Greater sciatic notch

The greater sciatic notch is a large concave area located on the posterior border of the ilium or the hip bone. It stretches from the posterior inferior iliac spine to the ischial spine. The ischial spine separates the greater sciatic notch above from the lesser sciatic notch below.

By the presence of the sacrospinous and sacrotuberous ligaments in the lateral wall of the pelvis, the greater sciatic notch is transformed into a complete opening known as the greater sciatic foramen. Similarly, the lesser sciatic notch also becomes the lesser sciatic foramen.

The greater sciatic notch or foramen serves as a passage for several important structures to travel from the pelvic cavity into the gluteal region. These structures include the piriformis muscle, the superior and inferior gluteal vessels and nerves, nerves to the deep lateral rotators of the hip joint (including piriformis, obturator internus, superior and inferior gemelli, and quadratus femoris), the sciatic nerve, pudendal nerves and vessels, and the posterior cutaneous nerve of the thigh.