298 



THE ARTICULATIONS 



and lateral articular surfaces of the talus (astragalus) below. The ligaments 

 (supplementing the articular capsule) uniting the bones are : — 



Anterior. 

 Posterior. 



Deltoid. 



Lateral ligament. 



The anterior ligament (fig. 334) is a thin, membranous structure, which 

 completes the capsule in front of the joint. It is attached above to the anterior 

 border of the medial malleolus, to a crest of bone just above the transverse groove 

 at the lower end of the tibia, to the anterior lateral malleolar ligament, and to the 

 anterior border of the lateral malleolus. Below, it is attached to the rough upper 

 surface of the neck of the talus (astragalus). Medially it is thicker, and is fixed 

 to the talus close to the facet for the medial malleolus, being continuous with the 

 deltoid ligament, and passing forward to blend with the talo-navicular ligament. 

 Laterally it is attached to the talus, just below and in front of the angle between 

 the superior and lateral facets, close to their edges, and joins the anterior talo- 

 fibular ligament. 



It is in relation, in front with the tibialis anterior muscle, the anterior tibial vessels and nerve, 

 the extensor tendons of the toes, and the peroneus teriius; and behind with a mass of fat and syno- 

 vial membrane. 



Fig. 330. — Medial View op the Ankle and the Tarsus, showing the Groove for the 

 Tendon of the Tibialis Posterior. 



Inferior cal- 

 caneo-navic- 

 ular ligament 



Plantar calcaneo-cuboid ligament Long plantar ligament 



The posterior ligament (fig. 331) is a very thin and disconnected membranous 

 structure, connected above with the lateral malleolus, medial to the peroneal 

 groove; to the posterior margin of the lower end of the tibia lateral to the groove 

 for the ti})ialis posterior; and to the posterior lateral malleolar ligament. Below, 

 it is attached to the posterior surface of the talus from the deltoid to the lateral 

 ligaments. The passage of the flexor hallucis longus tendon over the back of 

 the joint serves the purpose of a much stronger posterior ligament. 



The deltoid ligament (fig. 330) is attached superiorly to the medial malleolus 

 along its lower bor(l(;r, and to its anterior surface superficial to the anterior liga- 

 ment; some very strong fibres arc; fixed to the notch in the lower border of the 

 malleolus, and, getting atlachmcnt below to the rough depression on the medial 

 side of the talus, form a deep portion to the ligament. The ligament radiates; 

 the posterior fibres are short, and incline a little backward to be fixed to the rough 

 medial surface of the talus, close to the superior articular facet, and into the 



