What is a corticosteroid?
Corticosteroids are artificial chemicals that mimic naturally occurring stress hormones produced in the body at the adrenal cortex (hence the “cortico” portion of the name corticosteroid). The chemical produced by the body known as cortisol, is a fight-or-flight hormone, serving to prime the body for defense including mobilizing sugar and stopping inflammation. It is these very anti-inflammatory properties that are harnessed with corticosteroid injections performed in the office setting.
The wear and tear present in many joint diseases, including arthritis or tendinopathy, generates a reaction in the body to the damage. This inflammatory process causes pain and limitation in function. Steroids work at the cellular level to modulate the response to the damage, thereby alleviating pain. One can think of a corticosteroid injection as a longer-term numbing injection to the affected shoulder, knee, or elbow.
Who is a candidate for a corticosteroid injection?
Corticosteroid injections can be used for a variety of purposes in the orthopedic setting. One of them is for temporary relief of arthritis pain, up to three months(1). Other uses are for short term relief of painful rotator cuff tendinopathy(2). Generally, corticosteroid injections are offered when other simpler, more noninvasive options have been unhelpful, including interventions including home exercises, medications, observation, activity modification, and physical therapy.
Other secondary uses for corticosteroid injections include diagnostic localization of pain source. Many symptoms in and around the joints of the arm or leg do not always originate at the joint. For example, it has been shown that some patients experiencing knee pain can be improved with treatment of the hip(3). In other words, in select instances the hip is causing the knee pain. Other patients can experience cervical or lumbar spine disease that causes nerve pain at the shoulder and knee, respectively. In these cases, it is critical to ensure the source of the pain is confirmed, sometimes based on response to corticosteroid injections, prior to surgical intervention.
What is a corticosteroid injection like?
Corticosteroid injections are performed in the office with or without a numbing spray to make the injection more comfortable. The injection takes about two seconds. Sometimes, the injection is administered right into a painful area and a local anesthetic that is mixed with the steroid component can be helpful to alleviate pain almost immediately.
Because the steroid component of corticosteroid injections works at the cellular level, there is a bit of a delay before the full relief is experienced. This can take several days to take full effect. Prior to the full relief, the injected area can be sore, and elevation and icing can help. Be sure to wait the several days for any relief to materialize and wait until then to form any judgment about the effectiveness of the injections.
What else do I need to know about corticosteroid injections?
If you are a candidate for a surgical procedure such as a joint replacement or a rotator cuff repair, it is not recommended you have an injection in the month(s) preceding your surgery. Not only can injections increase susceptibility to infection after surgery(4, 5), but they can impair the body’s healing response. Additionally, having repeated corticosteroid injections to a tendon can cause some deleterious consequences to the collagen building blocks of the tendon(6), potentially increasing the risk of further damage or tearing.
Lastly, if you experience relief from corticosteroid injection and wish to repeat the injection, it is recommended enough time elapse between injections so they are gone from the painful area and local side effects do not become additive. Approximately three months is considered a safe interval. Generally, multiple repeated injections will eventually stop providing relief and can have other suboptimal effects including a transient rise in blood sugar.
- American Academy of Orthopaedic Surgeons Management of Osteoarthritis of the Knee (Non-Arthroplasty) Evidence-Based Clinical Practice Guideline (3rd Edition). https://www.aaos.org/oak3cpg Published August 31, 2021.
- Mohamadi A, Chan JJ, Claessen FM, Ring D, Chen NC. Corticosteroid Injections Give Small and Transient Pain Relief in Rotator Cuff Tendinosis: A Meta-analysis. Clin Orthop Relat Res. 2017 Jan;475(1):232-243. doi: 10.1007/s11999-016-5002-1. Epub 2016 Jul 28. PMID: 27469590; PMCID: PMC5174041.
- Wang W, Geller JA, Nyce JD, Choi JK, Macaulay W. Does ipsilateral knee pain improve after hip arthroplasty? Clin Orthop Relat Res. 2012 Feb;470(2):578-83. doi: 10.1007/s11999-011-2116-3. Epub 2011 Oct 14. PMID: 21997782; PMCID: PMC3254751.
- Forlenza EM, Burnett RA, Korrapati A BS, Yang J, Forsythe B, Della Valle CJ. Preoperative Corticosteroid Injections Demonstrate a Temporal and Dose-Dependent Relationship with the Rate of Postoperative Infection Following Total Hip Arthroplasty. J Arthroplasty. 2021 Jun;36(6):2033-2037.e1. doi: 10.1016/j.arth.2021.01.076. Epub 2021 Feb 2. PMID: 33618958.
- Forsythe B, Agarwalla A, Puzzitiello RN, Sumner S, Romeo AA, Mascarenhas R. The Timing of Injections Prior to Arthroscopic Rotator Cuff Repair Impacts the Risk of Surgical Site Infection. J Bone Joint Surg Am. 2019 Apr 17;101(8):682-687. doi: 10.2106/JBJS.18.00631. PMID: 30994585.
- Wei AS, Callaci JJ, Juknelis D, Marra G, Tonino P, Freedman KB, Wezeman FH. The effect of corticosteroid on collagen expression in injured rotator cuff tendon. J Bone Joint Surg Am. 2006 Jun;88(6):1331-8. doi: 10.2106/JBJS.E.00806. PMID: 16757768; PMCID: PMC3071041.
At a Glance
Dr. Thomas Obermeyer
- 15+ years of training and experience treating complex shoulder and sports medicine conditions
- Expert subspecialized and board-certified orthopedic care
- Award-winning outstanding patient satisfaction scores
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