JOINT INJECTION/ASPIRATION

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.

What benefit is derived from a joint aspiration?

Joint aspiration is usually done as a diagnostic or therapeutic procedure. Fluid obtained from a joint aspiration can be sent for laboratory analysis, which may include a cell count (the number of white or red blood cells), crystal analysis (so as to confirm the presence of gout or pseudogout), 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. Injection of a drug into the joint may yield complete or short-term relief of symptoms.

What benefit is derived from a joint injection?

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. Although corticosteroids may also be successfully used in osteoarthritis, their mode of action is less clear. Hyaluronic acid (Hyalgan ®, Synvisc ®) is a viscous lubricating substance that may relieve the symptoms of osteoarthritis of the knee.

What is usually injected into the joint space?

Most joint injections utilize anti-inflammatory medications called corticosteroids (such as methylprednisolone or triamcinolone). These medications act locally and have few systemic side effects (such as a fever, rash, or a disturbance of an internal organ). In degenerative joint diseases such as osteoarthritis, a joint lubricant such as hyaluronic acid (described above) may be used with aim of relieving pain.

Which joints are usually injected?

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.

What are the risks of joint injections and aspirations?

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.

For More Information

For a listing of rheumatologists in your area, check the American College of Rheumatology Find a Rheumatologist feature.

Updated: October 2003

This patient fact sheet is provided for general education only. Individuals should consult a qualified health care provider for professional medical advice, diagnoses and treatment of a medical or health condition.

© 2008 American College of Rheumatology