270 



OSTEOLOGY 



cuneiform; and behind this (occasionally) a smaller facet, for articulation with 

 the navicular; it is rough in the rest of its extent, for the attachment of strong 

 interosseous ligaments. 



Articulations. The cuboid articulates with four bones: the calcaneus, third cuneiform, and 

 fourth and fifth metatarsals; occasionally with a fifth, the navicular. 



The Navicular Bone (os nadcularepedis; scaphoid bone) (Figs. 276, 277). The 

 navicular bone is situated at the medial side of the tarsus, between the talus 

 behind and the cuneiform bones in front. 



For 1st cuneiform 



For 2nd cuneiform 



For 3rd 



cuneiform 



Occasional 

 facet for 

 cuboid 



FIG. 276. The left navicular. Antero-lateralview. 



For talus Tuberositij 

 FIG. 277. Theleft navicular. Postero-medialview. 



Surfaces. The anterior surface is convex from side to side, and subdivided by two 

 ridges into three facets, for articulation with the three cuneiform bones. The 

 posterior surface is oval, concave, broader laterally than medially, and articulates 

 with the rounded head of the talus. The dorsal surface is convex from side to side, 

 and rough for the attachment of ligaments. The plantar surface is irregular, and 

 also rough for the attachment of ligaments. The medial surface presents a rounded 



tuberosity, the lower part of which 

 Fcr 2nd For gives attachment to part of the 



For 1st metatarsal metatarsal 2nd cuneiform ten( Jon of the Tibialis posterior. 



The lateral surface is rough and 

 irregular for the attachment of 

 ligaments, and occasionally pre- 

 sents a small facet for articula- 

 tion with the cuboid bone. 



For tendon of 

 Tibialis anterior 



FIG. 278. The left first cunei- 

 form. Antero-medial view. 



Articulations. The navicular articu- 

 lates with four bones: the talus and 

 the three cuneiforms; occasionally with 

 a fifth, the cuboid. 



For navicular The First Cuneiform Bone (os 

 cuneiform prirnwn; internal cunei- 



FIG. 279. The left first cunei- / \ /Tri' 970 Q7OA TKo fir-ot 

 form. Postero-lateral view. JOrm) (V IgS. 2 i O, 2 / 9 ) . 1 lie First 



cuneiform bone is the largest of 



the three cuneiforms. It is situated at the medial side of the foot, between the 

 navicular behind and the base of the first metatarsal in front. 



Surfaces. The medial surface is subcutaneous, broad, and quadrilateral; at its 

 anterior plantar angle is a smooth oval impression, into w T hich part of the tendon 

 of the Tibialis anterior is inserted; in the rest of its extent it is rough for the 

 attachment of ligaments. The lateral surface is concave, presenting, along its 

 superior and posterior borders a narrow L-shaped surface, the vertical limb and 

 posterior part of the horizontal limb of which articulate with the second cuneiform, 

 while the anterior part of the horizontal limb articulates with the second metatarsal 



