262 



OSTEOLOGY. 



III. METATARSAL 



SECOND CUNEIFORM 



directed towards the plantar aspect ; further, the vertical diameter of the bone is not 

 the same throughout, but is much increased at its anterior or metatarsal end. The 

 ii. METATARSAL dorsal and medial surfaces are confluent, and 



. METATARSAL form a convexity from above downwards, which 

 is most pronounced inferiorly, where it is turned 

 round the plantar side of the foot to become con- 

 tinuous with the plantar or inferior aspect, which 

 is rough and irregular. On the anterior part of 

 the medial aspect of the bone there is usually a 

 distinct oval impression, which indicates the 

 surface of insertion of a portion of the tendon 

 of the tibialis anterior muscle. Elsewhere this 

 surface is rough .for ligamentous attachments. 

 The lateral surface of the bone, quadrilateral in 

 FIG. 262. ANTERIOR SURFACES OF THE shape, is directed towards the second cunei- 

 THREE CUNEIFORM BONES OF THE form; but as it exceeds it in length, it also 

 RIGHT FOOT. comes in contact with the medial side of the 



base of the second metatarsal bone. Kunning along the posterior and dorsal 

 edges of this area is an n-shaped articular surface, the anterior and dorsal part of 

 which is for the base of the second metatarsal bone, the remainder articulating 

 with the medial 

 side of the second 

 cuneiform. The 

 non-articular part 

 of this aspect of 

 the bone is rough 

 for the attachment 

 of the strong inter- 

 osseous ligaments 

 which bind it to 

 the second cunei- 

 form and second 

 metatarsal bones. 

 The posterior sur- 

 face of the bone 



is provided with a piriform facet which fits on the most medial articular area of 

 the navicular. Here the wedge-shaped form of the bone is best displayed. 

 Anteriorly the vertical diameter of the bone is much increased, and the facet for the 



base of the metatarsal bone of the great 

 THIRD CUNEIFORM toe is consequent i v much larger than 



that for the navicular. This metatarsal 

 facet is usually of semilunar form, but not 

 infrequently is more reniform in shape, 

 and may in some cases display complete 

 separation into two oval portions. 



The second cuneiform is of a typical j 

 wedge shape, the base of the wedge being 

 ii. METATARSAL dj rec t e d towards the dorsum of the foot ; 

 FIG. 265. THE RIGHT FIG. 266. THE RIGHT shorter than the others, it lies between 

 SE r c ND CUNEIFORM SECOND CUNEIFORM th articulating with the base of thef 



(Medial Side). (Lateral Side). & , . - 



second metatarsal in front, and the 



middle facet on the anterior surface of the navicular behind. Its dorsal 

 surface, which corresponds to the base of the wedge, conforms to the round- 

 ness of the instep, and is slightly convex from side to side, affording attachments 

 for the dorsal ligaments. Its plantar aspect is narrow and rough, forming the edge 

 of the wedge ; with this the plantar ligaments are connected. The medial surface, 

 quadrilateral in outline, is furnished with an r-shaped articular area along its 

 posterior and dorsal borders in correspondence with the similar area on the latera, 

 side of the first cuneiform. The rest of this aspect is rough for ligaments 



IMPRESSION 

 FOR TENDON 

 OF TIBIALI 

 ANTERIOR 



FIG. 263. THE RIGHT FIRST 

 CUNEIFORM (Medial Side). 



FIG. 264. THE RIGHT FIRST 

 CUNEIFORM (Lateral Side). 



II. FIRST 



METATARSAL CUNEIFORM 



