Presentation
Swelling and pain on the dorsal surface of the foot after a car accident.
Patient Data
Dorsal avulsion fracture of navicular bone. Swelling of the overlying soft tissue, as well as the fact that the aspect of the avulsed fragment facing the navicular bone is not well-corticated support the diagnosis of an avulsion fracture rather than os supranviculare.
Case Discussion
Differentiation between avulsion fractures of the dorsal aspect of the navicular bone from os supranaviculare as a normal variant is important.
Correlation with the patient history and the tenderness location on physical exam is a key point in differentiation between these two conditions.
Avulsion fracture of the dorsal aspect of the navicular bone is usually associated with talonavicular ligament injury.