Reading

Body Surface

The primary surface landmarks of the gluteal region and posterior thigh are associated with the inominate (iliac crest, greater trochanter and ischial tuberosity), femur (medial and lateral condyles and epicondyles), tibia (medial and lateral condyles) and fibula (head). The skin overlying the gluteal region and thigh is innervated by the dorsal rami of lumbar and sacral spinal nerves, and posterior cutaneous of thigh, medial cutaneous of thigh, lateral cutaneous of thigh, obturator nerves.

Skeleton and Joints

The bones and joints associated with the gluteal region and posterior thigh are the inominate and femur articulating at the hip joint, and the femur, patella and tibia articulating at the knee joint. The hip joint moves in flexion and extension, abduction and adduction, medial and lateral rotation, and circumduction (combining elements of the other movements). The knee joint moves in flexion and extension, and slight medial and lateral rotation (locking and unlocking knee with flexion and extension).

Fascial Organization

The fascia lata (deep fascia of the thigh) extends from the sacrum and inominate (iliac crest, inguinal ligament, inferior pubic ramus, ischial ramus and tuberosity, and sacrospinous ligament) to the knee. It is thickened laterally as the iliotibial tract and has three intermuscular septa attaching to the linea aspera of the femur. The septa divide the thigh into three ( anterior/extensor, posterior/flexor and medial/adductor) compartments. The lateral septum separates the anterior and posterior compartments. The medial septum separates the anterior and medial compartments and a third intermuscular septum separates the medial and posterior compartments.

Muscles

The gluteal muscles are subdivided into superficial and deep muscles. The superficial muscles are primarily active in extension ( gluteus maximus), flexion ( tensor fasciae latae), abduction ( gluteus mediusand gluteus minimis) and medial rotation (gluteus medius, gluteus minimis and tensor fasciae latae). The deep gluteal muscles are primarily activein abduction ( piriformis) and lateral rotation (piriformis, superior gemellus, obturator internus, inferior gemellus and quadratus femoris) of the hip. The posterior thigh muscles are primarily active in extension ( semimembranousus, semitendinosus and biceps femoris long head) thigh and flexion (semimembranosus, semitendinosus, biceps femoris long head and biceps femoris short head) of the knee.

Innervation

The superficial gluteal muscles are innervated by the superior and inferior gluteal nerves, whereas the deep gluteal muscles are innervated by branches of the lumbar and sacral plexuses. The muscles of the posterior compartment of the thigh are innervated by branches of the tibial and peroneal divisions of the sciatic nerve.

Blood Supply

The superficial gluteal muscles are primarily supplied by branches of the superior and inferior gluteal arteries. The deep gluteal muscles are supplied by branches of the superior gluteal, inferior gluteal, internal pudendal and internal pudendal arteries. The posterior compartment muscles are supplied by the perforating branches of the profunda femoral artery.

Anatomical Spaces or Features

The greater and lesser sciatic foramina are positioned deep to the superficial gluteal muscles. The greater sciatic foramen is bounded by the greater sciatic notch, and the sacrospinous and sacrotuberous ligaments. The greater sciatic foramen is traversed by the piriformis muscle, five major nerves (sciatic, superior gluteal, inferior gluteal, posterior cutaneous of the thigh and pudendal), and three arteries and veins (superior gluteal, inferior gluteal and internal pudendal). The lesser sciatic foramen is bounded by the lesser sciatic notch, and sacrospinous and sacrotuberous ligaments. The tendon of obturator internus, nerve to the obturator internus, pudendal nerve, and internal pudendal artery and vein traverse the lesser sciatic foramen.