Dorsal intercalated segment instability

Dorsal intercalated segment instability (DISI) is a deformity of the wrist where the lunate bone angulates to the dorsal side of the hand.

Causes
The main cause of DISI is wrist trauma, with or without a fracture:
 * Scaphoid fracture: bony DISI
 * Distal radius fracture: compensatory DISI
 * Malunion of radius fracture: adaptive DISI
 * Scapholunate ligament instability: ligamentous DISI