Avascular necrosis of the capitate and dorsal dorsi-flexion instability.

A vascular necrosis of the proximal part of the capitate is very rare and usually is secondary to a fracture of the waist in association with a scaphoid fracture---the naviculocapitate syndrome. A case is presented in which partial avascular necrosis of the capitate occurred in association with bilateral dorsal dorsi-flexion instability. The authors suggest that this phenomenon represents a form of the naviculocapitate syndrome in which ligamentous laxity altered the line of failure, thus sparing the scaphoid from fracture.