[Septic arthritis diagnosis : the role of microbiology].

Septic arthritis is a medical and surgical emergency. It is therefore essential to promptly differentiate an infectious from a non-infectious origin in order to improve the prognostic (mortality and morbidity). To do so the clinician needs not only to know which tests are available but also how to adequately use them and interpret their results. In this article, we review the various tests in use for the evaluation of acute arthritis, highlighting the most useful ones for the diagnosis of septic arthritis. We will also have a quick look at the use of intra-articular injection of corticosteroid.