For decades, people with lower-back pain were often told there was only one real solution to their misery: spinal fusion, in which two or more bony vertebrae are surgically “welded” together in hopes of reducing pain and stabilizing the back.

The trouble is, there has never been compelling evidence that this works well, partly because new problems, such as stiffness and increased pressure above and below the fused vertebrae often occur. And the risks are serious – life-threatening bleeding and accidental nerve injury leading to pain or weakness.

Happily, two developments are increasing the options for millions with aching backs: potentially better surgery and a new attitude toward exercise.

Late last fall, the US Food and Drug Administration approved the first artificial (plastic and metal) disc, called Charite. This disc, made by a Johnson & Johnson company, is surgically implanted between vertebrae to replace the natural spongy material that can bulge or dry out with aging. Other companies are also developing artificial discs for lower-back pain; research is also underway for artificial discs for the neck.

So far, about 1,000 American surgeons have started doing this surgery, said the medical director of the Spine Institute at St. John’s Hospital in Santa Monica, Calif., Dr. Rick Delamarter. Though there is little long-term data, early results suggest it may be equivalent to fusion in success with pain reduction but allows quicker recovery, more flexibility, and fewer problems in adjacent areas of the spine.

There is also growing evidence that many people do not need surgery at all. In 2001 a landmark Swedish study showed that while fusion did decrease pain (by 33% in the surgery group, versus 7% in the non-surgery group), after two years of follow-up, no differences were noted.

A Norwegian study in 2003 showed that an aggressive exercise program paired with cognitive behavior therapy reduced pain just as much as fusion after one year. (One key was teaching people that, contrary to their fears, it is safe to be physically active despite pain.) And a still unpublished English study found similar results.

Taken together, the three recent studies “show little or no advantage of fusion. After five to 10 years, everybody looks pretty much the same. The folks without surgery gradually get better on their own, and the ones who do have surgery have faster improvement but gradually have back pain again,” said the director of the multidisciplinary research center on spinal disorders at the University of Washington in Seattle, Dr. Richard Deyo.

“The trouble is,” he said, “American surgeons don’t believe these results.”

In 2002, the latest year for which figures are available, 293,000 Americans had the fusion surgery, according to the North American Spine Society, and the numbers have been rising every year. The operation is lucrative, not just for surgeons and hospitals, but for companies that make the special screws and “cages” to hold vertebrae together. The hardware alone can cost $5,000 to tens of thousands for one operation.

And many respected surgeons swear by the procedure, among them Dr. Richard Guyer of the Texas Back Institute, who said that 75% to 80% of people who have the operation say it helped them.

But the tide seems to be turning away from fusion surgery, at least for some patients.

“Non-fusion technologies such as artificial discs represent a paradigm shift in the surgical treatment of degenerative spine problems,” said the chief of spinal surgery at the Hospital for Special Surgery in New York, Dr. Frank Cammisa.

Some kind of surgery is necessary when there is a loss of bladder or bowel control, progressive weakness in the legs, paralysis, and pain that shoots down the leg (sciatica) that doesn’t get better over time. Surgery may also be necessary with spinal stenosis, when the spinal canal, through which the spinal cord passes, becomes narrow from arthritis. But surgery for these problems does not require a spine fusion.

But most people with lower-back problems should “aggressively pursue exercise and non-surgical approaches before turning to surgery,” said Dr. David Matusz, a spine surgeon at Johns Hopkins Medical Center.

This “conservative” therapy can also include rest and ice for a few days during the acute attack, then acupuncture, physical therapy, chiropractic, anti-inflammatory drugs like Advil or Aleve, and cortisone injections.

It’s not clear even at a basic physiologic level that surgery is the right approach to low back pain, Dr. James Rainville, chief of physical medicine and rehabilitation at New England Baptist Hospital in Boston, said. The simplistic assumption is that lower-back pain is caused by disc problems. But pain is actually a neurological phenomenon that “is not occurring solely in the spinal structures associated with movements.”

When a person feels acute back pain, the central nervous system goes into high gear, becoming “sensitized,” meaning that nerves become hyperactive, turning acute pain into chronic pain. Once chronic pain sets in, any little movement can be excruciating.

What exercise and cognitive behavioral therapy can do, and surgery does not, Dr. Rainville said, is retrain the brain and the rest of the nervous system to become less sensitive, allowing the feeling of pain to go away gradually.

Dr. Rainville runs what some call the “Back Boot Camp,” a multidisciplinary program that stresses non-surgical interventions. Chronic back pain is often not a simple mechanical problem in the spine, he said, but a neurological phenomenon in which nerves in the back become so hypersensitive that even normal actions, like putting on one’s shoes, can cause pain. “Just because your back hurts doesn’t mean you’re damaging it,” he said.

From this follows the idea that exercise can often help, not hurt, and can re-train the nervous system to be less sensitive. In other words, getting the back moving again can help desensitize overactive nerves. So can cognitive-behavioral therapy, in which a person learns not to be afraid that pain means damage. Dr. Rainville’s program also emphasizes “stretching like crazy” and using weights and a series of special exercises to strengthen muscles in the back.

So what should you make of all this if you have persistent lower-back pain? First, recognize that some back problems are inevitable. Disc degeneration from wear and tear is universal with aging, though much of the time this doesn’t cause pain and, even when it does, usually goes away on its own. “Bulging” discs, in which the disc pokes out and may press on a nerve, are also common and are sometimes called herniated or slipped discs. They, too, often get better on their own.

If, despite aggressive non-surgical approaches, you still have chronic lower-back pain, especially pain running down the leg that persists for several months, and if a CT or MRI scan shows that you have a disc or part of the vertebra pressing on a nerve, try to have the least invasive surgery possible.

This includes discectomy for relief of leg pain – removing just the troublesome disc or part of it. Bear in mind, though, that there’s still relatively little data on artificial discs and doctors don’t have much experience with them. You can also consider a laminectomy, in which part of the bony vertebra is removed to relieve pressure on a nerve that causes leg pain.

As a last resort, there is spinal fusion. But if you’re going this route, get a second opinion to be sure the operation is truly necessary and likely to help you.

Ms. Foreman is a lecturer on medicine at Harvard Medical School. Her columns are available at www.myhealthsense.com.