In a clinical setting, it is not uncommon for patients to arrive for treatment having already undergone a corticosteroid (cortisone) injection from their treating doctor. The trend that has been clear is that some specialists are “cortisone-happy” while others treat it as a last resort. Rehabilitation providers are sandwiched between these two ideologies from the medical profession. The patients themselves spend a great proportion of the initial consultation inquiring about cortisone and its benefits and limitations. The persistent questioning seems to indicate that they may have not been adequately debriefed prior to treatment, which is never ideal.
Admittedly, I am no cortisone expert, nor have I ever had the (dis)pleasure of undergoing the famed treatment, but this divide has left me curious. If my specialist recommended a cortisone shot, would I oblige or object?
Cortisone is a steroid hormone that is produced naturally in the body by the adrenal gland. Cortisone works by attacking the body’s inflammatory response to an acute injury. Cortisone can be applied via injection into the affected soft tissue, directly into a joint space, orally or via a skin cream. Cortisone injection into the affected tissue is the main focus of this investigation.
Cortisone is usually paired with a local anaesthetic and injected directly into the affected area. The most common sites for cortisone injection are the shoulder, elbow, hip, knee and ankle. There is a large discrepancy in the application of cortisone injection by medical practitioners in terms of dosage, frequency of use, sites of application and volumes of anaesthetic that is used.
The research on cortisone injection is extensive although largely not conclusive. Comparing studies is difficult as there are a wide variety of methods in the application of cortisone injections. The literature is focused on a few key injuries that are commonly treated with cortisone. Examination of the evidence helps us determine the effectiveness of cortisone injection.
A Chochrane review on the effect of cortisone injection on shoulder injuries was undertaken by Buchbinder, Green & Youd in 2009. In their analysis, the effects of cortisone injection vs placebo, non-steroidal anti-inflammatory drugs (NSAIDs) and physiotherapy interventions were examined. The authors concluded that:
“Corticosteroid injections may be of limited short-term benefit for shoulder pain.”
They added that small, short-term benefits could also be seen in rotator cuff disease and adhesive capsulitis (frozen shoulder).
In a 2006 study by Bissett et al. exploring cortisone injection, wait and see treatment and physiotherapy treatment in tennis elbow cases was undertaken in a community setting in Brisbane, Australia.
The study concluded that cortisone injection was the most effective form of treatment in the short term but had a significantly higher recurrence rate (72% of success cases regressed) in the mid-long term when compared to physiotherapy and wait and see.
Physiotherapy was found to be the most beneficial treatment in the mid-long-term with wait and see being comparable to physiotherapy after 52 weeks.
Interestingly, participants that were treated with physiotherapy had reduced reliance on alternative relief such as pain medication and anti-inflammatory medication than in the cortisone or the wait and see groups.
Another Chochrane review (Marshall, 2007) dealing specifically with carpal tunnel cases found that local cortisone injection was more beneficial in reducing carpal tunnel symptoms when compared to a placebo injection and oral cortisone tablets. However, the review found no significant difference between cortisone injection and the use of anti-inflammatory medication or wrist splinting. Additionally, they found no additional benefit of having multiple cortisone injections compared to just one.
An analysis of an NFL team’s hamstring injury history over 13 years (1985 – 1998) found that intramuscular cortisone injection helped athletes return to full participation at a quicker rate. Additionally, the study found that there was minimal reduction in muscle power following cortisone injection.
Risks and Side Effects
As with most drugs any potential benefits have to be weighed against the potential risks and side effects associated with the drug’s pathology. Cortisone injection, as with many drugs, comes with inherent risks. One study exploring the side effects in Achilles tendonitis cases concluded that
“The overall incidence of side effects with locally injected corticosteroids is ~1%. Most side effects are temporary, but skin atrophy and depigmentation can be permanent.” (Shrier, Matheson & Kohl III, 1996)
As can be expected with any injection, there is a small risk of infection if the needle passes any contamination through the skin barrier. Signs of infection are redness, swelling, pain persisting for more than 2 days or development of a fever following the injection. Infections can be managed if treated in a timely manner.
