CASE 11: Neuropathic (Charcot) arthropathy

There is severe osteoarthritis of the shoulder and of the wrist. Notice in particular the subluxation of the proximal carpal row with respect to the radius and the ulna. There is marked sclerosis of the glenoid labrum and carpus with disorganization of the joints. These are exaggerations of the findings seen in routine cases of Osteo arthritis, and they represent repeated insults to the joints above what would be expected. The findings are typical of neuropathic arthropathy, in which there may be severe trauma to the joints unsuspected by the patient.

There also is a poorly understood neurovascular mechanism in causing neuropathic arthropathy. In cases in which this predominates, instead of hypertrophic changes there are atrophic changes with what almost appears to be surgical amputation of the intraarticular parts of bones in the affected joints. This is particularly true of the humeral head in syringomyelia.

Any time the findings are those of osteoarthritis, but they seem out of proportion to those usually seen or there is rapid progression of disease, one must suspect neuropathic arthropathy. One of the most frequent causes today is diabetes mellitus. Formerly,a frequent cause was neurosyphilis.

The differential diagnosis should include other causes of accelerated degenerative changes such as the arthropathies of iCPPD deposition disease, hemochromatosis, and acromegaly.