What is Charcot foot?

Charcot foot is a rare but serious complication that can affect persons with peripheral neuropathy, especially those with diabetes mellitus. Charcot affects the bones, joints, and soft tissues of the foot or ankle. The bones become weak and can break and the joints in the foot or ankle can dislocate. If not caught in its earliest stage, the joints in the foot collapse and the foot eventually becomes deformed. A deformed foot can cause pressure sores to develop in the foot or ankle. An open wound with foot deformity can lead to an infection and even amputation.

What are the signs of Charcot foot?

In the early stages, the foot is red, feels warm to the touch, and there is significant swelling of the extremity.

What causes Charcot foot?

Researchers have not found one, single cause for Charcot foot. But there are certain known events that create the right conditions for it to develop. One common known event is an unrecognized sprain or injury. Because the individual has peripheral neuropathy, they cannot feel pain or other sensations and the injury can go unnoticed. If a broken bone in the foot or ankle is not correctly treated, the deformity can worsen, lead to foot sores and infection. Charcot foot has also been seen as a complication following organ transplantation in patients with diabetes. (This is due to the use of drugs to prevent organ rejection, which also have the side effect of causing bone loss and fractures.)

When the midfoot is involved in Charcot foot, the arch collapses, which rounds the bottom of the foot. This is called a rocker-bottom foot deformity. Depending on the location of the bone break, the toes can start to curve under like claws or the ankle can become deformed and unstable.

How is Charcot foot diagnosed?

In its early stages, Charcot foot is difficult to diagnose. X-rays are often normal. If X-rays and laboratory tests are normal, Charcot foot is diagnosed by knowing the signs of the condition. Charcot foot is suspected in persons who have diabetes and peripheral neuropathy and the following signs: a red, hot, swollen foot (without a foot ulcer) and an increased skin temperature in the affected foot (compared with the other foot).

How is Charcot foot treated?

Early diagnosis and treatment can prevent more damage and avoid deformity and other complications. Treatment has three goals: take the weight off the foot, treat bone disease (usually with cast; bisphosphonates and other supplements are sometimes used), and prevent new foot fractures.

Non-surgical treatment

The first and most important treatment is rest or to take the weight off of the affected foot (also called “offloading”). In the early stage of Charcot foot, offloading helps prevent inflammation and stops the condition from getting worse and prevents deformity. Protected weight-bearing (walking in a walking boot) in later stages can prevent complications from the existing deformity and avoid new deformities.

Surgical treatment

Surgery is recommended for those patients who have severe ankle and foot deformities that are unstable and at high risk of developing a foot ulcer. In addition, if the deformity makes braces and orthotics difficult to use, surgery may be indicated. After surgery, the patient will have to avoid putting full weight on the Charcot foot for an extended period of time.