Artificial spine joint tested in Pittsburgh approved by FDA
Five years ago, Nathan Snyder took a chance. After years of back pain, he had been diagnosed with spondylolisthesis, meaning that a vertebrae in his back had slipped out of place, and given two options: undergo spinal fusion surgery or become the first in Pittsburgh to get an experimental artificial joint implanted into his back.
Snyder, a financial advisor at Janney Montgomery Scott, took months to make his decision, dusting off his pre-med skills from college to read through studies and anatomical diagrams. Eventually satisfied by the data and device’s approval in Europe — and wary of the spinal fusion procedure he had seen his father-in-law suffer through five times — he decided to try it.
More than five years later, Snyder, 49, of Upper St. Clair, can’t believe how good he feels. He golfs again, plays basketball and does YouTube workouts in his home gym.
And the device, which eight Pittsburghers eventually received in clinical trials, was approved by the FDA in June.
“Over the last five years, we’ve implanted a number of patients and they’re all like [Snyder],” said Don Whiting, chair of neurosurgery at Allegheny Health Network. “They’re all doing very, very active things. It gives them back their motion and it doesn’t lead to adjacent disease.”
For decades, Whiting has been convinced of the potential for an artificial joint in the back. As far back as 2005 and 2006, he participated in different studies of motion preservation devices, though those previous designs were eventually withdrawn from the market.
“Everyone knows that it’s much better to have a hip replacement than to have a hip that doesn’t move, or is fused,” he said. “It’s just one of those things that makes intuitive sense, but the joints are so small in the spine it was a bit harder of a problem to solve than a hip and a knee.”
Snyder isn’t exactly sure what caused his back problems, but assumes that some of them may be attributable to playing football in high school at Beaver Falls and in college at Harvard. The pain started in his 30s, when he became less fit while raising four children.
By his mid 40s, everything hurt. He couldn’t golf anymore or play basketball, and even leaning forward to brush his teeth in the morning was often painful. He had sciatic pain up and down his legs. When his then-16-year-old unexpectedly asked him to go on a run with her on a vacation, he couldn’t even finish a couple of miles. It was at that point that he got an MRI, and found out that surgery was in his future.
When patients have spine problems that include slippage of the vertebrae, the standard treatment is to fix the problem surgically and then stabilize the spine by fusing two vertebrae into one. “By doing that, you eliminate the motion in that one segment,” said Whiting.
‘It gives them back their motion’
The problem: When one vertebra’s range of motion is eliminated by fusion, it puts stress on the vertebrae around it, which can result in additional spinal fusion surgeries.
“The good of the fusion is that it stops the abnormal motion,” said Whiting. “The bad is that by stopping the motion, it leads to adjacent disease. But that’s the standard, that’s what everybody does, and that’s how people treat stenosis and instability.”
The artificial joint, called the Total Posterior Spine System, or TOPS, can’t replace all spinal fusion surgeries. It can only be used when the disk in the front of the spine is still fairly healthy, for example, and is only approved for use between segments L3 and L5 in the lumbar region of the spine. It is also only approved for people with grade 1 spondylolisthesis, meaning that there isa 25% slippage or less.
The study that Snyder participated in looked at more than 300 patients at 37 sites around the country. Of the about 115 patients who had their devices implanted for two years at the time the report was written, the study determined that the TOPS device “demonstrated a clinically meaningful and substantial advantage” over spinal fusion in terms of its composite clinical success.
The next step, said Whiting, will be to convince insurance companies that the TOPS device is worth covering.
As for Snyder, a part of him wishes that he didn’t suffer with his back pain for so long. But another part of him is glad that he waited long enough to be eligible for the TOPS device instead of fusion. This summer, he was able to complete a Tough Mudder race with the same daughter that he wasn’t able to run with on vacation years ago.
“I cannot say enough,” he said. “I feel better than I did when I was 30 years old.”