Fascia of the Obturator internus

The fascia of the Obturator internus (or Obturator fascia) covers the pelvic surface of, and is attached around the margin of the origin of, the muscle.

Above, it is loosely connected to the back part of the arcuate line, and here it is continuous with the iliac fascia.

In front of this, as it follows the line of origin of the Obturator internus, it gradually separates from the iliac fascia and the continuity between the two is retained only through the periosteum.

It arches beneath the obturator vessels and nerve, completing the obturator canal, and at the front of the pelvis is attached to the back of the superior ramus of the pubis.

Below, the obturator fascia is attached to the falciform process of the sacrotuberous ligament and to the pubic arch, where it becomes continuous with the superior fascia of the urogenital diaphragm.

Behind, it is prolonged into the gluteal region.

The internal pudendal vessels and pudendal nerve cross the pelvic surface of the Obturator internus and are enclosed in a special canal—Alcock’s canal—formed by the obturator fascia.