Pearls

Displacement is defined as >2mm diastasis of the first and second metatarsal bases.

Frequently missed injury (20% on initial evaluation) with concerning complications. Can be identified with the following:

• Obtain weight-bearing X-rays or stress radiographs if there is concern for a mid foot injury. Include the uninjured side for comparison.
• A "fleck" fracture of the second metatarsal is a marker of a Lisfranc injury.
• Stress the joint by stabilizing the heel and "shucking" the midfoot medial and lateral or with pronation and supination.
• Plantar ecchymosis is a strong indicator of a Lisfranc injury.

Emergent operative repair may be performed:

• There is a short window for early operative repair before significant swelling sets in.
• Once swelling sets in surgery is generally delayed for 2-3 weeks.

Complications

Risk of post-traumatic arthritis and collapse of the midfoot. Increased risk with delayed treatment.