Table 8-1 Intra-articular Therapy Regimens
The most important maneuver before aspirating a joint is to locate the appropriate landmark. This can be best done by making a skin impression with the round end of a non-opened pen point or pen mark. Local anesthesia of the overlying skin and subcutaneous tissues is recommended. In general, if it is important to obtain fluid for diagnostic purposes, a larger needle should be used (so as to avoid the need for re-aspiration if the fluid is too thick to be aspirated by a small needle).
Fluid analysis is an extremely useful diagnostic tool in the evaluation of rheumatic diseases. It should be included in the initial evaluation of most arthritic conditions that generate effusions. It can yield a specific diagnosis in infectious and crystal-induced arthritis and can be helpful in categorization, definition and the diagnosis of other arthritides.