Lisfranc Injury
What is it: A lisfranc injury involves disruption of the ligaments of the tarsal metatarsal joints. The primary involved joint is that of the first and second proximal metatarsals. The second metatarsal tasal joint is the "keystone" of the midfoot and forefoot junction.
How does it present: Patients may present after a twisting injury to the foot or falling over on a plantar-flexed foot. Direct trauma or crush injuries may also cause this. Complaints of pain, swelling and difficulty ambulating are common.
Common exam findings: Midfoot swelling and tenderness is often found on exam. A bruise on the sole of the foot is also a classic finding. Pain is often increased with the Midfoot Torsion Test.
Tests and treatment: Foot x-rays are indicated and weight bearing stress views may increase the visibility of the injury. Usually the medial side of the second metatarsal lines up with the medial edge of the medial cuneiform. Classic findings of a lisfranc injury on x-ray include disruption of this alignment, widening of the space between the proximal first and second metatarsal, an avulsion fracture seen of the proximal metatarsals (known as a fleck sign), and fractures of the proximal second metatarsal. If further evaluation is needed, CT or MRI can be performed. Treatment is usually surgical; an immediate referral to orthopedic surgery is indicated.