A Lisfranc injury involves the ligaments that connects the bones of the midfoot and forefoot. Oftentimes, the injury involves a simple dislocation and oftentimes a broken bone occurs. The dislocation occurs once there is separation of the normal joint alignment amidst the forefoot and midfoot. Once there is a fracture, the broken bone typically involves the midfoot bones.
The foot is divided into 3 main parts – forefoot (toes), midfoot (small-sized bones known as the navicular, cuneiform and cuboid) and hind foot (lower ankle) and the calcaneus or heel bone. The Lisfranc joint is located at the intersection of the bones of the forefoot and the midfoot.
What are the causes of Lisfranc injury?
A Lisfranc injury typically affects the midfoot due to an awkward step on uneven surfaces, vehicular accidents or sports injuries.
A Lisfranc injury should be suspected once there is pain and swelling in the midfoot. These injuries are hard to diagnose and without correct treatment, it often yields to poor results. An individual who has symptoms of a Lisfranc injury must be assessed by a doctor.
What are the indications?
- Pain in the middle part of the foot
- Pain while walking or standing
- Swelling and bruising
The injury can be quite subtle on the X-ray results. For better clarity, it is oftentimes needed to apply force on the foot to emphasize the abnormal alignment. Further testing can be carried out with a CT scan or an MRI. It is sad to note that most of these injuries are not evident without acquiring the right test. Most cases of Lisfranc injuries are wrongly diagnosed as a foot sprain.
In most cases, the treatment for a Lisfranc injury involve surgery although some minor injuries can be managed using non-surgical measures. In case there is minimal separation of the bones, a rigid walking cast is applied for about 8 weeks. Nevertheless, the common treatment is to secure the broken bones with either internal or external fixation.
The surgery is aimed on restoring the normal alignment of the joints and securing them in the right position. The most secure fixation involves several metal screws that are placed on different bones to secure to midfoot to the forefoot in the right alignment.
In most cases, normal recovery takes 6-8 weeks without any weight on the foot. The affected foot is protected with a walking boot that is used for several weeks and the screws are removed after 4-6 months. Full recovery typically takes 6-12 months while severe injuries can result to lasting foot problems.