No one likes joint injections, least of all in an already painful joint. But it is important to realize that injections can be very effective treatments for arthritis. Whether you have rheumatoid arthritis (RA), osteoarthritis (OA), gout, or bursitis, injections can reduce swelling and pain and improve joint mobility.
Who needs a joint injection?
Joint injections are best for localized pain and swelling – that is, pain and swelling that are concentrated in a single joint. If you hurt "all over," a joint injection is not the best treatment option. But if one joint is giving you particular trouble, a joint injection may be helpful.
Joint injections should not take the place of other arthritis treatments. They should be part of an overall plan of arthritis care that may include oral medicines, exercise, rest, heat and ice, splints, the use of a cane or other assistive devices, and other treatments, depending on the type and severity of your arthritis. If medicine and other conservative treatments are not helping enough and a particular joint continues to be a problem, then your doctor may recommend a joint injection.
There are two main types of joint injections with evidence based literature to support their use: corticosteroid injections and hyaluronic acid injections. Alternative injections (PRP, Prolotherapy, Stem Cells) are being studied, but do not yet have the scientific support in peer reviewed orthopedic published research to be expected to work beyond the ‘placebo effect’. As such, insurance companies do not pay for these alternative injections.
What type of joint injection may help depends on the type of arthritis you have, the joint that is affected, and how your arthritis affects you. Here’s what you need to know about corticosteroid and hyaluronic acid injections, including what they are, what they do, risks and side effects, and other considerations.
Corticosteroids are powerful inflammation-reducing drugs. People with RA and other types of inflammatory arthritis (but not OA) often take corticosteroids such as prednisone by mouth to reduce inflammation throughout the body. When a corticosteroid is given directly into a joint, it reduces inflammation just in that joint, which can result in a decrease in pain and improved mobility.
What do corticosteroid injections do? When a joint is injured, your body tries to heal and protect itself, increasing blood flow to the joint and thereby allowing more immune‑system substances to reach the injured tissue. These changes cause pain, swelling, redness, and heat – the well‑known symptoms of inflammation. Under normal circumstances, inflammation helps the joints to heal and then subsides when the injury has resolved. But in people with arthritis, the inflammatory process does not stop. In time, the inflammation can cause severe pain and restrict normal movement in the joint. It can also damage the joint, weakening the muscles and tendons, eroding the cartilage and bone, and making the joint less stable. Corticosteroids, by limiting the dilation of the small blood vessels in and around the joint, help to reduce blood flow and decrease the accumulation of immune‑system cells associated with inflammation and joint damage.
The preparations of corticosteroids used in injections are different from those used in pills, and they are designed to stay concentrated within the joint. Corticosteroids used for joint injections also come in various strengths; stronger or weaker formulations are used depending on the joint being injected. Commonly used injectable corticosteroids include triamcinolone acetonide, methylprednisolone acetate, dexamethasone sodium phosphate, and betamethasone sodium phosphate. In some cases, your doctor may mix two types of corticosteroids to combine the benefits of a rapid and a long‑acting effect. The doctor may also mix the corticosteroid with a local anesthetic such as lidocaine to provide immediate pain relief or to dilute a less soluble and more potent corticosteroid so that it spreads to a wider area.
Who are corticosteroid injections for? Corticosteroid injections are useful for treating many different conditions in many different joints. They can provide short‑term relief for osteoarthritis in the knees, hips, shoulders and elbows. Gout and pseudogout – both conditions in which crystals in the joint cause inflammation and pain – can be treated with corticosteroid injections as well.
Corticosteroid injections are not only used for joints. They can also be used to treat "soft tissue" conditions such as bursitis and tendinitis. Bursitis refers to inflammation of a bursa, a small sac located near a joint where tendons and muscles attach to bone. Fluid from the bursa lubricates the area to prevent irritation in the joint. Occasionally, the bursa itself becomes irritated, swollen, and sore, and injecting corticosteroids into the bursa can reduce the inflammation. Bursae in the elbows, shoulders, hips, knees, and heels are all candidates for these injections.
Tendinitis is inflammation of a tendon, the connective tissue that attaches muscles to bone. Tendons can become sore from overuse or misuse, and injecting a corticosteroid into the tendon can reduce the discomfort. Common conditions such as tennis elbow or golf elbow are types of tendinitis for which corticosteroid injections are often used.
