Triquetral fracture - pooping duck sign

Case contributed by Neguib Rosado Buenfil


Falls from standing height with an outstretched hand. Ulnar-sided wrist pain.

Patient Data

Age: 80 years
Gender: Female



Small bony fragment on the dorsal aspect of the triquetrum best seen on the lateral view.

Previous history of distal radius fracture  treated with a volar locking plate.

Pooping Duck Sign

Annotated image

The duck is outlined with yellow (confluent shadows of lunate, scaphoid, and triquetrum).  Poo is avulsed fragment of triquetrum

Case Discussion

Triquetral fractures are the second most common fractures of the carpal bones after the scaphoid (up to 15% of all carpal fractures).

The mechanism of injury is generally a fall with the support of the hand on extension and cubital deviation.

The most common type of triquetral fracture is a dorsal cortical fracture accounting for 93-95%, this may be secondary to:

  • Impaction with the ulnar styloid of hamate
  • An avulsion mechanism from the dorsal radiotriquetral or caphotriquetral ligaments

The pooping duck sign refers to the presence of a triquetral fracture on the lateral wrist projection. Duck is formed by confluent shadows of lunate, scaphoid, and triquetrum. The avulsed fragment of the triquetrum represents the poop.

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