The pain started about five years ago -- deep aches in her legs most noticeable at the end of a long day in the office. It was a core-deep pain, as if something were terribly amiss in the bone marrow. At night she'd awaken with shooting pains in her buttocks, shins and thighs. At first they were intermittent. Then the pain-free periods grew briefer and fewer.

At first she listened to her friends and her longtime internist, all of whom confessed to similar leg pains and blamed them on drinking cheap white wine with too many sulfites. Upgrade your cellar, they teased her, but she cut out white wine entirely for a while and the pains continued. And they seemed to get worse.

Roberta (a friend who agreed to cooperate for this story but declined to have her last name published in order to protect her medical privacy) is neither a sickly person nor a whiner. As her 50th birthday neared, she retained the energy, outlook and physique of the competitive swimmer, windsurfer, hurdler and rugby player she had been in her youth. She still sailed, hiked and swam regularly, went scuba diving on vacations and worked out at her local gym.

But she also traveled internationally for her job and from time to time would return from Africa or Asia with some minor but persistent tropical malady that confounded her doctors. She and they wondered if the pains might be due to yet another exotic bug loose in her system. Yet test after test turned up nothing amiss. She tried to block the pain with meditation. When that failed, she tried to just work through it.

At last, the pains became near-constant. They would ebb and flow in degree, but they now reached up into her buttocks and lower back. Her neck had always been a lightning rod for stress, and now the pains seemed to harbor there as well. They were so bad she often had to work from home, or miss work altogether.

By last November they had increased so much she could barely sleep. They were joined by burning sensations in her arms that turned almost any motion or gesture to agony, and by numbness and a tingling in her toes. She tried acupuncture, which improved things slightly for a week or so, then seemed to make things worse. She sought out a chiropractor who had helped a back problem years ago, but her whole body was so sensitive she couldn't bear to have him touch her.

Her internist referred her to an orthopedist. The orthopedist referred her to a neurologist. The neurologist referred her to an orthopedic rheumatologist. There were blood tests and urine tests and a colonoscopy and an MRI. The MRI turned up a mysterious, dime-sized cyst between her fourth and fifth lumbar vertebrae, but nobody seemed to think it significant.

One doctor gave her steroid pills, which only made her gain weight. Another put her in a whiplash neck collar for a week or so, but that did nothing. Another said she should be checked for Lyme disease. No one thought to order a spinal X-ray.

By this time she was drained and depressed from lack of sleep and cranky from the constant pain. Her always-erect posture had eroded to that of an 80-year-old. She could barely walk or drive.

Meet the Doctor

One day, seeking distraction at a movie with her 19-year-old son, she ran into one of his soccer teammates, who, alarmed at her appearance, asked what was wrong. When she began reciting symptoms, he reached into his wallet and pulled out the business card of Steven C. Ludwig, chief of spine surgery and associate professor of orthopedic surgery at the University of Maryland Medical Center (UMMC).

"It's your back," the former goalie said. "Call this guy immediately. I had exactly the same symptoms as yours, and he fixed me completely."

From the moment she stepped into Ludwig's Timonium, Md., office, Roberta said, she was treated differently. With the exception of her long-trusted internist, none of the specialists she'd been referred to had appeared either interested in her case or concerned about her symptoms. They treated her, she said, as if her mysterious pains stemmed from some sort of female hysteria. "I had begun to wonder myself if it wasn't maybe somehow all in my head," she said.

The UMMC orthopedic center was decorated with the lacrosse sticks and baseball jerseys of former patients, but the atmosphere was professional and efficient. After a spinal X-ray and questions about her symptoms, the diagnosis took about 10 minutes. When Ludwig clipped the X-ray and the MRI film to the imaging lights, it was easy to see why.

Roberta, he explained, was suffering from a disorder called lumbar spinal stenosis, a constriction of the fluid-filled canal that contains the spinal cord.

