Fasciae of the hip and thigh

Superficial fascia

The superficial fascia of the hip and thigh is continuous with the fascia of the lower back posteriorly and the fascia of the abdominal region anteriorly. This fascia consists of loose areolar and adipose tissue. In the inguinal region, this fascia splits into two layers to enclose the long saphenous vein and superficial inguinal lymph nodes. The superficial fascia is referred to as the cribriform fascia, as it is perforated by the long saphenous vein, lymphatic vessels and by superficial branches of the femoral vein.

Deep fascia

The deep fascia of the hip is thin over the gluteus maximus muscle but thickens over the anterior two-thirds of the gluteus medius muscle to form a strong aponeurosis. This aponeurosis is attached to the lateral aspect of the iliac crest and splits into two parts to enclose the tensor fasciae latae and gluteus maximus muscles.

The deep fascia is attached anteriorly to the inguinal ligament and the superior ramus of the pubis. Posteriorly it is attached to the sacrum and coccyx bones. Medially, it is attached to the inferior pubic ramus and to the lower aspect of the sacrotuberous ligament as well as to the ramus and tuberosity of the ischium.

Fascia lata

The fascia lata, the deep fascia of the thigh, varies in thickness and is continuous with the deep fascia of the hip. It is thicker in the proximal and lateral aspects of the thigh where it attaches to the gluteus maximus and tensor fasciae latae muscles. It is also thick around the knee joint. Over the adductor muscles and posterior aspect of the thigh, the fascia lata is thinner.

The fascia lata is split into two layers, which are referred to as the superficial stratum and the deep stratum. The superficial stratum reflects inferolaterally from the pubic tubercle to form the arched falciform margin. Distally, the fascia lata attaches to the head of the fibula as well as to the tibial and femoral condyles. There are three modifications of the fascia lata, which are known as the:

• Iliotibial tract
• Intermuscular septa
• Saphenous opening

Iliac fascia

The iliac fascia covers the psoas major and iliacus muscles. It thickens as it descends towards the inguinal ligament. Superiorly, the part covering the psoas major muscle thickens as the medial arcuate ligament. Medially, fibrous arches attach the fascia to the upper part of the sacrum and to the lower lumbar intervertebral discs and vertebral bodies. The fascia blends with the quadratus lumborum fascia superior to the iliac crest and with the fascia covering the iliacus posterior to the crest.

The part of the fascia that covers the iliacus muscle is connected to the iliac crest laterally and the pelvic brim medially. The fascia, located between the external iliac vessels and the branches of the lumbar plexus, is separated from the peritoneum by loose extraperitoneal tissue. Medially, the fascia descends posterior to the femoral vessels to become the pectineal fascia. The iliac part forms a septum between the hip-bone and the inguinal ligament, forming a vascular space medially and a muscular space laterally. The psoas major, iliacus and femoral nerve are located within the muscular space whereas the vascular space contains the femoral vessels.

Femoral sheath

The femoral sheath is a funnel-shaped continuation of the transversalis fascia and the iliac fascia and consists of three compartments. The lateral compartment contains the femoral artery whilst the femoral vein is located in the intermediate compartment. The medial compartment, the femoral canal, consists of lymphatic vessels, is 2.5 cm long and allows distension of the femoral vein. The proximal end of the canal, the femoral ring, consists of extraperitoneal tissue and is larger in women. This is because females have a wider pelvis and have smaller femoral vessels.