Steroids offer mostly short-term carpal tunnel relief

By Kathryn Doyle

Steroid shots for carpal tunnel syndrome may help some patients in the short term, but most people end up having surgery whether or not they get the shots, according to a small new study.

Researchers in Sweden found that one year after diagnosis, three quarters of carpal tunnel patients who tried steroid shots and other treatments first had opted for surgery while more than 90% of those who did not get the shots had the surgery.

"We did not know how effective steroid injections are so we were not expecting any particular result," said lead author Dr. Isam Atroshi of Hässleholm Hospital.

The finding that steroids usually don't help enough to avoid surgery was "somewhat surprising," since many doctors routinely order the shots, Dr. Atroshi told Reuters Health.

He and his coauthors gave injections of 40 or 80 mg methylprednisolone, or a placebo, to 111 adults with carpal tunnel syndrome who had already tried wrist braces with no luck.

Ten weeks later, patients who had received the steroids were less likely to report pain, numbness or tingling than those who got a placebo.

At the one-year mark, however, 73% of the patients who got the 80 mg steroid shots had the surgery, as did 81% of patients who got the lower steroid dose and 92% of those who had a placebo shot.

Although patients who got the highest dose of steroids were less likely to have surgery by one year, there were no differences between the three groups in reported pain at that point, according to the results published online September 3 in the Annals of Internal Medicine.

Complications are unlikely with either treatment, Dr. Atroshi said.

"Surgery is effective because, by dividing the ligament that forms the roof of the tunnel, or 'opening' the carpal tunnel, there will be a rapid dramatic decrease in the pressure and symptom relief, and the effect is usually durable," he said.

The cause of carpal tunnel syndrome is not completely known, but it's not surprising that surgery is more effective than shots, according to Dr. Charles Leinberry, a hand surgeon at the Rothman Institute in Philadelphia.

Steroids temporarily reduce local swelling and relieve pressure in the tunnel, but surgery actually makes the tunnel bigger and is a permanent solution, said Dr. Leinberry, who was not involved in the study.

"Surgery adds approximately 25% to the volume of the carpal tunnel area and provides more room for the tendons and nerves present in the tunnel," he said.

Experts didn't think the new study's results would change the way carpal tunnel syndrome is treated.

Splints are usually the first-line therapy, and they can be very effective when used early, Dr. Leinberry said. He noted that imaging is usually done to assess the disease.

Steroids can help control pain for a short while if the disease is not severe, but can probably be skipped if the carpal tunnel syndrome is severe and requires surgery, he said.

Dr. José Luis Andreu at Hospital Universitario Puerta de Hierro Majadahonda in Madrid published a similar study in 2005 that found only 42% of patients who received triamcinolone shots ended up getting surgery. In his study, the patients could have a second shot if the first failed.

Steroids can be safe and effective, and are much simpler than surgery, but patients with moderate to severe carpal tunnel should be treated with surgery, he said.

"You should consider that a proportion of patients will need surgery after the injection because of lack of adequate response, but a proportion of patients will not need surgery and a lot of time and money will be saved," Dr. Andreu told Reuters Health by email.

Surgery is always more expensive than steroid injections, "however surgery is usually a permanent solution and therefore in the long run is more cost effective since it provides a cure," Dr. Leinberry said.

SOURCE: http://bit.ly/15wpbjP

Ann Intern Med 2013.