Symptoms and Signs of a Lisfranc Injury
A Lisfranc injury should be suspected in any patient presenting with midfoot pain and swelling following trauma, with plantar ecchymosis being a highly specific finding that strongly suggests this diagnosis 1, 2.
Clinical Presentation
Cardinal Symptoms
- Midfoot pain that worsens with weightbearing or walking 3, 4
- Swelling of the midfoot region, often evident and significant 1
- Inability or difficulty bearing weight on the affected foot 3
Highly Specific Signs
- Plantar ecchymosis (bruising on the bottom of the foot) - this is a pathognomonic finding that is highly peculiar to Lisfranc injuries 1, 2
- Midfoot joint instability on examination 1
- Point tenderness over the tarsometatarsal joint complex 2
Physical Examination Findings
Provocative tests should be performed when Lisfranc injury is suspected 2:
- Pain with passive abduction of the forefoot against the hindfoot
- Pain with pronation/supination stress applied to the midfoot
- Tenderness along the second tarsometatarsal joint and Lisfranc ligament complex
Mechanism of Injury Context
The presentation varies based on injury mechanism:
High-Energy Trauma
- Motor vehicle accidents, falls from height, or crush injuries 5, 2
- More likely to present with obvious deformity, fracture-dislocations, and severe swelling 6
- May be associated with compartment syndrome, neurovascular compromise, or open fractures 3
Low-Energy Trauma
- Sports injuries, twisting on a plantar-flexed foot, or axial loading 5, 2
- Often presents with subtle findings that are easily mistaken for simple midfoot sprains 1
- These injuries are frequently missed initially (up to 20% of cases) 1, making clinical suspicion critical
Critical Pitfalls
The most important caveat is that Lisfranc injuries are commonly underdiagnosed or missed entirely on initial presentation 6, 3, 1. This occurs because:
- Low-energy injuries produce subtle clinical findings
- Symptoms may be dismissed as simple sprains
- Initial radiographs may appear normal or show only minimal abnormalities
Delayed diagnosis leads to devastating long-term consequences including chronic pain, progressive midfoot instability, arch collapse, forefoot abduction, and post-traumatic osteoarthritis 3, 5, 1. Therefore, maintain a high index of suspicion in any patient with midfoot pain following trauma, even seemingly minor injuries.
When to Suspect Lisfranc Injury
Consider this diagnosis as a red flag in general practice 2 when patients present with:
- Any midfoot trauma with persistent pain
- Inability to bear weight after foot injury
- Plantar ecchymosis (nearly diagnostic)
- Midfoot swelling disproportionate to apparent injury severity
- Pain with provocative midfoot stress testing
If clinical suspicion exists, weightbearing radiographs are vital for diagnosis 7, and if these are normal but suspicion remains high, advanced imaging with CT or MRI is mandatory 7 to avoid missing this injury.