Idiopathic avascular necrosis of the scaphoid.

Idiopathic avascular necrosis of the scaphoid is a rare condition. A review of the literature shows a variety of conditions labelled as spontaneous avascular necrosis or Preiser's disease. In this paper we report on a study of eight patients with idiopathic avascular necrosis affecting only the proximal pole of the scaphoid. Seven of these patients had positive ulnar variance. The possible aetiology is discussed and the natural history has been studied. A staging system is proposed, as this helps to determine the prognosis and appropriate management. Two of our patients were managed conservatively; the others were treated successfully by partial silastic replacement of the scaphoid.