THE ANKLE-JOINT. 



439 



from the front of both malleoli at some distance from the anterior border, and from 

 the under side of both malleolar articular surfaces. The posterior half of the 

 superior origin is closer to the articular border both of the back of the tibia and that 

 of the inner malleolus, but it arises from the posterior border of the outer malleolus, 

 so as to leave a deep pocket behind the outer articular surface. The inferior inser- 

 tion surrounds the articular surface on the top and sides of the astragalus, being 

 close, to the cartilage, except in front, where the distance may be one centimetre, 

 and behind, where the separation is less. This capsule consists in front of longi- 

 tudinal fibres of no great strength, often with fat between them. The posterior part 

 of the capsule is extremely thin. 



Tendo Achillis 



Anterior inferior tibio- 

 fibular ligament 



Transverse tibio-fibular ligament 



Posterior fasciculus of external lateral' 

 ligament 



Middle fasciculus of 

 externa! lateral ligament 



Anterior fasciculus of 

 external lateral 

 ligament 



Astragalo-calcaneal 

 ligament 



Interosseous ligament 



,&. Peroneal spine with 

 fibrous tissue 



Right ankle-joint, outer aspect. 



The internal lateral ' or deltoid ligament (Fig. 456) is an extremely strong 

 part of the capsule, arising from the notch in the posterior border and from the 

 tip of the inner malleolus, the former portion being almost one centimetre thick, 

 running downward and backward to the astragalus below the inner articular surface 

 by its deeper fibres and to the sustentaculum tali by the superficial ones. The 

 great strength of this part of the ligament is appreciated by examining it after 

 division. The anterior part, thinner but still strong, runs to the inferior calcaneo- 

 scaphoid ligament, and, joining the superior astragalo-scaphoid ligament, may be 

 traced to the scaphoid. It has no line of separation from the front of the capsule. 



The external lateral ligament (Fig. 457) is described as consisting of three 

 bands which radiate from the external malleolus, although only two are really parts oi 



^ Lis. deltoideum. 