One study surveying rheumatologists on the risks of infection following cortisone injection given into a joint space found a low risk estimated at 4.6/100 000 injections. (Pal & Morris, 1999)
A cortisone injection can weaken tendons and potentially result in a rupture of a tendon in a small number of cases.
One study by Sellman (1994) outlining plantar fascia rupture following a cortisone injection concluded that:
“Corticosteroid injections, although helpful in the treatment of plantar fasciitis, appear to predispose to plantar fascia rupture.”
Additionally, another study noted that “Massive rupture of the common extensor origin is an uncommon complication but one with devastating effects.” (Smith, Kosygan, Williams & Newman, 1999)
Post Injection Flare
Post injection flare also known as steroid flare is a common yet minor side effect whereby the surrounding tissue responds with pain and inflammation for 2-3 days following the injection.
There are also reports and evidence suggesting possible acute skin decolouration post injection. Although skin pigmentation is usually temporary, there are a few reported cases suggesting there may be a long term/permanent effect.
There is a small risk of nerve damage if the needle interferes with any nerves although current methodology reduces (but does not eliminate) the risk of damage to nerves.
Long Term Risks
There has been strong evidence linking cortisone injection as well as oral corticosteroid use with diminished bone density. Osteoporosis is limited to the surrounding structures in cortisone injection cases. Osteoporosis is more prevalent in high dose, frequent injections and is at its greatest in the first 6 months of treatment. Fortunately, there have been numerous other medical advancements that attempt to prevent osteoporosis in high-risk patients usually comprising of cyclical etidronate therapy to slow the rate of bone decay.
Repeat and continual use and reliance on cortisone injections can result in weight gain as a result of hormonal imbalances caused by an external hormone supply.
Increased blood pressure can be observed in some cases following repeat cortisone injections.
Cortisone injection is considered to be a safer and cheaper alternative to surgical intervention. As with many drugs, there are inherent risks that each individual needs to account for before consenting to treatment. There are evidently a variety of potential side effects associated with cortisone injection; however, the prevalence of adverse effects following an injection can be considered rare.
Personally, I would turn to cortisone injection as a last resort given the failure of other more conservative treatments. Exercise therapy and physiotherapy have been shown to have vastly positive effects in many cases, with very little associated risk. Waiting and allowing for a natural healing process can also be beneficial with minimal risk undertaken.
In the case that quick relief is required for athletic or work demands, cortisone has some potential to create short-term relief, however individuals need to factor in the potential for long term adverse effects in their decision to undergo cortisone injection.
Bisset, L., Beller, E., Jull, G., Brooks, P., Darnell, R., & Vicenzino, B. (2006). Mobilisation with movement and exercise, corticosteroid injection, or wait and see for tennis elbow: randomised trial.Bmj, 333(7575), 939.
Buchbinder, R., Green, S., & Youd, J. (2003). Corticosteroid injections for shoulder pain. Cochrane Database Syst Rev, 1(1).
Marshall, S., Tardif, G., Ashworth, N., & others,. (2007). Local corticosteroid injection for carpal tunnel syndrome. Cochrane Database Syst Rev, 2.
Pal, B., & Morris, J. (1999). Perceived risks of joint infection following intra-articular corticosteroid injections: a survey of rheumatologists. Clinical Rheumatology, 18(3), 264–265.
Sellman, J. (1994). Plantar fascia rupture associated with corticosteroid injection. Foot \& Ankle International, 15(7), 376–381.
Shrier, I., Matheson, G., & Kohl III, H. (1996). Achilles tendonitis: are corticosteroid injections useful or harmful?. Clinical Journal Of Sport Medicine, 6(4), 245–250.
Smith, A., Kosygan, K., Williams, H., & Newman, R. (1999). Common extensor tendon rupture following corticosteroid injection for lateral tendinosis of the elbow. British Journal Of Sports Medicine, 33(6), 423–424.