[Charcot's osteoarthropathy : How to identify a superimposed osteomyelitis?].

Charcot's osteoarthropathy is defined as an osteodestructive process characterized by peripheral neuropathy with lack of protective proprioception in which improper weight bearing leads to recurrent microtrauma, triggering of a proinflammatory process, pathological bone remodeling, joint instability, and subsequent joint destruction. The most common cause is diabetes which can lead to neuropathy over time. Magnetic resonance imaging is the most important imaging modality enabling subtle analysis of soft tissue and bony changes. Thus, it plays a key role in detection of early disease stages, assessment of disease activity during follow-up, and identification of superimposed infections and osteomyelitis. Soft tissue infections comprise cellulitis, phlegmons and abscesses. The ghost-sign is the most helpful diagnostic criterion for identification of osteomyelitis. The presence of a skin ulcer with surrounding soft tissue infection should give rise for a careful search for sinus tract and osseous involvement.