Joint Injections (Joint Aspirations)
What Is a Joint Aspiration or Joint Injection?
Medication injections, such as corticosteroids, can be used as part of a treatment plan for people with arthritis. A steroid medication (sometimes called “cortisone”) is injected using a needle directly into a joint, such as a knee. The steroid treats the inflammation inside the joint, leading to decreased swelling and pain.
Sometimes joint fluid is removed before the steroid is injected (called aspiration) and then the steroid is injected into the joint. Fluid obtained from a joint aspiration can be examined by the healthcare provider or sent for laboratory analysis, which may include a cell count (the number of white or red blood cells), crystal analysis (to confirm the presence of gout or calcium pyrophosphate crystal disease), and/or culture (to determine if an infection is present inside the joint). Drainage of a large joint effusion can provide pain relief and improved mobility.
Joint injections may decrease the accumulation of fluid and cells in the joint and may temporarily decrease pain and stiffness. The positive effects of steroid injections are not permanent. Often, the improvement in inflammation, swelling and joint pain lasts for a few months before wearing off. In some milder conditions, a joint injection may produce longer periods of disease control.
Possible Risks/Side Effects
Occasional side effects include allergic reactions to the medicines injected into joints, tape or the disinfectant used to clean the skin. Infections are extremely rare complications of joint injections. Another uncommon complication is post-injection flare – joint swelling and pain several hours after the corticosteroid or hyaluronic acid injection – and usually subsides within several days. It is not known if joint damage may be related to too-frequent corticosteroid injections. Generally, repeated and numerous injections into the same joint/site should be discouraged. Other complications may include depigmentation (a whitening of the skin), local fat atrophy (thinning of the skin) at the injection site and rupture of a tendon near the injection site.
Joint injections also should not be given if an infection is present inside or around a joint and if someone has a serious allergy to one or more of the medications that are injected into a joint. If an infection is suspected, aspirating the joint to gather cultures is essential. Be sure to let your rheumatology provider know if you have previously had an allergic reaction to a steroid medication, a sterilizing soap (such as betadine or chlorhexidine), lidocaine or adhesives.
Updated March 2023 by Lisa Carnago, FNP, and reviewed by the American College of Rheumatology Communications and Marketing Committee.
This patient information is provided for general education only. Individuals should consult a qualified health care provider for professional medical advice, diagnosis and treatment of a medical or health condition.