Sciatic Foramina

The sacrotuberous and sacropsinous ligaments help to define the borders of the sciatic foramina.

  1. Sacrotuberous ligament - from sacrum to ischial tuberosity

  2. Sacrospinous ligament - from sacrum to ischial spine

Greater Sciatic Foramen

The greater sciatic foramen is divided into the suprapiriformis and infrapiriformis recesses by the piriformis muscle. This foramen is important to allow passage for the following structures as they leave the pelvic cavity:

  1. Superior gluteal artery, vein, and nerve

  2. Piriformis muscle

  3. Inferior gluteal artery, vein, and nerve

  4. Sciatic nerve

  5. Internal pudendal artery and vein

  6. Pudendal nerve

Lesser Sciatic Foramen

The lesser sciatic foramen allows passage for the following structures as the re-enter the pelvic before entering the perineum:

  1. Internal pudendal artery and vein

  2. Pudendal nerve