Diabetic (Charcot) Foot
Diabetes is a condition of elevated blood sugar that affects about 6 percent of the population in the United States, or about 16 million people. Diabetic (Charcot) foot problems are a major health concern and are a common cause of hospitalization.
Most foot problems that people with diabetes face arise from two serious complications of the disease: nerve damage and poor circulation. One of the more critical foot problems these complications can cause is Charcot arthropathy, which can deform the shape of the foot and lead to disability.
There are treatment options for the wide range of diabetic foot problems. The most effective treatment, however, is prevention. For people with diabetes, careful, daily inspection of the feet is essential to overall health and the prevention of damaging foot problems.
Nerve damage (neuropathy) is a complication of diabetes that leads to a loss of sensation in the feet. Some people with diabetes can no longer feel when something has irritated or even punctured the skin. A wound as small as a blister can progress to a serious infection in a matter of days.
Diabetes also damages blood vessels, decreasing the blood flow to the feet. Poor circulation weakens bone, and can cause disintegration of the bones and joints in the foot and ankle. As a result, people with diabetes are at a high risk for breaking bones in the feet.
When a diabetic fractures a bone in the foot, he or she may not realize it because of nerve damage. Continuing to walk on the injured foot results in more severe fractures and joint dislocations. Sharp edges of broken bone within the foot can point downward toward the ground, increasing the risk of chronic foot sores from the abnormal pressure.
Symptoms & Diagnosis
Although a patient with Charcot arthropathy typically will not have much pain, they may have other symptoms.
The most sensitive sign of early Charcot foot is swelling of the foot. This can occur without an obvious injury.
Redness of the foot can also occur in the early stages.
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.
Medical History and Physical Examination
Your doctor will talk with you about your general health as well as any symptoms you may have. If you know how you may have injured your foot, your doctor will also want to discuss that.
After discussing your symptoms and medical history, your doctor will carefully examine your foot.
X-rays. These imaging tests provide detailed pictures of dense structures, like bone. In the very early setting of Charcot, the x-rays may be normal. If the condition has progressed to the intermediate stages, multiple fractures and dislocations of the joints can be seen in an x-ray.
Magnetic resonance imaging (MRI) and ultrasound. These studies can create better images of soft tissues of the foot and ankle. These may be ordered if your doctor suspects a bone infection. If there is not a break in the skin, infection of the bone is extremely rare.
Bone scan/indium scan. A bone scan is a nuclear medicine test that is very effective in determining whether there is a bone infection. There are different types of bone scans, and the doctor must determine which type(s) are best to use for a particular problem. An indium scan is a specialized test that involves placing a marker on white blood cells. These cells are traced to learn whether they are going to the bone to fight an infection.
Both Charcot foot and bone infection will cause a positive bone scan (increased activity). However, only an infection will show significantly increased activity on the indium scan.