The Evolution of Spine Surgery: Looking to the Future
Technological improvements in imaging and surgical equipment have helped shape modern spine surgery, and neurosurgeons expect this trend to continue in the coming decades.
“When you think about the way we were doing things 10 years ago and say, ‘I can’t believe what we have now’ and ‘I can’t believe things used to be done that way,’ well, I think we’ll be saying the same thing 10 years from now,” said Barrow Neurosurgeon Dr. David Fusco.
He said this drive to explore and leverage new technology stems from collaboration between neurosurgeons, biomechanical researchers, and industry partners.
“We’re able to work with our industry partners pretty regularly in order to maximize the effectiveness and speed of product development,” he said.
Neurosurgeons also say the aging population, biomechanics research, and concerns over the cost of spine care will influence the future of spine surgery.
An Older Population
“The Baby Boomers are going to be in their 70s and 80s in the next 10 and 20 years,” Dr. Fusco said. “It’s the American expectation that you will be able to live your fullest life to the end of your life, and that’s no different in the spine surgery patients that we see. I think that desire and that large size of population will drive innovation in that direction.”
Barrow Neurosurgeon Dr. Steve Chang said he performs anywhere from two to 10 artificial disc replacements per month.
“Instead of fusing someone’s spine, we are able to use these newer devices to preserve the range of motion,” he said. “Most of the large studies have shown better outcomes in terms of both pain relief and return to work for artificial discs as opposed to traditional fusion.”
Artificial disc replacement may also reduce a patient’s chance of needing additional surgeries by minimizing stress on adjacent levels of the spine.
“There is an ongoing tension in spine surgery about how to repair degenerative issues while not setting the spine up for future failure,” Dr. Fusco said. “The key will be how to address degenerative spine and joint issues while minimizing the overall disruption to the spine itself. Patients want to have their degenerative disease repaired, and they want to be able to get back to doing what they were doing,”
Barrow Neurosurgeon Dr. Laura Snyder, who specializes in minimally invasive spine surgery, said patients who are treated with minimally invasive techniques often return to work more quickly than those who are treated with conventional open surgery.
“A lot of these surgeries we can even do in the outpatient setting, and people can go home the day of or the first couple days after surgery,” she said.
Patients wanting to return to work sooner and maintain mobility longer are not the only reasons spine surgery is evolving with the aging population.
“I think when dealing with innovation in spine surgery, we have to ask how we can operate on people who are older in a safer manner,” Dr. Chang said.
Neurosurgeons and scientists say understanding the forces and movements in the spine, an area of study called biomechanics, is crucial to developing procedures and devices that will allow patients to maintain their mobility longer.
“Ultimately, every tissue is a load-bearing structure,” said Dr. Brian Kelly, who leads the spinal biomechanics laboratory at Barrow. “So, if you’re endeavoring to replace that tissue and restore what was there initially, either through a prosthetic device or tissue engineering, you need to target loading and its normal movements.”
Dr. Kelly and his team use robotics and 3-D computer models to study cadaveric spines in an effort to better understand how disease, trauma, and surgical intervention affect the spine.
Dr. Kelly said that his team’s direct collaboration with top neurosurgeons is something that makes the spinal biomechanics laboratory at Barrow unique.
“As patients come in with trauma, disease, and so forth, the attending neurosurgeons at Barrow are concerned about many things,” he said. “The primary concern is pain, but if they do any type of corrective surgery, they are interested in how those changes affect the stability and mobility of the spine. How is the patient going to be able to go back and manage activities of daily living? That’s part of the package that neurosurgeons have to worry about.”
Dr. Kelly and his team try to assist the neurosurgeons by testing different constructs, such as implantable devices, and providing biomechanical assessments.
“Does it offer more stability? Does it restrict motion? In the longer term, is it a construct that’s going to survive? Those kinds of things are what neurosurgeons are concerned with,” he said.
Dr. Kelly said forces and loading in the spine have not been well defined because it is challenging to obtain measurements in a living person, which are called in vivo measurements.
Because there are many muscle groups acting in the spine and those muscles are very deep lined, it is difficult to gather electromyogram data from the muscles, according to Dr. Kelly. Electromyogram data would show which muscles are active and inactive and provide a sense of the load the muscles are applying. Another issue is that the spinal column consists of multiple joints.
“Even if we understood the load conditions of the spine, we’re not well positioned right now to simulate them on the bench,” Dr. Kelly added.
However, he believes robotics will help improve these simulations.
Robots in the Laboratory, Operating Room
The spinal biomechanics laboratory at Barrow has a custom-made, robotically controlled testing platform that simulates multi-directional movements of the spine and loading in all directions.
“That’s something that has not been done before is to be able to apply different combinations of loads in real time to a cadaveric specimen,” Dr. Kelly said. “Right now, there is a gap between what we can do on the bench and what happens in the patient in terms of simulating the mechanics and loads. One of our goals is to close that gap.”
Dr. Kelly noted that while robotics have been around for some time, programming a robot for spinal biomechanics testing has been cumbersome. He said that is changing as more scientists and commercial robotics companies become involved in biomechanical testing.
“I think it’s going to become more commonplace to see a biomechanics lab with a robot doing a lot of its core testing,” he said. “We’re on the cutting edge of that, but I anticipate some catching up.”
Dr. Kelly also expects robotics to play an increasing role in surgery, saying it could enhance accuracy.
Dr. Fusco said that 10 years from now, robotics will likely be used frequently for automated pedicle screw instrumentation.
Intraoperative navigated CAT scans have already made hardware placement more accurate by allowing neurosurgeons to view a 3-D image of a patient’s anatomy and direct specific trajectories for the hardware.
“The quality of that 3-D imaging, and the speed and efficiency with which you can use it in surgery, has only gotten better over time,” Dr. Fusco said. “I think the natural extension of that is a process that becomes so automated that the surgeon is not even placing the screw but directing a mechanism or robot, so to speak, to place the screws.”
Cost of Spine Care
The need to decrease spine care costs will also influence the approach to spine surgery in the future, specifically for degenerative disease, according to Dr. Fusco.
“We really need to look at the ongoing economic impact of spine care, the cost of surgical and nonsurgical care, and the cost benefit of different approaches to treating spinal degenerative disease,” he said. “Most people who have degenerative spine issues, which account for the vast majority of all spine care, don’t need surgery.”
Dr. Fusco foresees a trend in bundled spine care packages. Surgeons would partner with primary care doctors, physical therapists, and other specialists to provide individualized care for patients.
When you think about the way we were doing things 10 years ago and say, ‘I can’t believe what we have now’ and ‘I can’t believe things used to be done that way,’ well, I think we’ll be saying the same thing 10 years from now.
-Dr. David Fusco, Barrow Neurosurgeon
“Let’s make sure people who have spine problems are getting the correct care that they need and that patients have an entire care package consisting of surgical and nonsurgical care,” he said. “Let’s make sure we facilitate collaboration between these providers to cut down costs.”
Dr. Fusco also expects payments to be bundled, meaning insurance companies or government payers would provide a fixed amount of money to the treating surgeon or even the whole spine care team for a given diagnosis and prognosis.
The surgeon or the team would then have to decide how that money would best be spent for the patient. For example, physical therapy is less expensive than surgery, but it may not achieve the same outcome.
Dr. Fusco anticipates payments to be increasingly based on outcome. Surgeons would have to meet certain quality metrics to receive the payment they believe they deserve, which he said would maximize value-based care as opposed to just fee-for-service care.
“Groups who are able to provide the full spectrum of services and collaborate all the way from the primary care level to the surgical level are going to be the ones who are able to get patients in most efficiently and keep costs down,” he said.