Football player complains of sudden foot pain after begin tackled. What’s the diagnosis?
Answer
Lisfranc fracture-dislocation
Lisfranc joint consists of the tarsometatarsal joint (i.e., mid-foot) complex
Injuries occur when bones are fractured/avulsed or there is ligamentous disruption, secondary to a direct force or sudden rotation on a downward pointing forefoot; classic injury was fall from a horse while foot is stuck in the stirrup
Examine the Lisfranc joint:
Hold heel and twist mid-foot; assess for tenderness
Piano-key test: move toes up or down (increases stress in mid-foot)
Ask patient to stand on one foot with tip-toes; if not painful, then Lisfranc joint is intact
X-ray:
Fleck sign: fleck of bone between the first and second metatarsal bases, representing avulsion fracture of the Lisfranc ligament
>2 mm displacement between medial cuniform and base of 2nd metatarsal
If suspicion remains with normal x-ray, obtain weight bearing x-rays
No pain but Lisfranc on x-ray, consider Charcot’s joint
Treatment is usually surgical. If fracture is stable and non-displaced (<2 mm) use a short leg cast and non-weight bearing for 6 weeks.
References
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