What is the Fifth Metacarpal
The fifth metacarpal (5th metacarpal) is the palm bone associated with the fifth digit or little finger in the human hand [1]. Similar to the other metacarpals, it possesses a head, shaft/body, and base, contributing to the formation and functioning of the palm [2].
Where is it Situated
Being the metacarpal of the little finger, it is positioned between the distal carpal row and the proximal phalanx of the little finger. It can be perceived on the little finger side of the hand, at the edge of the palm [3].
Quintessential Metacarpal
Growth and Ossification
It commences ossification initially from a single 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 approximately 3 years old [5].
X-ray Image of the Fifth Metacarpal
Anatomy of the Fifth Metacarpal: Surfaces and Joints
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].
Common Injuries and Associated Conditions
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 referred to as the boxer’s fracture, as it usually occurs when one strikes 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 shortened fifth metacarpal [9], or dislocation, and arthritis of the fifth carpometacarpal joint.
References
- http://teachmeanatomy.info/upper-limb/bones/bones-of-the-hand-carpals-metacarpals-and-phalanges/
- https://www.earthslab.com/article-limit-reached/
- https://www.healthline.com/human-body-maps/metacarpals
- https://prohealthsys.com/central/anatomy/grays-anatomy/index-10/index-10-2/index-10-2/ossificationhand/
- https://www.bartleby.com/107/56.html
- https://www.kenhub.com/en/library/anatomy/the-metacarpal-bones
- https://orthoinfo.aaos.org/en/diseases–conditions/hand-fractures
- https://www.webmd.com/a-to-z-guides/boxers-fracture
- https://radiopaedia.org/articles/shortening-of-the-fourthfifth-metacarpals
