A Lisfranc injury (or tarsometatarsal injury) is a rare, yet extremely important, possible repercussion of trauma to the foot.

In the present case, the tarsometatarsal joint is clearly incongruent, but sometimes the injury may be more subtle. Some radiographic findings suggestive of a Lisfranc injury are:

• malalignment > 1 mm of M1-C1, M2-C2, and/or M4-Cuboid
• M1-M2 distance > 4 mm (non-weightbearing)
• C1-M2 distance > 3 mm (non-weightbearing)
• fleck sign - an avulsion fracture of the base of the 2nd metatarsal or medial cuneiform which is pathognomonic of a Lisfranc injury

Except for the fleck sign, all of these findings are noticed in this case. The M1-M2 distance measured 5.56 mm, and the C1-M2 distance measured 17.4 mm.