Michael Barbella , Managing Editor09.16.22
Jack Eichel’s reality came barreling in like a freight train.
His nerves were already in tatters—had been from the minute he walked into the Denver-area medical clinic early that morning—but they were now approaching overdrive as he waited for his first-ever surgical procedure to begin.
“I had never had surgery before, so you’re obviously nervous before surgery,” the former Buffalo Sabres captain recounted to subscription-based sports website The Athletic in April. “I...had dinner with my parents that night [before]. You wake up the next morning and...I went in by myself, and I was just sitting in the room and really didn’t have anyone there. The nurses were obviously great, but when you’re in that situation, you’re just like, ‘Hey, this is pretty real now.’”
Extremely real—he had reached the point of no return.
Yet it wasn’t so much the pre-surgical jitters that sent Eichel’s butterflies into a frenzy last year but rather the procedure itself and the public brouhaha that accompanied it. On Nov. 12, 2021, the former No. 2 draft pick became the first National Hockey League player to repair a herniated cervical (neck) disc through artificial disc replacement (ADR) surgery.
Eichel damaged the cushion-like pad between two neck vertebrae eight months earlier during the Sabres’ 5-2 loss to the New York Islanders. The 25-year-old center favored an ADR fix for his injury, but Sabres doctors recommended an anterior cervical discectomy fusion (ACDF), a more common surgery.
Both procedures relieve herniated disc pain but do so in different ways: Artificial discs replace the damaged original with an implant to preserve vertebral motion, while a fusion bonds the affected vertebrae together, preventing any painful movement. The latter has been used since the 1950s, and is considered the “gold standard” surgery for cervical disc degeneration (or injury). A 10-year study found that ACDF patients used fewer narcotics for pain and experienced fewer neurological issues but needed more revision surgeries than their ADR counterparts. Artificial discs, conversely, are associated with better pain and mobility outcomes, as well as fewer revisions.
Eichel’s penchant for ADR triggered an eight-month stalemate with his team, as Sabre doctors refused to authorize his treatment choice (the NHL’s collective bargaining agreement gives teams control over their players’ medical decisions). Eichel was equally as uncompromising, leading to a “divorce” that sent the top-rated hockey player to the more supportive Vegas Golden Knights. He underwent ADR surgery roughly a week after the trade, and was back on the ice in mid-February this year.
“The decision of the surgery is one that we respectfully defer to Jack and his representatives,” Golden Knights General Manager Kelly McCrimmon stated at a Nov. 4, 2021, news conference announcing the trade. “None of us in this room have the level of expertise that would be required for an opinion. I defer to the people that he’s [Jack’s] entrusted himself and his health to make that decision.”
Those people (and Eichel) based their decision on both career longevity and ADR’s long-term benefits (shorter recovery time, improved cervical global alignment, and better segmental angle), though ACDF’s potential for limited mobility and adjacent segment disease likely influenced the final determination too.
“Obviously, I wanted to look at how I am going to sustain my career and be as least invasive to myself,” Eichel recounted to The Athletic, explaining the thought process behind his decision. “I looked at it as fusion was going to change me permanently. With disc replacement, there’s still some major change that you’re doing, but you’re just kind of swapping a herniated disc for a prosthesis, and your neck looks the same as it did before. You also look at long-term benefits. There’s a lot that goes into it. It was a decision that I considered everything. If you just look at the numbers of medicine right now, the disc replacements are rising so quickly and fusions are starting to decimate. Medicine is always changing. The way we do things is always changing...”
Indeed, change is an inevitable constant in medicine (and life), and the surgical sands are shifting in ADR’s favor for diseased (or damaged) disc treatment, but Eichel is a bit off in his assessment of fusion’s impending demise. Grand View Research data suggest the global spinal fusion market is actually thriving, growing 4.4% annually and averaging 400,000 procedures per year in the United States. The market’s value is expected to jump 35% by 2028 to reach $8.5 billion.
The artificial disc replacement sector, by contrast, is worth only a fraction of fusion’s market total yet is slated to grow four times as much (18% annually) through 2028, more than doubling in value (to $4.37 billion), Insight Partners statistics show. Healthcare’s standard growth engines—aging populations, minimally invasive surgery, injury count—will do their part to move the ADR market forward but positive clinical data and technological advancements will be key to the sector’s future success.
