Ligaments of the Gluteal Region-Sacrotuberous Ligament-Sacrospinous Ligament-Greater Sciatic Foramen-Foramina of the Gluteal Region-Lesser Sciatic Foramen-Muscles of the Gluteal Region-

Ligaments of the Gluteal Region

The two important ligaments in the gluteal region are the sacrotuberous and sacrospinous ligaments. The function of these ligaments is to stabilize the sacrum and prevent its rotation at the sacroiliac joint by the weight of the vertebral column.

Sacrotuberous Ligament

The sacrotuberous ligament connects the back of the sacrum to the ischial tuberosity.

Sacrospinous Ligament

The sacrospinous ligament connects the back of the sacrum to the spine of the ischium.

Foramina of the Gluteal Region

The two important foramina in the gluteal region are the greater sciatic foramen and the lesser sciatic foramen.

Greater Sciatic Foramen

The greater sciatic foramen is formed by the greater sciatic notch of the hip bone and the sacrotuberous and sacrospinous ligaments. It provides an exit from the pelvis into the gluteal region.

The following structures exit the foramen:

■■ Piriformis

■■ Sciatic nerve

■■ Posterior cutaneous nerve of the thigh

■■ Superior and inferior gluteal nerves

■■ Nerves to the obturator internus and quadratus femoris

■■ Pudendal nerve

■■ Superior and inferior gluteal arteries and veins

■■ Internal pudendal artery and vein

Lesser Sciatic Foramen

The lesser sciatic foramen is formed by the lesser sciatic notch of the hip bone and the sacrotuberous and sacrospinous ligaments. It provides an entrance into the perineum from the gluteal region. Its presence enables nerves and blood vessels that have left the pelvis through the greater sciatic foramen above the pelvic floor to enter the perineum below the pelvic floor.

The following structures pass through the foramen

■■ Tendon of obturator internus muscle

■■ Nerve to obturator internus

■■ Pudendal nerve

■■ Internal pudendal artery and vein

Muscles of the Gluteal Region

The muscles of the gluteal region include the gluteus maximus, the gluteus medius, the gluteus minimus, the tensor fasciae latae, the piriformis, the obturator internus, the superior and inferior gemelli, and the quadratus femoris.

Note the following:

■■ The gluteus maximus is the largest muscle in the body. It lies superficial in the gluteal region and is largely responsible for the prominence of the buttock.

■■ The tensor fasciae latae runs downward and backward to its insertion in the iliotibial tract and thus assists the gluteus maximus muscle in maintaining the knee in the extended position.

 

Broad Ligaments-The Rectouterine Pouch (pouch of Douglas) and Disease-

Broad Ligaments

The broad ligaments are two-layered folds of peritoneum that extend across the pelvic cavity from the lateral margins of the uterus to the lateral pelvic walls. Superiorly, the two layers are continuous and form the upper free edge. Inferiorly, at the base of the ligament, the layers separate to cover the pelvic floor. The ovary is attached to the posterior layer by the mesovarium. The part of the broad ligament that lies lateral to the attachment of the mesovarium forms the suspensory ligament of the ovary. The part of the broad ligament between the uterine tube and the mesovarium is called the mesosalpinx. At the base of the broad ligament, the uterine artery crosses the ureter. Each broad ligament contains the following:

■■ The uterine tube in its upper free border

■■ The round ligament of the ovary and the round ligament of the uterus. They represent the remains of the gubernaculum.

■■ The uterine and ovarian blood vessels, lymph vessels, and nerves

■■ The epoophoron, a vestigial structure that lies in the broad ligament above the attachment of the mesovarium. It represents the remains of the mesonephros .

■■ The paroöphoron, also a vestigial structure that lies in the broad ligament just lateral to the uterus. It is a mesonephric remnant .

 

The Rectouterine Pouch (pouch of Douglas) and Disease

Since the rectouterine pouch (pouch of Douglas) is the most dependent part of the entire peritoneal cavity (when the patient is in the standing position), it frequently becomes the site for the accumulation of blood (from a ruptured ectopic pregnancy) or pus (from a ruptured pelvic appendicitis or in gonococcal peritonitis). Because the pouch lies directly behind the posterior fornix of the vagina, it is commonly violated by misguided nonsterile instruments, which pierce the wall of the posterior fornix in a failed attempt at an illegal abortion. Pelvic peritonitis, often with fatal consequences, is the almost certain result.

A needle may be passed into the pouch through the posterior fornix in the procedure known as culdocentesis. Surgically, the pouch may be entered in posterior colpotomy. The interior of the female pelvic peritoneal cavity may be viewed for evidence of disease through an endoscope; the instrument is introduced through a small colpotomy incision.