Driven by a rising geriatric population, an increase in spinal cord injuries and surgical innovations, the spinal fusion market size is anticipated to reach $8.64 billion by 2025, according to a recent market report.
Here, four spine surgeons share their insight on the future of spinal fusions:
Note: Responses are lightly edited for style and content.
Question: How do you see spinal fusions evolving in the future?
Joshua Schwind, MD. Hoag Orthopedic Institute (Irvine, Calif.): Historically, arthritis of the hip and knee were treated with fusions. As orthopedic surgeons' understanding of joint kinematics and motion preservation improved, the rate of fusion decreased. Today, most orthopedic surgeons in practice will have never treated a patient with fusion of the hip or knee. I predict a similar trend for the spine.
Fusion and its attendant loss of motion has deleterious effects on the remainder of the spinal column. However, it is the best and most predictable solution for a variety of disease processes. In the future, as we advance our understanding of materials, metallurgy, robotics and nanotechnology, rates of fusion will fall. I also believe that outcomes for fusion will improve as we create better implants and utilize less disruptive techniques.
Fred Naraghi, MD. Klamath Orthopedic Clinic (Klamath Falls, Ore.): Spinal fusion will continue to be indicated for instability, deformity correction and as a salvage procedure. But I think as we look at value-based care and try to make care more efficient for our patients — and considering outcomes and adjacent segment issues — fusion for disc degeneration will continue to decline.
Minimally invasive surgery, including endoscopic lumbar fusions are gaining more popularity, especially as endoscopic implants that can be placed through the scope become more available. Other advances like biologics are continuing to develop. However, the caveat with biologics is the significant lack of any meaningful clinical data to show superiority of one versus another.
Advances in implants, techniques, anesthesia and perioperative multimodal pain control are making outpatient spinal fusions safer and more practical at surgery centers. I think following the trend of total knee and hip arthroplasty, a growing trend would be to do more spinal procedures at surgery centers, especially as the cost of care can be lowered through ASCs versus traditional hospitals. It is imperative to improve our minimally invasive techniques in order to perform successful outpatient spinal surgery.
Brian Gill, MD. Nebraska Spine Hospital (Omaha): We have been doing spinal fusions for decades and will continue to do so for decades to come. I do think that surgeons are becoming smarter in types of fusions being performed such as minimally invasive, lateral approaches and limited levels. The advancement of technologies to better assess global alignment is resulting in better patient outcomes with not only deformity surgeries but for degenerative surgeries as well. I do think that ACDFs will largely be replaced with cervical disc replacements. The indications for cervical surgery are much clearer and largely agreed upon compared to lumbar disc replacement. Patient outcomes will largely direct type of procedure being performed. The data for lumbar disc replacement is there but it is not superior to lumbar fusions at this time. This may change as the technology advances, but it will take time.
Paul Houle, MD. Cape Cod Healthcare Neurosurgery (Hyannis, Mass.): I think the trend for spinal fusions is toward more minimally invasive approaches. It has been clearly demonstrated that simple one- and two-level lumbar fusions can be safely performed in both the acute care and ambulatory setting. Advances in multimodal therapies to control postoperative pain in conjunction with endoscopic spine techniques will make outpatient spinal fusions under conscious sedation common. In fact, in the very near future, cage technology will be introduced that will allow for true endoscopic transforaminal lumbar interbody fusions.
Spinal endoscopy has evolved to such a degree that direct visualization of the neural structures as well as the ability to visually confirm the effectiveness of the disc space preparation is possible via an incision not much larger than a No. 2 pencil. While artificial intelligence and robotics are currently garnering all the press, I am not convinced of their utility and cost effectiveness for simple one or two segment fusions, which account for the majority of lumbar spinal fusions in the U.S. What I do see is the wave of enthusiasm for endoscopic spine surgery as a platform to decompress and deploy expandable cages with minimal tissue destruction.