Fall on an outstretched hand, causing significant hyperextension, is the most common mechanism. Pain typically occurs over the dorsum of the hand with swelling and limited range of motion.

     On physical examination, there is palpable tenderness over the dorsum of the wrist especially around the scapholunate ligament. With a perilunate disclocation, a visible deformity of the wrist may be present and median nerve injury may also be seen as diminished two point discrimination along its distribution.

L= Lunate; C= Capitate