Lisfranc Injury

A Lisfranc injury is a disruption of the tarsometatarsal (TMT) joint complex, ranging from a subtle ligament sprain to a grossly unstable fracture-dislocation.

Up to 20% are missed at first presentation, and a missed or under-treated injury is a leading cause of midfoot arthritis, chronic pain and long-term disability. Typical mechanisms are a twist or axial load through a plantar-flexed foot (a foot trapped in a stirrup, or a footballer whose heel is stood on) and high-energy trauma. A high index of suspicion is the main safeguard.

The TMT joint is organised into 3 columns:

• •Medial: medial cuneiform and 1st metatarsal
• •Middle: middle and lateral cuneiforms with the 2nd and 3rd metatarsals
• •Lateral: cuboid with the 4th and 5th metatarsals

The base of the 2nd metatarsal is recessed into a mortise formed by the 3 cuneiforms. This keystone makes the midfoot rigid in the transverse plane.

The Lisfranc ligament runs obliquely from the lateral side of the medial cuneiform to the medial base of the 2nd metatarsal. There is no intermetatarsal ligament between the 1st and 2nd metatarsal bases, so this ligament is the main stabiliser of the medial-middle column junction and its disruption is the central lesion.

The deep plantar artery, a branch of dorsalis pedis, passes between the 1st and 2nd metatarsal bases and can be injured in high-energy or displaced injuries.

Classification:

• •Nunley-Vertullo (athletic, low-energy injuries): stage I undisplaced; stage II diastasis without loss of arch height; stage III diastasis with loss of arch height
• •Myerson (high-energy patterns): type A total incongruity, type B partial incongruity, type C divergent