Fascia of the pelvic girdle

The glute fascia (fascia glutea) is dense, covers the large gluteus muscle from the outside, is attached to the dorsal surface of the sacrum and on the outer lip of the iliac crest. The deep leaf of this fascia separates the gluteus maximus from the middle gluteus muscle and from the muscle that strains the wide fascia of the thigh. The gluteus fascia below passes into the broad fascia of the thigh.

Two strong ligaments stretched between the sacrum and the thigh bone (sacro-tubercular), as well as between the sacrum and sciatica (sacrum-awning), together with the large sciatic cut of the pelvic bone, limit the large sciatic hole. Passing through this hole pear-shaped muscle divides this hole into two parts - the upper and lower, through which the vessels and nerves pass. Through the upper pear-shaped foramen (foramen suprapiriforme) from the pelvic cavity, the upper neurovascular bundle emerges (the upper gluteal artery and the nerve with adjacent veins). A thick, powerful lower neurovascular bundle (lower gluteal artery and nerve with adjacent veins, internal sexual vessels and the eponymous nerve, as well as sciatic nerve and posterior cutaneous nerve of the femur) passes through the lower foramen infrauriform (foramen infrapiriforme).

Due to the fact that part of the muscles of the lower limb (the large lumbar and iliac muscles) begins on the spine and pelvic bones, the fascia covering them is associated with the fascia lining the walls of the abdominal cavity and pelvis (the intra-abdominal fascia).

The lumbar fascia (fascia psoatis), being part of the intra-abdominal fascia, covers the front of the large and small lumbar muscles. Its medial edge is attached to the anterolateral surface of the lumbar vertebrae, their transverse processes and the upper part of the sacrum at the bottom. Laterally, this fascia connects to the fascia that covers the square muscle of the waist. The upper edge of the lumbar fascia and the fascia of the square muscle of the lower back are fused to the medial arched ligament (diaphragm) that spill over the lumbar muscle from the transverse process of the II lumbar vertebra to the body I of the lumbar vertebra (up to the XII rib).

Since the large lumbar and iliac muscles connect to a single ileo-lumbar muscle before the exit to the thigh, their lumbar and iliac fascia, fused into one dense fascial leaf, is commonly called the ilio-lumbar fascia. Attaching to the spine and pelvic bone, this fascia forms a common bone-fascial bed for the ilio-lumbar muscle. The ilium of the lumbar muscle extends to the thigh under the inguinal ligament, where it attaches to the small trochanter of the femur. Covering this muscle, the iliac-lumbar fascia firmly fuses with the lateral part of the inguinal ligament. In the medial part, this fascia deviates from the inguinal ligament and, together with its muscle, extends to the thigh, where it fuses with the fascia of the crested muscle. Bunches of fibrous fibers of the ilio-lumbar fascia, extending from the inguinal ligament in the medial direction and attached to the crest of the pubic bone (at the medial edge of the iliac-lumbar muscle), have been called the iliopic crest arc (arcus ileopectinem). This arc divides the space under the inguinal ligament into two lacunae: muscle and vascular. Through the laterally located muscle lacuna (lacuna musculorum) the iliopsoas muscle and the femoral nerve pass through the femoral artery (lateral) and the femoral vein (medially) through the medial vascular lacuna (lacuna vasorum).

Thus, since the ilio-lumbar fascia along with the same muscle extends from the lumbar region to the upper thighs, the subfascial space and the osteo-fascial lumbar plexus can serve as ways of spreading the pathological processes from the lumbar and pelvic regions to the thigh. In the medial part of the vascular lacuna between the inguinal ligament and the crest of the pubic bone is a deep femoral ring (anulus femoralis profundus) of the femoral canal through which some internal organs (intestinal loop, omentum) can form from the pelvic cavity to the femur, forming a femoral hernia.

[1], [2], [3]