called Charcot joint or neuropathic joint, Charcot arthropathy refers
to a progressive degeneration of a weightbearing joint. It is characterized by joint dislocations, pathologic fractures, and debilitating deformities.
Charcot joint and Diabetes mellitus
Charcot joint occurs in <1% of all diabetics (both type 1 and type 2). It occurs in both males and females with equal frequency. Most patients (>66%) are over age 40 years and have had long-standing (>10 years), poorly controlled diabetes complicated by a diabetic peripheral neuropathy. Patients present with relatively painless swelling and deformity usually of the foot (most commonly tarsometatarsal joints) and ankle, although knee, hip, and spine can be involved. Occasionally it can be of sudden onset mimicking an infection. With progression of disease, the patient can develop "rocker bottom" feet owing to midtarsal collapse. Skin over bony prominences can ulcerate and become infected without the patient’s knowledge owing to abnormal sensation resulting from the neuropathy.
Radiographs frequently show severe abnormalities characterized by the 5 Ds: destruction, density (increased), debris, disorganization, and dislocation The increased density and sharp margins of the bony debris help separate a Charcot joint from infection. The etiology is a combination of repetitive microtrauma to a desensate foot and autonomic dysfunction leading to increased blood flow, hyperemia, and osteoclastic resorption of bone. Treatment includes protected weight-bearing, soft casts, good shoes, and aggressive treatment and prevention of skin ulcerations. Charcot joints, however, usually progress. There is no role for surgery (fusion, arthroplasty) other than amputation for severe cases. Diabetes mellitus has replaced neurosyphilis as the most common cause of a Charcot joint today.