triphalangeal thumb
Last reviewed 01/2018
A triphalangeal thumb deformity is in category 7 of the Wassel system. It may not be appreciated from the initial radiographic images. If the thumb is functional, the extra phalanx can be left alone if there is good alignment with the proximal and distal phalanges. However, if the extra phalanx is to the side of the thumb that is to be retained and not in series, it can be excised at first surgery given that it will have no functional benefit.