What Is Charcot Foot?

Charcot foot affects between 0.1% and 7.5% of patients with diabetes. While this number appears low, this condition can have serious, long-term impacts.

Charcot foot is a progressive condition that affects the foot and ankle. This condition was first described by Jean-Martin Charcot, a French physician born in 1825 who is considered the “father of neurology.”

The term Charcot foot was first used in 1868 after Charcot’s discovery, and during this time, syphilis was the most common cause, according to research from the National Library of Medicine (NLM). Then in 1936, William Jordan, another physician, discovered the association between diabetes mellitus and neuropathic arthropathies.

What is Charcot foot?

Charcot foot, also known as Charcot joint or Charcot arthropathy, is a form of neuropathic arthropathy that involves the progressive degeneration of a weight-bearing joint. The loss of protective sensation to the foot can lead to bone destruction, bone resorption, and bone deformity. Any part of the foot and ankle may be involved, and most Charcot cases involve several bones and joints of the foot and ankle.

What causes Charcot foot?

Charcot foot has different causes, but it is one of the most serious complications of a diabetic foot. This condition can lead to permanent disability and amputation if not treated promptly and properly. But what causes this condition?

Most diabetic foot problems come from two major issues:

• Poor blood supply to the foot due to microvascular damage from prolonged hyperglycemia
• Diabetic neuropathy from prolonged hyperglycemia

These put the diabetic foot at risk for trauma, infection, and eventual amputation.

Significant neuropathy can cause a diabetic patient to continue weight-bearing to a traumatized foot due to the absence of the sensation of pain. Over time, and if the pressure is not relieved, the bones of the foot may develop osseous subluxation, dislocation, deformity, and/or fracture.

It is important to note that diabetic neuropathy is not the only cause of this condition. Other conditions that cause neuropathy to the lower extremities contribute to the development of Charcot foot, including:

• Spinal cord injury
• Polio
• Infection
• Parkinson’s disease
• Inflammatory conditions
• Substance use
• Renal dialysis
• Alcoholic neuropathy

However, in wound care, diabetes mellitus is the most common cause of Charcot foot.

Signs and symptoms

Early signs of Charcot foot include redness, swelling, and warmth to the affected foot. This may develop due to acute trauma or develop over time when a patient has ongoing weight-bearing to an injured foot.

Swelling and redness may improve with elevation in the early stages of Charcot development. This, along with radiographic images, can help to differentiate acute Charcot foot from infection. Other considerations for differentiation include the absence of a wound or other source of infection.

Ongoing weight-bearing will worsen an injury, leading to the cascade of bone and joint damage, ultimately deforming the foot.

Later stages of this condition demonstrate the classic “rocker bottom” caused by the collapse of the midfoot. There may be large fluid collections noted around affected joints. Radiographic images showing the progression of Charcot foot from early to late stages can be found at resources, such as the NLM.

Risk factors

Long-term, poorly controlled diabetes puts patients at increased risk of developing neuropathy thus leading to the potential for trauma and injury to the insensate foot.

The risk of developing this condition also increases with obesity and age. Untreated injuries, a history of prior foot ulcers, peripheral arterial disease, and prior foot surgery (including amputation) are also risk factors for developing this condition.

Other modifiable risk factors include a history of substance use as this can lead to peripheral neuropathy. Taking a thorough medical history of patients will assist in identifying the cause of Charcot foot in nondiabetic patients.

Patient considerations

The early- and mid-stages of Charcot foot development may not be significant enough to cause patients to seek medical care. This is especially true if patients experience no pain and no open ulcers.

With symptoms like these, patients are likely to continue their everyday activities, putting more and more stress on the affected bones and joints. This causes further damage and moves the development of Charcot into later stages where bone deformity may be the reason the patient seeks medical care.

Patients may feel they’re no longer able to walk normally, they have poor balance, or their shoes no longer fit well. Modifications to ambulation and wearing ill-fitting footwear will increase the likelihood of the patient developing foot ulcers from pressure, friction, and shear. Development of chronic foot wounds in diabetic patients increases the risk of infection and ultimate amputation.

Treating Charcot foot

Treatment of early-to-mid-stage Charcot foot consists of stopping bone loss and preventing deformity. One option is a Charcot restraint orthotic walker (CROW) boot. A CROW walker is a boot designed to protect the foot, decrease ongoing deformity, and prevent the development of ulcers. Consulting with orthotic specialists and placing patients in a CROW walker are important parts of the treatment plan for early-stage Charcot foot patients.

These boots are custom made for each patient and are easy to remove for bathing and sleeping though should be worn regularly and at any time the patient is standing or walking. Patients will likely require radiographic images at routine intervals to monitor the progression of the condition.

A cast may also be used to immobilize the joint and offload the foot in the acute phase. It can also be an effective treatment for foot ulcers. The cast is likely to be discontinued after the acute phase has subsided, although lifelong protection will need to take its place.

Braces, orthotics, and offloading devices are used in the management phase. Offloading devices may include knee walkers, crutches, and wheelchairs. Patients should be educated on the importance of limiting weight-bearing to the affected foot and the risk of disease progression if normal activity and weight-bearing continue.

Later stages

Severe, late-stage Charcot foot may require surgery. If the collapse of bone is severe or an infection is present, the patient will likely need surgery to stabilize the foot. There are recent studies suggesting earlier surgical stabilization enhances the quality of life of the patient.

Orthopedic surgical options for late-stage Charcot foot include:

• Arthrodesis with fixation
• Achilles tendon lengthening
• Exostectomy

At times, certain complications and infections can be difficult to treat and some level of amputation may be the best course of treatment.

Charcot foot is a condition that is difficult to diagnose and can rapidly deteriorate into damage that cannot be reversed. Identifying the early signs and initiating testing and treatment will help keep your patients from the detrimental effects of this condition.