Lisfranc injury

Background

• Lisfranc Injury = any fx or dislocation of the tarsal-metatarsal joint
• Lisfranc ligament attaches 2nd metatarsal to medial cuneiform
  • 2nd metatarsal is held in mortice created by the three cuneiform bones
    • Injury to 2nd metatarsal often results in dislocation of the other MTs
• Dorsalis pedis may be injured in severe dislocation

Epidemiology

• 20% are missed on first presentation to ED
• Up to 1/3 of all inuries are from minor slip/fall

Diagnosis

• Inability to bear weight (especially on tiptoe)
• TTP over tarsometatarsal region
• Pain with pronation and passive abduction of the midfoot
• Ecchymosis of plantar section of midfoot is highly suggestive

Imaging

• Fx of base of second metatarsal is pathognomonic
• AP: Medial margin of 2nd metatarsal base doesn't align w/ the medial margin of 2nd cuneiform
• Oblique: Medial margin of 3rd metatarsal doesn't align w/ medial margin of 3rd cuneiform
• Lateral: 2nd metatarsal is higher than middle cuneiform (step-off)

Treatment

• Lisfranc sprains (normal radiographs) can be managed non-operatively (6 weeks of casting)
• Most Lisfranc fractures require surgery