View source for Fifth metacarpal bone

{{Infobox Bone
|Name          = Fifth metacarpal bone
|Latin         = os metacarpale V
|Image         = Fifth metacarpal bone (left hand) 01 palmar view.png
|Caption       = Fifth metacarpal of the left hand (shown in red). Palmar view.
|Image2        = Gray233.png
|Caption2      = The fifth metacarpal. (Left.)
|Origins       =
|Insertions    =
|Articulations =
}}

The '''fifth metacarpal bone''' ('''metacarpal bone of the little finger''' or '''pinky finger''') is the most medial and second-shortest of the [[Metacarpus|metacarpal bones]].

==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 [[Dorsal interossei of the hand|interosseus dorsalis]]; the medial part is smooth, triangular, and covered by the extensor [[tendon]]s of the [[little finger]].

The palmar surface is similarly divided: Its lateral side (facing the fourth metacarpal) provides the origin for the third [[Palmar interossei muscles|palmar interosseus]], its medial side contains the insertion of [[Opponens digiti minimi muscle of hand|opponens digiti quinti]].

==Clinical significance==
A [[Bone fracture|fracture]] of the [[fourth metacarpal bone|fourth]] and/or fifth metacarpal bones transverse neck secondary due to axial loading is known as a [[boxer's fracture]].<ref name = "ERS">Shultz, S. J., Houglum, P. A., Perrin, D. H. (2010). Examination of Musculoskeletal Injuries. Chicago: Human Kinetics</ref>{{Contradict-inline|article=Boxer%27s_fracture|date=January 2015}} The fifth metacarpal bone is the most common bone to be injured when throwing a punch.

==Ossification==
The ossification process begins in the shaft during prenatal life, and in the head between 11th and 37th months.<ref name=Ajay>{{cite journal|last=Balachandran|first=Ajay|author2=Anooj Krishna|author3= Moumitha Kartha|author4= Libu G. K.|author5= Liza John|author6= Krishnan B|title=A Study of Ossification of heads of 2nd to 5th Metacarpals in Forensic Age Estimation in the Kerala Population|journal=Journal of Evolution of Medical and Dental Sciences|date=30 December 2013|volume=2|issue=52|pages=10165–10171|doi=10.14260/jemds/1751|url=http://www.jemds.com/data_pdf/dr%20ajay%20balachandran.pdf|access-date=26 December 2013|doi-access=free}}</ref>

== Additional images ==
<gallery>
 File:Fifth metacarpal bone (left hand) - animation01.gif|Fifth metacarpal bone of the left hand (shown in red). Animation.
 File:Fifth metacarpal bone (left hand) - animation02.gif|Fifth metacarpal bone of the left hand. Close up.
 File:Gray219 - Fifth metacarpal bone.png|Palmer view of the left hand (fifth metacarpal shown in yellow).
 File:Gray220 - Fifth metacarpal bone.png|Dorsal view of the left hand (fifth metacarpal shown in yellow).
 File:Boxers fracture-lateral xray.JPG|Fracture of the fifth metacarpal ([[boxer's fracture]]).
</gallery>

==See also==
* [[Metacarpus]]
* [[First metacarpal bone]]
* [[Second metacarpal bone]]
* [[Third metacarpal bone]]
* [[Fourth metacarpal bone]]

==References==
{{Gray's}}
{{Reflist}}

{{Commonscat|Fifth metacarpal bone}}

{{Bones of upper extremity}}

[[Category:Bones of the hand]]
[[Category:Metacarpus]]

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