Michael Barbella, Managing Editor09.15.15
There’s a major faux pas in the first “Back to the Future” sequel, the 1989 film that gave moviegoers a fascinating—and in some cases remarkably accurate—glimpse of everyday life in the year 2015.
It wasn’t a blatant error. In fact, it probably was overlooked amid the slew of nifty technologies available to a middle-aged Marty McFly and his offspring—wonders like weather-predicting watches, power-lacing sneakers, holographic advertisements, personal credit card readers, giant flatscreen televisions, virtual windows, hanging indoor gardens, and hoverboards (perhaps the most dandy invention of them all).
Early in the film, Marty’s girlfriend/intended wife hides in her future home, watching her destiny play out from the confines of a front hall closet. She observes a dinnertime visit from elderly sweethearts George and Lorraine McFly, and overhears them talking about Marty’s descent into self-pity from a car accident many years earlier. George, 77, is hanging upside-down the entire time, firmly secured into an anti-gravity back injury treatment device called the Ortho-lev.
“Aw, Dad, you threw your back out again,” Marty says upon returning home after a long workday. “I really think you should get that spine operation.”
“I know, I know,” George replies. “But who’s got three extra hours to spend at the hospital?”
Three hours for spine surgery is a bit unrealistic, even by 2015 standards. Minimally invasive endoscopic discectomies typically are performed on an outpatient basis but most other spinal procedures (cervical, lumbar decompression and fusions) require a one- to five-day hospitalization. Total recovery times range from six weeks to 12 months.
George might have been better off printing out a replacement disc or vertebrae.
Nevertheless, the filmmakers’ spinal surgery pipe dream is easily forgivable, considering the number of technological wizardry the movie correctly predicted, namely, wearable computing (Google Glass), video conferencing (Skype), computerized voice control ordering (Siri), drone footage, super-thin digital cameras, smart watches, handheld tablet computers, dehydrated food, fingerprint identification abilities, handheld and/or wireless video games, and mobile credit card readers.
Yet director Robert Zemeckis and screenwriter Bob Gale came up with their fair share of blunders, too: flying cars, self-lacing sneakers (Nike has patented the technology but has not yet commercialized it), automatic dog walkers, hoverboards (a prototype currently uses magnetic repulsion to “hover” above metal surfaces), Pepsi Perfect, hanging indoor garden centers and, of course, the Ortho-lev.
George McFly’s preferred treatment option seems rather crude and primitive considering all the advancements made in medical technology over the last three decades, though it does fit well in an Internet-free world largely dependent on landline phones and faxes for communication.
A few pit stops en route to the future could have provided Marty with some better regimen choices for his father’s ailing back. A layover in 2005, for example, (the year Orthopedic Design & Technology made its debut) would have provided Marty with valuable insight on rechargeable spinal cord stimulation systems—devices that use low-intensity electrical impulses to selectively trigger nerve fibers along the spinal cord. Researchers surmise that stimulating these nerve fibers significantly diminishes or blocks the intensity of the pain message being transmitted to the brain, replacing the discomfort with a tingling sensation.
In March and April of 2005, the U.S. Food and Drug Administration (FDA) approved two implantable rechargeable devices: the Eon Neurostimulation System from Advanced Neuromodulation Systems Inc. (now a part of St. Jude Medical Inc.), and the Restore Rechargeable Neurostimulation System from Medtronic plc.
Featuring the market’s highest-capacity rechargeable battery at the time, the Eon system was designed to last at least seven years at high power settings and power up to 16 independent electrodes, giving clinicians more programming options to better manage patients’ pain. Recharging the device was comparable in simplicity to that of a cell phone (another innovation conspicuously absent from Hill Valley life in 2015).
Had Marty’s father chosen a spinal cord stimulator to relieve his back pain, that device likely would have been implanted in a minimally invasive procedure, which, some scholars argue, first took root in 1985 (it might even have garnered a mention in the Hill Valley Telegraph). Designed to reduce tissue damage, minimally invasive surgery (MIS) is performed through a series of small (typically three-quarter inch) incisions using thin tubes called trocars. Carbon dioxide gas may be used to inflate the area, creating a space between the internal organs and the skin. A miniature camera (usually a laparoscope or endoscope) is placed through one of the trocars so the surgical team can view the procedure as a magnified image on video monitors in the operating room. Then, specialized instruments are placed through the other trocars to perform the procedure.
