The greater sciatic foramen is a major route of communication between the pelvic cavity and the lower limb (Fig. 5.31). It is formed by the greater sciatic notch in the pelvic bone, the sacrotuberous and the sacrospinous ligaments, and the spine of the ischium.
The piriformis muscle passes through the greater sciatic foramen, dividing it into two parts.
The superior gluteal nerves and vessels pass through the foramen above the piriformis.