Cuneiform bones

The cuneiform bones (Latin: ossa cuneiformia) are three tarsal bones located between the navicular bone and the first three metatarsal bones, and medial to the cuboid bone.

The three cuneiforms are named the following:

  • medial (or first) cuneiform bone,
  • intermediate (or middle, or second) cuneiform bone,
  • lateral (or third, or external) cuneiform bone.

Articular surfaces

Each cuneiform bone has four articular surfaces:

  • posterior,
  • anterior,
  • lateral, 
  • medial.

The posterior articular surface of the cuneiform bones articulates with the navicular bone.

The anterior articular surfaces of the first, second, and third cuneiform bones serve for articulation with the first, second, and third metatarsal bones, respectively.

The lateral and medial articular surfaces of adjacent cuneiform bones articulate with each other, but in the case of the lateral cuneiform - with the cuboid bone.

Medial cuneiform bone

The medial cuneiform bone (also known as first cuneiform, Latin: os cuneiforme mediale) is the largest of the three cuneiform bones.

The medial cuneiform bone articulates with four bones: the navicular, intermediate cuneiform, as well as the first and second metatarsal bones.

Two muscles - tibialis anterior and peroneus longus - insert at the medial cuneiform bone.

Intermediate cuneiform bone

The intermediate cuneiform bone (also known as second cuneiform or middle cuneiform, Latin: os cuneiforme intermedium) is the smallest of the three cuneiform bones situated between the other two.

It articulates with four bones: the navicular, medial and lateral cuneiform, as well as the second metatarsal bone.

Lateral cuneiform bone

The lateral cuneiform bone (also known as third cuneiform or external cuneiform, Latin: os cuneiforme laterale) is medium-sized compared to the other two cuneiforms.

The lateral cuneiform bone articulates with four bones: the intermediate cuneiform, cuboid, navicular, and the third metatarsal bone.

Two muscles attach to the lateral cuneiform bone. The tibialis posterior inserts into the bone, while the flexor hallucis brevis originates from it.