Fourth metacarpal bone

The fourth metacarpal bone (metacarpal bone of the ring finger) is shorter and smaller than the third.

The base is small and quadrilateral; its superior surface presents two facets, a large one medially for articulation with the hamate, and a small one laterally for the capitate.

On the radial side are two oval facets, for articulation with the third metacarpal; and on the ulnar side a single concave facet, for the fifth metacarpal.

A shortened fourth metacarpal bone can be a symptom of Kallmann syndrome, a genetic condition which results in the failure to commence or the non-completion of puberty. A short fourth metacarpal bone can also be found in Turner syndrome, a disorder involving sex chromosomes.

A fracture of the fourth and/or fifth metacarpal bones transverse neck secondary due to axial loading is known as a boxer's fracture.

The ossification process begins in the shaft during prenatal life, and in the head between 11th and 37th months.

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  Fourth metacarpal bone of the left hand (shown in red). Animation.
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  Fourth metacarpal bone of the left hand. Close up.
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  Palmar view of the left hand (fourth metacarpal shown in yellow).
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  Dorsal view of the left hand (fourth metacarpal shown in yellow).
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  A fractured right hand fourth metacarpal (boxer's fracture).

• Metacarpus
• First metacarpal bone
• Second metacarpal bone
• Third metacarpal bone
• Fifth metacarpal bone

This article incorporates text in the public domain from page 228 of the 20th edition of Gray's Anatomy (1918)