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



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.

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.