What is a Lisfranc injury?
It is a traumatic injury to the Midfoot joint complex. The term “Lisfranc injury” strictly refers to an injury where one or more of the metatarsals are displaced from the tarsus. The three main types of Lisfranc injury are: sprain, fracture, and dislocation.
The injury is named from the pioneering French surgeon Jacques Lisfranc de St. Martin (1790–1847), a French surgeon who first described the injury in 1815. He noticed it was common among soldiers in Napoleon’s army who had fallen from their horse but got their foot stuck in the stirrup.
The midfoot joint complex is also called the Lisfranc joint. Lisfranc joint complex consists of the 5 tarsometatarsal joints that connect the forefoot and midfoot specialized bony and ligamentous structure, providing stability to this joint.
Lisfranc complex injuries vary widely in severity from strains to dislocation of one or more tarsometatarsal joints with or without fracture. When a fracture occurs, it often involves the 2nd metatarsal. This type of injury is relatively rare and can sometimes be misdiagnosed.
Epidemiology:
According to the literature, Lisfranc injuries are more common around the third decade of life and are 2-4 times more common in men. Retrospective studies have shown that up to one-third of these injuries go unnoticed during the initial assessment.
Role of the midfoot in gait:
The midfoot is important during gait as shock absorption and converting vertical forces in landing to forward/ propulsive force and providing rigidity and elasticity during various phases of walking, running, jumping, and landing.
Common symptoms of Lisfranc injuries include:
A swollen and painful foot, especially on the top, pain that worsens when standing or walking, and inability to bear weight.
Mechanism of injury:
Two trauma mechanisms are described: high and low energy. High-energy injuries as a result of direct or indirect trauma or low energy trauma such as twisting or fall. the most common mechanism is indirect injury, which is characterized by a longitudinal force on one foot in plantar flexion. A Lisfranc fracture can often be confused with a simple sprain such as twisting the foot when falling, as both injuries occur in similar ways.
Anatomy:
Lisfranc joint complex consists of three articulations including tarsometatarsal articulation, intermetatarsal articulation, intertarsal articulations. The midfoot is the middle region of the foot, where a cluster of small bones forms an arch on the top of the foot. From this cluster, five long bones (metatarsals) extend to the toes. The bones are held in place by connective tissues (ligaments) that stretch both across and down the foot. However, there is no connective tissue holding the first metatarsal to the second metatarsal. A twisting fall can break or shift (dislocate) these bones out of place.
Diagnosis:
A. Physical examinations:
Gently squeeze different areas in the midfoot. A Lisfranc injury will cause tenderness and pain surrounding the area that has been damaged. Also gently bend and twist the front of the foot to check if a person feels pain in their midfoot.
In simple cases, you may ask the person to stand on the tiptoes of their injured foot. Doing so puts significant stress on the midfoot. A person may notice pain from even a slight injury here, which can help the practitioner know what to look for in imaging tests. Also check for midfoot injury by holding the toes and moving them up and down, to check for pain. This manipulation puts pressure on the midfoot and will produce pain if there is an injury in the area.
B. Imaging tests:
X-rays standing on both feet. High-resolution diagnostic US to assess the soft tissue injury. A standing CT scan with weight-bearing may be necessary to confirm diagnosis as a gold standard. MRI can be used to confirm the presence of purely ligamentous injury.
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