Joint Injection is usually done as a diagnostic or therapeutic procedure. Fluid obtained from the joint 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 pseudo-gout), 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 are given to treat inflammatory joint conditions, such as rheumatoid arthritis, psoriatic arthritis, gout, tendinitis, 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. Hyaluronic acid (Hyalgan ®, Synvisc®) is a lubricating substance that may relieve the symptoms of osteoarthritis of the knee.
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 the primary goal of pain relief.
This procedure is commonly injected into 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. Usually, 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.