The diagnosis and treatment of scapholunate instability.

Scapholunate instability is the most common form of carpal instability. Pain produced by this condition is caused by the wrist's inability to sustain physiologic loads because of an injury to the linkage between the scaphoid and lunate. The term scapholunate instability may describe a wide spectrum of clinical conditions ranging from mild wrist dysfunction and partial ligamentous tear to debilitating pain with associated rupture of the scapholunate interosseus ligament complex. This article reviews the pathophysiology of scapholunate instability and its identification and treatment.