The number and size of incisions can vary depending on the organ or body part under repair. Some MIS procedures, however, can be performed almost exclusively through a single-entry port (using only one small incision). This type of surgery is known as single site laparoscopy.
Though they can take longer to perform than traditional “invasive” approaches, MIS procedures carry significant benefits to the patient and overall healthcare system, including less pain and scarring, a quicker recovery, and shorter hospital stays, the latter of which can help reduce skyrocketing medical costs.
“Orthopedic technology has had a remarkable progression over the last decade,” said Amir Matityahu, M.D., an associate professor of orthopedic surgery at the University of California-San Francisco and director of pelvic and acetabular trauma and reconstruction at San Francisco General Hospital. “In any surgery, the technology involved can be a big factor in determining its overall success. And in the last 10 years, there’s been a lot of small incremental changes in [orthopedic] technology—innovations that have either answered questions doctors have had, fulfilled a need or have given them solutions to a particular problem.”
Matityahu is responsible for at least one of those incremental changes: His Palo Alto, Calif., company, EPIX Orthopaedics Inc., designed a variable-angle nail (VAN) that can be adjusted to fit every patient. According to the firm’s website, the EPIX VAN system gives surgeons the freedom to infinitely adjust guidewire placement into the center-center position in the femoral head. The EPIX device enables in-situ movement of the lag screw to achieve anatomic reduction of the fracture, which may help improve patient outcomes by avoiding varus, cutout, and hardware failure.
In addition, the EPIX VAN system enables surgeons to increase the angle between the lag screw and nail up to 140 degrees, which embeds the nail deeper into the bone proximally, eliminating nail prominence.
Also, because it is adjustable, the EPIX System increases manufacturer efficiency and decreases on-shelf unused inventory to 55 nails, helping to reduce overall healthcare costs, the company claims. If the short (205 millimeter) nail is chosen, the inventory size decreases to one nail.
“There are genuine problems in orthopedics that need solutions. The most common fracture that we see in this country is the hip fracture. Every single hip that is fractured needs to be fixed or replaced depending on the type of injury. So what’s the problem? The problem is that hip fractures have a very high failure rate after they are fixed, around 10 to 20 percent of the time,” Matityahu explained. “Most of these [hip fracture] patients are elderly. If they have a problem after surgery it’s going to affect them profoundly because they’re older and they don’t have any reserve. One of the reasons why elderly people have a problem with fractures is because their bones are very thin. Another factor can be the surgical technique. EPIX Orthopaedics came up with a solution to this problem. That solution is a specific type of implant that basically helps the doctor do his job a little bit better. This is just one example, though. The solutions to problems like this are usually coming from doctors saying, ‘You know what, I’m having a problem with this,’ and either they solve the problem themselves like we did, or they go to a large manufacturer and collaborate with them to fix the problem.”
Stephen B. Murphy, M.D., has taken matters into his own hands as well. The New England Baptist Hospital orthopedic surgeon has designed numerous implants and instruments, and pioneered many new surgical methods currently in use, developing many of the algorithms used in virtually all computer-assisted navigation systems. He also patented the superior capsulotomy (“supercap”) total hip arthroplasty technique in 2005, and co-invented a similar procedure called “superpath.”
Murphy’s supercap procedure tackles hip replacements through a superior approach, leaving the short external rotators and both the anterior and posterior capsule intact. Simply stated, it preserves the soft tissue surrounding the hip and allows surgeons to replace nature’s handiwork without ever dislocating the joint or distorting the limb beyond the hip’s normal range of motion.
Study data indicate the procedure—combined with computer assisted surgical navigation—actually is safer than conventional total hip arthroplasty and dramatically accelerates recovery. In fact, it is the only minimally invasive surgical technique shown in scientific peer-reviewed literature to be a safer procedure than the control group.
“While total hip replacement has been a fairly successful operation, one of the big stumbling blocks continues to be patients having dislocations post-operatively. One of the ways that people have tried to get around that is to change the way the operation is performed,” noted Colin Burnell, M.D., assistant professor of orthopedic surgery at the University of Manitoba (Canada), site supervisor in postgraduate surgery education for the Department of Surgery at Concordia Hospital in Winnipeg, Manitoba, and orthopedic surgeon at Concordia Joint Research Group.
