Back Trouble? Blue Dye Shot May Offer Long-Lasting Pain Relief

(Istockphoto)

By Amanda Gardner

In March, a team of orthopedic surgeons in China reported that they had successfully treated low back pain by injecting a commonly available chemical into their patients' spines. The results of this simple and novel treatment were so extraordinary that they seemed to belong in an infomercial rather than a medical journal: Ninety percent of the patients experienced total or near-total relief.

How could it be? The type of low back pain featured in the study is notoriously difficult to treat. Caused by wear and tear to spinal disks, it often requires medication, cortisone shots, physical therapy, surgery, or all of the above—none of which is guaranteed to work. And yet the researchers claimed that a single shot of the chemical, known as methylene blue, relieved pain for two years in most patients.

"The results were astounding," says Nikolai Bogduk, MD, a professor of pain medicine at the Newcastle Bone and Joint Institute, in Newcastle, Australia. "If validated, this treatment will change the landscape monumentally. Patients will be able to get a one-stop, rapid fix—much like having abdominal pain fixed by having their appendix out or their gallbladder removed. But with less risk."

Dr. Bogduk was even more effusive in an editorial that accompanied the new study, which appears in the April issue of the journal Pain. The procedure would make spinal surgery "essentially obsolete" and would be "worthy of nomination for a Nobel Prize," he wrote, "if"—and here's the catch—"the results are true."

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Don't call your doctor to schedule an appointment just yet, in other words. While spine experts acknowledge that the treatment described in the study is credible, they are quick to add that the results may, in fact, be too good to be true. Other researchers need to replicate the study's findings before the treatment is put into use, they say. Plus, if injected incorrectly, the dye can be toxic—and could even make back pain much worse.

"If the results worldwide are what is reported here, then, yes, the treatment of back pain will change dramatically and it's worthy of significant attention," says neurosurgeon L. Gerard Toussaint III, MD, an assistant professor of neuroscience and experimental therapeutics at Texas A&M Health Science Center College of Medicine, in College Station.

Experts say that's a big "if." And yet, if future research yields results even close to what the Chinese surgeons reported, methylene blue could offer hope to the millions of people in the U.S. with chronic disk-related back pain.

Next page: More than just a pretty color

More than just a pretty color

Methylene blue is a versatile chemical. Although the bright blue substance is most commonly used by orthopedic surgeons and other specialists as a dye or "magic marker" during medical procedures, it's more than just a pretty color; doctors have used it to treat a wide range of ailments, including malaria, urinary tract infections, intractable anal itching, and Alzheimer's disease.

When injected, the chemical appears to kill off nerve endings and receptors that are responsible for sending pain signals to the brain. The team of researchers in China, led by Baogan Peng, MD, have used methylene blue to treat pain stemming from bone fractures, and in an unpublished study involving mice, they managed to destroy nerves in a disk lesion without harming the actual disk.

No nerves, no pain: That was the researchers' hypothesis. And it makes sense, says Anders Cohen, MD, the chief of neurosurgery and spine surgery at the Brooklyn Hospital Center, in New York City.

Disk-related (or discogenic) low back pain—which accounts for up to 43% of all low back pain cases, by some estimates—occurs when the nerves surrounding the lining of a damaged disk become irritated, Dr. Cohen explains. "Theoretically, [injecting] something to kill off nerve endings that are flaring in this disk could work," he says.

A viable treatment?

The study published in Pain included 72 patients who were considered candidates for spine surgery. The patients, who ranged in age from 20 to 65, had suffered from disk-related low back pain for at least six months and hadn't found relief from physical therapy, opioid medications, or nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen.

Instead of surgery, the patients had the troublesome disk in their back injected with either a shot of a 1% methylene blue solution or a saline placebo shot. The patients were then evaluated six months, one year, and two years later. Neither the patients nor the physicians who assessed them knew which patients had received methylene blue or placebo.

By six months, the patients who received the methylene blue injection experienced far less pain, on average, than the patients in the placebo group. At the two-year mark, 33 of the 36 methylene blue patients reported that they experienced only slight pain and used medication occasionally or never. One-fifth of the patients declared themselves cured, with no pain or disability whatsoever.

The results in the placebo group were strikingly different. After two years, 85% of the patients said they still experienced "moderate to severe" pain, and 43% said they still used pain medication on a regular basis.

The success rate of the methylene blue injection was at least as good as those seen with disk-replacement or spinal fusion surgery, the researchers noted.

"Our study has demonstrated that this treatment is a very effective new method," Dr. Peng says. "I think that it is revolutionary in the treatment of discogenic low back pain."

Next page: Results need to be replicated

Terry Amaral, MD, an orthopedic surgeon at Montefiore Medical Center, in New York City, says that methylene blue injections "could be a viable option" for disk-related low back pain, but that the results need to be replicated in other trials, preferably in other parts of the world. (Dr. Bogduk, in fact, has already received approval from the Newcastle Bone and Joint Institute to conduct a methylene blue study in Australia.)

"Back pain is not just physical," says Dr. Amaral. "There's a big psychological component, and cultural differences may play a role. Scientifically, kill[ing] off the nerves to get rid of pain makes sense, but it has to be proved in complex patients with many different factors involved."

Dr. Toussaint says that methylene blue may prove less effective in a broader patient population. The patients in the study were unusual in that they had only disk-related back pain, he says, and he points out that the study did not address whether methylene blue could be effective in patients who have disk-related back pain in addition to other back problems.

"I rarely see a patient with an isolated fissure in one disk and every other part of the spine looks normal. It's usually in combination with other things," says Dr. Toussaint, who practices at the Texas Brain and Spine Institute, in Bryan. "My real question is whether this is generalizable."

In the wrong hands, a risky procedure

Methylene blue injections are minimally invasive (especially compared to surgery), but they do carry some risks. Although in this study Dr. Peng and his colleagues reported no complications in the patients who received methylene blue, the chemical has proven dangerous in the past.

If used incorrectly, methylene blue can be toxic. In 2009, a Florida jury awarded a woman more than $38 million in damages for injuries she suffered from methylene blue following a botched surgery to fix a herniated disk. During a follow-up procedure, a neurosurgeon improperly injected the woman's spine with methylene blue (as a dye) to find the location of a spinal fluid leak. As a result, the woman experienced debilitating pain throughout her body, according to a report in the Miami Herald.

The same thing that makes methylene blue a credible treatment for disk problems also makes it dangerous, explains Victor Khabie, MD, the co-chief of orthopedic surgery at Northern Westchester Hospital, in Mt. Kisco, N.Y. "Methylene blue is a very corrosive substance to the spinal cord and covering," he says. "If it leaked out to the spine [during this procedure], it could cause an issue."

Dr. Bogduk says that methylene blue is safe—as long as it's administered correctly. Disk injection is easy for experienced surgeons accustomed to injecting cortisone, he says, but inexperienced or careless physicians armed with methylene blue could indeed pose a hazard.

"At this stage, I do not see any drawbacks to the drug itself," he says. "It will be doctors, not the drug, that produce drawbacks."