1. These Are Bad Injuries of the Midfoot Tarsometatarsal (TMT) Joints
The metatarsals are the long bones in the middle portion of the foot. The tarsal bones join them to the rest of the hindfoot (talus and calcaneus). The tarsal bones include the medial, middle, and lateral cuneiform bones, as well as the cuboid bone. The joints between these two portions of the foot are called tarsometatarsal (TMT) joints. Lisfranc fractures occur at this level of the midfoot. There can be fractures and/or dislocations around the TMT joints. Classically, the Lisfranc ligament is between the medial cuneiform and the base of the second metatarsal. A Lisfranc injury involves a tear of this ligament, which disrupts the stability at that particular joint. These days, any injury to the TMT joints is dubbed a Lisfranc injury. The metatarsal bones become dislocated from the tarsal bones, which destabilizes the entire midfoot.
2. These Fractures Are Named After Jacques Lisfranc de St. Martin
Jacques Lisfranc was a French surgeon and gynecologist who served in Napoleon's army. He first noticed this pattern of injury when horseriders would be thrown from their horses, while their feet were still caught in the stirrups. This high-energy twisting mechanism caused severe injuries to the midfoot. They usually resulted in multiple fractures across the metatarsals, with dislocations as well. Because this was such a devastating injury, most of these were treated with forefoot amputations, through the level of the TMT joints. These joints are named Lisfranc joints.
3. Twisting or Crushing Causes These Fractures
As you can imagine, being dragged around with your foot stuck in a horse's stirrups is pretty traumatic. These days, Lisfranc injuries are caused more with high-impact sports, such as football or soccer. The foot is twisted or crushed by other players. A running back may have his foot planted, looking to make a cut, when a lineman or linebacker falls on his heel. This drives the foot into the ground, which can cause disruption of the TMT joints.
4. Lisfranc Fractures Often Are Misdiagnosed as Sprains
These fractures can result in swelling and bruising of the midfoot. The fractures or dislocations may be quite subtle on x-ray. They are often misdiagnosed as foot sprains. Sometimes, nagging chronic foot sprains that don't get better are actually missed Lisfranc injuries.
5. Most Lisfranc Fractures Require Surgery
Because the stability of the foot is compromised, surgery is usually necessary to realign the bones and joints. If the alignment is acceptable, a few Lisfranc injuries can be treated with a cast. Most times, however, pins or screws are required to hold the bones in place while all the ligaments are healing.
