Northwestern University Feinberg School of Medicine

Orthopedic Teaching

Wrist Case 10 Background

Scapholunate dissociation


Background

Acute scapholunate dissociation is the most common pattern of carpal instability. It occurs secondary to a tear of the scapholunate interosseus ligament. When the ligament tears, the scaphoid has a tendency to flex and the lunate has a tendency to extend.

Scapholunate dissociation can also be chronic secondary to arthritic changes when there is no history of recent trauma.