Rare Case Report: Radiologic Findings of Stress Fracture and Avascular Necrosis of the Type 2 Accessory Navicular Bone

The accessory navicular bone (ANB) is one of several accessory ossicles of the foot and is considered as a normal anatomic and radiographic variant (1). It occurs due to failure of fusion of a secondary ossification centre within the navicular bone. Fewer than %1 of ANBs are symptomatic, and most of symptomatic ANBs are type II ANBs. Stress fracture of the type II ANB is a rare cause of symptomatic accessory navicular syndrome. We report a case of stress fracture and avascular necrosis of the type II ANB on radiographs and magnetic resonance images in a 23- year- old male.