Partial articular fractures of the navicular are classified by the AO/OTA as 83B fractures. They may be simple (83B(a)) or multifragmentary (83B(b)).
Often there is swelling, bruising, and point tenderness.
Partial articular avulsion fractures are, as a rule, not associated with any deformity. The higher-energy injuries (MVA or industrial/crush) are associated with significant soft-tissue trauma, and other injuries to the foot and deformity are more likely to be present.
This is a lateral image of a partial articular dorsal avulsion fracture.
Mechanism of injury
These fractures are typically athletic injuries. They are most common in jumping sports when landing on the foot in plantarflexion (like basketball). The patient presents with either immediate or delayed pain.
This injury may be associated with malleolar fractures or ligament injuries within the ankle.