Ozone Gas Used to Relieve Lower Back Pain

A minimally invasive technique that uses oxygen and ozone to alleviate lower back pain associated with herniated disks is proving to be a cost-effective treatment.

Kieran J. Murphy, M.D. University of Toronto

The procedure involves injecting a mixture of oxygen and ozone directly into the injured disk using image-guidance. As a result, the disk's volume is reduced and so are pain and inflammation. Researchers who conducted a meta-analysis of 48 peer-reviewed studies on the treatment—that included more than 8,000 patients—confirmed its effectiveness. They predict the treatment could become widely adopted in the U.S. within the next several years.

"A small reduction in volume is a big reduction in pressure," said study author Kieran J. Murphy, M.D., who presented the results at the Society of Interventional Radiology annual meeting in San Diego in March. "The benefit of ozone over other treatments, which generally work by removal or local dissolution of disk material, is that ozone just reduces the volume a little bit and lets the injured disk heal itself."

Dr. Murphy, an interventional neuroradiologist and vice-chair and chief of medical imaging at the University of Toronto, said the standard surgical treatments for herniated disk are open diskectomy and microdiskectomy, both of which involve removal of disk material and require longer recovery times than the ozone treatment.

Americans spend at least $50 billion each year on low back pain, the most common cause of job-related disability and a leading contributor to missed work, according to the National Institute of Neurological Disorders and Stroke, a part of the National Institutes of Health.

"Any radiologist who can do a discogram can do the ozone procedure," said Dr. Murphy. "It is very simple, using a 22-gauge needle."

Dr. Murphy and colleagues also conducted a second study to determine how the oxygen/ozone treatment works. Dr. Murphy said that study began in 2003, as he listened to a radiology lecture in Italy.

"I was sitting there listening to a study about using ozone in this manner and I thought the guy who was speaking was either mad or brilliant," he said. "I mean, this is really chemical engineering, not what you think of as medicine."

After his trip to Italy, Dr. Murphy spent five years studying the mechanism of action. "I wanted to develop a safe way to deliver the ozone into the disk, which early research had not yet done," he said. "In order to do this safely, you also need to have a generator that makes the ozone."

The meta-analysis indicated that the estimated mean improvement for patients after treatment—based on the 10-point visual analog scale (VAS; 0 being no pain and 10 being the worst pain), a standard tool for rating the effects of back pain—was a change of 3.9. The estimated mean improvement was 25.7 percent when using the Oswestry Disability Index (ODI), which measures one's ability to conduct everyday life activities such as washing, dressing or standing. An ODI score of 61 percent or higher represents back pain that has an impact on all aspects of daily living.

Researchers found the VAS and ODI improvement scores to be well above both the minimum clinically important difference and the minimum statistically significant detectable change, indicating that there are real changes that can be felt by the patient.

"The improvement in pain and function was impressive when we looked at patients, who ranged in age from 13 to 94 years, with all types of disk herniations," said Dr. Murphy. "This treatment really can help a lot of people."

Researchers who conducted a meta-analysis of a treatment using oxygen and ozone to alleviate lower back pain associated with herniated disks confirmed the approach as both effective and affordable. Researchers predict that the treatment could become widely adopted in the U.S. within the next several years. Shown is a CT image of the L2-L3 disc of a patient before and after the ozone-oxygen injection. Image courtesy of the Society of Interventional Radiology (SIR). From "A Meta-analysis of the Effectiveness and Safety of Ozone Treatments for Herniated Lumbar Discs," presented at the SIR 2009 annual meeting.

Much of the research in oxygen/ozone treatments has been done by interventional radiologists in Italy, with thousands of people there receiving the treatment over the past five years.

This procedure could become routine in the U.S. within the next several years, said Dr. Murphy. "So many people have already been successfully treated in Italy, Europe and China with this technique, which sets the groundwork for us to move forward to get U.S. Food and Drug Administration and Health Canada approval."

Daniel B. Brown, M.D., a professor of radiology and division chief of interventional radiology at Thomas Jefferson University Hospital in Philadelphia, applauded the concept of Dr. Murphy's studies.

"The whole idea of getting the pressure off those nerve roots just by injecting a small volume into a disk is very clever," Dr. Brown said. "It's already been used a lot outside of the U.S. and with great success. Dr. Murphy has developed a method for doing it more simply and what's also nice is that you can do it with a small needle and a permanent implant is not required."

While minimally invasive techniques, such as thermal ablation, can be used to treat patients with herniated disks, Dr. Brown said the ozone technique is less painful and more cost effective.

"Lower back pain is a very common, challenging problem," he said. "The burden on society from back problems is horrible. The best technological advances are ones that are simple and can help a large number of people and this seems to really meet those criteria."

The potential to benefit a large number of people worldwide is what makes the ozone treatment special, said Dr. Murphy. "This remarkably safe and cost-effective treatment crosses economic boundaries between our hospitals in America and any hospital in the world," he said. "You come up with something simple and cheap and you can affect the lives of hundreds of thousands of people every year. That is relevant."