A combination of age, genetics and the accumulated wear and tear of her active lifestyle had resulted in a gradual but dramatic displacement of her spine between the fourth and fifth lumbar vertebrae -- a condition known as spondylolisthesis. The fifth lumbar vertebra and those above it had pushed forward. As this occurred, the spine had sought to strengthen itself by generating more bone within the misaligned joint -- an arthritic condition that pinched the spinal canal even more than the misalignment. The benign, fluid-filled cyst in the area compounded the problem.

An MRI of her back just below the misalignment, Ludwig pointed out, showed a perfectly circular spinal canal about 1 1/2 inches in diameter: "There she has the spine of a 30-year-old woman."

But where it passed through the problem area, a succeeding MRI showed, her spinal canal was pinched into a constricted four-pointed star -- choked to less than one-fourth its normal diameter.

"This is a very common condition in 40- to 50-year-olds," Ludwig said, "but it's often confusing because its severity varies and it produces different symptoms in different people. Some people have relatively little pain and disability and elect just to live with it and watch a lot of TV."

In the case of Roberta, whom Ludwig described as "a very young and active 50," he recommended surgery.

"I can't guarantee that it will stop pains above your legs and lower back, but I think it will. I'm pretty sure that's just pain radiating up from below through your muscles and other nerves. But I guarantee it will stop the leg pain, which you say is both the worst pain and where this all started."

"How soon can you operate?" Roberta replied.

The Open Back

The following week Roberta was wheeled into an orthopedic operating room in the impressively modern UMMC in downtown Baltimore, just a few blocks north of Camden Yards. There doctors are developing procedures for remote surgery so a doctor can operate on a patient half a world away using surgical tools linked by satellite.

Roberta's procedure was more basic. Ludwig performs some 300 similar operations a year, sometimes four a day.

Once Roberta was scrubbed, draped, anesthetized and positioned facedown on the operating table, Ludwig opened a 6 1/2-inch incision along her spinal ridge, beginning just above her buttocks. With scalpel and retractors he spent 20 minutes slicing through and pulling aside her back muscles to expose her spine at the junction of the fourth and fifth lumbar vertebrae.

Then, using what doctors call a "bone biter," the 21st century medical equivalent of a ancient tool blacksmiths use to pull horseshoe nails, he "bit" off the two lamina, or dorsal ridges of the two vertebrae. This relieved a major part of the pressure on the spinal canal, which immediately began swelling back toward its normal diameter, like a tubular balloon released from a knot. But that was only part of the task.

Reaching into the cavity holding the membrane-encased nerve channel, Ludwig then shielded the nerves and their fluid-filled enclosure with dorsal retractors and began carefully scraping away the arthritic deposits and excess soft tissue that had been crowding them. The cyst that had shown up in the MRI burst harmlessly as it was being removed, but this had been expected. Biting off the two lamina and cleaning away the accumulated spinal debris took 40 minutes.

Surprisingly, at least to a layman, Ludwig did nothing direct or dramatic to correct the misalignment of the vertebrae.

"We've found that if we position the patient correctly on the operating table, the misalignment corrects itself with the pushing and pulling of the devices we install," he said. "The crux of the operation lies in stabilizing it in the correct position from then on."

To do that, he positioned two titanium rods on either side of her spine, each about 1 1/2 inches long and roughly the diameter of a pencil. The rods spanned the disc between the fourth and fifth lumbar vertebrae. Each would be held in place by a titanium screw at either end.

"The process of stabilizing the spine like this is not particularly difficult," Ludwig said. "The art lies in selecting the right size screws and rods." People, he said, vary enormously in the thickness and density of their backbones. Some tiny people have hefty spines, he said; some very large people, quite small ones.

Roberta's spine, he said, is about average in size for her 5-foot-9 height and athletic build. But her bone quality, he said, is "really excellent" -- far better than average in a female population where osteoporosis is close to epidemic.

For her he selected titanium screws about five millimeters in diameter and 55 millimeters -- more than two inches -- long. The task of setting them in place was not too different from that of a weekend do-it-yourselfer putting screws in a shelf, he said: "We both use power tools."