Positive data already exists: Studies have found that cervical disc arthroplasty (CDA) has a higher overall success rate (78.6% vs. 62.7%), NDI scores (87% vs. 75.6%), neurological success (91.6% vs. 82.1%), and equivalent or lower adjacent segment disease rates compared with ACDF. CDA patients also recover quicker, return to work sooner, and have reduced short-term dysphagia rates than their ACDF counterparts.1
“Both cervical and lumbar disc arthroplasties offer promising solutions to the problems associated with spinal fusion,” an April 2022 Bioengineering article stated. “While the overall rates of disc arthroplasty are dwarfed by the rates of fusion for the treatment of disc pathology, as implant design improves and clinical studies continue to demonstrate promising outcomes, it is expected that the rates of arthroplasty will continue to increase.”
Artificial disc design has markedly improved since the product’s 1960s birth in Sweden. The stainless steel ball-bearing premiere prosthesis performed so poorly that development was shelved for more than a decade; the second-generation 1980s version (Cummins-Bristol Disc) was a two-piece ball-and-socket style implant made of stainless steel, with anterior screws placed into the superior and inferior endplates.1 That device fared better than the first, but was still beset with performance challenges.
Advancements in technology and engineering over the last several decades has produced artificial discs with varying endplate surfaces (keels, spikes, screws, porous coatings), articulation types (ball-and-socket, saddle), and material composition (stainless steel, cobalt, titanium, molybdenum).1
Medtronic’s Prestige LP cervical disc, for example, is a two-component (ball and trough) device that attaches to the vertebrae on either side of a disc, and is made of a proprietary titanium ceramic composite devoid of nickel, cobalt, and chromium.
Centinel Spine’s prodisc C Vivo and prodisc C Nova, on the other hand, have four components—two titanium alloy endplates, a cobalt chrome alloy calotte insert, and an ultra-high molecular weight polyethylene inlay—and is inserted into vertebral bodies en-bloc. PMA-approved by the U.S. Food and Drug Administration (FDA) in July for 1-level indications (along with the prodisc C SK), both implants feature rough titanium surface on bone contacting for better integration and stability.
“The FDA approval of the prodisc C Vivo, Nova, and C SK devices offers the surgeon a new level of modularity and stability for cervical disc replacement,” Jason Tinley, M.D., orthopedic spine surgeon and founder of DFW Center for Spinal Disorders (Dallas-Fort Worth), said upon FDA consent. “The patient can now receive an implant that best conforms to their anatomy intraoperatively, with variable endplate characteristics that best suit the surgeon’s preference of technique.”
The prodisc C Vivo has keel-less endplates including a convex, superior endplate to match more concave vertebral anatomy, while the prodisc Nova and prodisc C SK are designed with flat endplates and low-profile keels for duplicating flat vertebral structures.
NuVasive Inc.’s Simplify Cervical Disc, meanwhile, is comprised of two PEEK (polyetheretherketone) endplates, a ceramic core for enhanced radiological visualization, and a porous titanium plasma coating. The implants are manufactured in a range of sizes—beginning with the lowest available disc height (4mm)—to better match patients’ anatomies and protect facet joints.
NuVasive asserts that the Simplify Cervical Disc boasts a higher overall clinical success rate for both 1- and 2-levels than any other approved cervical disc. Study results demonstrate a 19.4% superiority to fusion (93% vs. 73.6% success rate) for 1-level use and a 9.6% superiority (86.7% vs. 77.1% success rate) for 2-level use.
The FDA approved Simplify Disc for 1-level use in September 2020 and 2-level use in April 2021. It is the third cervical arthroplasty system approved by the FDA for 2-level disc replacement, challenging Medtronic’s Prestige and ZimVie Inc.’s Mobi-C for market share.
The three-component Mobi-C consists of two cobalt-chromium-molybdenum endplates and a flat-bottomed polyethylene insert with a rounded top that slides and rotates inside the disc for automatic self-adjustment to the cervical spine’s movements. The hydroxyapatite-coated plates are lined with teeth on the top and bottom that press into the vertebrae without chisel cuts, thereby sparing bone.
Like its 2-level rivals, the Mobi-C has proven its worth in clinical trials, outperforming ACDF by considerable margins at various endpoints. The device showed a 48.5% superiority over fusion at six months (74.5% vs. 26% success rate), a 32.3% advantage at 24 months (69.7% vs. 37.4%), a 29.5% supremacy at 48 months (65.5% vs. 36%), and a 26.2% superiority at 84 months (60.8% vs. 34.6%), according to ZimVie data.
“In the cervical disc degeneration space, as well as the pediatric scoliosis market, there is increasing interest and demand for non-fusion alternatives. Cervical disc replacement with the Mobi-C Cervical Disc has over 10 years of clinical history and proven superiority to anterior cervical discectomy and fusion for two-level indications,” noted Rebecca Whitney, senior vice president and Global Spine president of ZimVie. “Mobi-C patients experience a restoration of mobility and function but also see a significant decrease in the likelihood of subsequent surgeries and adjacent level disc degeneration in comparison to ACDF.”
