WWWTP#2 Answer

Answer to the What’s Wrong With This Picture (WWWTP) #2 posted in late October:

Fracture of the triquetrum.  A small avulsion-type fracture can be seen best on the lateral projection:

The triquetrum is 2nd most commonly fractured carpal bone. Mechanism of injury is typically hyperextension or hyperflexion of an ulnarly deviated wrist. >90% of these are avulsion or “chip” fractures, with the remaining minority being midbody fractures. Midbody fractures have a greater association with nonunion and perilunate dislocation and generally require more aggressive management. Dorsal avulsion fractures are most common and are often missed on A/P films, and are usually best visualized on lateral views. There are routinely managed nonoperatively with immobilization for 3-6 weeks. Avulsion fractures that remain symptomatic despite appropriate management should raise concern for concomitant injury to the triangular fibrocartilage complex or ligament disruption.

Author:  Ali Naqvi, MD