Aspiration of normal or asymptomatic pathological joints for diagnosis and research: indications, technique and success rate.

Although joint aspiration is a basic clinical skill, aspiration of normal joints, or asymptomatic clinically quiescent joints, is only rarely undertaken. There are two main indications for this procedure. Firstly, for definitive diagnosis of crystal-associated arthritis (gout and pseudogout) during the intercritical period and for subsequent monitoring of treatment success of gout; and secondly, to obtain normal synovial fluid for biomarker research. The justification for these indications, the success rate and the technical aspects related to this procedure are presented in this article.