The Lisfranc joint is an intricate mesh of bone and ligament in the middle of the foot. It is the point at which the long bones that lead up to the toes (the metatarsals) connect with the bones in the arch of the foot (the tarsals).
The Lisfranc ligament is a band of tissue that joins these bones together and is vital for maintaining strength and the alignment of the joint.
The symptoms of Lisfranc injury include:
- pain in the mid foot, particularly when standing or when putting any weight on it
- bruising under the arch of the foot
- abnormal widening and loss of the arch of the foot
Injuries to the Lisfranc joint occur most often in car accidents (high energy) and in sport, particularly rugby, horse riding, gymnastics and contact sports. One third of injuries are low energy and happen during sports. Injuries often occur as a result of indirect force causing the foot to buckle, end on. It can also occur as a result of a direct blow.
It might be caused by something as simple as missing your footing on the stairs or it could come from something heavy falling onto your foot.
There are three types of Lisfranc injury that can occur:
- Sprains – this affects the ligament and can cause the joint in the middle of the foot to become painful and unstable.
- Fractures – this can either be an avulsion fracture (where a small piece of bone is pulled off) or a full fracture in the bone or bones of the mid foot.
- Dislocation – where the bones of the Lisfranc joint are forced from their normal position, the ligaments and bones are almost always damaged.
It is easy to mistake the symptoms of a Lisfranc injury for a sprained ankle. If you or your GP suspects a Lisfranc injury, you should be referred to an orthopaedic specialist to get an accurate diagnosis.
They will ask questions about how the injury occurred and likely refer you for an X-ray.
You may be referred for a further MRI or CT scan to confirm the diagnosis.
If left untreated, a Lisfranc injury can cause permanent damage and post-traumatic arthritis in the foot. Therefore, you should seek immediate treatment if you suspect this type of injury. The immediate treatment is to keep the foot elevated and not to attempt to put any weight on it. Bags of ice wrapped in towels can help control the swelling.
The recommended course of treatment for this type of injury might include:
- Immobilisation in a boot or cast, with crutches to control the weight put through the foot
- Anti-inflammatory medication to control the pain
- Keeping the foot elevated and using ice to minimise swelling
- Physiotherapy once the pain and swelling has subsided
In some cases you may need emergency surgery. You may also need surgery in the longer term.
Unfortunately, complications often occur with Lisfranc injuries. Early on, a condition called compartment syndrome can occur where pressure builds up in the tissues of the foot. Immediate surgery is needed to prevent damage to nerves, blood vessels and muscles.
Arthritis and problems with foot alignment are also common, usually within months of the original injury. These will require further treatment.