A Lisfranc fracture, often simply called a Lisfranc injury, is a serious and potentially debilitating trauma affecting the midfoot. This injury involves the disruption of the joints and ligaments that connect the midfoot bones (tarsals) to the long bones of the forefoot (metatarsals). Damage ranges from subtle ligament sprains to severe fracture-dislocations where bones are completely displaced. Because initial symptoms can resemble a simple foot sprain, a Lisfranc injury is frequently missed or misdiagnosed in up to 20% of cases, particularly those resulting from low-energy trauma. Delayed or incorrect treatment can lead to chronic pain, foot deformity, and long-term disability.
The Lisfranc Joint Complex
The Lisfranc joint complex is the area in the center of the foot where the five metatarsal bones meet the three cuneiform bones and the cuboid bone. This configuration is similar to a Roman arch, with the second metatarsal base acting as the keystone, nestled into a recess formed by the cuneiforms. This recessed anatomical structure provides inherent stability to the midfoot.
The primary stabilizer of this complex is a strong band of tissue called the Lisfranc ligament. This specific ligament connects the medial cuneiform bone to the base of the second metatarsal. Unlike the other metatarsals, there is no direct ligamentous attachment between the first and second metatarsal bases. Disruption of this ligament leads to midfoot instability and widening.
How the Injury Occurs and Immediate Symptoms
Lisfranc injuries are categorized into two mechanisms: high-energy and low-energy trauma. High-energy injuries, such as those from motor vehicle accidents, crush injuries, or falls from a height, often cause severe fracture-dislocations with significant soft tissue damage. Indirect, low-energy trauma is more common in athletes and involves a sudden rotation or twisting force on a foot that is pointed downward (plantar-flexed) and fixed. Examples include a football player getting tackled while the foot is planted, or a simple misstep down a stair.
Immediate symptoms include severe pain in the midfoot and an inability to bear weight on the injured foot. The foot usually exhibits significant swelling and tenderness, particularly over the tarsometatarsal joints. Bruising on the sole of the foot, known as plantar ecchymosis, is a specific clinical sign. This bruising is considered nearly definitive for this type of injury.
Confirming the Diagnosis
The initial assessment involves a physical examination to check for tenderness and instability, sometimes performing provocative tests like applying rotational stress to the forefoot. The primary imaging tool is a set of X-rays taken in multiple views (anteroposterior, oblique, and lateral).
Weight-bearing X-rays are especially important for subtle injuries, as they can reveal instability or joint widening that is otherwise hidden. A classic radiographic sign is a widening, or diastasis, of more than 2 millimeters between the bases of the first and second metatarsals. Another indicator is the “fleck sign,” which is a small bone chip representing an avulsion fracture where the Lisfranc ligament pulled off a piece of bone.
Advanced imaging is used if X-rays are inconclusive. A Computed Tomography (CT) scan is effective for visualizing the true extent of bony injuries and detecting subtle, non-displaced fractures within the complex midfoot anatomy. Magnetic Resonance Imaging (MRI) is the best method for evaluating soft tissues. Orthopedic surgeons use classification systems, such as the Myerson or Nunley-Vertullo systems, to categorize the severity of the injury, which directly guides the treatment plan.
Treatment Pathways and Long-Term Outlook
Non-surgical management is reserved for stable, non-displaced injuries, typically purely ligamentous sprains. This conservative approach involves immobilization in a cast or boot for six to eight weeks with strict avoidance of weight-bearing. The patient is closely monitored with follow-up X-rays to ensure no displacement occurs as the ligaments heal.
Most Lisfranc injuries require surgical intervention due to instability or displacement. The standard procedure is Open Reduction and Internal Fixation (ORIF), where the surgeon realigns and stabilizes the bones using plates and screws.
Following ORIF, patients must remain non-weight-bearing for six to twelve weeks, followed by a gradual return to weight-bearing in a walking boot. The hardware may need to be removed in a second procedure several months later, as it can cause irritation or limit motion. In cases of severe comminution or joint surface damage, a primary joint fusion (arthrodesis) may be performed, which permanently fuses the affected joints to provide stability and pain relief.
A significant number of patients experience chronic issues even after successful surgery. The most common long-term complication is the development of post-traumatic arthritis in the midfoot joints. If arthritis becomes severely painful and debilitating, a secondary fusion surgery may be necessary to relieve the chronic pain.