The Mobi-C is one of several non-fusion alternatives in ZimVie’s spinal product repository. The company also developed an idiopathic scoliosis treatment that uses a patient’s natural growth to straighten the spine.
The Tether - Vertebral Body Tethering System uses a polyethylene-terephthalate tensioning cord that allows the spine to bend and flex during treatment. It acts as an “internal brace” for the spine, exerting pressure on the column’s outside curve while simultaneously allowing the inside curve to continue growing.
Besides the tensioning cord, the Tether also comprises a titanium alloy vertebral body anchor, a cannulated, hydroxyapatite-coated vertebral body bone screw, and a titanium set screw. It received humanitarian device exemption (HDE) approval in August 2019 and has been used thenceforth by roughly 50 U.S. surgeons to treat more than 1,200 children, ZimVie statistics indicate.
“Rather than a traditional scoliosis correction via spinal fusion, Tether patients benefit from a non-fusion curvature correction that retains their flexibility and ability to grow,” Whitney said. “Because the procedure is performed while the patient is skeletally immature and growing patients can be treated sooner than they would be with traditional fusion. These children also have a faster return to school and athletic activities like swimming, cheerleading, and gymnastics due to the minimally invasive approach.”
Such an approach is becoming a universally accepted standard in the spine sector as patients and clinicians seek surgical solutions that shorten recovery times, reduce complications, and minimize body trauma. This paradigm shift away from conventional open procedures is expected to drive growth in the global minimally invasive spinal implant market this decade, boosting its value 73% to $6.4 billion by 2028, Research and Markets data indicate.
“We believe the minimally invasive surgery segment is growing rapidly due to improvements in recovery and cosmesis, as well as the focus on continued advancements of the technology in this segment,” explained Keith Evans, vice president and general manager of Stryker Spine’s Enabling Technologies business unit. “Surgeons are looking for safer and less invasive surgical techniques to decrease the likelihood of revision surgery.”
Medtronic currently dominates the market, having leveraged its leading position in the MIS pedicle screw sector to surpass former frontrunner NuVasive. San Diego-based NuVasive, however, still tops the MIS interbody sector, and has been runner-up in the spinous process fixation segment. It ranks third in the MIS pedicle screw market.
Medtronic cemented its lead over NuVasive last fall by debuting three new minimally invasive spinal implants. The Catalyft PL and PL40 (for the Catalyft expandable interbody system) are designed for anterior rim engagement and feature an easily inserted beveled tip, StealthStation Navigation integration, simplified bone graft delivery, and active expansion at a precise angle and lift for minimally invasive sagittal alignment.
The Space-D access system enables pedicle-screw-based distraction, retraction, and compression, and is compatible with Medtronic’s other screw system, the CD Horizon Solera Voyager.
Finally, the Accelerate graft delivery system with Grafton DBF allows for more controlled and efficient graft material delivery into the disc space or other locations, and enables more bone graft fusion placements.
“Minimally invasive surgery strives for equal outcomes through smaller incisions and easier access to the spine, pushing for implants and instruments to be smaller and mindful of visibility,” said Josh Johnson, vice president and general manager of Stryker Spine’s Core Spine business unit. “To achieve the same outcome, implants often need to be adjustable in-situ.”
To achieve optimal outcomes, MIS implants must be small, efficient, simple, customizable (in certain cases), and cost-effective. Surgical instrumentation must follow suit, though, for procedural success.
MIS screw insertion, for example, can be quite complex, requiring numerous tools like Jamshi needles and guidewires, and multiple instrument passes in and out of the body. DePuy Synthes’ VIPER PRIME System, however, inserts pedicle screws in a single instrument pass, and the company’s CONCORDE Clear Discectomy tool removes degenerated discs in less than four minutes.
Similarly, Accelus’s FlareHawk 7 platform features instruments that allow direct visualization of disc preparation and implant delivery. Adjustable shaver blades help surgeons assess disc height and simultaneously prep the disc space and endplates, while patented curettes with modular handles and shaft diameters provide compatibility with nearly every endoscope working channel on the market, the company claims.
Released last summer, FlareHawk7 is a multidirectionally expandable lumbar fusion device that provides sagittal and coronal correction, foraminal height restoration, and the stability to promote fusion. It incorporates the company’s Adaptive Geometry, enabling the device to be inserted at an ultra-low 7mm tall by 7mm wide profile before expanding up to 12mm tall and 11mm wide.
