Arteries of the Gluteal Region-Superior Gluteal Artery-Inferior Gluteal Artery-The- Trochanteric Anastomosis

Arteries of the Gluteal Region

Superior Gluteal Artery

The superior gluteal artery is a branch from the internal iliac artery and enters the gluteal region through the upper part of the greater sciatic foramen above the piriformis. It divides into branches that are distributed throughout the gluteal region.

 

Inferior Gluteal Artery

The inferior gluteal artery is a branch of the internal iliac artery and enters the gluteal region through the lower part of the greater sciatic foramen, below the piriformis. It divides into numerous branches that are distributed throughout the gluteal region.

The Trochanteric Anastomosis

The trochanteric anastomosis provides the main blood supply to the head of the femur. The nutrient arteries pass along the femoral neck beneath the capsule. The following arteries take part in the anastomosis: the superior gluteal artery, the inferior gluteal artery, the medial femoral circumflex artery, and the lateral femoral circumflex artery.

The Cruciate Anastomosis

The cruciate anastomosis is situated at the level of the lesser trochanter of the femur and, together with the trochanteric anastomosis, provides a connection between the internal iliac and the femoral arteries. The following arteries take part in the anastomosis: the inferior gluteal artery, the medial femoral circumflex artery, the lateral femoral circumflex artery, and the first perforating artery, a branch of the profunda artery.

Veins of the Lower Limb

The veins of the lower limb can be divided into three groups: superficial, deep, and perforating. The superficial veins consist of the great and small saphenous veins and their tributaries, which are situated beneath the skin in the superficial fascia.

The constant position of the great saphenous vein in front of the medial malleolus should be remembered for patients requiring emergency blood transfusion. The deep veins are the venae comitantes to the anterior and posterior tibial arteries, the popliteal vein, and the femoral veins and their tributaries. The perforating veins are communicating vessels that run between the superficial and deep veins. Many of these veins are found particularly in the region of the ankle and the medial side of the lower part of the leg. They possess valves that are arranged to prevent the flow of blood from the deep to the superficial veins.

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.