What is Charcot Foot?

What is Charcot Foot?

Charcot foot is a sudden softening of the bones in the foot that can occur in people who have significant nerve damage (neuropathy). The bones are weakened enough to fracture, and with continued walking the foot eventually changes shape. As the disorder progresses, the arch collapses and the foot takes on a convex shape, giving it a rocker-bottom appearance, making it very difficult to walk.



Charcot foot is a very serious condition that can lead to severe deformity, disability and even amputation. Because of its seriousness, it is important that patients with diabetes—a disease often associated with neuropathy—take preventive measures and seek immediate care if signs or symptoms appear.

The Charcot foot was identified as early as 1703 by English physician William Musgrave and again by the American physician John Kearsley Mitchell in 1831, but it was Jean-Martin Charcot, a 19th century French neurologist, who first described the underlying pathology of the condition that now bears his name. In 1936 Charcot foot was linked to neuropathy as a result of diabetes mellitus.

Symptoms

The symptoms of Charcot foot can appear after a sudden trauma or even a minor repetitive trauma (such as a long walk). A sudden trauma includes such mishaps as dropping something on the foot, or a sprain or fracture of the foot. The symptoms of Charcot foot are similar to those of infection. Although Charcot foot and infection are different conditions, both are serious problems requiring medical treatment.

If your foot swells without explanation and is warm to the touch with no apparent break in the skin, you may have Charcot foot. When these symptoms occur, be sure your healthcare provider or foot doctor (podiatrist) examines your foot. Charcot foot must be differentiated from the red, hot, swollen foot caused by infection. With infection, you should go the emergency room immediately

Charcot foot symptoms may include:
* Warmth to the touch (the foot feels warmer than the other)
* Redness in the foot
* Swelling in the foot and/or ankle
* Pain or soreness
* Strong Pulse
* Misshaped foot

What Causes Charcot Foot?

Charcot foot develops as a result of neuropathy, which decreases sensation and the ability to feel temperature, pain or trauma. When neuropathy is severe, there is a total lack of feeling in the feet. Because of neuropathy, the pain of an injury goes unnoticed and the patient continues to walk—making the injury worse.

People with neuropathy (especially those who have had it for a long time) are at risk for developing Charcot foot. In addition, neuropathic patients with a tight Achilles tendon have been shown to have a tendency to develop Charcot foot.

Diagnosis

Early diagnosis of Charcot foot is extremely important for successful treatment. To arrive at a diagnosis, the surgeon will examine the foot and ankle and ask about events that may have occurred prior to the symptoms.

X-rays are also essential for diagnosis. In some cases, other imaging studies (MRIs and/or Bone Scans) and lab tests may be ordered. Once treatment begins, x-rays are taken periodically to aid in evaluating the status of the condition.

Stage Description
0 Localized heat and swelling. Bone scan may be positive. Minimal radiological findings
1 Localized osteopenia, subchondral cysts, erotions and possibly diastasis
2 Joint subluxations
3 Joint dislocations and joint collapse
4 Healing: slcerosis and fustion with trabecular patterns

The inflammatory mechanisms which occur in Charcot's osteoarthropathy lead to increased temperature in the effected extremity. Handheld infrared dermal thermometers can be used to monitor skin temperature increases and thus be used as a screening device for risk of ulceration or development of acute stage of Charcot. Although no well-established criteria exists, some studies suggest that increases of 3-4 degrees F between the affected and the contralateral lower extremity is predictive of an active phase of Charcot. "Foot cooling" as the inflammation subsides has also been a useful tool in the treatment process.

The Charcot foot is considered resolved when radiographic signs indicate the bones and joints have fused and when erythema, and edema are absent and temperature has equilibrated between the two feet.

Treatment

Following your doctor’s treatment plan for Charcot foot is extremely important. Failure to do so can lead to the loss of a toe, foot, leg or life.

Treatment for Charcot foot consists of:
* Immobilization. Because the foot and ankle are so fragile during the early stage of Charcot, they must be protected so the soft bones can repair themselves. Complete non-weightbearing is necessary to keep the foot from further collapsing. The patient will not be able to walk on the affected foot until the surgeon determines it is safe to do so. During this period, the patient may be fitted with a cast, removable boot or brace, and may be required to use crutches or a wheelchair. It may take the bones several months to heal, although it can take considerably longer in some patients.
* Custom shoes and bracing. Shoes with special inserts may be needed after the bones have healed, to enable the patient to return to daily activities—as well as help prevent recurrence of Charcot foot, development of ulcers and possibly amputation. Bracing is required in cases with significant deformity.
* Activity modification. A modification in activity level may be needed to avoid repetitive trauma to both feet. A patient with Charcot in one foot is more likely to develop it in the other foot, so measures must be taken to protect both feet. While in the acute phase, NO walking on the affected foot is recommended.
* Surgery. In some cases, surgery may be required. The foot and ankle surgeon will determine the surgical procedure best suited for the patient based on the severity of the deformity and the patient’s physical condition.

Preventive Care

The patient can play a vital role in preventing Charcot foot and its complications by following these measures:
* Diabetes patients should keep blood sugar levels under control. This has been shown to reduce the progression of nerve damage in the feet.
* Get regular check-ups from a foot and ankle surgeon.
* Check both feet every day—and see a surgeon immediately if there are signs of Charcot foot.
* Be careful to avoid injury, such as bumping the foot or overdoing an exercise program.
* Follow the surgeon's instructions for long-term treatment to prevent recurrences, ulcers and amputation.
* Be sure to have your Primary Care Doctor or Endocrinologist check your feet at each visit including a pulse check and neuropathy check with a tuning fork.