Arthrocentesis

In medicine, an arthrocentesis is the aspiration of fluid from the synovial space of a joint. It may be done to obtain a diagnostic specimen, or therapeutically to evacuate fluid that is creating excessive pressure inside the joint space. Related, an intra-articular injection is a drug administration route into the synovial fluid of a joint space; intra-articular injection may follow arthrocentesis.

The procedure is usually done under local anesthesia. Orthopedists and rheumatologists tend to perform it most often, although it certainly can be used in primary care and emergency medicine.