The basic process of problem solving has led two of Chattanooga’s orthopedic surgeons, Dr. Scott Hodges and Dr. Craig Humphreys of the Center for Sports Medicine and Orthopaedics, to invent, patent and continue pursuing the development of a total joint replacement for the lumbar spine.
Considering the millions of people who suffer daily with lower back pain – often opting for relief through surgery and giving up some of their freedom of movement in return – the widespread acceptance and use of their total lumbar joint replacement could positively impact the lives of many across the globe.
“This is a project like the IBM ads when the guy gets up at 2 a.m. with the idea flashing in his head,” explains Hodges, who met Humphreys while both were at Loyola University Chicago pursuing specialized orthopaedic studies. “It was truly that kind of experience. Around 1999 to 2000, there was a lot of enthusiasm for replacing discs in the lower spine, where you have three motion segments, a disc and two joints. These work in coordination, and one doesn’t move without the other.
“Motion is the way we were made,” Hodges continues, “so preservation of motion in the spine was felt to be something we needed to work toward. Right now, with fusions, we sacrifice motion for pain relief and accept stiffness. It does create an abnormal mechanical environment, so there was enthusiasm for replacing the disc. The problem with replacing the disc is that you have to go through the front. The first-time surgery is not that difficult, but it will wear out and need to be revised or replaced. This revision surgery is of concern because there are increased risks, and the pathology which causes nerve compression actually arises in the back.”
As Hodges and Humphreys made early morning rounds at local hospitals, they continued a dialogue which led to a potential solution. One morning several years ago, Humphreys brought an idea to the hospital.
“I had written it out at 2 a.m.,” remembers Humphreys.
The revolutionary idea involved the replacement of an entire lumbar disk and joint as one segment. From there, the idea progressed to drawings, clay models and a patent for a concept like none other in existence.
According to Hodges, the surgery required for implementing the total joint is quite similar to that involved with fusion. The game changer is the fact that range of motion is preserved more fully.
Of course, developing a viable solution was only part of the equation. Hodges, a native of North Carolina and a graduate of Southern Adventist University, and Humphreys, who was raised primarily in Alaska and was recruited to Chattanooga 15 years ago by Hodges, still faced an arduous trek toward approval and availability in the United States – a long journey that is still in progress.
“We worked on it ourselves, and it got to be very expensive,” remarks Humphreys. “Ultimately, we realized that we needed a partner. We went to three different companies, and Medtronic said they would finance the project if we would put in the time to improve the design, put it in cadavers to make sure it worked, and do everything we could to make it a success.”
With extensive testing completed, the doctors had to find a location to initiate surgical procedures.
“South Africa is about as far away from Chattanooga as you can get,” says Humphreys, “but they have good surgeons, good hospitals; we speak a common language, and they don’t have to have European certifications.
“We operated on three patients and waited six months to make sure things were going safely; then (we) did three more, then another; and then we waited two years, making the instrumentation better,” Humphreys continues. “Then we launched a prospective study, which will look a lot like an FDA (U.S. Food and Drug Administration) trial. We brought five surgeons to Memphis and all went back to South Africa, each looking to do five operations over the next four to five months. We will watch those patients for six months to a year and then do a limited release in Australia, Turkey or South America. We’ll continue to improve it, and when we are close we will apply for the FDA trial.”
Each patient who underwent surgery in South Africa was determined to have no better course of action; had a viable alternative been available, lumbar joint replacement would not have been performed. One of the South African surgeons actually had a back problem himself and has undergone the surgery. Each patient has progressed well.
After Hodges and Humphreys have invested their own time, talent and treasure, the eight-year effort appears closer than ever to its FDA-approval phase.
The FDA trial itself will require 1,000 patients who will be enrolled at major academic centers across the U.S. over an 18-month period. The progress of these patients will be monitored over a two-year period, and the entire process is expected to take five years. At the same time, an evaluation of the procedure’s cost effectiveness will be made, particularly for the purposes of future insurance coverage.
By the time the proposed FDA trial is complete, Medtronic will have invested approximately $50 million in the lumbar total joint replacement project.
“We know that fusions are good operations,” offers Hodges, “but they have a lot of limitations and negativity surrounding them by patients who have heard this story or that story. We know the pathology that we need to address and we know there is a large market out there that
needs this.
“Two major issues existed,” says Hodges. “One was whether we could do the replacement without having the implant too close to the nerves, and we solved that with our design. The second was to determine, once the implant was in, whether it would be stable. We did all the biomechanical testing and believed in what we were doing. We didn’t have 100 percent assurance on it, but we were going to find out.”
While Medtronic may someday realize a profit – and the doctors themselves may someday receive a royalty for their work – that is far from being their sole reason for seeking FDA approval. Throughout the course of events, both Hodges and Humphreys have recognized that the project could become something much larger than two doctors in Chattanooga could accomplish alone. For them, a higher power has been involved from the beginning.
“I always thought this was partially driven by God,” says Humphreys. “We have had things fall into place and happen that just seemed to be too weird to be coincidental. There have been times we thought the project was dead, but it has been revived again.”
“Faith teaches you to believe in yourself and others, to know you need to do good for others and to help society,” adds Hodges. “Faith is one of the things that keeps driving me.”
Challenging themselves to improve surgical outcomes, raising the standard of care, and positively impacting the quality of life for patients around the world will indeed be the richest of rewards for these two local doctors whose dream of total lumbar joint replacement is likely to last long after they are gone.