Neuroarthropathy of the extremities: magnetic resonance imaging features.

The objective of this article was to review the magnetic resonance imaging (MRI) findings of four different neuroarthropathic extremities, and discuss the role of MRI in establishing a correct diagnosis. The shoulder, ankle, and knee had predominantly atrophic neuroarthropathic changes, whereas both atrophic and productive changes could be seen in the elbow. Bone marrow edema, suggesting a recent stress fracture, was detected in the elbow and knee. Osteochondral defects, or "detritic" synovitis with effusion, were extensive in all joints but exceptionally profound in the shoulder with amputation-like osteolysis and a total loss of the humeral head. Radiologists may encounter the joint manifestations of neuropathy, which may be confused with various pathologies, including tumor and septic arthritis, before the neurological diagnosis is established. MRI is helpful in detecting the extension of the disease as well as to differentiate chronic Charcot's arthropathy from septic arthritis before radiographic findings suggest the diagnosis.