“Instead of going through muscles from either the side or the back, it’s put in between muscles through the front of the patient with the hopes of leaving most of the supporting tissues intact that will increase the stability of the hip,” he continued. “What that has done is introduced a whole new learning curve to the procedure, which has been associated with some complications from many of the surgeons trying to use it. And it really seems to be trying to reinvent the wheel in order to compensate for some of our shortfalls in being able to position the implant properly. That really opens the door for us to continue to perform the operation in a way that we know well, that we’re good at, but also improve our accuracy with the use of new instruments and techniques.”
Some of the new tools and surgical procedures developed over the last decade could theoretically have come from the collective creativity of Zemeckis and Gale. Indeed, advancements like robotic-assisted surgery, patient-specific cutting guides, customized joints, and 3-D-printed implants wouldn’t be much of a stretch in a world that spawned hoverboard technology, skyways, rejuvenation clinics, and controlled weather.
Custom joints and patient-specific guides/instrumentation have gained traction in the last decade as clinicians sought ways to improve both implant alignment and surgical efficiency. Most of the major orthopedic device makers offer these products, though Smith & Nephew plc was the first to market with the 2008 launch of its Visionaire cutting guides and disposable size-specific tools.
The iTotal knee replacement system from Bedford, Mass.-based ConforMIS reportedly removes less bone than traditional off-the-shelf implants, an asset that could help dissipate the forces across the bone-implant junction more naturally. The iTotal also elevates the lateral joint line more than the medial joint line according to patient anatomy. This dual suspension allows the iTotal to keep the joint line at the natural 3 degrees of varus rather than directly perpendicular to the mechanical axis. Surgeons also can choose to replace only one or two of the knee joint’s three compartments.
The majority of custom implants and patient-specific guides are created from preoperative 3-D computed tomography (CT) or magnetic resonance imaging scans, typically taken four to six weeks before the procedure. From those images, a sterile revers mold of the patient’s knee is made, fitting snuggly onto the ends of the bones that comprise the knee joint. The molds guide the location of the bony cuts, helping to ensure a more accurate placement.
“Instead of putting rods inside a patient’s body to line things up we are now taking a custom-ma- de plastic jig that fits right onto a patient’s bone and that is what guides the surgeon, helping him make the cuts in precisely the right places,” Burnell said. “I think this is the major advancement in instrumentation that we’ve seen over the last several years. The marriage of 3-D printing and imaging is allowing us to use a patient’s own imaging—their own anatomy—to design a jig that will fit directly onto that patient’s bone and have the implant fit properly. One couldn’t exist without the other; it’s really both of those innovations together that have really allowed this advancement to occur.”
One-half of that couple, though, is thriving quite well on its own. Three-dimensional printing has proven itself a robust and versatile technology in recent years, responsible for such novelties as a bone fracture healing cast, ceramic/polymer bone scaffold, prosthetic limbs, synthetic tissues, and anatomical practice models (for surgery).
However, the technology still is relatively new and has yet to attain a true foothold in the medtech arena. Consequently, much of its use has been relegated to the academic and experimental realm (with the exception of hearing aids and dental braces): Doctors like Nicola Bizzotto, M.D., an orthopedic and trauma surgeon at the University of Verona Hospital (Italy), and Jason L. Koh, M.D., chairman of orthopedic surgery at NorthShore University HealthSystem in Evanston, Ill., have taken advantage of 3-D printing to create replicas of damaged joints or fractures. The practice models enable clinicians to simulate complex fixes/surgeries, and help them determine the best technique and equipment for a particular procedure.
Nevertheless, the technology is making some headway in the commercial market. A research team at the BIOMED Research Institute in Belgium, for example, successfully implanted the first 3-D-printed titanium mandibular prosthesis in June 2011. The implant was made by using a laser to successively melt thin layers of titanium powders.
