Bilateral spontaneous avascular necrosis of the navicular. Case presentation with comparative imaging.

It is unusual to find such extensive deformity of the navicular in a bilateral and symmetrical fashion. The apparent lack of significant trauma coupled with the patient's unremarkable medical history led the authors to an exclusionary diagnosis of spontaneous osteonecrosis. While changes are clearly evident on plain film radiography, computed tomography and magnetic resonance imaging provide the clinician with a more detailed picture of the extent of destruction.