For each of the four screw holes, he used a high-speed electric burr to pierce the hard outer sheath of the vertebra, then inserted a probe into the softer marrow to create a pathway for the screw. The process was carefully monitored via a real-time X-ray, or fluoroscope, to route the channel away from any vulnerable nerve and to assure its positioning in bone large and dense enough to secure the screws.

Roberta's nerve function was also monitored during the operation, via small electrodes inserted in her hands and feet. These assured that the spinal nerves continued to carry the requisite tiny flow of electricity that triggers muscle movement. In addition, after each screw was driven in place, using the surgical equivalent of a Phillips screwdriver, a tiny amount of electrical current was sent through the screws themselves. When it wasn't picked up by the electrodes in her feet, the doctors were certain the screws were well insulated from the spinal cord.

Installing the screws and pins took about 20 minutes. During the final 20-minute part of the operation, Ludwig drilled from the spinal incision into Roberta's right hip bone -- the iliac crest of the pelvis -- just inches away. From there, using the surgical version of a miniature ice cream scoop, he removed a portion of bone marrow about the size of a large chickpea. This he packed alongside the titanium rods onto the two abraded vertebrae, into which it would grow and fuse them into one.

Then the surgeons removed the retractors that had spread Roberta's back muscles away from the spine, and closed the incision with 18 "staples," or knots of surgical thread.

From the moment Roberta was rolled into the operating room until Ludwig emerged from checking her into the recovery room, the operation took Ludwig and his seven assistants -- nurses, anesthesiologists, neurophysiologists and a physician's assistant -- almost exactly three hours.

The Pain, Gone

When she emerged from anesthesia, Roberta found herself coping with postoperative pain, which is almost always initially severe. But she said it was no worse than what she'd been suffering constantly for the past four months, and now at least it was only in her spine. The pain in her legs and arms was entirely gone, as was the near-lifelong hypersensitivity of her head and neck.

Within 24 hours she was walking shakily to the bathroom. Within a week she was walking two miles with a walker. Within 10 days she had bettered that distance with the help of just a cane. Little more than two weeks after the operation she was walking even further, cane-free and -- with the help of pain pills -- almost pain-free, though she still experienced some discomfort, tired easily and was sleeping a lot.

Ludwig said it would be two months or more before she was fully recovered, in part because her legs had been weakened by her long bout with pain and because it would take exercise and physical therapy to teach her new spine to twist and bend again. Most spinal fusion patients, he said, never entirely recover their preoperative flexibility, but most, he said, rarely notice their slight degree of restricted movement.

Roberta says no one but she can fully appreciate how miraculously the operation has changed her life. "I hate to think of what would have happened had I not found Ludwig. I can't believe so many doctors missed the diagnosis."

Ludwig, however, says it's not that simple. While each year as many as 500,000 people in the United States are diagnosed with spondylolisthesis, each may have different symptoms and some may have no symptoms at all.

"We get patients in here who, when you see their X-rays, you can't believe they're actually walking," he said. "But they're in no particular pain. They get referred by another doctor alarmed at what he sees on the X-ray."

Moreover, Ludwig said, what symptoms do appear may mimic other muscular or neurological conditions that have nothing to do with spinal ailments. There are a lot of patients like Roberta, he said, with symptoms that most doctors can't put their fingers on. They may be spine-related, they may not. The art is in telling the difference.

The four-year-old spinal center at UMMC, he said, sees at least 3,000 patients a year, "and only a small percentage require surgery."

In Roberta's case, Ludwig said, her very specific medical history, the onset and progression of her symptoms, "correlated perfectly with what we were able to see with the X-ray and MRI imagery of her back. And that made all the difference."


Ken Ringle, a 33-year veteran reporter for The Post, writes these days from retirement.

Cross-sectional MRIs of lower back region show, at one vertebra (top), a round, healthy spinal canal (center of image, in white) and, at another vertebra, the spinal canal pinched into a V (below) by vertebral dislocation and arthritic deposits.