In general, joints that contain excessive fluid should be sampled however, if none exist, at least two to three joints should be sampled, especially the carpal and tarsal joints. Synovial fluid analysis is also recommended in disorders characterized by persistent or fluctuating fever of unknown origin, shifting leg lameness, or generalized malaise in which arthralgia is suspected. The technique of arthrocentesis to acquire synovial fluid for analysis is no more difficult or imbued with risk than pleurocentesis or abdominocentesis.

Arthrocentesis and joint fluid analysis are integral to the clinical evaluation of not only primary joint disorders but systemic diseases in which joint effusion is part of the clinical picture.