What are the risks and side effects? Of the risks that come with corticosteroid injections, the most feared is an infection in the joint. Fortunately, the risk of infection is extremely low. Other side effects of corticosteroid injections include flushing of the face, which is common but usually doesn’t last long. Shrinkage (atrophy) or discoloration of the skin at the injection site can also occur. In some cases, a person may have an allergic reaction to something in the injection. Some people have a temporary flare of arthritis in the injected joint that begins a few hours after the injection and lasts a couple of days. (An infection, on the other hand, wouldn’t show any symptoms until several days after the injection.) The flare can be treated with ice and pain‑relieving drugs.
People whose joint pain is caused by an infection – a condition called septic arthritis – should not get a corticosteroid injection. (Septic arthritis is treated with antibiotics and draining of the joint.) In fact, an active infection anywhere in the body would be a signal not to get a corticosteroid injection.
People with poorly controlled diabetes should also avoid corticosteroid injections, as the corticosteroids increase the risk of raising already high blood glucose levels. Even people with well controlled diabetes should still monitor and manage their blood sugars carefully after an injection, as it may take a few days for their blood sugar levels to assimilate to their pre‑injection patterns. People who have been diagnosed with bone thinning (osteoporosis) in the bones surrounding a joint may choose to use these injections carefully as well, because long term use can further weaken bone. Corticosteroid injections are not given into a replacement joint.
Doctors are usually cautious about giving a corticosteroid injection to someone taking a blood‑thinning medicine such as warfarin (Coumadin) or heparin because of the risk of bleeding. If you take one of these drugs, your doctor may test your blood before giving you an injection to make sure you are not at too great a risk of bleeding.
There are a few conditions that should not be treated with a corticosteroid injection. These include Achilles tendinitis or tendinitis in the knee cap (patellar tendon), as these tendons are at risk of being weakened by the corticosteroid drug.
How long do corticosteroid injections last? It depends what problem is being treated. The answer depends on several factors and differs from person to person. In some cases, one injection may resolve the issue permanently. Other times, the benefit of the injection may last only a month or two.
If the pain relief of a corticosteroid injection wears off after a short time, you may need to wait awhile before you have another one. The standard recommendation is that corticosteroid injections should not be given into the same joint more than four times within a year, or every three months if done on an ongoing basis. The concern is that repeated corticosteroid injections could degrade cartilage and weaken tendons or ligaments in the joint. There is also a possibility that too much corticosteroid could get into the bloodstream, which might bring about the same side effects as oral corticosteroids: thinning bones, increased blood glucose, and weight gain. With local injections, however, the risk of these bodywide side effects is thought to be low.
Hyaluronic acid injections
A second, less common type of joint injection uses hyaluronic acid, or hyaluronan, and is sometimes known as viscosupplementation. Many people refer to these as rooster comb shots because some labs harvest the hyaluronic acid from the red comb on the top of a rooster’s head. Some call them "chicken juice", "lubrication shots", "gel shots", "cartilage replacement shots (erroneously)", "joint cushion shots (errounously)", "silicone shots (erroneously)", or "WD40 for the knee (need I even say, erroneously, but I get what they mean)". These injections have been in long use in Europe, and they were approved for use in the United States in 1997. The brands of hyaluronic acid available are Euflexxa, Gel‑One, Hyalgan, Monovisc, Orthovisc, Supartz, Synvisc, and Synvisc‑One.
What do hyaluronic acid injections do? Hyaluronic acid is a substance found naturally in the synovial fluid in the joint. It gives synovial fluid the viscous quality that helps to lubricate and absorb shock in the joint. In a joint affected by OA, there may be less hyaluronic acid in the joint fluid. Injecting a synthetic version of hyaluronic acid into the joint is thought to improve the viscosity of synovial fluid, thereby allowing for smoother movement and reduced pain.
Who are they for? Hyaluronic acid injections are approved by the US Food and Drug Administration (FDA) for knee OA only. They are not approved to treat RA, gout, or OA in joints other than the knee. However, some doctors give them to people with joint damage due to RA or another type of inflammatory arthritis. Although there have been studies of viscosupplementation in the hip joint, they have not been promising, and the FDA has not granted approval for this use.
Viscosupplementation may be used in people whose knee pain greatly interferes with their quality of life and who have not found relief in other treatments, including corticosteroid injections. It is also an option for people who have a health condition that makes them a poor candidate for joint replacement, who are fearful of having a joint replacement, or who for another reason have to wait for some time to have a joint replacement.
