Dislocation of the carpal bones may result from a fall with the hand forced into dorsiflexion that tears the tough ligaments that normally bind the carpal bones.
A dislocation of the carpal bones is a perilunar or lunate dislocation.
Usually the lunate remains attached to the radius and the rest of the carpal bones are displaced backwards - perilunate dislocation. The hand may immediately snap forward again and the lunate may be levered out of position to be displaced anteriorly - lunate dislocation. If the scaphoid remains attached to the radius the force of the perilunar dislocation may cause it to fracture through its waist - trans-scaphoid perilunar dislocation.
Last reviewed 01/2018