Osteoarthritis Shoulder Injection Study

Osteoarthritis (OA) affects 54.4 million US adults and 23.7 million (43.5%) have arthritis-attributable activity limitation. As the condition progresses, pain and functional disability increase. Patients usually begin treatment with conservative measures including physical therapy and administration of nonsteroidal anti-inflammatory drugs before obtaining a corticosteroid injection. Corticosteroid injections have a patient-specific duration that often provide relief for a month before the effects begin to taper with most individuals returning to baseline by 2-3 months post injection.

Unfortunately, data on intraarticular injections is not robust and primarily focused on hip, knee, and disease processes rather than the glenohumeral joint. For example, steroid concentrations have been studied in adhesive capsulitis, where 20 and 40mg of triamcinolone acenotide were used with no statistical significance between the two. When a placebo was added, both doses were better than the placebo, but once again no difference was seen between the two steroid concentrations. Another study, looking at knee osteoarthritis, found that high dose steroids had a larger effect on duration, but other studies have shown no difference in duration between the 40mg and 80mg concentration of triamcinolone acetonide.

Intraarticular injections do have adverse effects. Similar to steroids taken orally or intravenously, intraarticular injections have a similar side effect profile. Fortunately, intraarticular injections are localized, by the nature of the procedure, and the chances of experiencing a significant side effect is rare. The most common side effects are steroid flare, allergic reaction, facial erythema, hypo-pigmentation, fat pad necrosis, cutaneous atrophy, and a transient increase in blood glucose. Some of the rare side effects have been seen in case reports include idiopathic central serous chorioretinopathy, decrease in breast milk production, sepsis, tendon rupture, and cataracts. In addition, the administration of steroid injections are limited to being done every three months due to risk of weakening tendons, and acceleration of cartilage loss.

There is a void of literature for understating the ideal injectable steroid concentrations in glenohumeral osteoarthritis. Because of this, providers who perform intraarticular injections tend to perform them based on prior training experience or anecdotal evidence. We aim to evaluate the ideal steroid concentration that will maximize treatment effect for glenohumeral osteoarthritis, but at the same time minimize side effects, and better train our future providers.