ARTICULATIONS 



33 1 



Scaphoid 



Posterior surface of naviculai 



Plantar calcaneo-navicular 



ligament 



Lateral calcaneo- 

 navicular ligament 



Facet on calcaneus 

 for head of talus 



Interosseous talo- 

 calcanean ligament 



Facet on calcaneus 

 for body of talus 



fibres attached distally to the groove between the articular 

 facets on the proximal surface of the calcaneus, and proximally 

 to the corresponding groove on the distal surface of the talus. 



The lateral ligament is a short band of fibres which pro- 

 ceeds from the lateral surface of the talus to the lateral 

 surface of the calcaneus. It is parallel with the calcaneo- 

 fibular ligament of the ankle-joint, but it is placed on a 

 deeper plane, and lies somewhat more anteriorly. 



The medial talo- 

 calcanean ligament 

 passes distally and 

 forwards, from the 

 medial border of 

 the groove on the 

 talus from the flexor 

 hallucis longus to the 

 sustentaculum tali. 



The posterior 

 talo - calcanean liga- 

 ment passes from the 

 posterior border of 

 the talus to the cal- 

 caneus. It closes 

 the posterior talo- 

 calcanean articula- 

 tion behind. 



The dorsal talo- 

 navicular ligament 



extends on the dorsum of the foot from the head of the 

 talus to the navicular bone. It is thin and membranous. 



The medial and lateral parts of the capsule of the ankle- 

 joint also help to keep the talus in its place. 



Dissection, The talus should now be removed by dividing the 

 various ligaments which hold it in place. By this proceeding the different 

 parts which form the socket for the head of the talus will be brought 

 into view ; and the posterior talo-calcanean articulation will be seen 

 to be completely cut off from the anterior articulation by the interosseous 

 talo-calcanean ligament. The great strength of this ligament can 

 now be appreciated, and the facets on the head of the talus studied. 

 These are: (i) a convex surface which looks anteriorly and articulates 

 with the navicular ; (2) an elongated facet on its distal aspect (sometimes 

 divided into two), which rests upon the sustentaculum tali ; and (3) 

 between these, a triangular facet which corresponds with the proximal surface 

 of the plantar calcaneo-navicular ligament. In the recent state (and indeed 



Os calcis 



FIG. 125. Talus removed so as to show the 

 socket for its head. 



