ARTICLE IN BRIEF
Investigators reported that patients with carpal tunnel syndrome who were given a steroid injection had better symptom relief at 10 weeks than patients who were given a placebo injection. But by the end of a year, most patients had undergone surgery regardless of whether they had received a steroid injection, although the patients who had the steroid treatment were less likely to have surgery.
Steroid injections can help temporarily relieve symptoms of carpal tunnel syndrome (CTS), but they do not eliminate the need for surgery for most patients, according to a randomized, controlled trial that followed patients for a year.
Methylprednisolone injections are commonly given to patients with CTS, even though there has been little research on whether the shots do much good in the long term. This latest study, conducted in Sweden, found that CTS patients who were given a steroid injection had better symptom relief at 10 weeks than patients who were given a placebo injection. But by the end of a year, most patients had undergone surgery regardless of whether they had received a steroid injection, although the patients who had the steroid treatment were less likely to have surgery, according to the study, published in the Sept. 3 issue of the Annals of Internal Medicine.
Lead researcher Isam Atroshi, MD, PhD, associate professor of orthopedics at Lund University in Sweden, told NeurologyToday that the findings should help guide doctors in deciding how best to care for patients with CTS.
He noted that a variety of practitioners — including family doctors, neurologists, rheumatologists, neurosurgeons, and hand surgeons — care for patients with CTS and “there has been a large variation in the use of non-surgical treatment among doctors when they treat patients who have exactly the same condition.”
“Some doctors use steroids repeatedly on almost every patient because they believe it is effective and others never use steroid injections because they do not believe they have any benefit,” said Dr. Atroshi, who is chief of the Hand Surgery Section at Hässleholm and Kristianstad Hospitals. “Neither practice has been supported by good scientific evidence.”
The study authors pointed out that in a survey of US hand surgeons, 80 percent reported using steroid injections for their CTS patients. Patients and doctors often wrestle with the question of how long to try nonsurgical options before turning to surgery.
Carpal tunnel release surgery is one of the most common surgical procedures. By some counts, an estimated 500,000 people a year in the US have CTS surgery. Surgical results are typically good, but surgery “has disadvantages, which are mainly surgical-related pain, hand weakness, and complications from surgery,” the new study noted. “The costs of postoperative work absence, which usually lasts several weeks, are high.”
The Swedish research team compared three groups of 37 CTS patients, who were randomized to receive either an 80-mg shot of methylprednisone; a 40-mg injection of the steroid, or a placebo injection. The participants, who were between the ages of 18 to 70, had mild to moderate symptoms of CTS (those with severe symptoms were excluded from the study) and had been treated unsuccessfully with wrist splinting for two months. Nerve conduction tests showed median neuropathy at the wrist. The primary care physicians had referred the study participants to the same orthopedic department because their persistent symptoms warranted consideration for surgery. They were told they could have surgery if they chose after three months in the study if their condition did not improve.
Researchers gathered baseline information on the participants using a battery of assessments, including the 1-item CTS symptom severity scale, which measures daytime and nighttime pain, numbness, and tingling; the 11-item QuickDASH, which measures difficulty in performing daily activities; and the SF-6D survey, which assesses bodily pain.
The primary endpoints were the change in the CTS symptom severity score — rated on a scale of 1 for no symptoms to 5 for severe symptoms — at 10 weeks and the rate of surgery at one year.
“The number of patients who had improved by one point or greater from before to 10 weeks after injection was 38 of 74 in the steroid group and five out of 37 in the placebo group,” Dr. Atroshi told Neurology Today in an e-mail interview.
The relief provided by the steroid injections did not persist, however, and by the one-year mark there were no differences between those who received steroids and those who got the placebo.
Seventy-three percent of those who received an 80-mg steroid injection and 81 percent of those who received a 40-mg injection had surgery, compared with 92 percent of the placebo group. That represents a 21-percent reduction in the need for surgery when the 80-mg group was compared to the placebo group, Dr. Atroshi said. Also, while three out of four patients who got a steroid shot still ended up with surgery, the time to surgery was longer for them compared with the placebo group, he said.
Even temporary relief of symptoms may be helpful for patients who are reluctant to go the surgical route, perhaps because they worry about complications or missing time at work, he said. In other cases, patients may not be good surgical candidates.
“It would be helpful if the treating physician could inform their patient about how big their chance of improvement is and the odds of needing or not needing surgery, and the patients can participate in the decision to try a steroid injection first or choose surgery,” he said.
One limitation of the study is that it was done at a single center and it is not known whether the results would translate into a health care model different from the Swedish system.
Dr. Atroshi said his team is now further analyzing its data to see whether having had a steroid injection has any effect, negative or positive, on surgical outcome.
A bigger goal, the team noted in its report, is to “find a medical treatment that effectively resolves CTS without the need to divide the transverse carpal ligament.”
John C. Kincaid, MD, professor of neurology at Indiana University School of Medicine, told Neurology Today that the research from Sweden was “a well-done study and it needed to be done.”
Dr. Kincaid, whose research focuses on nerve action potentials, said he was surprised that the steroid injections did not give more long-lasting relief and that upwards of three-fourths of treated patients still went on to have surgery within a year.
Still, even temporary relief is good because it could allow time to sort out those patients whose symptoms will resolve without surgery, thus avoiding potential surgical risks and complications, Dr. Kincaid said. A steroid injection may “buy some time.”
Russell Gelfman, MD, assistant professor of physical medicine rehabilitation at Mayo Clinic in Rochester, MN, said there are a few questions left unanswered by the Swedish study: Could repeat injections be used to manage carpal tunnel syndrome long term? Also, what specific patient characteristics make it more likely that surgery will or will not be necessary?
“Carpal tunnel surgery is so common that even if you prevent only 25 percent of people from having the operation, it may be meaningful for the health care system as a whole,” Dr. Gelfman said.
LINK UP FOR MORE INFORMATION:
•. Atroshi I, Florendell M, Hofer M, et al. Methylprednisolone injections for the carpal tunnel syndrome: A randomized, placebo-controlled trial. Ann InternMed
2013; 159: 309–317.
© 2013 American Academy of Neurology
archive on carpal tunnel syndrome: bit.ly/1cm9eM2.
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