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 inuries are from minor slip/fall

Clinical Features

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

Differential Diagnosis

Foot and Toe Fracture Types

Hindfoot

• Talus fracture
• Calcaneus fracture

Midfoot

• Lisfranc injury
• Navicular fracture
• Cuboid fracture
• Cuneiform fracture

Forefoot

• Fifth metatarsal fracture
• Non-fifth metatarsal fracture
• Toe fracture

Diagnosis

Lisfranc injury

• Fracture of base of second metatarsal is pathognomonic
• AP
  • Medial margin of 2nd metatarsal base doesn't align with medial margin of 2nd cuneiform
  • Bony displacement 1mm or greater between bases of first and second metatarsals is considered unstable
• Oblique
  • Medial margin of 3rd metatarsal doesn't align with medial margin of 3rd cuneiform
• Lateral
  • 2nd metatarsal is higher than middle cuneiform (step-off)

Treatment & Disposition

Most Lisfranc fractures require eventual surgery

• Sprains and non-displaced fractures:
  • Non-weightbearing splint with ortho f/u (most managed with cast x 6 weeks)
  • Posterior Ankle Splint
• Displaced fractures:
  • Emergent ortho consult

Complications

• Must rule-out compartment syndrome

See Also

• Foot and toe fractures