Corticosteroid or steroid injections are commonly used to treat a variety of inflammatory conditions of the upper extremity. Examples of these include steroid injections for trigger finger (stenosing tenosynovitis), de Quervain’s tendonitis, carpal tunnel syndrome, arthritis, tennis elbow (lateral epicondylitis), and rotator cuff tendonitis (see Figure 1).
What is a corticosteroid injection?
Steroid injections typically contain a mixture of a synthetic cortisone and a local anesthetic such as lidocaine or bupivacaine. Cortisone is a steroid normally produced by the adrenal gland and is a powerful anti-inflammatory. There are several available synthetic preparations such as triamcinolone, betamethasone, and dexamethasone, and they are also commonly referred to by their trade names. They all have similar mechanisms although they vary in strength and duration of action (short versus long-acting). No single preparation has been found to be superior to others so the choice of medication is left up to the individual provider. These anti-inflammatory steroids are distinctly different from the anabolic steroids that have been abused by some athletes for body-building and performance enhancement. The local anesthetic dissolves the steroid and anesthetizes the area of the injection, diminishing discomfort during the procedure.
How does corticosteroid injection work?
Steroid injections work by decreasing inflammation. Once the inflammation subsides, the associated pain usually improves as well.
How are steroid injections performed?
The area to be injected is first cleansed with an antiseptic such as an iodine preparation,alcohol, or other skin disinfectant. The injection is then given with a small needle (see Figure 2). Typically, only a small amount of steroid and local anesthetic is injected. Afterwards, the area is covered with gauze or an adhesive bandage.
Steroid injections should take effect within a few days and the benefits can last for many weeks. The exact timing, however, varies from patient to patient. For some conditions, one injection can be sufficient to completely get rid of the inflammation and pain while for more severe cases, several injections may be required. Most patients respond well to injections although a small subset may not experience any relief of symptoms.