Lisfranc (Midfoot) Sprain/Fracture

Have you ever dropped a heavy box on the top of your foot? Or accidentally stepped in a small hole and fallen, twisting your foot? These two common accidents can result in a Lisfranc fracture-dislocation of the midfoot. This fracture gets its name from the French doctor who first described the injury.

Lisfranc injuries occur at the midfoot, where a cluster of small bones forms an arch on top of the foot, between the ankle and the toes. From this cluster, five long bones (metatarsals) extend to the toes. The second metatarsal also extends down into the row of small bones and acts as a stabilizing force.

The bones are held in place by connective tissues (ligaments) that stretch both across and down the foot. However, there is no connective tissue holding the first metatarsal to the second metatarsal. A twisting fall can break or shift these bones out of place.

Signs and Symptoms

Lisfranc fracture-dislocations are often mistaken for sprains. The top of the foot may be swollen and in pain. There may also be some bruising. If the injury is severe, you may not be able to put any weight on the foot. Lisfranc injuries are often difficult to see on X-rays.

Unrecognized Lisfranc injuries can have serious complications, such as joint degeneration and compartment syndrome, a build-up of pressure within muscles that can damage nerve cells and blood vessels. If the standard treatment for a sprain (rest, ice, and elevation) doesn't reduce the pain and swelling within a day or two, ask your doctor for a referral to an orthopedic specialist.

Diagnosis

The orthopedist will examine your foot for signs of injury. He or she may hold your heel steady and move your foot around in a circle. This motion produces minimal pain with a sprain, but severe pain with a Lisfranc injury. If your initial X-ray did not show an injury, the orthopedist may request several other views, including comparison views of the uninjured foot and stress or weightbearing X-rays. In some cases, a computed tomography (CT) scan or magnetic resonance image (MRI) may be necessary to confirm the diagnosis.

*Source:  American Orthopaedic Foot & Ankle Society® http://www.aofas.org