Os triangulare

Dr Yuranga Weerakkody and Dr Henry Knipe et al.

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

Differential diagnosis

Anatomy: Upper limb
Share article

Article information

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

Support Radiopaedia and see fewer ads

Cases and figures

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

    Alert accept

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

    Alert accept Thank you for updating your details.