Orthopedic surgeons, primary care physicians, and rheumatologists often use steroid injections into the shoulder to relieve the pain and reduce inflammation in patients with adhesive capsulitis (also known as “frozen shoulder”). But the optimal dose of steroid remains unclear. Current practice is not based on scientific evidence, but rather, experience, cost, and availability of the drug.
In this study from South Korea, surgeons from the Ajou University Medical Center propose that a high-dose corticosteroid would perform better than low dose in terms of reducing pain and restoring function. To test their hypothesis, they set up a randomized, triple-blind, placebo-controlled dose-comparative study. Triple blind means that no one (not the patient, not the person injecting the drug, and not the evaluator) knew who was getting what (drug, drug dose, placebo).
There were 53 total patients divided (randomly) into three groups: low-dose corticosteroid (20 mg triamcinolone acetonide), high-dose steroid (40 mg of the same drug), and placebo (saline injection). The two dosages selected were based on current practice by most physicians. Injections were guided using ultrasound for accurate placement of the drug or placebo. Everyone in all three groups was given a 10-minute follow-up exercise program to do three times daily for 12 weeks.
Outcome measures included pain level, range-of-motion, function, and level of disability. All patients were tested before treatment and again after treatment at regular intervals (one week, three weeks, six weeks, and 12 weeks after injection).
There is much concern about using high-dose corticosteroid drugs because of the potential for negative (adverse) effects. Other studies have shown that higher levels of steroid can cause complications and problems. For example, changes in skin coloration, tendon ruptures, nerve lesions, and loss (atrophy) of tissue have been reported. But too low of a dose might not provide the desired change in symptoms, so determining the optimal dose for this particular problem would be very helpful.
Everyone in the study got better. The two steroid groups had significantly more improvement than the placebo group. But there were no significant differences between the low- and high-dose patients in terms of pain, motion, and function. A few patients experienced some reactions to the drugs (e.g., facial flushing, dizziness) but no one had any infections, skin or soft tissue changes, or other adverse effects.
The authors concluded that a 20-mg dose of steroid injection given early on in the course of adhesive capsulitis is advised. This gives the same benefit as higher dose treatment but with lower risk for local and systemic side effects.
They further commented that this particular drug is a long-acting corticosteroid. Different results might be obtained if using a short-acting steroid. This is also a short-term study and results may change as time goes by. Further follow-up of these patients will be done and outcomes reported at a later date.