An experimental new treatment for chronic pain appears to provide substantial relief in some of those with advanced degenerative arthritis.

Recently, scientists have begun treating chronic pain using electrical currents, produced by powerful radio waves, which "stun" certain nerves and slow pain signals on their way to the brain.

For those with arthritis in the knee, studies show this form of nerve pain relief is better than steroid injections and appears to last for up to a year in 65 percent of patients.

A small new paper, presented at a recent conference, now suggests similar benefits for those with chronic hip and shoulder joint pain. 

Today, radiofrequency ablation (RFA) is sometimes used to reduce pain caused by arthritis, but cooled radiofrequency ablation (CRFA) uses internally cooled probes to deliver more energy into the tissue, creating lesions many times larger and providing prolonged pain relief, as well as improved function. 

There are also no significant adverse side effects that have been found. Unlike surgery, the procedure is non-invasive, and unlike pain medication, there's no risk of repeated use or addiction.

The research is still preliminary, but the authors say the results are "very impressive and promising."

"The patients with shoulder pain had a decrease in pain of 85 percent, and an increase in function of approximately 74 percent," says Gonzalez. 

"In patients with hip pain, there was a 70 percent reduction in pain, and a gain in function of approximately 66 percent."

The study was composed of 12 patients with shoulder pain and 11 patients with hip pain, who had become unresponsive to anti-inflammatory pain control and steroid injections. A few weeks prior to treatment, they were given an anaesthetic nerve block near the respective arthritic joint.

At the actual procedure, patients were moderately sedated and given a local anaesthetic. A needle, roughly 50- to 150-millimetres long, was then inserted into several target locations near the main sensory nerves. 

Sliding an electrode through the needle, a pulse of electricity was delivered to the nerve for 1 and a half minutes, raising the temperature of the tissue up to 80 degrees Celsius. 

Three months later, not only did both groups self-report a significant decrease in their pain, they also said they saw an improvement in their joint's dynamic function.

Today, when it comes to joint arthritis, many patients opt for surgery at a certain point, but for those who are poor surgical candidates or those who want to delay surgery, treatments like cooled radiofrequency ablation that provide sustained pain relief could be really helpful.

Especially since some studies suggest cooled radiofrequency ablation perform better than other treatments, like steroid injections, when it comes to sustained pain relief.

"This procedure is a last resort for patients who are unable to be physically active and may develop a narcotic addiction," says Gonzalez.

"Until recently, there was no other alternative for the treatment of patients at the end of the arthritis pathway who do not qualify for surgery or are unwilling to undergo a surgical procedure." 

The results have yet to be published, but Gonzalez is already thinking about the next step. He suspects the therapy can be used for far more than just osteoarthritis.

"We're just scratching the surface here," he says. "We would like to explore efficacy of the treatment on patients in other settings like trauma, amputations and especially in cancer patients with metastatic disease."

The results were presented at the annual meeting of the Radiological Society of North America.