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Lisfranc Fracture
Definition:
A Lisfranc fracture, so-called after Jacques Lisfranc, a French surgeon in Napoleonic times, is a dislocation or fracture and dislocation of the joint between the midfoot and forefoot (tarsometatarsal joint). It is a relatively uncommon but severe injury with the potential for long-term complications.
The ankle (tarsus) consists of seven bones. The anklebone (talus) and the heel (calcaneus) form the posterior part of the foot. The cuboid and navicular bones connect with the calcaneus and talus respectively and, articulating with the distal (furthest from the body) ends of the cuboid and navicular are the medial, intermediate, and lateral cuneiform bones. Together these form part of the arch of the foot and connect at their distal ends to the long bones of the foot, the metatarsals. Transverse ligaments hold the proximal (nearest to the body) ends of the four lateral (outer) metatarsals in their correct positions. Between the first and second metatarsals, however, there is no transverse ligament, and the particular structure of the bones at this point creates a weak area in the midfoot.
Causes:
A Lisfranc fracture is normally caused by a direct or indirect trauma to the midfoot, such as dropping a heavy object onto the foot or twisting the foot suddenly. Car accidents, industrial accidents, sporting injuries and falls from a height are common causes.
Symptoms:
Typical symptoms may include:
- Pain and swelling on the top of the foot
- Unwillingness or inability to put weight on the foot, due to pain
- Bruising on the top of the foot and sometimes also in the sole
- Gentle pressure on the joint area will cause pain to be felt, radiating to the sides of the foot.
- Depending on the position of the dislocation, a lump might be visible on top of the foot
- Obvious deformity of the foot
Diagnosis:
This type of injury is often misdiagnosed because a dislocated joint can reduce (reposition) itself unaided. The original injury can therefore be difficult to detect. The extreme swelling can be an indication of a Lisfranc fracture, which carries a high risk of secondary complications, so early diagnosis and a careful and thorough examination is critical in order to preserve normal foot function and avoid chronic pain.
While waiting to see the doctor, resting, elevation, and the application of ice to the painful area may help to relieve symptoms. You can also take over-the-counter pain medication such as acetaminophen (Tylenol), ibuprofen (Advil), naproxen (Aleve) or aspirin, as directed.
After your medical history has been taken, and the circumstances of the injury noted, your foot will be physically examined. One method of preliminary diagnosis is to gently move your foot in a circle while holding the heel steady. This will elicit only mild pain if the foot is sprained, but severe pain in the case of a Lisfranc fracture. The blood supply to the foot will be checked to ensure no damage to blood vessels has been sustained.
Several X-rays may be taken, including your uninjured foot for comparative purposes. These may include weight-bearing X-rays, which can be uncomfortable but only take a few seconds. CT (computed tomography) or MRI (magnetic resonance imaging) scans may also be required to better view the hard and soft tissues of the foot.
Lisfranc injuries are graded according to severity, and treatment depends on the level of damage suffered by the joint.
Treatment:
Follow medical advice carefully for the best outcome. Returning to normal activity too soon after sustaining a Lisfranc fracture greatly increases the risk of further injury. A complication known as compartment syndrome might develop, where swelling and bleeding from the injury causes pressure within the muscle, which can damage blood vessels and nerves.
If the injury is relatively mild and the bones have not been displaced, treatment will consist of resting the foot by wearing a cast and using crutches when walking. Putting weight on the foot is kept to an absolute minimum. A cast is recommended due to the potential for long-term disability after this type of injury. After about 6 weeks, when the cast has been removed, you will probably need to use a rigid arch support in your shoe. You will be taught how to do exercises to restore range of motion in the ankle and foot, and to strengthen the supporting muscles.
Surgery is a common treatment for moderate to severe cases of Lisfranc fractures. Unless there is an imperative need for immediate surgery, it should be delayed until the swelling has gone down, in order to minimize the risk of damaging soft tissues. Surgery is performed to realign the dislocated bones and hold them in position during the healing process. Immediately following surgery, a padded splint would be worn until the swelling from the procedure had resolved, usually within 2 weeks. A short leg cast would be applied to immobilize the foot for between 6-8 weeks and possibly up to 3 months. Crutches would be used when walking, but weight-bearing activities would be prohibited until the cast was removed. If internal fixing devices such as pins, screws or wires were used to keep the bones in place during healing, they would be removed at this time. A walking brace or boot would need to be worn for several more weeks, and then an arch support in a stiff-soled shoe would be used until all symptoms had disappeared.
There is always the risk of post-traumatic arthritis developing after injury to a joint. In some cases it might be necessary to undergo further surgery to fuse the joint if post-traumatic arthritis from a Lisfranc fracture is causing intolerable pain.
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