Sciatic Foramen

GREATER SCIATIC FORAMEN:
  • The greater sciatic foramen is an opening (foramen) at the back of the human pelvis.
  • It is formed by the sacrotuberous and sacrospinous ligaments.
  • The piriformis muscle passes through the foramen and occupies most of its volume.
  • The greater sciatic foramen is wider in women than in men.
BOUNDARIES:
  • It is bounded as follows:
  • Anterolaterally by the greater sciatic notch of the ilium
  • Posteromedially by the sacrotuberous ligament
  • Inferiorly by the sacrospinous ligament and the ischial spine
  • Superiorly by the anterior sacroilliac ligament
CONTENTS:
  • The piriformis, which exits the pelvis through the foramen, occupies most of its volume.
  • The following structures also exit the pelvis through the greater sciatic foramen:

Location Name Vessels Nerves
Above the Piriformissuprapiriform foramensuperior gluteal vessels superior glutea lnerve inferior gluteal nerve pudenda
lnerve sciatic nerve
Below the Piriformis infrapiriform foramen inferior gluteal vessels internal pudendal vessels posterior femoral cutaneous nerve
Nerve to obturator internus
Nerve to quadratus femoris
The foramen contains:
  • 7 nerves:
  1. Sciatic Nerve:
  2. Superior Gluteal Nerve:
  3. Inferior Gluteal Nerve:
  4. Pudendal Nerve:
  5. Posterior Femoral Cutaneous Nerve
  6. Nerve to Quadratus Femoris
  7. Nerve to Obturator Internus
  • 3 Vessel Sets:
  1. Superior Gluteal Artery & Vein
  2. Inferior Gluteal Artery & vein
  3. Internal Pudendal Artery & vein
  • Muscle:
  • Piriformis
LESSER SCIATIC FORAMEN:
  • The lesser sciatic foramen is an opening (foramen) between the pelvis and the back of the thigh.
  • The foramen is formed by the sacrotuberous ligament which runs between the sacrum and the ischial tuberosity and the sacrospinous ligament which runs between the sacrum and the ischial spine.
BOUNDARIES:
  • The lesser sciatic foramen has the following boundaries:
  • Anterior: the tuberosity of the ischium
  • Superior: the spine of the ischium and sacrospinous ligament
  • Posterior: the sacrotuberous ligament
  • Alternatively, the foramen can be defined by the boundaries of the lesser sciatic notch and the two ligaments.
CONTENTS:
The following pass through the foramen:
  • The tendon of the Obturator internus
  • Internal pudendal vessels
  • Pudendal nerve
  • Nerve to the obturator internus
Exam Question
  • The tendon of the Obturator internus, Internal pudendal vessels, Pudendal nerve, Nerve to the obturator internus are the structures passing through lesser sciatic foramen Sciatic Nerve,Superior Gluteal Nerve, Inferior Gluteal Nerve, Pudendal Nerve, Posterior Femoral Cutaneous Nerve ,Nerve to Quadratus Femoris ,Nerve to Obturator Internus,
  • Superior Gluteal Artery & Vein , Inferior Gluteal Artery & vein, Internal Pudendal Artery & vein , Piriformis muscle are the structures passing through Greater sciatic foramen
Don't Forget to Solve all the previous Year Question asked on Sciatic Foramen