Steroids (short for corticosteroids) are synthetic drugs that closely resemble cortisol, a hormone that your adrenal glands produce naturally. Corticosteroids are different from the male hormone-related steroid compounds that some athletes use.
Steroids work by decreasing inflammation and reducing the activity of the immune system. Steroids are used to treat a variety of inflammatory diseases and conditions.
Avascular necrosis (AVN), also called osteonecrosis, aseptic necrosis, or ischemic bone necrosis, is a condition that occurs when there is loss of blood to the bone. Because bone is living tissue that requires blood, an interruption to the blood supply causes bone to die. If not stopped, this process eventually causes the bone to collapse.
Avascular necrosis most commonly occurs in the upper leg. Other common sites are the upper arm, knees, shoulder, and ankles.
Steroid drugs are available in several forms that vary in how easily they dissolve or how long they stay in the body.
Steroids may be given systemically, which means throughout the "system" or body, or locally to the precise place where a problem exists.
Systemic steroids can be given either through a vein (intravenously, or IV), into a muscle (intramuscularly), or by mouth (orally). Local steroids can be given as eye drops, ear drops, and skin creams, or by direct injection into joints, bursae (lubricating sacs between certain tendons and the bones beneath them), or around tendons and other soft tissue areas.
Why Are Steroids Injected?
Injecting steroids into one or two local areas of inflammation allows doctors to deliver a high dose of medication directly to the problem area. When doctors give steroids by mouth or intravenously, they cannot be sure an adequate amount of the steroid will eventually reach the problem area.
What Conditions Are Treated With Steroid Injections?
Steroids are often injected directly into joints to treat conditions such as rheumatoid arthritis, gout, or other inflammatory diseases. Steroids also can be injected into inflamed bursae, or around tendons near the shoulder, elbow, hip, knee, hand, or wrist.
The decision to prescribe steroids is always made on an individual basis. Your doctor will consider your age, level of physical activity, and other medications you are taking. Your doctor also will make sure you understand the potential benefits and risks of steroid injections.
When Should Steroid Injections Not Be Used?
Steroids should not be injected when there is infection in the area to be injected or elsewhere in the body. If a joint is already severely destroyed, injections are not likely to provide any benefit.
If a patient has a potential bleeding problem or is taking anticoagulants (often referred to as blood thinners), steroid injections may cause bleeding at the site. For these patients, injections are given only with great caution.
Frequent steroid injections, more often than every three or four months, are not recommended because of the increased risk of weakening tissues in the treated area.
What Are the Expected Benefits of Steroid Injections?
Local steroid injections are generally well tolerated and are less likely than other forms of steroid medications to produce serious side effects.
Before a joint is injected with a steroid, joint fluid may be removed for testing. Testing the joint fluid is especially important if the diagnosis is uncertain. Steroid injections often reduce joint inflammation, helping preserve joint structure and function.
Steroid injections may help avoid the need for oral steroids or increased doses of oral steroids, which could have greater side effects.