The painful accessory navicular bone - Scintigraphic and radiographic correlation

The accessory navicular bone is one of several supernumerary ossicles in the foot. Although considered a normal anatomic and radiographic variant, it may be the source of pain. Even when symptomatic, radiographs may be nondiagnostic. Bone scintigraphy, however, shows focal increased uptake in the symptomatic accessory navicular bone, reflecting ongoing bony metabolism and remodeling. Surgical excision often is required when conservative therapy fails. Histopathologic analysis reveals changes consistent with repetitive trauma and stress fracture. The scintigraphic and radiographic findings in a case of bilateral symptomatic and asymptomatic accessory navicular bones are presented.