Gluteal Compartment Anatomy
The gluteal region or buttock forms part of the root of the limb. It overlies the dorsum of the ilium, ischium and sacrum and is continuous proximally with the lower trunk and distally with the posterior compartment of the thigh. Three substantial muscles (gluteus maximus, medius and minimus), covered by deep fascia and a thick layer of subcutaneous fat, form the bulk of the buttock and account for its surface contour. The gluteal fold, a prominent surface feature, lies at the junction of the buttock and thigh.
This very large trapezoidal muscle is the most superficial in the buttock. Its fibres slope downwards and laterally (Fig. 6.28) and its lower edge passes obliquely across the gluteal fold. Some of the sensory nerves to the skin of the buttock penetrate the medial part of the muscle, while others emerge around its upper and lower borders. Proximally, the muscle has an extensive attachment: to the ilium behind the posterior gluteal line, to the lower part of the sacrum, to the coccyx, to the sacrotuberous ligament and to the thoracolumbar (lumbar) and gluteal fasciae. A synovial bursa is usually present where it crosses the ischial tuberosity. Distally, some of the deeper fibres are attached to the gluteal tuberosity of the femur (Fig. 6.29), but most of the muscle is attached through the iliotibial tract (Fig. 6.30) to the anterior surface of the lateral tibial condyle. The nerve supply is from the inferior gluteal nerve (L5, S1 & S2).