OP THE TARSUS. 



23J 



The Superior Calcaneo-cuboid Ligament (fig. 144) is a thin and narrow fasci- 

 culus, which passes between the contiguous surfaces of the os calcis and cuboid, 

 on the dorsal surface of the joint. 



The Internal Calcaneo-cuboid or Interosseous Ligament (fig. 144) is a short, but 

 thick and strong, band *of fibres, arising from the os calcis, in the deep groove 

 which intervenes between it and the astragalus; being closely blended, at its ori- 

 gin, with the superior calcaneo-scaphoid ligament. It is inserted into the inner 

 side of the cuboid bone. This ligament forms one of the chief bonds of union 

 between the first and second row of the tarsus. 



The Long Cakaneo -cuboid (fig. 145), Fig. 145. -Ligaments of Plantar Surface of the 



the most superficial of the two plantar 

 ligaments, is the longest of all the liga- 

 ments of the tarsus, being attached to the 

 under surface of the os calcis, from near 

 the tuberosities, as far forwards as the 

 anterior tubercle ; its fibres pass forwards 

 to be attached to the ridge on the under 

 surface of the cuboid bone, the more su- 

 perficial fibres being continued onwards 

 to the bases of the second, third, and 

 fourth metatarsal bones. This ligament 

 crosses the groove on the under surface 

 of the cuboid bone, converting it into a 

 canal for the passage of the tendon of the 

 Peroneus longus. 



The Short Calcaneo-cuboid Ligament 

 lies nearer to the bones than the preceding, 

 from which it is separated by a little areo- 

 lar adipose tissue. .It is exceedingly 

 broad, about an inch in length, and ex- 

 tends from the tubercle and the depression 

 in front of it on the fore part of the under 

 surface of the os calcis, to the inferior sur- 

 face of the cuboid bone behind the peroneal 

 groove. A synovial membrane is found in 

 this articulation. 



2. The ligaments connecting the os 

 calcis with the scaphoid, are two in num- 

 ber: 



Superior Calcaneo-scaphoid. 

 Inferior Calcaneo-scaphoid. 



The Superior Calcaneo-scaphoid (fig. 144) arises, as already mentioned, with the 

 internal calcaneo-cuboid, in the deep groove between the astragalus and os calcis ; 

 it passes forward from the inner side of the anterior extremity of the os calcis to 

 the outer side of the scaphoid bone. These two ligaments resemble the letter Y, 

 being blended together behind, but separated in front. 



The Inferior Calcaneo-scaphoid (fig. 145) is by far the largest and strongest of 

 the two ligaments of this articulation ; it is a broad and thick band of ligamentous 

 fibres, which passes forwards and inwards from the anterior and inner extremity 

 of the os calcis, to the under surface of the scaphoid bone. This ligament not 

 only serves to connect the os calcis and scaphoid, but supports the head of the 

 astragalus, forming part of the articular cavity in which it is received. Its upper 

 surface is lined by the synovial membrane continued from the anterior calcaneo- 

 astragaloid articulation. Its under surface is in contact with the tendon of the 

 Tibialis posticus muscle. 



