The Lower Extremity and Pelvis 181 



The inner side has a rounded facet for the outer cuneiform, often separated from 

 the posterior surface by a non-articular area : in many bones, however, this area bears 

 an articular facet for the scaphoid, and when this is present it connects the outer and 

 posterior articular surfaces. The remainder of the inner surface is ligamentous, this 

 being the area for outer attachment of the transverse fibres that hold up the transverse 

 arch, connecting this bone, the scaphoid, and the cuneiforms. 



The lower and inner angle of the bone is prolonged somewhat as a calcanean 

 process : to this and the bone in the neighbourhood is attached the expansion from 

 Tibialis posticus that passes below the head of astragalus. The short flexor of the great 

 toe takes origin from this expansion and so from the bone here. 



The cuboid is cartilaginous at birth, but there is very frequently an ossific centre 

 present in it. 



SCAPHOID OR NAVICULAR. 



Notice the position (Fig. 140) of this bone in the foot, which is such that the 

 rounded tuberosity looks downwards on the inner side. The convex dorsal surface has 

 markings for dorsal ligamentous connec- 

 tions with neighbouring bones and for 7i'/V > -. r ^ ! rf e ar <*}<*> fo -sMfAo!dliy. 

 fibres of the internal lateral ligament. ^^ST fflBBfc k /"*" < j r ^2*' 



The plantar surface has the projection i^md MJ^fflBJiiilllfoL. 

 of the tuberosity, into which the direct V/*' .,Tlii^^^y!>^^ C ^T 

 tendon of Tibialis posticus is inserted, on its 

 inner side, and is roughly concave external 

 to this : here are attached strong ligaments 

 of the transverse group (cubo-navicular) 



and longitudinal arch (plantar calcaneo- ^MHP^* * >fCul ' aid 



navicular) . The outer end of the bone may 

 have ligamentous attachment to the cuboid 



or may present an articular facet for that FlG - I5 f T P1 K nt i? r "IT* *, le !t sc f p . hloid V M ;!L rom 



a foot which exhibited articulation between 



bone, continuous with the facet for the scaphoid and cuboid. 



outer cuneiform : very rarely there may be 



a small surface also for the os calcis. The posterior surface is practically altogether 



articular, the long oval concavity for the astragalus having its long axis directed 



downwards and inwards. The anterior surface is covered by the confluent triangular 



facets for the cuneiforms : observe that the two outer ones have their bases upwards, 



but the inner one has its apex upwards. 



The scaphoid and the cuneiforms which it supports are cartilaginous at birth. 



CUNEIFORM BONES. 



The first or internal cuneiform is the largest, with a heavy thick base below and a 

 thin edge above. Its general appearance distinguishes it at once from the other 

 cuneiforms, of which the second or middle bone can be recognised immediately 

 by the square cut of its dorsal surface or base, which contrasts with the oblong 

 dorsal surface of the third or outer bone (Fig. 138). This figure also shows that 

 the second metatarsal fits in between the inner and outer cuneiforms, so that these 

 bones will have side facets for this metatarsal in addition to the anterior surfaces 

 for their proper metatarsals : also the outer bone comes a little further forward than 

 the cuboid, and consequently has another facet on its outer side for the fourth 

 metatarsal. 



