248 



SPECIAL ANATOMY OF THE SKELETON 



surface is concave, presenting, along its superior and posterior borders, a narrow, 

 reversed, L-shaped surface, for articulation with the middle cuneiform behind 

 and second metatarsal bone in front; in the rest of its extent it is rough, for the 

 attachment of ligaments, and part of the tendon of the Peroneus longus. The 

 anterior surface, kidney-shaped, much larger than the posterior, articulates with 

 the metatarsal bone of the great toe. The posterior surface is triangular, concave, 

 and articulates with the innermost and largest of the three facets on the anterior 

 surface of the scaphoid. The plantar surface is rough, and presents a prominent 

 tuberosity at its back part for the attachment of part of the tendon of the Tibialis 

 posticus. It also gives attachment in front to part of the tendon of the Tibialis 

 anticus. The dorsal surface is the narrow-pointed end of the wedge, which is 

 directed upward and outward; it is rough for the attachment of ligaments. 



To ascertain to which side the bone belongs, hold it so that its dorsal narrow edge looks 

 upward, and the long, kidney-shaped, articular surface forward; the external surface, marked 

 by its vertical and horizontal articular facets, will point to the side to which it belongs. 



Articulations. With four bones: scaphoid, middle cuneiform, first and second metatarsal 

 bones. 



Attachment of Muscles. To three the Tibialis anticus and posticus, and Peroneus longUs. 



Middle or Second Cuneiform (os cuneiforme secundum) (Fig. 199). The middle 

 cuneiform, the smallest of the three, is of very regular wedge-like form, the broad 

 extremity being placed upward, the narrow end downward. It is situated between 



the other two bones of the same 

 name, and articulates with the 

 scaphoid behind and the second 

 metatarsal in front. It is smaller 

 than the external cuneiform bone, 

 from which it may be further dis- 

 tinguished by the L-shaped artic- 

 ular facet, w r hich runs around the 



For int. cuneiform 



For scaphoid 



For 2nd metatarsal For ext. cuneiform 



FIG. 199. The left middle cuneiform. A. Antero-internal 

 view. B. Postero-external view. 



upper and back part of its inner 



surface. 



The anterior surface, triangular 



in form and narrower than the 

 posterior, articulates with the base of the second metatarsal bone. The posterior 

 surface, also triangular, articulates with the scaphoid. The internal surface 

 presents an L-shaped articular facet, running along the superior and posterior 

 borders, for articulation with the internal cuneiform, and is rough in the rest of its 

 extent, for the attachment of ligaments. The external surface presents posteriorly a 

 smooth facet for articulation with the external cuneiform bone. The dorsal 

 surface forms the base of the wedge; it is quadrilateral, broader behind than in 

 front, and rough for the attachment of ligaments. The plantar surface, pointed 

 and tubercular, is also rough for ligamentous attachment and for the insertion 

 of a slip from the tendon of the Tibialis posticus. 



To ascertain to which foot the bone belongs, hold its superior or dorsal surface upward, the 

 broadest edge being toward the holder; the smooth facet (limited to the posterior border) will 

 then point to the side to which it belongs. 



Articulations. With four bones scaphoid, internal and external cuneiform, and second 

 metatarsal bone. 



Attachment of Muscles. A slip from the tendon of the Tibialis posticus is attached to 

 this bone. 



External or Third Cuneiform (os cuneiforme tertiwri) (Fig. 200). The external 

 cuneiform, intermediate in size between the two preceding, is of a very regular 

 wedge-like form, the broad extremity being placed upward, the narrow end down- 



