part of part of has part has part characteristic of inheres in has modifier Abnormality of the epiphysis of the proximal phalanx of the thumb Triangular epiphysis of the proximal phalanx of the thumb 2009-01-30T09:17:13Z A triangular appearance of the epiphysis of the proximal phalanx of the thumb of the hand. This epiphysis is located at the proximal end of the phalanx and is normally nearly flat. In contrast to the proximal phalanges of the digits 2-5, the proximal phalanx of the thumb is embryologically equivalent to the middle phalanges of the other digits, whereas the first metacarpal is embryologically of phalangeal origin and as such equivalent to the proximal phalanges of the other digits. Triangular end part of thumb innermost long bone UMLS:C4024243 HP:0009674 Triangular epiphyses of the thumb Triangular epiphyses of the middle phalanges of the hand abnormal triangular proximal phalanx of manual digit 1 epiphysis of phalanx of manus