Joint injections or aspirations (taking fluid out of a joint) are usually performed under local anesthesia in the office or hospital setting. After the skin surface is thoroughly cleaned, the joint is entered with a needle attached to a syringe. At this point, either joint fluid can be obtained and sent for appropriate laboratory testing or medications can be injected into the joint space. This technique also applies to injections into a bursa or tendon to treat tendonitis and bursitis, respectively.
Joint injections are given to treat inflammatory joint conditions, such as rheumatoid arthritis, psoriatic arthritis, gout, tendonitis, bursitis and occasionally osteoarthritis. Corticosteroids are frequently used for this procedure, as they are anti-inflammatory agents that slow down the accumulation of cells responsible for producing inflammation within the joint space.
Commonly injected joints include the knee, shoulder, ankle, elbow, wrist, thumb and small joints of the hands and feet. Hip joint injection may require the aid of an X-Ray called fluoroscopy for guidance. Facet joints of the lumbar spine (low back area) may also be injected by experienced rheumatologists, orthopedists, anesthesiologists, radiologists and physiatrists.
Common side effects include allergic reactions (to the medicines injected into joints, to tape or the betadine used to clean the skin, etc). Infections are extremely rare complications of joint injections and occur less than 1 time per 15,000 corticosteroid injections. Another uncommon complication is “post-injection flare” – joint swelling and pain several hours after the corticosteroid injection – which occurs in approximately one out of 50 patients and usually subsides within several days. It is not known if joint damage may be related to frequent corticosteroid injections. Generally, repeated and numerous injections into the same joint/site should be discouraged. Other complications, though infrequent, include depigmentation (a whitening of the skin), local fat atrophy (thinning of the skin) at the injection site and rupture of a tendon located in the path of the injection.
Are there situations where a joint injection should not be given?
Yes. The most common reasons for not performing a joint injection are the presence of an infection in or around a joint and if someone has a serious allergy to one or more of the medications that are injected into a joint.