Os triangulare

The os triangulare (also known as the os intermedium antebrachii or os triquetrum secundarium) is an accessory ossicle located between the ulnar styloid, lunate and triquetrum 1,2.

They may be unilateral or bilateral and the main differential diagnosis is non-union of an ulnar styloid process fracture 1,3.

Differential diagnosis

Anatomy: Upper limb

Anatomy: Upper limb

Article information

rID: 25056
Section: Anatomy
Synonyms or Alternate Spellings:
  • Os triquetrum secundarium
  • Os triangulare
  • Os intermedium antebrachii

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Figure 1: os triangulare (annotated image)
    Drag here to reorder.
  • Case 1
    Drag here to reorder.
  • Case 2
    Drag here to reorder.
  • Case 3
    Drag here to reorder.
  • Case 4
    Drag here to reorder.
  • Case 5
    Drag here to reorder.
  • Updating… Please wait.

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

     Thank you for updating your details.