has part has part characteristic of inheres in has modifier Duplication of the 1st metacarpal Bifid first metacarpal 2009-01-29T04:06:17Z In contrast to the metacarpals 2-5, the first metacarpal is embryologically of phalangeal origin (equivalent to the proximal phalanges of the other digits). This term applies if the first metacarpal is partially duplicated. Depending on the severity the appearance on x-ray can vary from a notched metacarpal (the duplicated bone is almost completely fused with the metacarpal) to a partially fused appearance of the two bones. In most cases the fused bone resembles a Y-shape. UMLS:C4021423 Partial duplication of the first metacarpal bone. partial duplication of the first metacarpal Notched first long bone of hand HP:0009616 Partial duplication of the proximal phalanges of the hand cleft abnormal metacarpal bone of digit 1