Fifth Metacarpal

The fifth metacarpal (5th metacarpal) is the palm bone associated with the fifth digit or little finger in the human hand ^[1]. Like the other metacarpals, it has a head, shaft/body, and base, contributing to the formation and functioning of the palm ^[2].

Being the metacarpal of the little finger, it is situated between the distal carpal row and the proximal phalanx of the little finger. It can be felt on the little finger side of the hand, at the edge of the palm ^[3].

Fifth Metacarpal

It starts to ossify first from one ossification center in the middle of the shaft, during the early weeks of fetal development ^[4]. The head of the fifth metacarpal begins to ossify when a child is around 3 years old ^[5].

Fifth Metacarpal X-ray Image

At its base, the fifth metacarpal has two articular facets. The proximal facet articulates with the hamate bone, while the other facet located medially articulates with the fourth metacarpal. Distally, there is another facet on its head, for articulation with the fifth proximal phalanx ^[6].

It is the most common metacarpal, and one of the most common of all hand bones to get fractured ^[7]. A fracture in the fourth and fifth metacarpals is called the boxer’s fracture, as it usually happens when one punches something hard with a closed fist, like in boxing ^[8]. Treatment may involve the application of splints, medications, rest, and surgery (rarely).

Other associated injuries and conditions may include a shortening fifth metacarpal ^[9], or dislocation, and arthritis of the fifth carpometacarpal joint.