The treatment of osteoarthritis is progressive in nature and begins with nonsurgical interventions such as changing activity levels, physical therapy, occupational therapy, heat/ice, pain medications such as ibuprofen or nonsteroidal anti-inflammatory drugs, and injections. Osteoarthritis is the most common form of arthritis. It develops when cartilage, the smooth protective covering of the bones in the joints, breaks down resulting in damage to the surface of the bones causing pain, inflammation, stiffness, and reduced activity. The goal for these types of treatments is to relieve pain, optimize activity level, and delay surgical intervention. There are two very different medications that are used for hip and knee injections. The onset, mechanism and duration of action, and effect vary depending on the exact medication used in the injection.
Steroid medications are synthetic drugs closely resembling the hormones that are naturally produced by the body in the adrenal glands. Steroids are effective in pain relief by diminishing the inflammation in the joint area and by reducing the activity of the immune system. Steroids are sometimes administered systemically (distributed throughout the entire body) by ingestion, intravenously, or intramuscularly. Steroids are also administered locally by drops into eyes and ears, by creams onto the skin, or by the direct injection into joints, bursae (the lubricating sacs between tendons and bones), or into soft tissue areas. Methylprednisolone is the most frequently used steroid medication for this type of injection.
Steroid injections help relieve symptoms in many, but not all, patients by reducing the inflammation in the joint. The decision to move forward with a steroid injection is made only after your doctor has individually assessed your condition and taken into consideration age, current level of physical activity, and other medications that are being taken.
Steroid injections should not be used:
- If an infection is present in the joint or anywhere else in the body
Steroid injections may be administered after careful consideration in patients
- Who have a potential bleeding problem or are on anticoagulants since there is an increased risk for bleeding at the site
Before administering a steroid injection your physician may aspirate joint fluid for testing, especially if a diagnosis is uncertain. A local anesthetic is often administered just prior to the steroid injection or in conjunction with the steroid injection. One needle is inserted, but two syringes are given through the same needle. The immediate pain relief can be attributed to the action of the local anesthetic and then the actual steroid portion of the injection has a rapid onset usually within 24-48 hours. The pain relief typically lasts from six to 12 weeks and serves as an interim treatment until the acute symptoms from a flare up subside. The steroid injection often reduces the joint inflammation thereby preserving joint structure and function. No more than three-four injections per year in the same location, at intervals not closer than every three-four months, are typically administered because it increases the risk of weakening tissues and structures in the injected area. Studies have shown that there is little to no systemic effects from injecting steroids in this manner.
Steroid injections are an effective way to decrease pain and temporarily improve function, but it is important to recognize that they do not cure the disease. Activity modification may be necessary to prevent recurrence of pain after the steroid relief has dissipated. Rarely, side effects such as infection, allergic reaction, localized bleeding, tendon rupture, and skin discoloration might occur.
An alternative to steroid injection for pain relief in patients with osteoarthritis is the use of viscosupplementation. During this procedure, a thick fluid comprised of an extremely large carbon molecule similar to Hyaluronic acid is injected into the joint (most frequently the knee). Hyaluronic acid is a natural substance found normally in the synovial (joint) fluid. Its dual purpose is to act as a lubricant to enable bones to move smoothly and efficiently and to function as a shock absorber for joints. Research studies have shown that people with osteoarthritis have a lower than normal concentration of Hyaluronic acid in their joints.
This injection is often not the first choice injection because Hyaluronic acid is more expensive than steroids but the cost is usually covered by insurance.
Hyaluronic acid may be used
- If symptoms aren’t improved by pain medications or nondrug treatments
- If you are unable to take nonsteroidal anti-inflammatory drugs
- If steroid shots aren’t effective or are contraindicated
Five different versions of Hyaluronic acid injections are available for use. Some types require only one injection, but others require up to five injections to be administered weekly depending on the product that is selected by your physician.
Hyaluronic acid does not have an immediate pain relief effect. Over the course of the series of injections you may experience less pain in your joint. Immediately following the injection a local reaction may occur which includes pain, warmth, and minor swelling. These symptoms, if they occur, are short-lived and can be relieved by the application of ice to the injection site. Rare complications include a localized allergic reaction, infection and bleeding.
This injection might generate effects that can last for several months. Just as with steroid injections, Hyaluronic acid has anti-inflammatory and pain relieving properties, while additionally lubricating the moving parts within the joint. The injection’s effects may last up to several months but as with steroid injections, the medication does not reverse the damage caused by advancing arthritis.
Steroid and Hyaluronic Acid injections can be helpful to those arthritis sufferers who have not responded to the basic nonsurgical treatment options, or for those looking for a bridge to delay the need for a surgical procedure. This intervention, as well as other options, should be discussed with your orthopedic surgeon.
Reference: American Academy of Orthopedic Surgeons