The number of injections you receive depends on the type of hyaluronic acid you use. Some have to be given over a course of several injections. Hyalgan and Supartz are given in five weekly injections. Euflexxa is given weekly for three weeks, and Orthovisc is given weekly for three or four weeks. Synvisc is given in three weekly injections. Synvisc‑One, Monovisc, and Gel‑One each require only one injection. Each course of injections should be repeated no more frequently than every six months.
What are the risks and side effects? Possible side effects of hyaluronic acid injections include a post‑injection flare of pain and swelling. People are advised to avoid strenuous or weight‑bearing activity for 48 hours after the injection. Some of the same concerns about corticosteroid injections apply to hyaluronic acid injections as well: People taking blood‑thinning medicines are at greater risk of bleeding after these injections, and an injection should not be given into an infected joint. In addition, people with avian or egg allergies should know that some hyaluronic acid preparations use avian products.
Do hyaluronic acid injections work? Some research has raised questions about the effectiveness of hyaluronic acid injections. A 2003 report published in The Journal of the American Medical Association looked at many studies of hyaluronic acid for knee OA. It found that the injections had "at best, modest efficacy" and that the best available data did not support their effectiveness. A 2009 review by the Cochrane Collaboration (an independent organization that reviews evidence for medical treatments) found that viscosupplementation relieves knee OA pain as well as nonsteroidal anti‑inflammatory drugs (NSAIDs) such as ibuprofen (Advil) with more local reactions but fewer body‑wide side effects. Some of the studies reviewed found that pain relief lasted longer with viscosupplementation than with corticosteroid injections. The American Academy of Orthopaedic Surgeons most recent published guidelines said the evidence for hyaluronic acid injections was inconclusive and did not recommend for or against their use.
The injection procedure
When you receive a joint injection, whether of a corticosteroid or hyaluronic acid, the doctor’s goal is to position a needle into what is called the joint space, the space between the ends of the bones. Before inserting the needle, the physician will feel your joint to determine exactly how to position the needle. Once the entrance point is identified, the physician will clean the area with alcohol and may, depending on the injection, spray the area with a freezing spray. The coldness of the spray helps to reduce pain on the skin from the needle stick.
Ultrasound can be used in the office to aid in localizing the needle in joints or body parts that are difficult to palpate manually, like some shoulder injections.
If you have a joint effusion, ("water on the knee"), before giving the injection, the doctor may first aspirate the joint, or draw fluid out of it using a needle and syringe. The doctor will then examine the fluid by eye and may send it to a lab to evaluate it for signs of infection (white blood cells), injury (red blood cells), crystals (indicating gout or pseudogout), or inflammation. In addition to its usefulness for diagnosis, joint aspiration can cause the joint to feel more comfortable and mobile. Aspirating the fluid in a knee joint also lowers the risk that the fluid will pool behind the knee, a condition called Baker cyst. Once the fluid has been drained, the intended medicine is injected into the joint, and a bandage is placed on the injection site.
And you’re done. You may not feel better immediately, but if you had a corticosteroid injection, within a few days you should notice a reduction in pain and swelling. If you had a viscosupplement injected, it may take a few weeks. If you are unsure about joint injections, remember that keeping your joints healthy helps you maintain a healthy body and a positive outlook. So if you have a problem joint, don’t let an aversion to needles put you off from a treatment that may help you. Talk to your doctor about whether corticosteroid or hyaluronic acid injections are good options for you.
PRP stands for Platelet Rich Plasma. Blood can be drawn from your arm as in any routine blood test, and that tube of blood can be spun in a centrifuge to separate the different cell layers. The small platelet rich plasma layer can then be selectively redrawn into a syringe and re‑injected into a painful area with the hope that this higher concentration of some of your own cells can aid in healing.
Prolotherapy is the process by which high osmotic concentrations (typically of salt water or sugar or cortisone) of small doses of fluid are injected just below the skin in painful body parts in hopes of drawing out swelling from deeper areas. It is not meant to correct any underlying imperfections other than provide a possible short term temporary shift of minor swelling. Research here is controversial
Stem Cell Therapy is a third form of "Alternative Injection" whereby a patient’s own "immature" or "pluripotential" stem cells can be harvested from either their bone marrow or their fat cells elsewhere and reinjected into painful body parts in efforts to deliver cytokines, growth factors, and building blocks for potentially rebuilding tissue. An exciting alternative is Amniotic Stem Cell Therapy. There is a tremendous amount of research being performed and published regarding the pros and cons of Amniotic Fluid derived stem cell therapy. This research has led to widening popularity as an exciting treatment alternative in orthopedic conditions. Read more about this treatment under the separate "Stem Cell" section under the "Services" tab.