An injection of cortisone can bring short-term pain relief to people with tendon inflammation in the shoulder or elbow, but seems to work no better than oral painkillers, according to a research review.

Injections of anti-inflammatory corticosteroids are among the common treatments for various injuries to the tendons, the bands of fibrous tissue that attach muscle to bone at the body joints.

But that is despite a lack of strong evidence that the tactic is effective, according to the researchers on the new review, led by Dr. Cecile Gaujoux-Viala of Cochin Hospital in Montpellier, France.

For their study, the researchers combined the results of 20 clinical trials that tested steroid injections for “tendonosis” of the shoulder or elbow - including “tennis elbow” and tendonitis of rotator cuff in the shoulder.

They found that in the short term - up to eight weeks after treatment - steroid injections were better at easing pain and improving joint function compared with physical therapy or no treatment.

The advantage was not seen over the longer term, however. Nor were the injections more effective than non-steroidal anti-inflammatory drugs (NSAIDs) such as naproxen and diclofenac, in the short or long run.

“This is an important finding,” Gaujoux-Viala told Reuters Health in an email, “since NSAIDs are a widely used and relatively safe therapeutic option in tendonitis.”

And in practice, she noted, steroid injections are usually given only after a patient has tried NSAIDs but failed to get enough pain relief. None of the studies in this review tested that particular strategy, Gaujoux-Viala said.

The review, published in the Annals of Rheumatic Diseases, included a total of 744 tendonosis patients treated with steroid injections and 987 “control” patients who received no therapy, NSAIDs or physical therapy, depending on the study.

While steroid injections brought patients more relief than physical therapy or no therapy for up to eight weeks, there was no evidence they were more effective when patients were evaluated anywhere between 12 and 48 weeks after the first treatment.

The study also found that injections were more likely to work for patients who’d had symptoms for less than 12 weeks, compared with those with longer-standing pain.

“Our results indicate that the optimum timing for steroid injections may be in the early weeks of tendonitis symptoms,” Gaujoux-Viala said - though the usual practice of trying other therapies first still stands.

“I think it is reasonable to wait at least 15 to 21 days, with a treatment combining a short course of NSAIDs and physiotherapy, before trying steroid injections,” the researcher said.

The most common side effects of steroid injections in this study were short-term pain - seen in almost 11 percent of patients - and skin thinning or pigment loss near the injection site. Such skin effects, Gaujoux-Viala noted, can be permanent.

There have also been reports that multiple steroid injections over time can end up weakening the injured tendon and leaving it more vulnerable to rupture. Studies suggest that this risk is small, Gaujoux-Viala said - at least in the relatively healthy people included in most studies, and at the corticosteroid doses used.

SOURCE: Annals of Rheumatic Diseases, December 2009.