Injectable Corticosteroids

Abstract & Commentary

Synopsis: Injectable corticosteroids are frequently used to decrease musculoskeletal inflammation. While frequently beneficial, this technique is not without potential risks.

Source: Noerdlinger MA, Fadale PD. The role of injectable corticosteroids in orthopedics. Orthopedics. 2001;24(4):400-405.

In this article, Noerdlinger and Fadale discuss the mode of action of corticosteroids, the type of injectable corticosteroids available, the indications and complications following steroid injections, as well as present their technique for instilling corticosteroids into commonly injected sites. The article contains an excellent chart describing the various injectable corticosteroids giving their generic name, trade name, equivalent dose, and recommended doses for the injections of small and large joints. There is also a second chart that details the pathway of inflammatory mediators and indicates the site of action of the corticosteroids. Corticosteroids, derivatives of cholesterol, inhibit phospholipase A2, thus preventing development of arachidonic acid from membrane phospholipid. Arachidonic acid is the precursor of prostaglandins, thromboxanes, and leukotrienes—the mediators of inflammation.

In their discussion on the indications for injecting steroids into tendons, ligaments, tendon sheaths, bursas, and joints, Noerdlinger and Fadale state their purpose as trying "to separate science from fiction," listing references for some of the areas where controversy still lingers over the use of injectable corticosteroids. For example, Noerdlinger and Fadale write that "the literature is inconclusive regarding the effect of steroid injections with tendonitis." They cite studies substantiating benefit and others reporting no difference from placebos following steroid injections in rotator cuff tendonitis.1,2 They further state that the literature is equivocal in regard to the benefit of injectable corticosteroids for lateral epicondylitis. They cite work done previously where, in a blinded study, there was no difference in outcome between oral nonsteroidal anti-inflammatory drugs (NSAIDs) and steroid injections for this overuse syndrome.3

In addition, Noerdlinger and Fadale also emphasize that steroid injections for those with symptomatic arthritis can significantly decrease the pain by decreasing inflammation; however, there are no long-term benefits from such injections.

Comment by Letha Y. Griffin, MD, PhD

Noerdlinger and Fadale stress the dilemma often faced by those treating inflammation of the musculoskeletal system—that is, when do the potential risks of injectable corticosteroids outweigh the benefits? Noerdlinger and Fadale stress the risks of corticosteroids on articular cartilage (primarily potential cellular degeneration) are dose-dependent and believe that "if high concentrations of corticosteroids are avoided the harmful effects . . . can be avoided." However, they do not clearly define "high concentrations." Noerdlinger and Fadale do stress that it is not only the dose but also the time course over which the drug is delivered that influences the development of potential complications, and suggest that low dose, short-term, or intermitted injectable corticosteroids do not significantly affect collagen synthesis and strength. Surprisingly, they recommend injecting corticosteroids into tendons without sheaths, although they caution that the steroid should not be injected as a bolus but instead should be "peppered" into the tendon—ie, small amounts should be injected throughout an area through a single skin puncture site. Most orthopedists would be extremely hesitant to follow this advice over concern for potential tendon rupture. Actually, in their section on injection technique for the Achilles tendon, Noerdlinger and Fadale do caution against injection corticosteroids into the substance of this tendon.

Noerdlinger and Fadale only briefly mention the potential development of avascular necrosis following injection of corticosteroids and do not provide the reader with any reference for further information on this feared, yet rarely reported, complication from corticosteroids. Additionally, the article would also have been greatly enhanced if Noerdlinger and Fadale had chosen to include diagrams to compliment their text on injection techniques. Not withstanding the above comments, this article is a nice review on the use of injectable corticosteroids in the treatment of musculoskeletal inflammation.

References

1. Adebajo AO, et al. A prospective, double blind, dummy, placebo controlled study comparing triamcinolone hexacetonide injection with oral diclofenac 50 mg TDS in patients with rotator cuff tendonitis. J Rheumatol. 1990;17:1207-1210.

2. Withrington RH, et al. A placebo-controlled trial of steroid injections in the treatment of supraspinatus tendonitis. Scan J Rheumatol. 1985;14:76-78.

3. Saartok T, Eriksson E. Randomized trial of oral naproxen or local injection of betamethasone in lateral epicondylitis of the humerus. Othopedics. 1986;9: 191-194.