Chronic back pain has become so much a part of everyday American life that it has long since exhausted its potential for headlines. But commonplace as it has become for an estimated 4 million people, back pain retains its unique ability to scavenge the nation's health care budget. Indeed, lower back pain -- from injections and disc removal (discectomy) to spinal fusion surgery -- now costs more than $100 billion each year.

For 32-year-old Melton Smith, though, the cost was not measured by a financial statistic but by a diminished quality of life, near-constant pain and a persistent second-guessing of his psychological health. That the pain began nine years ago, not with some dramatic injury, but with a romp in a swimming pool, only intensified the hurt.

"I was lifting my niece in the pool when I felt some pain in my back. I couldn't walk for three or four days," says the San Francisco computer network specialist. Smith, who was living in his native state of Texas at the time, was also in the Air Force. "I went to see several military doctors over the next few years and none of them ordered an X-ray. They told me that since there was no family history of back pain, the pain must be in my head."

Over time, and despite increasing distress -- "I couldn't put on my socks or underwear without pain" -- Smith tried to tough it out. But as his range of physical activities continued to shrink, so did his optimism. Skiing, hiking, workouts at the gym: Smith abandoned them all as his condition worsened. Trips to the doctor were pointless, he told himself, since the message was always the same: There's nothing wrong.

But something was terribly wrong, and when Smith left the military in 2000 for an information technology job in San Francisco, he decided to give the civilian medical establishment a try. "It took me a while to make an appointment, but the pain became so unbearable, I had to do something."

An X-ray, followed by an MRI, clearly showed the source of pain. And it was not psychosomatic. "I was diagnosed with degenerative disc disease. I felt vindicated."

Now at this point in his long trail to relief -- and after consulting with an orthopedic surgeon -- Smith would likely have been faced with several possible options. One of the most popular, spinal fusion surgery, requires that surgeons attach rods and screws to the bones of the spine to hold them in place until the bones heal together. In this procedure, the disc, which consists of collagen on the outer edges and spongy, pulplike tissue at its nucleus, is essentially encased in bone. The goal is to eliminate motion and the pain it causes, an ironic if logical response to a complaining disc damaged by wear and tear, injury or other event.

But as David Bradford, UCSF professor of orthopedic surgery, explains, the popularity of spinal fusion surgery is not always justified by the results. "The ability of the bone to fuse varies with each patient. Fusion at one or more levels can also cause stiffness and decreased motion and transfer stress elsewhere in the spine." As a result, patients are not always guaranteed a successful outcome.

For Smith, his delay in seeking treatment had one benefit: a novel option. UCSF, to which he had been referred once his back problem was properly diagnosed, was just beginning a four-year clinical trial of an artificial replacement disc, successfully tested in Europe. Called Prodisc, it is a ball-and-socket prosthetic device attached to chromium-cobalt plates that merge with the natural bone and anchor it. Says Bradford, "The artificial disc is designed to restore normal structure and function, not limit it."

Smith's youth and the limited area of damage (one level of his spine) made him an ideal candidate. And in July of last year, he underwent the two-hour disc replacement surgery. His recovery period was rapid: He was back at work in a week. "I still hurt from the incision, but each day got better. There wasn't a dramatic moment where I suddenly realized I was pain-free, but I noticed that I could move around easier." Smith was conservative at first, trying out the new range of motion and waiting for the stabbing pain. It never came.

While Bradford is quick to point out that artificial disc replacement is not ideal for everyone -- those with scoliosis, or curvature of the spine, are one example -- it does seem to offer hope to others with debilitating back pain. Smith would certainly qualify. "The big milestone was being able to go to the gym and work out," he says. "I now feel so confident, I'm ready to jump rope."