Oxford Performance Materials Inc. of South Windsor, Conn., has perhaps had the most commercial success with 3-D printed implants, developing three FDA-cleared products over the last three years. The company made medical history with its first FDA-approved device, a polyetherketone ketone (PEKK) cranial plate designed to fill voids in the skull from trauma or disease. The plate successfully was implanted in 2013.
That triumph prompted the company to expand the printing technology to other bones, culminating in last summer’s FDA clearance of Oxford’s OsteoFab patient-specific facial device, a customizable implant for facial reconstruction. Finally, in July this year, Oxford received the regulatory green light for its SpineFab VBR Implant system, a load-bearing polymer device for long-term implantation.
Oxford’s SpineFab device is a vertebral body replacement intended for use in the thoracolumbar regions of the spine to replace a collapsed, damaged, or unstable vertebral body due to tumor or trauma. The company promises to 3-D print the SpineFab VBR System implants in 48 sizes using only biocompatible polymer and laser light.
The company is manufacturing the implants utilizing its OsteoFab process, which combines 3-D printing technology with the firm’s proprietary OXPEKK powder formulation to print orthopedic and neurological implants. The result, according to executives, is a “beneficial set of attributes, including radiolucency, bone-like mechanical properties, and bone on-growth characteristics.”
“This fundamental change in how surgical tools, equipment, and implants can be made has the potential to be significantly disruptive to the industry,” said Fred Hamlin, senior engineer in the Medical Technology division at United Kingdom-based Cambridge Consultants Ltd.
Conservative Change
Disruption is not a prerequisite for great innovation, though. Some of the most important orthopedic advancements over the last decade have improved surgical techniques and implants, but haven’t necessarily revolutionized the industry in the same way as 3-D printing.
Consider, for instance, knee replacements that allow the components to move inside the knee. The plastic insert rotates on a post, enabling the knee’s rotation to be determined by the muscular forces around the joint.
In the broad spectrum of innovation, such a product is certainly not radical. Yet there are numerous advantages that make this a truly great invention: The knee assumes the rotation that best fits the patient’s need and therefore is not limited by the surgeon’s personal choice. Furthermore, allowing the liner to rotate decreases the stress placed on the plastic, which could, in turn, boost the plastic’s longevity. Short and intermediate term study data have shown no difference between knee replacements with moveable components and those with a fixed bearing.
Similarly, the disposable arthroscope is a major advancement for both optical quality and patient safety. Single-use scopes help to reduce hospital-acquired infections while providing surgeons with the best optical quality for the procedure.
The overall grandeur of any device, however, is very subjective. Roy K. Aaron, M.D., an orthopedic surgery professor at Brown University’s Warren Alpert Medical School, deems highly cross-linked polyethylene to be the industry’s greatest technological advancement in the last decade. “The polyethylene component of a hip replacement has been greatly strengthened by cross-linking,” said Aaron, who also is director of the Orthopedic Cell Biology Lab at Brown and director of the orthopedic program in Clinical/Translational Research. “It’s made it much more resistant to wear. As a consequence you can use thinner plastic than you were able to use in the past. That means you can use a bigger ball on the femoral component—a bigger head size—and that gives you a larger turning range, which has resulted in a much lower rate of dislocation of the implant.”
For Matityahu, one of the industry’s major achievements was the development of locking plates, an innovation he claims has provided orthopedic surgeons with a better way to fix osteoporotic bones with very low density.
“It sounds simple but it actually has revolutionized what we’re doing,” he told ODT. “Our population in general is getting older and the bone quality in older people may not be very good. Locking plates are flat pieces of metal with holes in it for screws. The metal plate is attached to the bone with screws. Imagine you have a screw that you put into a piece of very soft wood. What happens? It very easily pulls out. The same thing can happen in older patients. How do you fix that? What has been developed is a way to lock the head of the screw to the plate. You have a plate with eight holes and four screws on each side. You can lock the screw heads into the plate, and that creates a fixed angle construct, meaning the screws can’t toggle, they are fixed in space relative to the plate. For those screws to come out, it takes a lot of force. It’s really a better way to fix bones with very low density.”
All Aboard!
Marty McFly’s storyline ended on Oct. 27, 1985, with the destruction of the DeLorean he used to travel through three centuries. As he inspects the damage, Marty’s dear friend (and eccentric scientist) Emmett “Doc” Brown shows up in a time-traveling 1880s-style train.
