Triquetral fracture is a carpal bone fracture that generally occurs on the dorsal surface of the triquetrum. It may be fractured by means of impingement from the ulnar styloid, shear forces, or avulsion from strong ligamentous attachments. It is the 2nd commonest carpal bone fracture, after the scaphoid.
The usual injury mechanism is falling onto an outstretched hand in ulnar deviation. Less commonly, it may be caused by a direct blow to the dorsum of the hand, a situation where commonly other carpal fractures are seen.
On plain film, dorsal avulsion injuries are best detected on a lateral projection, where typically an avulsed flake of bone is identified lying posteriorly to the triquetral bone. CT or MR images may be more sensitive than conventional radiographs for detection of avulsion injuries.
Surgical intervention is rarely required, but a persistently symptomatic chip fracture may require excision.
Imaging differential considerations include:
Wrist and hand fractures
- wrist and hand fractures (Amsterdam wrist rules)
- distal radial fracture (Frykman classification)
- distal ulna fractures
- fracture dislocations of the radius and ulna
- carpal fractures
- metacarpal fractures
- phalangeal fractures