaments and the Multifidus; the latter corresponds with the posterior extremity of the auricular surface.

Below the posterior inferior spine is a deep notch, the greater sciatic notch.