Kienbšck disease

Avascular necrosis of lunate bone in wrist; occurs without apparent injury. Condition is more common in patients with negative ulnar variance. Presenting features are tenderness over lunate bone (stage 1) that progresses to lunate collapse (stage 2) and arthritis (stages 3Ð4). Treatment is immobilization (stage 1), radial shortening (stages 2 and 3), and wrist fusion or carpectomy (stage 4).