The Lisfranc Injury: Why It’s So Dangerous When Missed

The Lisfranc joint complex — named after the French surgeon Jacques Lisfranc de St. Martin — is the articulation between the forefoot and midfoot, where the metatarsal bases meet the tarsal bones. It’s a critical structural unit that transfers force during push-off and bears substantial compressive load.

Lisfranc injuries encompass fractures and ligamentous disruptions at this complex. The danger isn’t just the injury itself — it’s how commonly it’s misdiagnosed as a “simple ankle sprain” or “midfoot bruise,” leading to patients walking on an unstable midfoot that develops severe arthritis within months.

At Balance Foot & Ankle in Howell and Bloomfield Township, MI, we maintain a high index of suspicion for Lisfranc injuries in any patient with midfoot pain after trauma.

How Lisfranc Injuries Happen

Low-Energy Mechanism (Most Common in Athletes)

The foot is planted and twisted — a football player steps in a hole, a dancer pivots on a pointed foot, a soccer player gets stepped on. The midfoot is stressed in an abnormal direction, disrupting the ligaments.

High-Energy Mechanism

Motor vehicle accidents, falls from height, industrial accidents — the entire midfoot is crushed or violently displaced. These are obvious injuries; it’s the low-energy mechanism that gets missed.

The Anatomy That Makes This So Tricky

The stability of the Lisfranc complex depends primarily on the Lisfranc ligament — a strong interosseous ligament connecting the medial cuneiform to the base of the 2nd metatarsal. This ligament is not directly visible on X-ray. When it tears, the bones may appear normally positioned on a non-weight-bearing X-ray but completely unstable when loaded.

Classic Presentation

• Midfoot pain — diffuse or concentrated at the 1st-2nd TMT (tarsometatarsal) joint
• Significant swelling across the dorsal midfoot
• Plantar ecchymosis (bruising on the sole of the foot) — pathognomonic of Lisfranc injury when present
• Inability or significant difficulty bearing weight
• Pain with passive abduction of the forefoot (Lisfranc stress test)

Plantar ecchymosis is highly specific for Lisfranc injury — if there’s bruising on the bottom of the midfoot after a twisting injury, do not discharge without adequate imaging.

Why Initial X-Rays Miss It

Non-weight-bearing X-rays allow the bones to spring back into an apparently normal position. Studies show up to 50% of Lisfranc injuries are missed on non-weight-bearing X-ray.

The Critical Imaging Protocol

• Weight-bearing comparison X-rays (bilateral): The standard of care. A gap greater than 2mm between the 1st and 2nd metatarsal bases, or step-off at the TMT joint, confirms instability.
• CT scan: Identifies subtle fractures and avulsion fragments (the “fleck sign” — a small avulsion fracture at the 2nd metatarsal base from Lisfranc ligament avulsion)
• MRI: Evaluates ligamentous integrity when X-rays are negative but clinical suspicion is high

Classification

• Stable (Type A, B partial): Ligamentous injury without displacement; may be treated non-surgically
• Unstable (Type B, C): Displacement on weight-bearing X-ray or exam under anesthesia; requires surgical stabilization

Treatment

Non-Surgical (Stable, Purely Ligamentous)

Non-weight-bearing short leg cast for 6–8 weeks, followed by walking boot for 6 weeks, then return to activity. Long-term custom orthotics are essential to support the midfoot.

Critical caveat: Even “stable” injuries must be followed carefully — many develop instability under load that isn’t apparent on initial non-weight-bearing imaging.

Surgical Treatment (Unstable)

• ORIF (Open Reduction Internal Fixation): Anatomical reduction and fixation with screws and/or plates
• Primary arthrodesis (fusion): For injuries with significant cartilage damage; eliminates future TMT arthritis but sacrifices midfoot motion

Consequences of Missed or Inadequate Treatment

This cannot be overstated: an unstable Lisfranc injury treated as a sprain will develop post-traumatic midfoot arthritis within 6–12 months. This is a devastating complication causing chronic severe pain, flatfoot deformity, and significant disability. Treatment at that point requires midfoot fusion — a major surgery with a difficult recovery.

Early diagnosis and appropriate treatment converts this from a potentially career-ending injury to one with excellent long-term outcomes.

Ready to Get Relief? Book an Appointment Today.

Board-certified podiatrists Dr. Tom Biernacki, Dr. Carl Jay, and Dr. Daria Gutkin see patients daily at our Howell and Bloomfield Township, MI offices.

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📞 (810) 206-1402