Autologous Bone Marrow Grafts Promising for Low Back Pain

Fort Lauderdale, Florida — Interest is growing in the potential for autologous bone marrow injections to treat lower back pain, one of the most common types of pain and among the most difficult to treat.

At this year's American Academy of Pain Medicine (AAPM) 29th Annual Meeting, researchers here reported positive results at 2 years after such biocellular grafts, with additional anecdotal evidence for some patients up to 3 years after injection.

For lead researcher D. Joseph Meyer, MD, PhD, a specialist in anesthesiology and pain medicine in Columbia, Missouri, the results are encouraging. "I think these preliminary observations are very intriguing and in my opinion, they're exciting," he said.

Dr. Meyer hopes these new data will "spark some interest" among his colleagues to develop a prospective long-term study.

Bone Marrow Aspirate

For this study, researchers at the Columbia Interventional Pain Center and at the Bluetail Medical Group in Chesterfield, Missouri, collected data on 24 consecutive patients (17 men; average age, 45 years) who had had low back pain for an average of 4 years and had not responded to numerous treatment approaches. All had evidence of lumbar disc degeneration, as seen on MRI or computed tomography.

Dr. D. Joseph Meyer

From each patient, investigators obtained 60 mL of iliac bone marrow aspirate, which they then spun down and concentrated in a centrifuge device to obtain a 8-mL bone marrow aspirate concentrate (BMAC). They injected 1 to 1.5 mL of this concentrate into each affected lumbar disc annulus under fluoroscopy, and then immediately injected another 0.5 to 1 mL outside the annulus. They treated no more than 2 discs in each patient. Patients also got a small amount of injected steroid.

The whole process "literally took 20 minutes to an hour," said Dr. Meyer.

During follow-up, none of the 24 patients experienced worsening of their pain, although just 12 received only the autologous treatment; the others had other therapies.

Of the12 patients treated solely with disc BMAC, researchers had information on 11 at 5 to 12 months. Of these, 8 experienced significant improvement in their pain, reporting an average of 74% pain relief. They also experienced a significant improvement in being able to tolerate activity and/or a significant drop in medication use.

Dr. Meyer also reported on the 8 patients at 2 years. Five of the 8 had significant pain relief (average 81% pain relief). The 3 who didn't respond in the first year still did not respond in the second year.

Although not included in the poster, Dr. Meyer said that the 3 patients he and his colleagues have tracked out to the 3-year mark "are doing great."

Limitations of the study include the fact that it was an uncontrolled retrospective case review from which no statistical conclusions can be drawn.

Dr. Meyer believes these are the first published findings of this treatment approach in low back pain, which affects an enormous number of people. The pain is typically due to degenerative discs, although it's largely a clinical diagnosis.

"In the vast majority of cases, there's obvious evidence of disc degeneration," said Dr. Meyer. "But there is no one test; it's more considered to be a diagnosis of exclusion."

Treatment options for this type of pain include surgery and spinal fusion, but these interventions garner only mediocre results.

Cellular grafts are the "latest evolutionary development" in the hunt to find an injection that cures low back pain, said Dr. Meyer. In the past, researchers have investigated injections of fibrin, a natural "sealant" that helps in the healing process, and more recently, platelet-rich plasma.

This new approach encompasses bone marrow cells and cells from the body's own fat stores, sources that have "multipotent abilities," said Dr. Meyer.

Such treatments are being investigated for a variety of painful conditions in addition to low back pain, including degenerative joint conditions, arthritis, and sports injuries.

Although he's optimistic about the study's implications, Dr. Meyer is also realistic. "I never use the word 'regenerate'," he said. "There's nothing statistically positive in the poster; these are observations."

However, he said he hopes the results will help define the benefits of BMAC and spur further research. "I hope that as we study this in a more controlled prospective fashion we can refine the technique, and learn what is actually happening."

Catabolic Steroid?

After presentation of the study results, Robert Martin, MD, a sports medicine specialist, Coastal Spine and Pain Center, Jacksonville, and Orange Park, Florida, criticized the treatment approach for including a steroid.

"We have been injecting steroids for years and years and years, and we know that it causes atrophy of tissue," he later told Medscape Medical News. "If you want an anabolic process, if you want tissue to strengthen and growth, you don't put a catabolic steroid in there."

Catabolic steroids are reported to break down muscle mass, while anabolic steroids build muscle mass, he noted. In fact, added Dr. Martin, a steroid will "sabotage" the very reparative process the injection is supposed to stimulate.

It's great that the research team is pursuing an innovative treatment approach, "but my thinking is that if you're going to think outside the box, then get outside the box," said Dr. Martin.

He also pointed out that the patients in the study could have pain in addition to discogenic pain. It's much more difficult to differentiate various types of pain — for example, arthritis and musculo-tendon pain — in patients with back pain than in those with, say, knee pain, he said.

Dr. Meyer has disclosed no relevant financial relationships.

American Academy of Pain Medicine (AAPM) 29th Annual Meeting. Abstract 203. Presented April 11, 2013.