Corticosteroid injection overview
PAOS Forum Post by north central regional director Mike Harvey, PA-C, MBA
Corticosteroid Joint Injections
Intra-articular corticosteroid injections are a common modality in the care of musculoskeletal complaints. The typical indications for intra-articular steroid injections include inflammatory arthropathies such as osteoarthritis, rheumatoid arthritis, gout and psoriatic arthritis. Bursitis and tendinitis are other common use of steroid in joints such as the shoulder and hip.
There are several different injectable steroid preparations available. Preparations vary based on solubility, crystal structure, duration of action and chemical structure. Two very common preparations used in orthopedics, are triamcinolone hexacetonide (Kenalog) and methylprednisolone acetate (Depo-Medrol). These preparations are designed to stay at the injection site and exert a local effect. Choice of these two preparations seem to be more driven by user preference, cost, availability and versatility.
Dose selection and local anesthetic mixture seem to vary widely by provider. Often larger doses are chosen for larger joints and the dose is decreased for intermediate and small joints. Lidocaine and Marcaine are often mixed with the steroid preparation. Epinephrine should be avoided in hand and toe injections. The volume of local anesthetic is often varied based on joint size as well. The smaller joints can’t accept as much volume as large joints. Injecting large volume of medication into a joint can result in additional joint discomfort and extravasation into systemic system.
Although complication from joint injections are rare, patients should be informed of the risks.
· Development of a septic joint is the most feared complication. The risk is about 1 in 3000 procedures.
· Facial flushing may occur in about 10% of patients and more common in women. The flushing may last for up to a few days.
· Postinjection flare is one of the more common side effects and occurs in about 5% of injections. It is characterized by localized inflammatory response that should resolve within 48 hours. The flare is thought to be caused by a chemical synovitis in response to the crystals in steroid preparations. Triamcinolone is associated with higher rates of post injection flares due to being less soluble.
· Skin and fat atrophy and skin hypopigmentation may occur at the injection site. Darkly pigmented skin is more susceptible to hypopigmentation and depigmentation.
· Osteonecrosis is uncommon and is reported in 0.1 to 3 percent of injected joints.
· Tendon rupture appears to be associated with injections placed directly into the tendon.
· Nerve injury is associated with injection directly into the nerve sheath.
· There are mixed studies suggesting that repeated steroid injections lead to cartilage loss.
· Steroid injection can lead to transient hyperglycemia which can pose a risk to patients with diabetes. This increase usually resolves in 1-2 days but may want to monitor their levels for up to a week. Patients with uncontrolled diabetes may not be a good candidate for steroid injections.
· Local bleeding is uncommon, but patients on anticoagulation medications are at increased risk for bleeding. Joint injection for patients on warfarin is not contraindicated, but use of smaller needles may be of value and patients with higher INRs are at a higher risk of bleeding.
UptoDate-Joint aspirations or injection in adults: Technique and indications.
UptoDate-Joint aspirations or injection in adults: Complications
UptoDate-Intraarticular and soft tissue injections: What agent(s) to inject and how frequently?
Sam Dyer, PA-C, MHS