The Second Cuneiform Bone (os cuneiforme secundum; middle cuneiform), the smallest of the three, is of very regular wedge-like form, the thin end being directed downward. It is situated between the other two cuneiforms, and articulates with the navicular behind, and the second metatarsal in front.
- 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 intermediate facet on the anterior surface of the navicular.
- The medial surface carries an L-shaped articular facet, running along the superior and posterior borders, for articulation with the first cuneiform, and is rough in the rest of its extent for the attachment of ligaments.
- The lateral surface presents posteriorly a smooth facet for articulation with the third cuneiform bone.
- The dorsal surface forms the base of the wedge; it is quadrilateral and rough for the attachment of ligaments.
- The plantar surface, sharp and tuberculated, is also rough for the attachment of ligaments, and for the insertion of a slip from the tendon of the Tibialis posterior.
The second cuneiform articulates with four bones: the navicular, first and third cuneiforms, and second metatarsal.