A single injection of the nonsteroidal anti-inflammatory drug (NSAID) ketorolac shows superiority over corticosteroid injections in the treatment of shoulder impingement syndrome, according to a double-blind, randomized study presented at the American Orthopaedic Society for Sports Medicine (AOSSM) 2011 Annual Meeting.
Corticosteroid injections are a common treatment for subacromial impingement syndrome; however, they are associated with some adverse effects, including tendon rupture, subcutaneous atrophy, and changes to articular cartilage. Previous research has shown, meanwhile, that NSAID injections also have efficacy in treating such patients.
In an effort to compare the two treatment approaches, researchers enrolled 48 patients diagnosed with isolated external shoulder impingement syndrome.
The patients were randomly assigned to receive either a single injection of 6 cc of 1% lidocaine with epinephrine and 40 mg triamcinolone or 6 cc of 1% lidocaine with epinephrine and 60 mg ketorolac.
Improvement was assessed according to the University of California– Los Angeles Shoulder Assessment Score, and the results at a 4-week follow-up visit showed that patients in both treatment groups had increased range of motion and decreased pain.
The mean improvement in the assessment score for the NSAID group, however, was 7.15 compared with just 2.13 in the steroid group (P = .03).
The NSAID group showed an increase in forward flexion strength (NSAID, 0.26; steroid, −0.07; P = .04) and improved patient satisfaction over the steroid group.
"These results demonstrate that both groups had good immediate response. However, only the NSAID group had a sustained response," said lead author Kyong Su Min, MD, from the Madigan Healthcare System in Tacoma, Washington.
"Two clinically important and pertinent advantages of NSAID injections are that there is no reported tissue atrophy or cartilage damage with NSAID injections, and the injections are not limited by frequency," he added.
The relief provided by the subacromial injection of both ketorolac and triamcinolone is believed to result from the drugs' local anti-inflammatory effect, he noted.
Ketorolac injections are often used in settings such as college athletics because of their robust pain-relieving properties, said Christian Lattermann, MD, an assistant professor of orthopaedic surgery and sports medicine from the University of Kentucky in Lexington.
"They are extremely powerful and have been used a lot in college sports as a pain medication because of their extremely strong anti-inflammatory effect," explained Dr. Lattermann, who is director of the university's Center for Cartilage Repair and Restoration Medical Center.
Although sparing patients some of the adverse effects of corticosteroid injections, however, the treatment is not without some adverse effects of its own, he cautioned.
"Ketorolac injections are not completely without side effects. They can cause bleeding, and you also have to make sure the kidneys are okay before using them, for instance. In addition, patients cannot take oral NSAIDs while they're receiving injections, so those are some down sides," he noted.
"If someone has a gastric ulcer, you shouldn't use it, and it's not entirely clear whether, in those high of doses, it is more or less detrimental to the rotary cuff than cortisone," Dr. Lattermann stated.
The study is valuable, however, in demonstrating ketorolac's potential efficacy in comparison to corticosteroid injections.
"I think it's a valid study and a very interesting idea and suggests ketorolac may be a useful alternative, particularly if corticosteroid treatment failed," Dr. Lattermann.
The study's authors and Dr. Lattermann have disclosed no relevant financial relationships.
American Orthopaedic Society for Sports Medicine (AOSSM) 2011 Annual Meeting: Abstract 34. Presented July 10, 2011.
Nancy A. Melville • Medscape Medical News © 2011 WebMD, LLC