“The trend towards minimally invasive procedures has driven demand for sleeker, more refined implant designs with a smaller footprint,” noted Anisha Godhwani, marketing manager for gSource LLC, an Emerson, N.J.-based provider of spinal and orthopedic surgical instruments. “The ability to perform more surgeries more quickly shapes what gSource creates—we want to be able to shorten the time surgeries take with our instrumentation. The changes in instrumentation mirror that of [implant] development, with a focus on fewer, more multipurpose devices that reduce the cost and processing requirements for a surgical implant set.”
Many of the implant development changes prompting corresponding modifications in MIS instruments have been spawned by emerging technologies like additive manufacturing (a.k.a., 3D printing) and surgical navigation/robotics—two of the faster-growing and more lucrative sub-segments of the global spine industry.
MarketWatch Inc. projects the 3D printed orthopedic implants sector to more than double by 2028, swelling 16.2% annually to reach $4.95 billion. The manufacturing technique has mostly benefited titanium cage design, producing implants with better bone integration prowess, improved visualization, and varying sizes.
Globus Medical Inc.’s HEDRON IC, for instance, features a biomimetic porous scaffolding designed to promote bone formation onto and through the implant, while Camber Spine’s SPIRA - C has an osteopromotive surface and a patented arch design for redistributing load for maximum end plate contact and full arthrodesis promotion.
“3D printed titanium cages is the biggest trend in spine at the moment. We see a lot of companies shifting most of their spinal cages into 3D printed cages for better bone on-growth and in-growth,” Allen Daniel George, vice president at Gesco Healthcare, an India-based firm that designs and manufactures neuro, orthopedic, and spinal implants and instruments. “With the help of leading-edge software, we can lattice titanium cages to have stiffness levels of PEEK but have a reasonable load-bearing capacity. We never thought this would be possible before. We can also expect pedicle screws to be 3D printed in the future.”
The healthcare community can also expect 3D printed implants and instruments for extremities, large joint, and pediatrics, too.
“We are seeing steady adoption of additive for spinal implants. Since the spine market was the first sector to adopt additive manufacturing processes, we are seeing most organizations work on moving that technology forward,” David Novak, vice president of Corporate Business Development at manufacturing and engineering services provider Cretex Medical, told Orthopedic Design & Technology. “The focus is around challenging their spinal implant designs to make the most of what additive technology has to offer. For example, spinal OEMs continue to refine osteoconductive lattices that promote rapid fixation while mimicking the compressive characteristics of natural bone to reduce complications like subsidence or expulsion. We are also seeing OEMs that are not purely spine beginning to move additive manufacturing into other portions of their business, like extremities. The knowledge these organizations have learned from the work that has been done in spine has yielded immediate benefits as they take this technology into other segments of their business.”
One of those segments is robotics. Additive manufacturing has been used for years to create models for improving robot-guided spinal surgery precision. Case in point: Experts at the 3D printing lab within the Mayo Clinic’s Department of Neurosurgery have developed an open-access 3D-printed simulator for resident and medical student education in spinal anatomy and pedicle screw placement.
Otherwise known as Spinebox, the simulator design can be 3D printed on any desktop device for less than $10 and disseminated to neurosurgical and orthopedic residence undergoing training in spinal surgery.
In a similar vein, Florida Atlantic University researchers have devised a 3D printed robotic replica of a human spine modified to include an artificial disc implant with a soft magnetic sensor array to allow clinicians to preview the effects of surgical interventions before a procedure.
“While navigation has been growing with navigated taps/drivers and supportive tracking arrays, robotics support surgeons in a way they couldn’t before and with the adoption of
augmented reality are allowing for optimal pre-operative planning while more precise positioning of implants intraoperatively,” noted François Samson, strategic marketing senior manager at orthopedic contract manufacturer Intech.
Robotic-assisted surgery is a relatively new branch of the eternally-evolving spine industry, having been born in 2004 with the FDA approval of the Mazor SpineAssist for pedicle screw placement. The market has developed rapidly since then, with robotic spinal systems developed by Medtronic (Mazor X), Globus Medical (ExcelsiusGPS), Zimmer Biomet (Rosa Spine), NuVasive (Pulse), Brainlab (Cirq), Curexo (Cuvis-spine), and Fusion Robotics (Fusion Robotics System).
“There has been an increase in the development of enabling technologies in the spine market, such as surgical guidance, robotics, augmented reality, and virtual reality, all with the goal of driving efficiency and predictable improvements in spine surgery,” Stryker’s Evans said. “Current robotics technologies on the market are in the early adoption phase, meaning only a small percentage of overall procedures utilize robotics. However, given the trends in joint replacement and soft tissue robotics, there is a growing belief that robotics will have a significant impact on spine surgery as technologies improve to meet the needs of the market.”
