RA Diagnostic Test: Arthrocentesis
A joint aspiration procedure (arthrocentesis) may be performed to obtain joint fluid to test in the laboratory. A sterile needle and syringe drain fluid from the joint, which is then analyzed to detect causes of joint swelling such as arthritis. Removing this joint fluid can also help relieve joint pain. In some cases, cortisone may be injected into the joint during the aspiration procedure for more immediate pain relief.