Trial tests an alternative to spinal fusion for back pain

February 15th, 2019
Andy Post at his desk
Andy Post says his coworkers have seen a more cheerful guy emerge since TOPS surgery helped to relieve debilitating back pain. Photo courtesy of Andrew Post.

Pain has been a companion of Andy Post’s for a good portion of his 54 years. A self-described weekend warrior, he played football and hockey in high school and skied frequently as a student at Colorado College. The wear-and-tear affected the facet joints in his spine – the ones that make the back flexible, bendable and twistable. For years, he learned to manage and live with the discomfort caused by spurs and a cyst – a fluid-filled sac – in one of the facet joints.

“I just tried to keep going,” Post said.

That changed three years ago. Sprinting to get across a street in Boulder before the “Walk” signal changed, Post felt the cyst squeeze his spinal cord “like a tube of toothpaste.” The pain that had been manageable for many years became debilitating.

Life-altering pain

“It changed everything,” he said. “I stopped doing anything. The pain came to dominate my existence.” His social life suffered. His personality changed.

“People close to me were telling me that I was not as bright and cheery a guy as I used to be,” he said. Post’s wife of 15 years, Peg, helped him manage his pain and made his life easier, but he knew his condition had exacted a toll on their relationship.

“The guy she fell in love with as an active guy,” Post said.

The problem worsened after he tried running for a train at the Federal Center in Lakewood late last summer. He froze after one step, his right leg seized by sensations of pins and needles. In the days that followed, Post periodically suffered pain like electrical shocks down the right leg to his big toe. The assaults arrived without warning.

“It was a pain you just can’t prepare for,” he said.

The pressure on the vertebrae in Post’s spine was so severe that he faced the prospect of spinal fusion, a procedure that could reduce his back pain but also limit his mobility – a hard decision for a once-active guy. But a clinical trial of an alternative to fusion has not only relieved Post’s back pain but also brightened his outlook on life.

Back attack

Ground zero for Post’s agony was two vertebrae in his lower back. The facet joints were damaged, which caused his spine to slip out of alignment. This, in turn, caused spinal stenosis, or narrowing of the space housing the nerves and their outlets to the rest of the body. The compression triggered his severe back and leg pain, said Dr. Evalina Burger, orthopedic surgeon at UCHealth University of Colorado Hospital on the Anschutz Medical Campus. Burger also chairs the Department of Orthopedics at the University of Colorado School of Medicine.

In spinal fusion, Burger explained, surgeons remove bone and joint between the vertebrae, relieving the nerve compression, and bridge the space with a rod secured with screws in the remaining bone. The procedure stabilizes the spine but substituting a rigid rod for a flexible joint decreases the patient’s mobility, she said.

A photo of Dr. Evalina Burger
Orthopedic surgeon Dr. Evalina Burger of UCHealth says an FDA trial of a new device could relieve pressure on the spine that leads to debilitating back pain. Photo by UCHealth.

The procedure also risks further spine degeneration, Burger said. To illustrate the dilemma, she compared the spine to a chain – the links being bones, ligaments and discs, which are the rubbery shock absorbers between the vertebrae. A weakened link in a chain can be welded to the one above it to keep it from breaking, but the chain as a whole becomes less flexible. That, in turn, puts more stress on the links above the welded spot. By the same logic, spinal fusion creates stress on the vertebrae above the rod. That may contribute to further deterioration of the spine and require additional fusion procedures that makes free movement even more difficult, Burger said.

“We’ve been looking for ways to not add stress to those levels of the spine that are not diseased yet,” she said.

Spinal shock absorber

A multisite clinical trial of the TOPS (Total Posterior Spine System) device from Premia Spine, headquartered in Israel, is designed to do just that. Last October, Andy Post became the first patient in Colorado to receive the device, which Burger implanted. The trial compares how well patients who receive TOPS function compared to those who receive standard fusion surgery.

In the trial, both groups get decompression surgery to relieve the narrowing in their spines. The control group gets spinal fusion; two in three get the TOPS device. The TOPS surgery involves securing two titanium plates with screws in the vertebrae above and below the decompressed space. In between the plates sits a bearing sealed in housing that absorbs stress between the vertebrae and allows the spine to flex, rotate and move laterally, just as a natural disk would.

However, the bearing is placed at the back of the vertebrae rather than the center, where a normal disk would sit. “It’s a motion-sparing device with the function of a disk,” Burger said. While spinal fusion surgery requires patients to wear a back brace and restrict their movements for six weeks to three months, TOPS patients have no such restrictions, Burger said.

