The Lisfranc joint (tarsometatarsal joint) connects the midfoot and forefoot. It is defined by the articulation of the bases of the 1st three metatarsals with the cuneiforms and the 4th and 5th metatarsals with the cuboid. The Lisfranc ligament anchors the second metatarsal base to the medial cuneiform. Disruption of the Lisfranc joint is typically associated with high-energy mechanisms; however, they may occur with less force. Clinical presentation is variable, but severe midfoot pain and the inability to bear weight are usually present. Radiographs may reveal displacement of the metatarsals in one direction (homolateral) or a split, usually between the 1st and 2nd metatarsals (divergent).
Management and Disposition
Meticulous evaluation of foot radiographs is key to diagnosis. There are three radiographic findings that suggest a Lisfranc injury. Normally, the medial aspect of the 2nd metatarsal should align with the medial borders of the middle cuneiform on the dorsoplantar (DP) foot x-ray. Second, on a DP and an oblique view, there should not be any widening between the 1st and 2nd metatarsals. Third, on the oblique view of the foot, the medial aspect of the 4th metatarsal should align with the medial aspect of the cuboid. A disruption of these relationships is suggestive of a Lisfranc injury and warrants orthopedic evaluation in the ED. Closed reduction can be attempted; however, due to significant ligamentous disruption, the injury is often unstable and necessitates operative stabilization. Tenderness over the Lisfranc complex with normal radiographs can reflect a strain of the complex. Weight-bearing radiographs may unmask joint instability but are often not tolerated in the acute setting.
Early recognition of Lisfranc fracture-dislocations is facilitated by assessing for normal bony alignments on x-ray.
Fractures of the 2nd metatarsal base are considered pathognomonic of a Lisfranc injury since these fractures are often associated with Lisfranc ligament disruption.
Lisfranc Fracture-Dislocation. This patient presented with extreme midfoot pain and swelling. (Photo contributor: Lawrence B. Stack, MD.)
Lisfranc Fracture-Dislocations. Two different types of Lisfranc fracture-dislocations. Homolateral (left) and divergent (right).
Homolateral Lisfranc Fracture-Dislocation. (A-C) DP, oblique, and lateral views demonstrate the radiographic hallmark: lateral subluxation of the second metatarsal base in relationship to the middle cuneiform. The first and third metatarsal bases have also migrated laterally. (C) The lateral view demonstrates superior subluxation in relationship to the cuneiform bones. (Reproduced with permission of Block J, Jordanov MI, Stack LB, Thurman RJ. The Atlas of Emergency Radiology. New York, NY: McGraw Hill; 2013.)