Synonyms and Keywords
Charcot arthropathy, Charcot neuroarthropathy.
What is a Charcot Foot?
Charcot foot is the breakdown in the joints or sudden softening of the bones in the foot. The condition often affects people who have significant nerve damage (neuropathy). A complication of diabetes, the disorder weakens the bones enough for them to fracture easily, even without any major trauma. Since neuropathy impairs the nerves, causing pain to go unnoticed while sapping the muscles’ ability to support the foot properly, the patient’s foot eventually changes shape from continued movement and walking. It targets most commonly the mid-foot, destroying the bone and soft tissue of weight-bearing joints there and in the ankle. As the affliction progresses, the arch collapses and the foot takes on a convex contour, giving it a rocker-bottom appearance that makes walking a very difficult feat. In most cases only one foot is affected. However, it can strike both feet over time.
Charcot foot is a very serious condition that can result in severe foot deformity, disability, and even amputation. In addition, patients are more likely to develop ulcers from the deformity. Named after Jean-Martin Charcot (1825-1893), the first person to describe the disintegration of ligaments and joints due to disease or injury, Charcot foot should not be confused with the foot deformity associated with the Charcot-Marie-Tooth disease — they are as different as apples and oranges.
What Causes a Charcot Foot?
Charcot foot develops as a result of neuropathy, which decreases sensation and the ability to feel temperature, pain, or trauma. A severe neuropathy will deprive the feet of any feeling, so the pain of traumas goes unnoticed and often untreated as the patient continues to walk, progressively making the injury worse, snowballing from a slackness of the ligaments to joint dislocation, bone and cartilage damage, then deformity.
Who Gets a Charcot Foot?
Charcot foot occurs most often in those with diabetes, because they are also the greatest risk for neuropathy. According to the American Diabetes Association, 60-70% of diabetics develop peripheral nerve damage that can lead to Charcot foot and about 0.5% of these patients develop the condition. Neuropathic patients with a tight Achilles tendon, especially, have shown a greater tendency to develop Charcot foot. Chronic hyperglycemia — high blood sugar — is also a common cause.
The disorder occurs at the same rate in men and women, with both feet affected in approximately 20% of the cases. Onset usually occurs after the age of 50, and after the patient has had diabetes for 15 to 20 years.
What are the Symptoms of a Charcot Foot?
Whereas neuropathy often takes decades to unfold, Charcot’s foot can happen in a matter of months or even weeks! The symptoms of Charcot foot can appear after a sudden trauma (such as dropping something on the foot or a sprain) or minor repetition of pressure (such as a long walk). The earliest signs of the condition include the foot or affected part being warmer than the other foot, with some swelling and redness possible; this usually all there is and can come on quite suddenly. The patient generally experiences little pain and the circulation usually remains well, until the untreated foot arch collapses and a deformity starts to develop. Some people with Charcot’s foot can sense a “deep” aching type of pain, but it never matches the severity of the actual injury.
Other initial symptoms of Charcot foot may include:
- Insensitivity to heat in the foot
- Instability of the joint
- Unusually strong pulse
- Loss of sensation in the foot, especially to pain
- Swelling of the foot and ankle, caused by fluid leaking out of the joint capsule
- Dislocated foot joints
- Misalignment of the bones that form a joint, with the ends of the bones grinding against each other and often producing a coarse grating sound
- Weak foot muscles
Calluses and diabetic foot ulcers may occur, too, as a result of bony protrusions (due to the emerging deformity) exerting pressure inside the shoes. The ulceration can become infected and spread to the bone and joints, causing tiredness and a fever.
Compression of blood vessels and nerves is another possibility, though it often does not show symptoms due to the loss of feeling in the foot.
How do You Diagnose a Charcot Foot?
Early diagnosis of Charcot foot is essential for successful treatment. The surgeon will examine your foot and ankle, ask about events that may have occurred prior to the symptoms, review your medical history (i.e., history of diabetes), and order imaging tests (such as x-rays, MRI) and laboratory tests for confirmation.
X-rays are used to detect any abnormal buildup of fluid in the joints, large bony projections that form along joints, fractures, bone fragments, and joint misalignment or dislocation. Once treatment begins, x-rays are taken periodically to help evaluating the status of the condition. MRI (magnetic resonance imaging) is employed to help differentiate between Charcot foot and osteomyelitis (bone infection): joint margins for Chacot foot are clearly defined on MRI scan, as opposed to blurry for osteomyelitis.
Laboratory tests include drawing fluid from the joint to uncover bone and cartilage fragments and blood, which may be present in some cases of Charcot foot.
How do You Treat a Charcot Foot?
