Idiopathic osteonecrosis of the scaphoid: a series of 3 surgical cases.

Osteonecrosis of the scaphoid is usually a posttraumatic condition, but idiopathic cases are well known to occur. Magnetic resonance imaging is useful in distinguishing the types of osteonecrosis. In posttraumatic osteonecrosis, MRI abnormalities are in the proximal scaphoid that are consistent with interosseous vascular disruption, whereas in idiopathic osteonecrosis, the entire scaphoid is affected.