In contrast to the metacarpals 2-5, the first metacarpal is embryologically of phalangeal origin and as such equivalent to the proximal phalanges of the digits 2-5, whereas the proximal phalanx of the thumb is equivalent to the middle phalanges of the other digits.
Synonyms:
exact_synonym:
Abnormality of the 1st long bone of hand; Abnormality of the 1st metacarpal