If diagnosed early, the primary initial goal is the prevention of further joint destruction and foot deformity. Rest and protection of the affected part is a key. Placing the foot in a cast, walking boot, or ankle foot orthosis should relieve pressure and prevent a complete breakdown of the joints. Replace these periodically until there is no temperature difference between the two feet. The process can take up to 6-9 months. Meanwhile, elevation of the foot will reduce blood flow, decreasing inflammation and bone loss. Crutches or wheelchair may also be considered to avoid placing weight on the patient’s foot, especially for those with diabetes. Should the joint is broken down, customized shoes or surgery may be a necessity.
Treatment outcomes vary by the location of the disorder, the severity of damage to the joint, and whether surgical repair was necessary. The bones normally heal in 55 to 97 days, and up to 1-2 years for complete recovery.
Self-Care at Home
If you have a Charcot foot, following medical advice is important since the condition can by very disabling if not managed early and properly, especially if you have diabetes — a disease often associated with neuropathy, the main cause of Charcot foot.
Avoid weightbearing on the affected foot as much as possible. Don’t put yourself in situations, such as running or jumping or standing for a considerable time, that may lead to trauma.
Check your feet frequently for any swelling. Don’t wait, seek professional help if you notice any. Waiting a couple of days could mean the difference between a good and poor outcome.
Because Charcot foot is closely linked to neuropathy, anything that can block neuropathy’s progression will help control it as well. So, a healthy diet of vegetables and fruits supplemented with vitamins C and B12 to maintain a healthy weight, regular nonweight-bearing exercise (such as swimming or cycling), along with quitting tobacco and alcohol, should vastly improve your condition.
It is important to follow the doctor’s treatment plan for Charcot foot. Failure to do so can result in the loss of a toe, foot, leg, or life.
Non-surgical treatment for Charcot foot consists of primarily of immobilization. Because the foot and ankle are so fragile during the early stage of Charcot, you must protect them so the weakened bones can repair themselves. Avoid putting weight on them is absolutely necessary to keep the foot from collapsing. You will not be able to walk on the affected foot until the doctor says it is safe to do so. During this time, you’re fitted with a cast, removable boot, or brace, and maybe even crutches or a wheelchair.
The doctor may consider prescribing Fosamax, used to treat osteoporosis (a condition in which the bones become thin and weak and break easily) to increase bone density (thickness) and prevent breakdown.
Prevention with specialized footwear and foot orthoses becomes very important if the treatment was not started early enough and/or the foot is deformed, thus making the case a high risk for ulcer. Even after the Charcot foot has healed, shoes with special inserts may be needed to prevent the condition from happening again. Cases with significant deformity will require foot bracing as well.
Patients with this disorder can usually resume regular activities after treatment, though modification in activity level is often necessary to avoid repetitive trauma to both feet. A patient with Charcot in one foot is more likely to develop it in the other foot, so prevention must be taken to protect both feet. If you have diabetes, you must monitor strictly your blood sugar levels, signs of injuries to the foot, and recurrence of the disease.
Only about 25% of cases require surgery. Structures within the foot can be reshaped and bony protrusions removed surgically to circumvent recurring ulcers. After surgery, the foot is constantly monitored for signs of infection, like redness, swelling, warmth, etc. The foot-and-ankle surgeon will determine the proper timing and the appropriate procedure for the individual case.
Osteoctomy is the most common surgical procedure for treating Charcot foot. This involves making a surgical incision on the bottom of the foot and removing abnormal bone growth as well as bone and cartilage fragments. After the procedure, the patient usually wears a brace or cast for about 4 weeks or until healing is complete.
Mid-foot realignment arthrodesis is performed to remove bony overgrowths and repair the collapsed arch. In this the surgeon makes an incision in the foot and inserts screws and plates to stabilize the bones an joints, while removing bone and cartilage fragments. After the surgery, your foot is put in a non weight-bearing cast for about 3 months, then in a weight-bearing cast for another month or so, followed by custom-made shoes and inserts for walking. A similar procedure, the hind-foot and ankle realignment arthrodesis, is used when you’re unable to walk and braces are no longer helpful. You must wear a non weight-bearing cast for about 3 months afterward, and then a special brace to protect the arch for 2-3 months more. Both the brace and the foot must be monitored closely the entire time because you may not feel pressure from a poor fit.
How to Prevent a Charcot Foot?
You can play a vital role in preventing Charcot foot and its complications by following these measures:
- Keep blood sugar levels under control can help fend off nerve damage in the foot. This can easily be done through healthy eating habits and taking vitamins C and B12.
- Practice good foot care. Don’t walk barefooted, always wear socks or stockings with shoes, and make sure the footwear fits comfortably.
- Check both feet every day for redness, swelling, or any sign of injury. See a podiatrist or surgeon immediately if you notice symptoms of Charcot foot.
- Be careful to avoid excessive trauma, such as bumping the foot or overdoing an exercise program.
- Follow the podiatrist or surgeon’s instructions for long-term treatment to prevent recurrences, ulcers, and amputation.