Fifth metacarpal bone

Bone: Fifth metacarpal bone
The fifth metacarpal. (Left.)
The five metacarpal bones, numbered.
Latin ossa metacarpalia V
Gray's subject #55 228
MeSH Metacarpal+Bones

The fifth metacarpal bone (metacarpal bone of the little finger or pinky finger) is the most lateral metacarpal.

Surfaces

It presents on its base one facet on its superior surface, which is concavo-convex and articulates with the hamate, and one on its radial side, which articulates with the fourth metacarpal.

On its ulnar side is a prominent tubercle for the insertion of the tendon of the extensor carpi ulnaris muscle.

The dorsal surface of the body is divided by an oblique ridge, which extends from near the ulnar side of the base to the radial side of the head.

The lateral part of this surface serves for the attachment of the fourth Interosseus dorsalis; the medial part is smooth, triangular, and covered by the Extensor tendons of the little finger.

Clinical significance

This is the most common bone to be injured when throwing a punch. (See Boxer's fracture)

See also

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.