In other words, the robots are here to stay.
Reference
His nerves were already in tatters—had been from the minute he walked into the Denver-area medical clinic early that morning—but they were now approaching overdrive as he waited for his first-ever surgical procedure to begin.
“I had never had surgery before, so you’re obviously nervous before surgery,” the former Buffalo Sabres captain recounted to subscription-based sports website The Athletic in April. “I...had dinner with my parents that night [before]. You wake up the next morning and...I went in by myself, and I was just sitting in the room and really didn’t have anyone there. The nurses were obviously great, but when you’re in that situation, you’re just like, ‘Hey, this is pretty real now.’”
Extremely real—he had reached the point of no return.
Yet it wasn’t so much the pre-surgical jitters that sent Eichel’s butterflies into a frenzy last year but rather the procedure itself and the public brouhaha that accompanied it. On Nov. 12, 2021, the former No. 2 draft pick became the first National Hockey League player to repair a herniated cervical (neck) disc through artificial disc replacement (ADR) surgery.
Eichel damaged the cushion-like pad between two neck vertebrae eight months earlier during the Sabres’ 5-2 loss to the New York Islanders. The 25-year-old center favored an ADR fix for his injury, but Sabres doctors recommended an anterior cervical discectomy fusion (ACDF), a more common surgery.
Both procedures relieve herniated disc pain but do so in different ways: Artificial discs replace the damaged original with an implant to preserve vertebral motion, while a fusion bonds the affected vertebrae together, preventing any painful movement. The latter has been used since the 1950s, and is considered the “gold standard” surgery for cervical disc degeneration (or injury). A 10-year study found that ACDF patients used fewer narcotics for pain and experienced fewer neurological issues but needed more revision surgeries than their ADR counterparts. Artificial discs, conversely, are associated with better pain and mobility outcomes, as well as fewer revisions.
Eichel’s penchant for ADR triggered an eight-month stalemate with his team, as Sabre doctors refused to authorize his treatment choice (the NHL’s collective bargaining agreement gives teams control over their players’ medical decisions). Eichel was equally as uncompromising, leading to a “divorce” that sent the top-rated hockey player to the more supportive Vegas Golden Knights. He underwent ADR surgery roughly a week after the trade, and was back on the ice in mid-February this year.
“The decision of the surgery is one that we respectfully defer to Jack and his representatives,” Golden Knights General Manager Kelly McCrimmon stated at a Nov. 4, 2021, news conference announcing the trade. “None of us in this room have the level of expertise that would be required for an opinion. I defer to the people that he’s [Jack’s] entrusted himself and his health to make that decision.”
Those people (and Eichel) based their decision on both career longevity and ADR’s long-term benefits (shorter recovery time, improved cervical global alignment, and better segmental angle), though ACDF’s potential for limited mobility and adjacent segment disease likely influenced the final determination too.
“Obviously, I wanted to look at how I am going to sustain my career and be as least invasive to myself,” Eichel recounted to The Athletic, explaining the thought process behind his decision. “I looked at it as fusion was going to change me permanently. With disc replacement, there’s still some major change that you’re doing, but you’re just kind of swapping a herniated disc for a prosthesis, and your neck looks the same as it did before. You also look at long-term benefits. There’s a lot that goes into it. It was a decision that I considered everything. If you just look at the numbers of medicine right now, the disc replacements are rising so quickly and fusions are starting to decimate. Medicine is always changing. The way we do things is always changing...”
Indeed, change is an inevitable constant in medicine (and life), and the surgical sands are shifting in ADR’s favor for diseased (or damaged) disc treatment, but Eichel is a bit off in his assessment of fusion’s impending demise. Grand View Research data suggest the global spinal fusion market is actually thriving, growing 4.4% annually and averaging 400,000 procedures per year in the United States. The market’s value is expected to jump 35% by 2028 to reach $8.5 billion.
The artificial disc replacement sector, by contrast, is worth only a fraction of fusion’s market total yet is slated to grow four times as much (18% annually) through 2028, more than doubling in value (to $4.37 billion), Insight Partners statistics show. Healthcare’s standard growth engines—aging populations, minimally invasive surgery, injury count—will do their part to move the ADR market forward but positive clinical data and technological advancements will be key to the sector’s future success.
