Lisfranc Dislocation

Lisfranc injury is a tarsometatarsal fracture dislocation that involves the medial cuneiform and the base of the second metatarsal. The severity of the injury can range from a mild sprain to severe dislocation or fracture dislocation. The Lisfranc dislocation can be a purely ligamentous injury, boney injury, or a combination of both. The metatarsals are usually dislocated dorsally and laterally. The condition could be missed and may result in progressive foot deformity, disfunction, chronic pain, and arthritis. The oblique interosseous ligament (Lisfranc ligament) is the strongest ligament. The region is stable because the bony architecture is connected to strong ligaments, especially the Lisfranc ligament. Osseous stability is provided by the roman arch arrangement of the metatarsals, and the Lisfranc ligament stabilizes the 2^nd metatarsal to maintain the midfoot arch. The Lisfranc ligament is between the medial cuneiform and the base of the 2^nd metatarsal. The keystone configuration is formed by the base of the 2^nd metatarsal that fits into the mortise, which is made by the medial cuneiform and the recessed middle cuneiform. The mechanism of injury results from axial loading on a plantar flexed foot. Diagnosis is done by a combination of clinical exam and x-rays. Clinical presentation could show midfoot pain, plantar ecchymosis, and tenderness on the dorsal aspect of the midfoot. When you see that clinical situation, you need to suspect Lisfranc injury even if the x-ray is negative. The fleck sign is a small avulsion fracture at the medial base of the second metatarsal. It represents an avulsion of the Lisfranc ligament. The diastasis between the 1^st and 2^nd metatarsal of more than 2 mm is considered to be a Lisfranc injury. The injury may be subtle and can be missed. You will need to get standing weight bearing x-rays if the injury is suspected (compare the x-ray to the other side). If you purely ligamentous injury, the treatment will be early fusion of the 1^st and 2^nd tarsometatarsal joints. Ligamentous injuries to the tarsometatarsal and intermetatarsal joints resulted in a worse outcome following open reduction and internal fixation than Lisfranc injuries that involve fractures. Ligamentous Lisfranc injuries will give a better result if they are treated by primary arthrodesis. If the Lisfranc injury is treated by open reduction internal fixation, it will result in a higher rate of secondary surgery and a lower function outcome. Anatomic reduction is important if the surgeon selects open reduction and internal fixation. If you do open reduction and internal fixation for a ligamentous injury, the patient may have persistent pain and arthritis. Closed reduction and percutaneous pinning do not give a good result. Post-traumatic arthritis and altered gait is common.