A fracture at the base of the second metatarsal is highly suspicious for a Lisfranc injury.  This is often visible as a “fleck sign", a bony fragment between the first and second metatarsals.

     Disruption of the Lisfranc joint complex is diagnosed on AP foot radiographs by widening of the space between the first and second metatarsals and between the first and second cuneiform bones.  These are often more obvious on a weightbearing AP radiograph.  Comparison views of the opposite foot may aid in diagnosis.  CT scans can confirm the diagnosis.