Positive data already exists: Studies have found that cervical disc arthroplasty (CDA) has a higher overall success rate (78.6% vs. 62.7%), NDI scores (87% vs. 75.6%), neurological success (91.6% vs. 82.1%), and equivalent or lower adjacent segment disease rates compared with ACDF. CDA patients also recover quicker, return to work sooner, and have reduced short-term dysphagia rates than their ACDF counterparts.1
“Both cervical and lumbar disc arthroplasties offer promising solutions to the problems associated with spinal fusion,” an April 2022 Bioengineering article stated. “While the overall rates of disc arthroplasty are dwarfed by the rates of fusion for the treatment of disc pathology, as implant design improves and clinical studies continue to demonstrate promising outcomes, it is expected that the rates of arthroplasty will continue to increase.”
Artificial disc design has markedly improved since the product’s 1960s birth in Sweden. The stainless steel ball-bearing premiere prosthesis performed so poorly that development was shelved for more than a decade; the second-generation 1980s version (Cummins-Bristol Disc) was a two-piece ball-and-socket style implant made of stainless steel, with anterior screws placed into the superior and inferior endplates.1 That device fared better than the first, but was still beset with performance challenges.
Advancements in technology and engineering over the last several decades has produced artificial discs with varying endplate surfaces (keels, spikes, screws, porous coatings), articulation types (ball-and-socket, saddle), and material composition (stainless steel, cobalt, titanium, molybdenum).1
Medtronic’s Prestige LP cervical disc, for example, is a two-component (ball and trough) device that attaches to the vertebrae on either side of a disc, and is made of a proprietary titanium ceramic composite devoid of nickel, cobalt, and chromium.
Centinel Spine’s prodisc C Vivo and prodisc C Nova, on the other hand, have four components—two titanium alloy endplates, a cobalt chrome alloy calotte insert, and an ultra-high molecular weight polyethylene inlay—and is inserted into vertebral bodies en-bloc. PMA-approved by the U.S. Food and Drug Administration (FDA) in July for 1-level indications (along with the prodisc C SK), both implants feature rough titanium surface on bone contacting for better integration and stability.
“The FDA approval of the prodisc C Vivo, Nova, and C SK devices offers the surgeon a new level of modularity and stability for cervical disc replacement,” Jason Tinley, M.D., orthopedic spine surgeon and founder of DFW Center for Spinal Disorders (Dallas-Fort Worth), said upon FDA consent. “The patient can now receive an implant that best conforms to their anatomy intraoperatively, with variable endplate characteristics that best suit the surgeon’s preference of technique.”
The prodisc C Vivo has keel-less endplates including a convex, superior endplate to match more concave vertebral anatomy, while the prodisc Nova and prodisc C SK are designed with flat endplates and low-profile keels for duplicating flat vertebral structures.
NuVasive Inc.’s Simplify Cervical Disc, meanwhile, is comprised of two PEEK (polyetheretherketone) endplates, a ceramic core for enhanced radiological visualization, and a porous titanium plasma coating. The implants are manufactured in a range of sizes—beginning with the lowest available disc height (4mm)—to better match patients’ anatomies and protect facet joints.
NuVasive asserts that the Simplify Cervical Disc boasts a higher overall clinical success rate for both 1- and 2-levels than any other approved cervical disc. Study results demonstrate a 19.4% superiority to fusion (93% vs. 73.6% success rate) for 1-level use and a 9.6% superiority (86.7% vs. 77.1% success rate) for 2-level use.
The FDA approved Simplify Disc for 1-level use in September 2020 and 2-level use in April 2021. It is the third cervical arthroplasty system approved by the FDA for 2-level disc replacement, challenging Medtronic’s Prestige and ZimVie Inc.’s Mobi-C for market share.
The three-component Mobi-C consists of two cobalt-chromium-molybdenum endplates and a flat-bottomed polyethylene insert with a rounded top that slides and rotates inside the disc for automatic self-adjustment to the cervical spine’s movements. The hydroxyapatite-coated plates are lined with teeth on the top and bottom that press into the vertebrae without chisel cuts, thereby sparing bone.
Like its 2-level rivals, the Mobi-C has proven its worth in clinical trials, outperforming ACDF by considerable margins at various endpoints. The device showed a 48.5% superiority over fusion at six months (74.5% vs. 26% success rate), a 32.3% advantage at 24 months (69.7% vs. 37.4%), a 29.5% supremacy at 48 months (65.5% vs. 36%), and a 26.2% superiority at 84 months (60.8% vs. 34.6%), according to ZimVie data.
“In the cervical disc degeneration space, as well as the pediatric scoliosis market, there is increasing interest and demand for non-fusion alternatives. Cervical disc replacement with the Mobi-C Cervical Disc has over 10 years of clinical history and proven superiority to anterior cervical discectomy and fusion for two-level indications,” noted Rebecca Whitney, senior vice president and Global Spine president of ZimVie. “Mobi-C patients experience a restoration of mobility and function but also see a significant decrease in the likelihood of subsequent surgeries and adjacent level disc degeneration in comparison to ACDF.”