In addition to giving patients greater freedom of movement, TOPS allows for more flexible surgical decision-making, Burger said. “We don’t burn a bridge,” she said. “We have screws in the bone, as we would in a fusion procedure. So if the device wears out or fails, we change to a fusion. It’s an easy conversion; everything is the same.” In contrast, she said, “A fusion procedure can never be reversed.”

Growing need for alternatives

TOPS also has a track record; it was approved for use in Europe in 2012. Burger said she has been watching the device develop since she saw it demonstrated at a spine conference exhibit in 2014.

“I was mesmerized,” she recalled. “It was a ‘wow’ moment for me.” In the years that followed, she kept in touch with Premia Spine, letting the company know that as soon as it was ready to seek FDA approval for TOPS, the Orthopedics team at UCH would be interested.

“I really think this is a product that holds promise,” she said.

The TOPS device includes a bearing between two titanium plates that absorbs pressure between vertebrae and allows twisting, bending and other movements – unlike spinal fusion. Photo courtesy of Premia Spine.
The TOPS device includes a bearing between two titanium plates that absorbs pressure between vertebrae and allows twisting, bending and other movements – unlike spinal fusion. Photo courtesy of Premia Spine.

The promise is profound positive change for many people suffering from debilitating back pain. Burger estimates that one in four people develop spinal stenosis at some point in their lives – and that the number is bound to increase in an aging society. The team at UCH performs spinal decompressions “on a daily basis,” she said, for a total of more than 2,000 a year.

A quick glance around a grocery store reveals the burden of the disease, Burger said. “People with spinal stenosis are the ones leaning over their carts,” she said. “As long as they lean forward, they open up their spines.” They also adapt by walking less, or with assistance, and that comes at a further cost, she said.

“They can become asocial because they don’t want to be out,” Burger said. “They also become inactive, and inactivity leads to loss of bone quality and is bad for the cardiovascular system. Once you lose mobility it has detrimental effects on the entire system.”

Standing tall again

After three years of life-altering pain and a daily 800-milligram regimen of naproxen, Andy Post decided he’d had enough. Although he wasn’t enthusiastic about spine fusion surgery, he was ready to go through with it after an MRI at the UCHealth Spine Center – Anschutz Medical Campus revealed the extent of his problem. The TOPS trial offered him an alternative. He investigated the device, was intrigued by the technology and the prospect of a shorter recovery, and decided to go forward with the surgery.

Post didn’t know he had gotten the TOPS device until the day after the surgery, but he said he sensed its effects immediately.

“I knew the procedure fixed the problem right away,” he said. “At no point has the device’s presence made itself felt. The biggest challenge of the convalescence was not doing too much.”

Three months after the procedure, he rose from a chair while talking with a visitor. He raised his arms, bent at the waist and twisted his torso freely. Only tight hamstrings prevented him from touching his toes, he said.

“I can move in any direction I want to,” Post said. “I never think about it.”

The sole setback of the surgery was a hematoma (bleeding outside a blood vessel) that Burger said was a standard surgical risk she believes was unrelated to the TOPS device itself. Post said he also had nerve pain that providers relieved with medication. Neither of those challenges has dimmed his view of the procedure, which he said he would recommend “without hesitation,” along with Burger’s surgical skill and care.

Some of the people he works with as a principal engineer in software development at Charter Communications are surprised at the guy they now see, Post said.

“People had gotten to know me as a pretty staid, stick-in-the-mud type of individual,” he said. “My sense of humor is coming back.”

It’s not a stretch to say Andy Post feels he’s regained the identity his back pain took from him.

“It’s easy to be lame,” he said. “Once you’ve been lame, you tend to do things that lame people do. I was getting up slowly from my chair and carefully straightening up. I have realized I don’t have to do that anymore. I hadn’t been walking with a normal gait. That’s gone.”

For more information about the TOPS trial, contact David Calabrese at david.calabrese@ucdenver.edu or 303-724-9265

About the author

Tyler Smith has been a health care writer, with a focus on hospitals, since 1996. He served as a writer and editor for the Marketing and Communications team at University of Colorado Hospital and UCHealth from 2007 to 2017. More recently, he has reported for and contributed stories to the University of Colorado School of Medicine, the Colorado School of Public Health and the Colorado Bioscience Association.