Charcot arthropathy (Charcot Foot) is a progressive disease of neurologic origin.
It is a serious concern for diabetics.
Jean-Martin Charcot, a French neurologist, is given credit for first describing this disease in the 1800's, although he primarily attributed it to complications of syphilis. The first published report of diabetes as a causative factor in Charcot arthropathy was reported in 1936. And today, Charcot arthropathy is primarly associated with diabetes.
Charcot arthropathy usually affects the foot and the ankle joints. Type II diabetics in particular are most prone to the ravages of neuropathic changes in the lower extremities. Neuropathy is prevalent in up to 7% of diabetic patients.
Neuropathic arthropathy is either atrophic (wasting away or decrease in size of the body part) or hypertrophic (growing abnormally large). The interaction of several component factors (diabetes, sensory-motor neuropathy, autonomic neuropathy, trauma, and metabolic abnormalities of bone) results in an acute localized inflammatory condition that may lead to varying degrees and patterns of bone destruction, subluxation, dislocation, and deformity. The hallmark deformity associated with this condition is midfoot collapse, described as a "rocker-bottom" foot shown here, although the condition appears in other joints and with other presentations.
Often a person will develp Charcot foot and not know it due to diabetic neuropathy and will continue to walk on the foot, making the condition worse and worse.
The first step in treating in Charcot arthropathy is obviously making the correct diagnosis. This is not always easy to do. The symptoms of Charcot arthropathy are often confused with cellulitis. Cellulitis is an infectious condition that usually affects the foot, ankle and legs and has the same characteristics. But with Charcot arthropathy there is no infectious agent that can be identified and it is not amenable to antibiotic therapy. However, many Charcot arthropathies have ulceration associated.
In the beginning phases of this disease, plain film x-rays are usually not helpful. Magnetic resonance imagine is the best diagnostic tool. Other tests that are helpful include white blood counts and sedimentation rate.
The underlying condition of Charcot arthropathy lies in the neurologic diagnosis: loss of sensation which is characterized by decreased sensitivity to light touch, cold, heat and pressure. The monofilament test which measures how much pressure loss has taken place is a good screening device to detect degenerization of the the nerves in diabetics. However, if the diagnosis is in question, quantitative sensory testing is the best diagnostic tool. Also used for diabetic Charcot arthropathy is an older technique called bone scanning. Indium radionucleotide sometimes can help differentiate infection from Charcot arthropathy.
What can YOU do?
Newer techniques to re-establish sensitivity to the extremity have been pioneered by Johns Hopkins University professor Dr. A. Lee Dellon. This technique decompresses multiple peripheral nerves in the lower extremity and 85% of the cases have been shown to have excellent results. However, this technique needs to be instituted before complete bony destruction has ensued. If the neuropathy is not reversed, outcomes are poor.
In advanced cases of Charcot arthropathy where bone destruction has taken place, reconstructive surgery can be performed. This technique usually requires extensive surgical reconstruction with either internal or external fixators.
In the interim, before surgical care is instituted, non-weightbearing full-contact casting is employed. But even with these techniques, amputation of the extremity is still inevitable in a large percentage of cases. It is estimated that 100,000 non-traumatic amputations occur every year in the United States.
In summary, Charcot arthropathy is a devastating disease that is difficult to diagnose, usually has poor outcomes, and is extremely expensive to treat.