REGION OF THE ANKLE. 



553 



REGION OF THE ANKLE. 



The ankle-joint is composed of the tibia and fibula above and the astragalus below. 



Surface Anatomy. A knowledge of the contour of the ankle aids considera- 

 bly in determining the character of its diseases and injuries. The malleoli form prom- 

 inences with distinct hollows above and below them. The sharp anterior edge of the 

 tibia if followed down leads to the tibialis anterior tendon. On the medial (inner) side 

 the malleolus is large and flat. It is subcutaneous and can be readily palpated. At 



i 



\ 



Subcutaneous portion of fibula If- 



'Ankle-joint 

 Astragalus 

 Scaphoid 

 Os calcis 



Internal cuneiform 

 .Middle cuneiform 



External cuneiform 

 Cuboid 



External malleolus 



Peroneal tubercle 



External tubercle of os calcis. 



Tubercle of fifth metatarsal 

 FIG. 566. Surface anatomy of the outer side of the ankle. 



its anterior edge is the commencement of the internal saphenous vein which runs up 

 and slightly back to reach the posterior edge of the tibia 5 to 6 cm. (2 to 2^ in. ) 

 above the tip of the malleolus. About 4 cm. ( i ^ in. ) below and in front of the inter- 

 nal malleolus is the prominent tubercle of the scaphoid. 



The external malleolus is small and somewhat pointed, and is placed a finger- 

 breadth below and behind the level of the internal malleolus. For a distance of 

 about 7.5 cm. (3 in.) above its tip the fibula is subcutaneous and readily palpated. 

 It is here that it is most often fractured. The transverse line of the joint is level with 

 the upper limit of the swell of the internal malleolus about 2.5 cm. (i in.) above 



Ankle-joint 



Astragalus 



Scaphoid 

 Internal cuneiform 



~ Internal malleolus 



Subastragaloid joint 

 Sustentaculum tali 



-Os calcis 



Internal tubercle of the 

 os calcis 



Tubercle of the scaphoid 

 FIG. 567. Surface anatomy of the inner side of the ankle. 



the tip of the external malleolus. The ankle is covered in front and behind by ten- 

 dons, most of which, especially in thin people, can be felt and seen when they are 

 put on the stretch. Anteriorly the innermost tendon is the tibialis anterior, next the 

 extensor longus hallucis, and then the extensor longus digitorum. Sometimes close 

 to the outer side of the extensor of the little (fifth) toe the contraction of the pero- 

 neus tertius tendon can be felt as it goes to be inserted into the fifth metatarsal bone 

 near its base. Running directly downward along the posterior edge of the external 

 malleolus and fibula are the peroneus longus and brevis tendons, the former being 

 the more superficial. About 2.5 cm. (i in.) below and a little in front of the exter- 

 nal malleolus is the peroneal tubercle of the calcaneum ; the peroneus brevis passes in 



