Intra-articular corticosteroids. Guide to selection and indications for use.

Physicians have used intra- and periarticular corticosteroids for treating a variety of rheumatic diseases for nearly 50 years. Yet publications that have carefully examined the mechanisms of action, the pharmacokinetics and the comparative safety and efficacy of the available agents are sparse. This limits our ability to choose a drug scientifically. Similarly, we know little about the long term outcomes of joints infected with corticosteroids versus those not injected. Highly branched esters of methylprednisolone or triamcinolone are the preferred agents used by American rheumatologists. Pharmacokinetic studies reveal that triamcinolone hexacetonide, the least soluble of all the corticosteroid esters, is retained in the joint for 2 to 3 weeks. Intra-articular corticosteroids may implement their anti-inflammatory effect by down-regulating genetic expression of several pro-inflammatory proteins. A literature review suggests that judicious use of intra- and periarticular corticosteroids is very helpful in temporarily reducing pain and inflammation in musculoskeletal structures and may facilitate increased motion and function in selected cases. Their use in juvenile arthritis also appears to be safe and beneficial. Infection in or about the joint in the chief contraindication to use. Adverse effects are very few but the number of injections per joint should probably be limited to 4 or less per year.