Charcot foot

Overview – what is Charcot foot?

Charcot foot is a problem which can affect the foot in people with neuropathy (nerve damage with numbness). The bones of the foot become very fragile and can start to break or dislocate in response to very minor forces – even in response to the forces which occur with standing or walking.

The commonest cause of the Charcot foot is diabetes, but it can occur in people who have a different cause of nerve damage. It is rare – and affects only about 1% of people with neuropathy in diabetes. However, when it occurs, it can lead to gross deformity or ulceration of the foot. It may even result in amputation of the lower part of the leg.

Symptoms – what are the signs / symptoms of Charcot foot?

The early signs of Charcot foot are inflammation (swelling, heat and redness) in the affected area of the foot or ankle. These symptoms are often mistaken for infection.

There may be some aching discomfort, or it may be painless (because of nerve damage). In most cases only one foot is affected. However, in some rare cases people can develop Charcot foot in both feet.

Symptoms of Charcot foot may include:

• Swelling
• Warmth – the affected foot feels warmer than the other
• Change in foot colour
• Change in foot shape

If you notice any of these symptoms in either of your feet, take the weight off that foot immediately and talk to your doctor or podiatry team for more information and advice.

Causes of Charcot foot

Sometimes it is brought on by a minor injury (such as tripping over something), or recent foot surgery, but it often just starts for no obvious reason.

Diagnosis of Charcot foot

The diabetes podiatry clinic will examine your foot, and may carry out some simple non-invasive tests, such as temperature and neuropathy testing. You will be asked to have an X-Ray of the affected foot. This is the best way to see if there are any bony changes to the foot.

If there are no obvious changes on the X-ray, you may be asked to have an MRI (Magnetic Resonance Imaging) scan. This will show areas of inflammation within the bone, which is the earliest sign of the condition.

Treatment – what treatment will I be offered for Charcot foot?

The only effective treatment is to reduce the weight on the foot and ankle and prevent it from moving until the inflammation has settled.

This is normally done with some form of cast (in the same way as if you had broken a bone). The cast allows you to do minimal weight bearing but prevents putting too much pressure on your foot.

Treatment options:

• Non-removable lightweight fibre-glass cast of the lower limb (to the knee)
• Removable lightweight fibre-glass cast (can be taken off in bed or for shower)
• Removable cast walker with prescription insole.

The non-removable cast is the preferred treatment for Charcot foot, as it is the best way to offload and immobilise the foot, however it is not suitable for everyone. The removable casts do not support the foot as well as the non-removable cast, however when worn, they can still be effective at offloading the foot.

The treatment can vary according to method of cast used, and how much rest you can have. What we do know is that the average length of time in a cast in the UK is 9 months.

A surgical procedure may be needed for Charcot foot, to reshape your foot. If reshaping the foot and constant rest doesn’t help, you may need an amputation.

Outlook for Charcot foot

Charcot foot sometimes flares up again within a year or so of apparent healing, but this may be because it was never properly healed in the first place.

Prevention of Charcot foot

• Track and report changes to your feet to a podiatrist
• Good diabetic control with a healthy lifestyle
• Inspect your feet and toes every day for red or raw areas of skin. Make sure shoes provide support and fit you properly; avoid rubbing or tight spots
• Keep shoes and feet dry
• Care for your skin and nails daily
• Stopping smoking and keeping your blood sugar levels, blood fats and blood pressure within your target range can also prevent Charcot foot from developing. And it’s important to avoid big changes to the amount of day to day physical activity you do

Harm – the risk factors

Inaction or insufficient action on charcot foot can cause harm.

• Your foot may become deformed if you do not get appropriate treatment early enough and you continue to walk on it, this could also possibly lead to amputation

If you have any concerns about the treatment or care you are receiving, it is important to speak up.

Learn more about harm

Resources

• Diabetes UK
• NICE Guidance