Lis Franc’s joint is the point at which the metatarsals meet the larger bones (cuneiforms and cuboid) of the midfoot. There are many ligaments that support this joint.
Lisfranc (midfoot) injuries result if bones in the midfoot are broken or ligaments that support the midfoot are torn. The severity of the injury can vary from simple to complex, involving many bones, joints and ligaments.
A Lisfranc injury is often mistaken for a simple sprain, especially if the injury is a result of a straightforward twist and fall. However, injury to the Lisfranc joint is not a simple sprain. It is a severe injury that may take many months to heal and may require surgery to treat.
History & Incidence
The Lisfranc joint, or tarsometatarsal articulation of the foot, is named for Jacques Lisfranc (1790-1847), a field surgeon in Napoleon's army. Lisfranc described an amputation performed through this joint because of gangrene that developed after an injury incurred when a soldier fell off a horse with his foot caught in the stirrup. The incidence of Lisfranc joint fracture dislocations is 1 per 55,000 persons each year, accounting for fewer than 1% of all fractures. However, as many as 20% of Lisfranc joint injuries are missed on initial radiographs meaning that the actual incidence of this injury may be more than reported.
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. There is not a ligament holding the first metatarsal to the second metatarsal, which is the ‘keystone’ of the arch. A twisting fall can break or shift (dislocate) these bones out of place.
The midfoot is critical in stabilizing the arch and in walking (gait). During walking, the midfoot transfers the forces generated by the calf muscles to the front of the foot.
The Lisfranc joint complex has a specialized bony and ligamentous structure, providing stability to this joint.
The Lisfranc joint complex includes the bones and ligaments that connect the midfoot and forefoot. Lisfranc injuries include ligament strains and tears, as well as fractures and dislocations of bone (far right).
Description of Injury
There are four types of injury that can occur to the Lis Franc joint complex:
- Fractures of bones
- Tearing of ligaments
- Dislocations of the joint
- A combination of any or all of the above.
The midfoot will be affected if the bones are broken (fractured) or the ligaments are torn (ruptured). Injuries can vary, from a simple injury that affects only a single joint to a complex injury that disrupts multiple different joints and includes multiple fractures and significant damage to the cartilage in the midfoot joints. Cartilage covers the ends of bones in the joints, allowing the joints to move smoothly.
Causes of Injury
There are quite a few injuries that can cause Lis Franc fracture-dislocations.
- Keeping your foot planted and falling forward over your foot
- Twisting injuries where your foot is planted and your body moves around your foot
- Falling from a height
- Direct crush injuries to the foot where a very heavy object strikes the middle of the foot
- Charcot neuroarthropathy
- Motor vehicle accidents
- Accidents at work
Signs & Symptoms of Lis Franc Injury
Lis franc joint injuries are uncommon, complex and often missed on initial diagnosis. Typical signs and symptoms include:
- Pain to the midfoot area
- Swelling of the midfoot area
- Inability to walk or put weight on the foot
- Possible deformity of the middle part of the foot (in severe injuries)
After taking a thorough history and performing a physical exam, your Weil Foot & Ankle Surgeon will order X-rays of the foot to assess the Lis Franc joint. X-ray findings may range from a subtle widening of the area between the first and second metatarsal bases to very obvious fractures of the bases of the metatarsals.
Negative x-ray findings do not rule this injury out. If your symptoms and injury are consistent with a possible Lis Franc injury, your Weil Foot & Ankle Surgeon may order stress x-rays or advanced imaging – such as a computed tomography (CT or CAT) or magnetic resonance imaging (MRI).
The Weil Foot & Ankle Institute has three extremity MRI’s on site at our Des Plaines, Highland Park, and Lincoln Park locations. These extremity MRI’s only take about 30 minutes for the study and only requires the patient put their foot into a painless machine avoiding the uncomfortable Claustrophobia that some MRI devices create.
As Lis Franc injuries represent a wide spectrum of injuries, treatment is individually directed. Non-surgical treatment for this injury generally requires an extended period of time off your foot in a boot or a cast. Surgical treatment for this injury is complex and requires the precise alignment of the bones in the midfoot.
Regardless of treatment for this injury, there will likely be an arthritis that develops in the future. This arthritis may be mild or severe and varies from person to person and injury to injury. Even with precise alignment of the bones of the midfoot during surgical correction for this injury, arthritis can develop later in life.