Before embarking on his next timeless adventure, Doc gives Marty a photo of the two of them at an 1885 festival and reminds him that his future hadn’t yet been written. Marty bids him a fond farewell and watches the train convert into an aerial craft and disappear into eras unknown.
Marty, of course, remains in 1985 to live out his future (with Jennifer by his side, presumably). Had he boarded the train, though, he may have been tempted to swing by the year 2025 to preview the newest technological and medical advancements available to his 57-year-old self (assuming he hasn’t visited the rejuvenation clinic).
A decade from now, scientists and biomedical researchers might have perfected stem cell treatments to reverse the degenerative process in intravertebral discs (perhaps he’ll lick the lower back trouble that afflicted his father). Stem cells might also be used by then to improve the recovery of patients with spinal cord injuries.
There’s also the possibility that doctors could monitor the progress of joint replacement and fracture repair patients via smart implants, providing clinicians with biological and mechanical data from the treated site. “If the patient is not supposed to be walking, and the implant indicates that it is being loaded, that will tell us that the patient is not following directions,” Matityahu said. “Smart implants can give the doctor a much more accurate way of determining whether a fracture is healing the proper way.”
Biomedical engineers likely will still be searching for the ideal biocompatible material to increase implant longevity, and 3-D printing is certain to play an even bigger role in product design and development, perhaps allowing surgeons to complete procedures faster, cheaper and more efficiently.
“I don’t foresee a major change in the way implants look or what they are made of. What I see is a drive to do more of the same operations faster because the system is going to be significantly stressed as the baby boomers start coming through,” Burnell predicted. “Anything that can help expedite the surgical process will be welcomed, whether it be disposable instruments so you don’t have to wait for a set to be cleaned, or custom cut blocks to help speed the intraoperative process up, making sure the implants are in there right so we don’t have to take time to redo ones we’ve already performed. In terms of the next 10 years, most of the innovation is going to come from changing instrumentation and changing load to get things done faster to keep up with demand.”
Unless 3-D printed replacement body parts are perfected by then.
It wasn’t a blatant error. In fact, it probably was overlooked amid the slew of nifty technologies available to a middle-aged Marty McFly and his offspring—wonders like weather-predicting watches, power-lacing sneakers, holographic advertisements, personal credit card readers, giant flatscreen televisions, virtual windows, hanging indoor gardens, and hoverboards (perhaps the most dandy invention of them all).
Early in the film, Marty’s girlfriend/intended wife hides in her future home, watching her destiny play out from the confines of a front hall closet. She observes a dinnertime visit from elderly sweethearts George and Lorraine McFly, and overhears them talking about Marty’s descent into self-pity from a car accident many years earlier. George, 77, is hanging upside-down the entire time, firmly secured into an anti-gravity back injury treatment device called the Ortho-lev.
“Aw, Dad, you threw your back out again,” Marty says upon returning home after a long workday. “I really think you should get that spine operation.”
“I know, I know,” George replies. “But who’s got three extra hours to spend at the hospital?”
Three hours for spine surgery is a bit unrealistic, even by 2015 standards. Minimally invasive endoscopic discectomies typically are performed on an outpatient basis but most other spinal procedures (cervical, lumbar decompression and fusions) require a one- to five-day hospitalization. Total recovery times range from six weeks to 12 months.
George might have been better off printing out a replacement disc or vertebrae.
Nevertheless, the filmmakers’ spinal surgery pipe dream is easily forgivable, considering the number of technological wizardry the movie correctly predicted, namely, wearable computing (Google Glass), video conferencing (Skype), computerized voice control ordering (Siri), drone footage, super-thin digital cameras, smart watches, handheld tablet computers, dehydrated food, fingerprint identification abilities, handheld and/or wireless video games, and mobile credit card readers.
Yet director Robert Zemeckis and screenwriter Bob Gale came up with their fair share of blunders, too: flying cars, self-lacing sneakers (Nike has patented the technology but has not yet commercialized it), automatic dog walkers, hoverboards (a prototype currently uses magnetic repulsion to “hover” above metal surfaces), Pepsi Perfect, hanging indoor garden centers and, of course, the Ortho-lev.
