[Differential diagnosis of synovitis].

The synovial membrane is a site where many diseases with different etiologies can become manifest. Tumors and storage diseases are some of the rare conditions, whereas crystal deposition diseases, acute bacterial infections and in particular chronic uncharacteristic synovitis are frequently encountered. The latter present a diagnostic problem, because they can barely be assigned to concrete diagnoses. This report will give an overview of the differential diagnosis of joint diseases and will focus on the so-called synovitis score as a tool for the systematic evaluation of chronic uncharacteristic synovitis, providing a possibility to differentiate between degenerative and rheumatic synovitis with a specificity of 60.5% and a sensitivity of 95.5%.