Charcot Foot

Charcot Arthropathy, also referred to as “Charcot Joint” or “Charcot Foot” is a Neurogenic arthropathy, that  results in progressive destruction of bone and soft tissues at weight bearing joints due to damaged nerves.

Loss of sensation, pain and the position of the joints in the foot, cause the muscles to lose their ability to support the joints properly. This loss of feeling and motor control allows minor traumas such as stress fractures to go undetected and untreated.

This undetected trauma can lead to joint dislocation, cartilage damage, bone erosion and deformity of the foot.

“Charcot Foot” occurs most often in people with diabetes mellitus. Onset occurs after the patient has been diabetic for 15 to 20 years, usually at the age of 50 or older. The disorder occurs at the same rate in men and women.

Causes of Charcot Foot:

Peripheral neuropathy and adequate blood supply are two factors that must be present for Charcot Arthropathy to occur.

Many factors may cause peripheral neuropathy, these include:

• Diabetes (most common cause of polyneuropathy).
• Hereditary condition- Charcot Marie Tooth.
• Alcoholism.
• Malnutrition- VitB and folate deficiency.
• Infections- HIV, Syphilis, Leprosy.
• Metabolic- thyroid dysfunction, renal or hepatic failure.
• Physical- trauma or injury to the nerves, sciatica.
• Drugs/ medicine- cytotoxic drugs.
• Heavy Metal- lead, mercury exposure.

Along with these factors there are two theories as to why Charcot Foot may occur;

Neurovascular theory

• Underlying condition results in autonomic neuropathy, causing the blood vessels to expand (vasodilation) increasing the amount of blood flow to the extremities. This leads to a mismatch of bone destruction and synthesis leading to osteopenia (low bone mineral density), and increase likelihood of stress fractures etc.

Neurotrauma theory

• Undetected trauma or injury due to sensation loss. This microtrauma leads to progressive destruction and damage to the bone and joints of the foot.

Symptoms of Charcot Foot:

• Typically unilateral but may present in both feet.
• Sudden onset.
• Insensitivity in the foot/feet.
• Strong pedal pulses.
• Swelling of the foot without obvious injury.
• Redness may be seen in the effected area of the foot.
• Increase heat (3-7 degrees) in the joint of the foot effected.
• The swelling, redness, and changes to the bone that are seen on X-ray may be confused for a bone infection. A bone infection is very unlikely if the skin is intact and there is no ulcer present.
• This condition commonly effects the midfoot, but can present in the rearfoot or forefoot.
• If the condition has progressed to the intermediate stages, multiple fractures and dislocations of the joints can be seen on an X-ray (In the very early setting of Charcot Foot, the X-rays may be normal).
• Dislocation of the joint(s).
• Instability of the joint(s).
• Muscle weakness and slack ligaments.
• Deformity in advance stages as the bones may sublux and collapse causing a “rocker bottom foot”.
• Calluses and ulcers may form when these bony protrusions rub inside the shoes
• Infection from ulceration, due to deformity.

Treatment for Charcot Foot:

The goal of treatment for a Charcot Foot is to heal the broken bones, as well as prevent further deformity and joint destruction. The total healing process may take 1-2 years.

The sooner Charcot Arthropathy is diagnosed and treated, the better the final outcome. Patients must carefully inspect both feet everyday and control their blood sugar levels. Both responsibilities are important in recognising Charcot Foot early, and in avoiding future complications and deformity.

Nonsurgical Treatment

• Casting changed every 1-2 weeks to accommodate for changes in leg size and fluid to keep the foot in a “normal position” to reduce deformity, until the condition has settled down, with regular X-rays.
• Crutches and removal cast walkers to follow for a few months.
• Wheelchair if necessary.
• Customised pressure relieving insoles and orthopaedic footwear.
• If deformity is too great a CROW walker may be manufactured for the patient to wear.
• Education on daily inspection of the feet and warning signs of another Charcot Foot episode.

Surgical Treatment

Surgery may be recommended if the Charcot Foot deformity puts the patient at a high risk for ulcers, or if protective shoe wear is not effective. Unstable fractures and dislocations also require surgery to heal.

• Achilles tendon lengthening decreasing the pressure on the midfoot and front of the foot. This allows any forefoot ulcer to heal and reduces the chance that it will return.
• Removal of bony prominence on the bottom of the foot.
• Fusion and repositioning of the bones if required.
• After this type of operation, there is typically a period of no weight on the foot for at least 3 months.

At Proactive Podiatry we will assess your foot risk status for Charcot Arthropathy. We will also provide education and advice on how to best check and monitor your feet and what to do if you are concerned with changes in your feet, especially if you are at high risk of developing Charcot Foot.