Arthrocentesis or aspiration is a treatment to relieve joint pain and swelling. Arthrocentesis is appropriate for larger joints including the knee, hip, sacroiliac, shoulder, elbow, and wrist. It is useful for treating joint swelling caused by infection, gout, and rheumatoid arthritis. Arthrocentesis is also used as a diagnostic tool.
Arthrocentesis involves removing fluid from a joint with a sterile needle and syringe. The joint fluid is sent to a laboratory for examination. Tests often performed on the fluid include cell count, culture, crystal analysis, and rheumatoid factor. Anesthetic and or corticosteroid medications can be injected to help relieve pain and inflammation.