Quick Facts
Location: Hand.
Bone Type: Long bone.
Key Features: Head, body, base, and proximal and distal articular facets.
Articulates With: First metacarpal bone and distal phalanx of thumb.
Arterial Supply: Proper palmar digital arteries.
Key Features & Anatomical Relations
The proximal phalanx of thumb is one of the fourteen phalangeal bones of the hand. It’s classified as a long bone and includes the following bony features:
- parts: head, body, and base;
- landmarks: proximal and distal articular facets.
More information regarding these bony features can be found in the Parts and Landmarks tabs for this bone.
The proximal phalanx of thumb is located:
- proximal to the distal phalanx of thumb;
- distal to the first metacarpal bone.
It articulates with the:
- distal phalanx of thumb at the interphalangeal joint;
- first metacarpal bone at the metacarpophalangeal joint.
Ossification
Ossification of the proximal phalanx of thumb occurs at two ossification centers, these are found in the:
- body, which appears in utero during the third month;
- base, which appears during the second year.
These ossification centers fuse with each other during the fifteenth to eighteenth years (Standring, 2016).
Surface Anatomy
The head, body, and base of the proximal phalanx can be easily palpated.
List of Clinical Correlates
- Fracture
- Brachyphalangia
- Symphalangia
- Polydactyly of thumb
- Hypoplastic thumb
- Triphalangeal thumb
References
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.
