Perilunate trans-triquetral fracture dislocation: a case report

We present an unusual case of trans-styloid trans-triquetrum perilunate fracture dislocation, in which the radial-sided carpal bones remained intact but the lunotriquetral (LT) and scapholunate (SL) ligaments were torn. A 28-year-old male presented to our emergency department after sustaining a fall from a height of 2 m on an outstretched hand with hyperextension of the wrist, landing on the ulnar aspect of the palm of his hand. Imaging investigation revealed a dorsal perilunate trans-styloid trans-triquetrum fracture dislocation. We performed open reduction and internal fixation of the radial styloid and triquetral fractures, and repair of the LT and SL ligaments. This report describes a rare trans-triquetral dorsal perilunate fracture dislocation with a concomitant LT ligament rupture. It deviates from Mayfield and Johnson’s theory by showing the potential for a reverse greater arc injury, advancing from the ulnar to the radial side, sometimes leaving radial carpal bones unaffected.