The Mobi-C is one of several non-fusion alternatives in ZimVie’s spinal product repository. The company also developed an idiopathic scoliosis treatment that uses a patient’s natural growth to straighten the spine.
The Tether - Vertebral Body Tethering System uses a polyethylene-terephthalate tensioning cord that allows the spine to bend and flex during treatment. It acts as an “internal brace” for the spine, exerting pressure on the column’s outside curve while simultaneously allowing the inside curve to continue growing.
Besides the tensioning cord, the Tether also comprises a titanium alloy vertebral body anchor, a cannulated, hydroxyapatite-coated vertebral body bone screw, and a titanium set screw. It received humanitarian device exemption (HDE) approval in August 2019 and has been used thenceforth by roughly 50 U.S. surgeons to treat more than 1,200 children, ZimVie statistics indicate.
“Rather than a traditional scoliosis correction via spinal fusion, Tether patients benefit from a non-fusion curvature correction that retains their flexibility and ability to grow,” Whitney said. “Because the procedure is performed while the patient is skeletally immature and growing patients can be treated sooner than they would be with traditional fusion. These children also have a faster return to school and athletic activities like swimming, cheerleading, and gymnastics due to the minimally invasive approach.”
Such an approach is becoming a universally accepted standard in the spine sector as patients and clinicians seek surgical solutions that shorten recovery times, reduce complications, and minimize body trauma. This paradigm shift away from conventional open procedures is expected to drive growth in the global minimally invasive spinal implant market this decade, boosting its value 73% to $6.4 billion by 2028, Research and Markets data indicate.
“We believe the minimally invasive surgery segment is growing rapidly due to improvements in recovery and cosmesis, as well as the focus on continued advancements of the technology in this segment,” explained Keith Evans, vice president and general manager of Stryker Spine’s Enabling Technologies business unit. “Surgeons are looking for safer and less invasive surgical techniques to decrease the likelihood of revision surgery.”
Medtronic currently dominates the market, having leveraged its leading position in the MIS pedicle screw sector to surpass former frontrunner NuVasive. San Diego-based NuVasive, however, still tops the MIS interbody sector, and has been runner-up in the spinous process fixation segment. It ranks third in the MIS pedicle screw market.
Medtronic cemented its lead over NuVasive last fall by debuting three new minimally invasive spinal implants. The Catalyft PL and PL40 (for the Catalyft expandable interbody system) are designed for anterior rim engagement and feature an easily inserted beveled tip, StealthStation Navigation integration, simplified bone graft delivery, and active expansion at a precise angle and lift for minimally invasive sagittal alignment.
The Space-D access system enables pedicle-screw-based distraction, retraction, and compression, and is compatible with Medtronic’s other screw system, the CD Horizon Solera Voyager.
Finally, the Accelerate graft delivery system with Grafton DBF allows for more controlled and efficient graft material delivery into the disc space or other locations, and enables more bone graft fusion placements.
“Minimally invasive surgery strives for equal outcomes through smaller incisions and easier access to the spine, pushing for implants and instruments to be smaller and mindful of visibility,” said Josh Johnson, vice president and general manager of Stryker Spine’s Core Spine business unit. “To achieve the same outcome, implants often need to be adjustable in-situ.”
To achieve optimal outcomes, MIS implants must be small, efficient, simple, customizable (in certain cases), and cost-effective. Surgical instrumentation must follow suit, though, for procedural success.
MIS screw insertion, for example, can be quite complex, requiring numerous tools like Jamshi needles and guidewires, and multiple instrument passes in and out of the body. DePuy Synthes’ VIPER PRIME System, however, inserts pedicle screws in a single instrument pass, and the company’s CONCORDE Clear Discectomy tool removes degenerated discs in less than four minutes.
Similarly, Accelus’s FlareHawk 7 platform features instruments that allow direct visualization of disc preparation and implant delivery. Adjustable shaver blades help surgeons assess disc height and simultaneously prep the disc space and endplates, while patented curettes with modular handles and shaft diameters provide compatibility with nearly every endoscope working channel on the market, the company claims.
Released last summer, FlareHawk7 is a multidirectionally expandable lumbar fusion device that provides sagittal and coronal correction, foraminal height restoration, and the stability to promote fusion. It incorporates the company’s Adaptive Geometry, enabling the device to be inserted at an ultra-low 7mm tall by 7mm wide profile before expanding up to 12mm tall and 11mm wide.
