STEVE BRAWNER

Dr. Justin Seale, a surgeon at St. Vincent Health System's Spine Center of Excellence, implants an X-Stop Spacer into the spine of patient Nora Johnson with help from scrub tech Barbara Collins

For Nora Johnson, a half-hour procedure and a small implanted device may be the difference between debilitating back pain and the ability to walk normally.

Johnson, 79, broke her tailbone when she lost her balance while exiting her car last October. Months of rehabilitation did not remove the numbness in her legs that forced her to use a walker or a wheelchair.

On January 8, she was rolled into the operating room at Little Rock's St. Vincent's Infirmary Medical Center, where surgery under the experienced hands of Justin Seale, MD, awaited. She said she wasn't nervous. "I'm anticipating the surgery. I'd like to get it over with," she said.

Johnson suffers from lumbar spinal stenosis, a degenerative narrowing of the lower part of the spinal canal that carries nerves to the legs. When nerves are pinched, patients suffer from a set of symptoms known as neurogenic intermittent claudication. These include pain, numbness, weakness or cramping in the lower back, buttocks or legs. Other symptoms are painful tingling that shoots down the back of the legs, weakness or fatigue, or difficulty maintaining balance. Bending forward or sitting usually relieves the pain by introducing flexion to the back.

In the past, the only available treatments were nonsurgical care or a laminectomy – the removal of part of the bone around the nerve.

But thanks to Medtronic's X-STOP Spacer, Johnson was out of surgery in a little more than half an hour and slept in her own home that night.

The X-STOP Spacer is an interspinous process decompression device that fits between two bones in the back of the spine, the spinous processes, opening up the space and removing the pressure by maintaining the spine in a neutral or flexed position and increasing the size of the canal around the nerves. The procedure requires only a small incision, and the spacer stays in place without being attached to the bone or ligaments or fused to the spine.

Seale has performed the surgery almost 40 times and estimates his patient satisfaction rate at about 60-70 percent. He cut his teeth on the surgery while doing more than 30 procedures participating in a study program in Denver.

Seale said he's learned to be selective about who receives the surgery, focusing on those who, like Johnson, stoop forward when they walk or whose pain improves when they sit. Most recipients are at least 60 years old.

More than 40,000 of the devices have been implanted since it became available in Europe in 2002 and in the United States in 2005. Some 3,200 U.S. surgeons have been trained in its use. According to the product's Web site, studies have shown that, two years after implantation, 84 percent of spacers maintained the space between spinal segments, 96 percent had not been dislodged, and 94 percent did not result in complications. Ninety-three percent of patients did not require an additional surgery, and 73 percent reported being satisfied.

The original spacer was composed entirely of titanium, but the company announced on Oct. 14, 2008, that a newer version was being made available in the United States composed partly of polyetheretherketone polymer. The new product has a more elliptical shape, increasing the contact area with bone by 30 percent over the original model. A larger 16 mm implant also is being made available for the first time. The new version has been available in Europe since March 2004.

It's the kind of product that likely will be in greater demand in the coming years to treat aging baby boomers' backs. According to Denise Franklin, a spokesperson with Medtronic, lumbar spinal stenosis is the most common reason for back surgery, and 1.4 million Americans primarily age 65 and over suffer from it.

Most of the procedure involved prep work – the actual insertion required only a few minutes and a little elbow grease as he wrestled it into place. "You want to get the biggest device in possible to take as much pressure off, so if you see someone really not struggling to get one in, they probably could have gotten a bigger one in there," Seale said during the surgery, wearing an Arkansas Razorbacks surgeon's cap. "I've never put one in that wasn't a little bit of a struggle."

He was pleased that the operation went well, though he wouldn't know the results for certain until Johnson tried to walk. She went home that day with medication for back pain, with the pain expected to resolve about two weeks later and the final results known a week or two afterwards.

"The procedure went excellently. No problems with that," he said. "The whole reason to do it is for the patient, to see how she does afterwards."