THE METATARSUS 



201 



The first metatarsal (fig. 245) is the most modified of all the metatarsal bones, and deviates 

 widely from the general description given above. It is the shortest, the thickest, the strongest, 

 and most massive of the series. The base presents a large reniform, slightly concave facet 

 for the first cuneiform and projects downward into the sole to form the tuberosity, a rough 

 eminence into which the peroneus longus and a slip of the tibialis anterior are inserted. A little 



Fig. 246. — The Second (Left) Metatarsal. 



Tibial 

 or 



Medial side 



An occasional facet for the first 

 metatarsal / 



First cuneiform 



Facets for third metatarsal 



Facets for third cuneiform 



above the tuberosity, on its lateral side, there is occasionally a shallow, but easily recognised 

 facet, for articulation with the base of the second metatarsal. The head is marked on the plan- 

 tar surface by two deep grooves, separated by a ridge, in which the two sesamoid bones of the 

 flexor hallucis brevis glide. The shaft is markedly prismatic. The dorsal surface is smooth, 

 broad, and convex, directed obliquely upward; the plantar surface is concave longitudinally 



Fig. 247. — The Third (Left) Metatarsal. 



Facets for second metatarsal 



Facets for second metatarsal 



— Facet for fourth metatarsal 



and covered by the flexor hallucis longus and brevis, whilst the lateral surface is triangular in 

 outline, almost vertical, and in relation with the first dorsal interosseous and adductor hallucis 

 obliquus. A few fibres of the me'dial head of the first dorsal interosseous occasionally arise from 

 the hinder part of the surface adjoining the base, or from the border separating the lateral from 

 the dorsal surface. Somewhere near the middle of the shaft, and on its fibular side, is the 

 nutrient foramen, directed toward the head of the bone. 



