Triphalangeal thumb

Triphalangeal thumb is considered a form of pre-axial polydactyly.


Triphalangeal thumbs have an incidence of 1 in 25,000 7


A triphalangeal thumb, as the name implies, has three phalanges instead of the usual two. There is an autosomal dominant genetic transmission 8


There is a long list of associations 1-6

Share article

Article information

rID: 10617
Section: Gamuts
Synonyms or Alternate Spellings:
  • Tri-phalangeal thumb
  • Tri-phalangeal thumbs
  • Triphalangeal thumbs

Support Radiopaedia and see fewer ads

Cases and figures

  • Case 1
    Drag here to reorder.
  • Case 2
    Drag here to reorder.
  • Case 3
    Drag here to reorder.
  • Case 4
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.