George McFly’s preferred treatment option seems rather crude and primitive considering all the advancements made in medical technology over the last three decades, though it does fit well in an Internet-free world largely dependent on landline phones and faxes for communication.
A few pit stops en route to the future could have provided Marty with some better regimen choices for his father’s ailing back. A layover in 2005, for example, (the year Orthopedic Design & Technology made its debut) would have provided Marty with valuable insight on rechargeable spinal cord stimulation systems—devices that use low-intensity electrical impulses to selectively trigger nerve fibers along the spinal cord. Researchers surmise that stimulating these nerve fibers significantly diminishes or blocks the intensity of the pain message being transmitted to the brain, replacing the discomfort with a tingling sensation.
In March and April of 2005, the U.S. Food and Drug Administration (FDA) approved two implantable rechargeable devices: the Eon Neurostimulation System from Advanced Neuromodulation Systems Inc. (now a part of St. Jude Medical Inc.), and the Restore Rechargeable Neurostimulation System from Medtronic plc.
Featuring the market’s highest-capacity rechargeable battery at the time, the Eon system was designed to last at least seven years at high power settings and power up to 16 independent electrodes, giving clinicians more programming options to better manage patients’ pain. Recharging the device was comparable in simplicity to that of a cell phone (another innovation conspicuously absent from Hill Valley life in 2015).
Had Marty’s father chosen a spinal cord stimulator to relieve his back pain, that device likely would have been implanted in a minimally invasive procedure, which, some scholars argue, first took root in 1985 (it might even have garnered a mention in the Hill Valley Telegraph). Designed to reduce tissue damage, minimally invasive surgery (MIS) is performed through a series of small (typically three-quarter inch) incisions using thin tubes called trocars. Carbon dioxide gas may be used to inflate the area, creating a space between the internal organs and the skin. A miniature camera (usually a laparoscope or endoscope) is placed through one of the trocars so the surgical team can view the procedure as a magnified image on video monitors in the operating room. Then, specialized instruments are placed through the other trocars to perform the procedure.
The number and size of incisions can vary depending on the organ or body part under repair. Some MIS procedures, however, can be performed almost exclusively through a single-entry port (using only one small incision). This type of surgery is known as single site laparoscopy.
Though they can take longer to perform than traditional “invasive” approaches, MIS procedures carry significant benefits to the patient and overall healthcare system, including less pain and scarring, a quicker recovery, and shorter hospital stays, the latter of which can help reduce skyrocketing medical costs.
“Orthopedic technology has had a remarkable progression over the last decade,” said Amir Matityahu, M.D., an associate professor of orthopedic surgery at the University of California-San Francisco and director of pelvic and acetabular trauma and reconstruction at San Francisco General Hospital. “In any surgery, the technology involved can be a big factor in determining its overall success. And in the last 10 years, there’s been a lot of small incremental changes in [orthopedic] technology—innovations that have either answered questions doctors have had, fulfilled a need or have given them solutions to a particular problem.”
Matityahu is responsible for at least one of those incremental changes: His Palo Alto, Calif., company, EPIX Orthopaedics Inc., designed a variable-angle nail (VAN) that can be adjusted to fit every patient. According to the firm’s website, the EPIX VAN system gives surgeons the freedom to infinitely adjust guidewire placement into the center-center position in the femoral head. The EPIX device enables in-situ movement of the lag screw to achieve anatomic reduction of the fracture, which may help improve patient outcomes by avoiding varus, cutout, and hardware failure.
In addition, the EPIX VAN system enables surgeons to increase the angle between the lag screw and nail up to 140 degrees, which embeds the nail deeper into the bone proximally, eliminating nail prominence.
Also, because it is adjustable, the EPIX System increases manufacturer efficiency and decreases on-shelf unused inventory to 55 nails, helping to reduce overall healthcare costs, the company claims. If the short (205 millimeter) nail is chosen, the inventory size decreases to one nail.
