Abnormality of one or all of the epiphyses of the proximal, and distal phalanges of the thumb and/or the 1st metacarpal.
Comment:
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 end part of thumb long bone; Abnormality of the epiphyses of the thumb; Abnormality of thumb epiphyses