“The trend towards minimally invasive procedures has driven demand for sleeker, more refined implant designs with a smaller footprint,” noted Anisha Godhwani, marketing manager for gSource LLC, an Emerson, N.J.-based provider of spinal and orthopedic surgical instruments. “The ability to perform more surgeries more quickly shapes what gSource creates—we want to be able to shorten the time surgeries take with our instrumentation. The changes in instrumentation mirror that of [implant] development, with a focus on fewer, more multipurpose devices that reduce the cost and processing requirements for a surgical implant set.”
Many of the implant development changes prompting corresponding modifications in MIS instruments have been spawned by emerging technologies like additive manufacturing (a.k.a., 3D printing) and surgical navigation/robotics—two of the faster-growing and more lucrative sub-segments of the global spine industry.
MarketWatch Inc. projects the 3D printed orthopedic implants sector to more than double by 2028, swelling 16.2% annually to reach $4.95 billion. The manufacturing technique has mostly benefited titanium cage design, producing implants with better bone integration prowess, improved visualization, and varying sizes.
Globus Medical Inc.’s HEDRON IC, for instance, features a biomimetic porous scaffolding designed to promote bone formation onto and through the implant, while Camber Spine’s SPIRA - C has an osteopromotive surface and a patented arch design for redistributing load for maximum end plate contact and full arthrodesis promotion.
“3D printed titanium cages is the biggest trend in spine at the moment. We see a lot of companies shifting most of their spinal cages into 3D printed cages for better bone on-growth and in-growth,” Allen Daniel George, vice president at Gesco Healthcare, an India-based firm that designs and manufactures neuro, orthopedic, and spinal implants and instruments. “With the help of leading-edge software, we can lattice titanium cages to have stiffness levels of PEEK but have a reasonable load-bearing capacity. We never thought this would be possible before. We can also expect pedicle screws to be 3D printed in the future.”
The healthcare community can also expect 3D printed implants and instruments for extremities, large joint, and pediatrics, too.
“We are seeing steady adoption of additive for spinal implants. Since the spine market was the first sector to adopt additive manufacturing processes, we are seeing most organizations work on moving that technology forward,” David Novak, vice president of Corporate Business Development at manufacturing and engineering services provider Cretex Medical, told Orthopedic Design & Technology. “The focus is around challenging their spinal implant designs to make the most of what additive technology has to offer. For example, spinal OEMs continue to refine osteoconductive lattices that promote rapid fixation while mimicking the compressive characteristics of natural bone to reduce complications like subsidence or expulsion. We are also seeing OEMs that are not purely spine beginning to move additive manufacturing into other portions of their business, like extremities. The knowledge these organizations have learned from the work that has been done in spine has yielded immediate benefits as they take this technology into other segments of their business.”
One of those segments is robotics. Additive manufacturing has been used for years to create models for improving robot-guided spinal surgery precision. Case in point: Experts at the 3D printing lab within the Mayo Clinic’s Department of Neurosurgery have developed an open-access 3D-printed simulator for resident and medical student education in spinal anatomy and pedicle screw placement.
Otherwise known as Spinebox, the simulator design can be 3D printed on any desktop device for less than $10 and disseminated to neurosurgical and orthopedic residence undergoing training in spinal surgery.
In a similar vein, Florida Atlantic University researchers have devised a 3D printed robotic replica of a human spine modified to include an artificial disc implant with a soft magnetic sensor array to allow clinicians to preview the effects of surgical interventions before a procedure.
“While navigation has been growing with navigated taps/drivers and supportive tracking arrays, robotics support surgeons in a way they couldn’t before and with the adoption of
augmented reality are allowing for optimal pre-operative planning while more precise positioning of implants intraoperatively,” noted François Samson, strategic marketing senior manager at orthopedic contract manufacturer Intech.
Robotic-assisted surgery is a relatively new branch of the eternally-evolving spine industry, having been born in 2004 with the FDA approval of the Mazor SpineAssist for pedicle screw placement. The market has developed rapidly since then, with robotic spinal systems developed by Medtronic (Mazor X), Globus Medical (ExcelsiusGPS), Zimmer Biomet (Rosa Spine), NuVasive (Pulse), Brainlab (Cirq), Curexo (Cuvis-spine), and Fusion Robotics (Fusion Robotics System).
“There has been an increase in the development of enabling technologies in the spine market, such as surgical guidance, robotics, augmented reality, and virtual reality, all with the goal of driving efficiency and predictable improvements in spine surgery,” Stryker’s Evans said. “Current robotics technologies on the market are in the early adoption phase, meaning only a small percentage of overall procedures utilize robotics. However, given the trends in joint replacement and soft tissue robotics, there is a growing belief that robotics will have a significant impact on spine surgery as technologies improve to meet the needs of the market.”
In other words, the robots are here to stay.
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