There's new hope for low back pain. Researchers are injecting a protein into worn out spinal discs to see if it will stimulate the growth of new cartilage, making the disc almost like new again.

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Spinal Disk Problems
In young, healthy people, the spinal disks have a high water content to help them maintain flexibility and strength. As we age, the disks can gradually lose some of their water content and become less flexible. The affected disks shrink, reducing the space between the vertebrae putting pressure on the nearby spinal nerves. In addition, the tough outer covering can develop tiny cracks or tears. The gel-like contents may seep out and press on the spinal nerves. This is called a herniated disk.

Most herniated disks occur in the low back, in the area below the waist. A patient may experience a sharp, shooting pain (called sciatica) that extends from the buttocks down the back of the leg. Other symptoms may include: weakness, numbness or tingling in the leg, loss of bladder or bowel control or a burning pain centered in the neck.

According to the American Academy of Orthopaedic Surgeons, more than 4.3 million patients visited physician offices for spinal disk problems in 2005. The risk for degenerative disk disease increases with age. Repetitive strenuous activities, smoking, being overweight, sudden pressure on the back and improper lifting increase the risk for a herniated disk.

Treating Degenerated Disks
Jeff Fischgrund, M.D. is an Orthopedic Spine Surgeon with Beaumont Hospitals in Michigan. He says most people with pain from disk degeneration eventually get better without any treatment. Medications (over the counter or prescription) can reduce pain and inflammation. Physical therapy and/or exercise therapy may also be helpful. When pain persists, doctors may recommend surgery to stop the disk from pressing on the spinal nerves. Part or all of the disk may be removed (called a diskectomy). To restore the separation between the upper and lower vertebrae, tiny metal rods and screws may be placed in the spine to hold the vertebrae apart. Then, small fragments of bone are placed into the disk space. As the bone fragments heal, they form a solid piece of bone that fuses the top and lower vertebrae into a single segment. This is called spinal fusion.

In 2005, more than 325,000 spinal fusions were performed in the U.S. Spinal fusion provides pain relief for about 80 percent of patients who undergo the procedure. Fusion leads to a loss of motion in a very small area of the spine. Most people don’t notice much of a difference in their ability to bend. However, research shows that, over time, spinal fusion can put pressure on the adjacent spinal disks (above and below the affected vertebrae) and can lead to deterioration of those disks.

An Experimental Alternative
Many researchers are looking for another way to treat degenerated disks without having to perform a spinal fusion. At Beaumont Hospitals, investigators are testing an injectable product called Osteogenic Protein 1 (OP-1, also known as recombinant human bone morphogenetic protein-7, or rhBMP-7). OP-1 is a laboratory-made liquid version of a protein that’s made by the body. When injected into bone, it stimulates the formation of new bone. Injection into cartilage stimulates growth of new cartilage.

Now doctors are trying injections of OP-1 into degenerated spinal disks. The goal is to see if the treatment will stimulate enough cartilage growth inside the disk to restore the natural height of the disk and take the pressure off the spinal nerves. Doctors use X-rays to confirm the location of the disk and the placement of the needle. Then the OP-1 is injected inside the disk. The injection takes only a few minutes. The patient is monitored for a few hours to make sure there is no reaction to the injection, then sent home. Participants are back to normal activities within 24 to 48 hours.

In animal studies, the treatment restored disk height within 6 weeks. In humans, the OP-1 disk injections are in early phase 1 trials. Half the patients are getting the OP-1 and half are getting a placebo. Fischgrund estimates it may take several months to see an improvement in those who have received the real drug. If the treatment proves to be safe and effective, doctors will start larger, long-term studies of OP-1. Currently, no one knows how long the treatment will last. Fischgrund says it’s possible patients may need to have periodic booster injections of OP-1 to maintain its effects.

AUDIENCE INQUIRY
New studies on the protein may start up in the Spring of 2009. For more information call 248-551-3533.

For general information on back pain,
American Academy of Orthopaedic Surgeons, public website, http://orthoinfo.aaos.org
National Institute of Arthritis and Musculoskeletal and Skin Diseases, http://www.niams.nih.gov
North American Spine Society, http://www.spine.org