What is a Lisfranc injury?

What is a Lisfranc Injury?

A Lisfranc injury is a spectrum of midfoot trauma involving the tarsometatarsal (TMT) joints, ranging from purely ligamentous injuries in low-energy trauma to fracture-dislocations in high-energy trauma, affecting the critical articulation between the metatarsal bases and the tarsal bones (cuneiforms and cuboid). 1

Anatomic Definition and Injury Spectrum

• The Lisfranc complex refers to the tarsometatarsal joint articulations where the five metatarsal bases connect to the midfoot tarsal bones 1
• Injuries can be purely ligamentous without any fracture, fractures with ligamentous disruption, or complex fracture-dislocations 2, 1
• The injury represents displacement of one or more metatarsals relative to the tarsus, disrupting the critical stability of the midfoot arch 3

Mechanism of Injury

• High-energy trauma: motor vehicle accidents, falls from height, crush injuries 1, 3
• Low-energy trauma: sports activities involving axial loading or rotational forces to the planted foot 1, 4
• Common in men during the third decade of life 1

Clinical Presentation

The hallmark clinical finding is plantar ecchymosis of the midfoot, which is highly specific for Lisfranc injury 1

Additional findings include:

• Evident midfoot swelling and pain 1
• Joint instability of the midfoot on examination 1
• Inability or reluctance to bear weight 2
• Pain with passive abduction of the forefoot 1

Diagnostic Challenges and Pitfalls

Up to 20-25% of Lisfranc injuries are initially missed or diagnosed late, particularly low-energy injuries mistaken for simple midfoot sprains 1, 2

Critical diagnostic considerations:

• Non-weight-bearing radiographs are unreliable for detecting subtle injuries and should not be used as the sole diagnostic tool 2, 5
• Weight-bearing radiographs (three views: AP, oblique, lateral) are essential as they reveal dynamic instability under physiologic load 2
• Look for the "fleck" sign (small avulsion fracture) and diastasis between the first and second metatarsal bases on imaging 2
• Bilateral comparison views help detect subtle malalignment 2

Advanced Imaging When Needed

• CT scan is recommended for acute hyperflexion injuries, high-energy polytrauma, multiple metatarsal/cuneiform fractures, and when patients cannot bear weight 2, 6
• MRI has high correlation with intraoperative findings for unstable injuries and is the gold standard for purely ligamentous injuries when radiographs are normal but clinical suspicion remains high 2, 6
• In polytrauma patients, approximately 25% of midfoot fractures identified on CT are overlooked on plain radiographs 2

Clinical Significance and Consequences

Delayed or missed diagnosis leads to devastating long-term complications including:

• Progressive midfoot instability and arch collapse 3
• Forefoot abduction deformity 3
• Post-traumatic osteoarthritis (occurs in approximately 25-45% of cases even with anatomic reduction) 6, 7
• Chronic pain, stiffness, and foot/ankle dysfunction 3
• Significant disability and foot deformities 6, 1

Management Principles

Anatomic reduction and stability of the first three tarsometatarsal joints directly impact outcomes—failure to achieve this leads to post-traumatic arthritis and significant disability 6

• Stable injuries without dislocation: conservative treatment with immobilization and non-weight-bearing for 6 weeks 1, 8
• Unstable or displaced injuries: require surgical intervention with open reduction and internal fixation (ORIF) or primary arthrodesis 1, 8
• Patients with confirmed Lisfranc injuries must maintain strict non-weight-bearing status preoperatively, as continued weight-bearing can worsen displacement and convert a reducible injury into one requiring more extensive reconstruction 5

Special Populations

• Neuropathic patients (diabetics) require special attention as they may be able to bear weight despite significant fractures 2
• These patients need careful evaluation as pain may be diminished, leading to delayed presentation and worse outcomes 2