What is Charcot foot?
Charcot foot is one of the complications of diabetes. It happens when diabetes affects the nerves in the foot, reducing sensation and combined with arthritis in the foot and ankle joints.
How does Charcot foot happen?
When there is raised blood sugar level due to diabetes, particularly if this is poorly controlled for a prolonged period (hyperglycemia), this can affect the nerves in the arms and legs, leading to nerve damage and reduced sensation. This is referred to as diabetic peripheral neuropathy. This will make it hard for you to feel the pain in your feet if there is increased stress or if there is an injury. You may continue to use your foot as usual, causing more damage to the bones, joints, tendons, and ligaments. Therefore, this can lead to significant arthritis with bone collapse and changes to the bone shape within the foot without noticing any symptoms. If there is a wound or ulcer in the foot, there will be an increased risk of infection, which in severe cases can extend to the bone, leading to bone infection (osteomyelitis).
The treatment can be difficult also because diabetes can affect the blood supply to the foot, interfering with the healing process and limiting the ability of the medicines (like antibiotics) to reach the area of infection. Therefore, it can lead to life-threatening infections and sometimes requires amputation of the infected part to prevent spread to the rest of the body.
What are the other names used to describe a Charcot foot?
Charcot foot has a few terms used interchangeably, Charcot arthropathy, Charcot neuropathy and Diabetic foot.
How common is Charcot foot?
Charcot foot is considered rare and seen in <1% of diabetics. Incidence can differ from one part of the world to another.
How to tell if I have a Charcot foot & what are the symptoms of Charcot arthropathy?
The clinical features of Charcot foot include:
Foot pain, although this can be minimal due to diabetic neuropathy.
Foot swelling and redness.
Discolouration or redness.
In advanced cases, Charcot arthropathy can lead to deformities and changes to the shape of the foot, for example, a flat foot deformity.
The feet may feel warm. This can be a sign of infection, particularly if an ulcer or dark soft tissue discolouration occurs. It is very important to seek urgent medical attention if any symptoms of infection are developing.
What conditions can mimic a Charcot foot?
Other conditions that can be mistaken for a Charcot foot include:
How to diagnose a Charcot foot?
The diagnosis required clinical assessment by a foot specialist. The presence of the above-mentioned clinical features in the context of prolonged and poorly controlled diabetes should raise the possibility of the diagnosis. The clinician will fully examine your feet, including a neurological examination and inspection for any deformities and skin ulcers.
What are the useful tests to assess for a Charcot foot?
Imaging is very useful for the assessment. A foot X-ray is usually the first modality of choice. It will assess the bony alignment for any foot deformity or arthritis. It can also provide useful information about the presence of infection, but sometimes more advanced imaging (like an MRI) scan is needed to assess for this. The assessment will also include routine blood tests and blood sugar level checks.
How to manage Charcot arthropathy?
The management of diabetes itself is an important part of the management. This is multifactorial, requires lifelong adjustments, and is beyond the scope of this article. The article describes the usual management of Charcot foot, which include:
Resting the area to allow for any ulcers to the heel. This may require you to use support like crutches or special orthotic footwear to relieve the pressure from the area.
You may need antibiotics treatments if there is an infection in the area. Infection in the bone is a serious condition and usually requires a prolonged course of antibiotics and monitoring of the area as well as blood inflammatory markers to measure the response. Repeated imaging is also usually done to assess the response after antibiotic treatment.
Physiotherapy
This will help by designing a customised rehab program to help maintain muscle strength and joint movement.
Charcot foot surgery
Surgery is indicated in more advanced cases, for example, if an infection is difficult to control using antibiotics or other conservative measurements. In such cases, surgical debridement or even amputation of the infected part might be necessary to prevent the spread of infection. Surgery is also sometimes indicated to stabilise the foot and ankle joints. These can include various surgical treatments, including joint fusion. A specialist foot and ankle surgeon will be the best person to advise you regarding the surgical treatment options.
Can an ultrasound-guided steroid injection help in Charcot Arthropathy?
Generally, steroid injections are not routinely used in managing Charcot arthropathy unless there is pain secondary to the focal area of arthritis, which can be targeted using an ultrasound-guided steroid injection to reduce the inflammation, pain and swelling in the area. This indication is uncommon in our practice and needs careful assessment and referral from a foot and ankle specialist. Using ultrasound guidance ensures accuracy and safety when a steroid injection is performed. To find out more, please see our FAQs about steroid injections.
Foot & Ankle conditions and treatments
