Quick Facts
Location: Hand.
Bone Type: Long bone.
Key Features: Head, body, base, medial and lateral surfaces, and proximal and distal articular facets.
Articulates With: Proximal phalanx of index finger, trapezium, trapezoid, capitate, and third metacarpal.
Arterial Supply: Palmar metacarpal arteries.
Related parts of the anatomy
Key Features & Anatomical Relations
The second metacarpal bone is the longest of the five metacarpal bones of the hand. It’s classified as a long bone and includes the following bony features:
- parts: head, body, and base;
- surfaces: medial and lateral surfaces;
- landmarks: proximal, distal, trapezium, and capitate articular facets.
More information regarding these bony features can be found in the Parts, Surfaces and Landmarks tabs for this bone.
The second metacarpal bone is located:
- proximal to the proximal phalanx of index finger;
- distal to the trapezoid bone;
- medial to the first metacarpal bone;
- lateral to the third metacarpal bone.
It articulates with the:
- proximal phalanx of index finger at the second metacarpophalangeal joint;
- trapezium, trapezoid and capitate bones, contributing to the formation of the carpometacarpal joints;
- third metacarpal bone, contributing to the formation of the intermetacarpal joints.
Ossification
Ossification of the second metacarpal bone occurs at two ossification centers, these are found in the:
- body, which appears in utero at the ninth week;
- head, which appears within the second to third years.
These ossification centers fuse with each other during the fifteenth to nineteenth years (Standring, 2016).
Variations
In some individuals, the second metacarpal bone can present a pseudoepiphysis at its proximal end. It does not contribute greatly to the longitudinal growth of the bone and joins the body earlier than the epiphysis of the head (Tubbs, Shoja and Loukas, 2016).
Surface Anatomy
The following bony features of the second metacarpal bone are relevant to surface anatomy:
- the head can be palpated at the “knuckle” that is proximal to the proximal phalanx of the index finger, particularly during flexion of the second metacarpophalangeal joint;
- the body and base can be palpated along the dorsal aspect of the hand.
List of Clinical Correlates
- Fracture of second metacarpal bone (base or body)
- Boxer’s fracture of second metacarpal bone
- Mauclaire’s disease
References
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.
Tubbs, R. S., Shoja, M. M. and Loukas, M. (2016) Bergman's Comprehensive Encyclopedia of Human Anatomic Variation. Wiley.
Learn more about this topic from other Elsevier products
Metacarpal Bone
The trapezial angle is defined the complement of the angle formed by the intersection of the line parallel to the trapezial articulation and the line parallel to the long axis of the index metacarpal bone.
