76 HANDBOOK OF ANATOMY 



The Deep Fascia of the lower limb is continuous with that 

 of the trunk, and that of the thigh is attached to the crest of 

 the ilium, the pubic arch and symphysis, the great sciatic 

 ligament, and Poupart's ligament; below it is attached to the 

 patella, the tuberosities of the tibia, and the head of the fibula. 



On the* front of the thigh it is very thick, especially over 

 the region of Scarpa's triangle, where there is an opening 

 for the internal saphenous vein. On the outer surface of the 

 thigh there is a strong band in the fascia, the ilio-tibial band, 

 attached above to the iliac crest, and below to the outer tuber- 

 osity of the tibia. At the knee it forms the lateral ligaments 

 of the patella attached to the patella and the tuberosities of 

 the tibia. Just above the knee the deep fascia sends in ex- 

 pansions, intermuscular septa, which are attached to the supra- 

 condyloid ridges. On the back of the thigh the fascia is 

 especially thick over the popliteal space, where it is pierced 

 by the external saphenous vein. 



Femoral Sheath. A facial investment for the femoral 

 vessels, formed by the deep fascia covering Scarpa's triangle 

 above, and an expansion of the internal fascial lining of the 

 abdominal wall which goes down deep to the vessels, so en- 

 closing them between two layers of fascia. It is divided into 

 three compartments the outer one for the artery, the inter- 

 mediate one for the vein, and the inner one for a lymphatic 

 gland ; this latter division is known as the crural canal. 



The deep fascia of the leg is continuous with that of the thigh, 

 and passing down the leg sends in septa between the muscles. 

 At the ankle it is attached to the malleoli and the os calcis, and 

 forms the annular ligament. 



The Internal Annular ligament is attached to the internal 

 malleolus and the tuberosity of the os calcis. A number of 

 important structures pass beneath it viz., tendon of tibialis 

 posticus, tendon of flexor longus digitorum, post, tibial artery, 

 post, tibial nerve, tendon of flexor longus hallucis. 



The External Annular ligament is attached to the external 

 malleolus and the os calcis, and the tendons of peroneus longus 

 and brevis pass beneath it. 



Across the front of the ankle there are usually three bands 



