When shoulder pain from arthritis becomes unbearable and nothing else will touch it, surgeons may recommend steroid injections. Up to one-third of the adult population in America suffers from shoulder disorders at any point in time. So, it’s a problem that affects many people every day.
But in today’s evidence-based medicine, the question comes up: what’s the evidence that injections directly into the shoulder joint (intra-articular) really reduce shoulder pain and stiffness associated with arthritis or adhesive capsulitis (frozen shoulder)?
In this study, researchers from Rush University Medical Center in Chicago, Illinois reviewed the literature from 1948 to 2011 looking for any information, studies, and evidence about the use of shoulder injections. They did not limit their search to articles on just steroid injections but also included hyaluronic acid injections (another form of injection treatment) for shoulder disorders.
We won’t hold you in suspense about the results. They found very few studies and the level of evidence was very weak. In fact, it turns out that current clinical recommendations are all based on expert opinion and consensus (agreement among physicians). Consensus is also based on expert opinion but with experience and case series added in to assist in coming to agreement.
A closer look at the two different injection approaches (steroids versus hyaluronic acid) revealed little scientific evidence to support steroid injections. Steroid injections seem to work better and more consistently for people with adhesive capsulitis compared with shoulder osteoarthritis. Hyaluronic acid injected into the joint may be more effective for both frozen shoulders and arthritis but some high-quality, well-designed studies are needed to provide evidence of this.
Researchers have much to consider when creating future studies in this area. For example, why aren’t there better results with these injections? Is it because of inaccuracy in delivery of the needle (injection) into the shoulder joint? Are results better with more experienced clinicians? Injections are given by many different people — sometimes orthopedic surgeons or primary care physicians but rheumatologists and physician assistants also perform these injections.
Very often, patients are receiving multiple treatments at the same time such as physical therapy and antiinflammatory medications. It’s possible the combination does more harm than good. Or it could be the dosage and specific type of steroid that makes a difference. But what that is for the most effective, optimum results remains unknown.
And finally, the benefits of these kinds of injections must be weighed against the potential adverse side effects. With any injection, there’s the pain of the injection itself — both during and afterwards. Most of the time, this is temporary and only lasts a short time. Joint infection can occur when bacteria is introduced into the joint by the needle pushing through the skin. Anyone with infectious arthritis, a joint replacement implant, or fracture is not a candidate for injection therapy.
With steroid injections, some people have a flare-up reaction that can last several days. Sometimes the protective fat around the joint is lost. It takes the body up to six months to replace or restore this fat. With hyaluronic acid injections, pain and swelling in the joint may get worse instead of better at first. Some people even respond with an acute systemic inflammatory response. It looks like they are developing gout or a blood infection but it’s just a reaction to the injection.
The authors conclude it’s not likely that physicians will stop using steroid (or hyaluronic acid) injections for these two problems. But they are doing so on the basis of very limited evidence. It’s mostly opinion and conjecture and that is not a strong enough recommendation in today’s evidence-based practice.