Many people with arthritis-related back pain might be prevented from getting long-lasting pain relief under the current management guidelines, US researchers said Friday.

Their findings add to an ongoing controversy about how best to manage this kind of pain, which accounts for up to 15 percent of chronic lower back pain.

Today, doctors perform one or two so-called diagnostic nerve blocks, in which they inject anesthetics into the joints of the spine. If the blocks alleviate the pain, it’s likely that the joint was the culprit.

The next step is to burn the nerves that carry pain signals from the joint with radiofrequency waves, a procedure used in hundreds of thousands of Americans every year, according to Dr. Steven P. Cohen of Johns Hopkins University School of Medicine in Baltimore.

In the new study of 151 patients, published in the journal Anesthesiology, Cohen and colleagues suggest skipping the diagnostic blocks and going directly to radiofrequency treatment.

Doing so, they found, provided 50 percent pain relief for at least three months in a third of all patients; in those receiving one or two diagnostic blocks, 16 percent and 22 percent improved, respectively.

“Maybe we should consider just doing the treatment,” Cohen told Reuters Health, adding that radiofrequency treatment had few side effects and wasn’t any more dangerous than nerve blocks.

“A lot of people could benefit,” he said.

The researchers also found that the cost per successful treatment was lower when doctors didn’t do any nerve blocks, amounting to almost $6,300, or about $10,000 less than when blocks were done.

In a commentary on the study, Jan Van Zundert of Maastricht University Medical Centre in The Netherlands and colleagues said the results suggested current guidelines were “withholding patients from prolonged pain relief.”

Still, most patients with lower back pain wouldn’t benefit from radiofrequency treatment, and so would be treated in vain.

When looking at how many patients actually benefited from the treatment, the rate was almost twice as high in those who had two blocks done compared to those who had none.

As a result, millions of patients worldwide would be candidates for treatment although they might not benefit from it, said Dr. Nikolai Bogduk, a pain expert at the Newcastle Bone & Joint Institute in New South Wales, Australia.

Bogduk, a strong proponent of using nerve blocks, said a true analysis of cost would need to take this into account.

According to Cohen, the cost of radiofrequency treatment is about $650 for the first joint, and $350 per additional joint. A nerve block costs about half, he said.

SOURCE:  Anesthesiology, July 23, 2010.