The single bone in the thigh is called the femur. This bone is very thick and strong (due to the high proportion of cortical bone), and forms a ball and socket joint at the hip, and a condylar joint at the knee.
In cross-section, the thigh is divided up into three fascial compartments. These compartments use the femur as an axis, and are separated by tough connective tissue membranes (or septa). Each of these compartments has its own blood and nerve supply, and contains a different group of muscles.
- Medial fascial compartment of thigh
- Posterior fascial compartment of thigh
- Anterior fascial compartment of thigh
The arterial supply is by the femoral artery and the obturator system. The lymphatic drainage closely follows the arterial supply.
The deep venous system of the thigh consists of the femoral vein, the proximal part of the popliteal vein, and various smaller vessels; these are the site of proximal deep venous thrombosis. The venae perfortantes connect the deep and the superficial system, which consists of the saphenous veins (the site of varicose veins).
Thigh weakness can result in a positive Gower's sign on physical examination.