“There are genuine problems in orthopedics that need solutions. The most common fracture that we see in this country is the hip fracture. Every single hip that is fractured needs to be fixed or replaced depending on the type of injury. So what’s the problem? The problem is that hip fractures have a very high failure rate after they are fixed, around 10 to 20 percent of the time,” Matityahu explained. “Most of these [hip fracture] patients are elderly. If they have a problem after surgery it’s going to affect them profoundly because they’re older and they don’t have any reserve. One of the reasons why elderly people have a problem with fractures is because their bones are very thin. Another factor can be the surgical technique. EPIX Orthopaedics came up with a solution to this problem. That solution is a specific type of implant that basically helps the doctor do his job a little bit better. This is just one example, though. The solutions to problems like this are usually coming from doctors saying, ‘You know what, I’m having a problem with this,’ and either they solve the problem themselves like we did, or they go to a large manufacturer and collaborate with them to fix the problem.”
Stephen B. Murphy, M.D., has taken matters into his own hands as well. The New England Baptist Hospital orthopedic surgeon has designed numerous implants and instruments, and pioneered many new surgical methods currently in use, developing many of the algorithms used in virtually all computer-assisted navigation systems. He also patented the superior capsulotomy (“supercap”) total hip arthroplasty technique in 2005, and co-invented a similar procedure called “superpath.”
Murphy’s supercap procedure tackles hip replacements through a superior approach, leaving the short external rotators and both the anterior and posterior capsule intact. Simply stated, it preserves the soft tissue surrounding the hip and allows surgeons to replace nature’s handiwork without ever dislocating the joint or distorting the limb beyond the hip’s normal range of motion.
Study data indicate the procedure—combined with computer assisted surgical navigation—actually is safer than conventional total hip arthroplasty and dramatically accelerates recovery. In fact, it is the only minimally invasive surgical technique shown in scientific peer-reviewed literature to be a safer procedure than the control group.
“While total hip replacement has been a fairly successful operation, one of the big stumbling blocks continues to be patients having dislocations post-operatively. One of the ways that people have tried to get around that is to change the way the operation is performed,” noted Colin Burnell, M.D., assistant professor of orthopedic surgery at the University of Manitoba (Canada), site supervisor in postgraduate surgery education for the Department of Surgery at Concordia Hospital in Winnipeg, Manitoba, and orthopedic surgeon at Concordia Joint Research Group.
“Instead of going through muscles from either the side or the back, it’s put in between muscles through the front of the patient with the hopes of leaving most of the supporting tissues intact that will increase the stability of the hip,” he continued. “What that has done is introduced a whole new learning curve to the procedure, which has been associated with some complications from many of the surgeons trying to use it. And it really seems to be trying to reinvent the wheel in order to compensate for some of our shortfalls in being able to position the implant properly. That really opens the door for us to continue to perform the operation in a way that we know well, that we’re good at, but also improve our accuracy with the use of new instruments and techniques.”
Some of the new tools and surgical procedures developed over the last decade could theoretically have come from the collective creativity of Zemeckis and Gale. Indeed, advancements like robotic-assisted surgery, patient-specific cutting guides, customized joints, and 3-D-printed implants wouldn’t be much of a stretch in a world that spawned hoverboard technology, skyways, rejuvenation clinics, and controlled weather.
Custom joints and patient-specific guides/instrumentation have gained traction in the last decade as clinicians sought ways to improve both implant alignment and surgical efficiency. Most of the major orthopedic device makers offer these products, though Smith & Nephew plc was the first to market with the 2008 launch of its Visionaire cutting guides and disposable size-specific tools.
The iTotal knee replacement system from Bedford, Mass.-based ConforMIS reportedly removes less bone than traditional off-the-shelf implants, an asset that could help dissipate the forces across the bone-implant junction more naturally. The iTotal also elevates the lateral joint line more than the medial joint line according to patient anatomy. This dual suspension allows the iTotal to keep the joint line at the natural 3 degrees of varus rather than directly perpendicular to the mechanical axis. Surgeons also can choose to replace only one or two of the knee joint’s three compartments.
The majority of custom implants and patient-specific guides are created from preoperative 3-D computed tomography (CT) or magnetic resonance imaging scans, typically taken four to six weeks before the procedure. From those images, a sterile revers mold of the patient’s knee is made, fitting snuggly onto the ends of the bones that comprise the knee joint. The molds guide the location of the bony cuts, helping to ensure a more accurate placement.
“Instead of putting rods inside a patient’s body to line things up we are now taking a custom-ma- de plastic jig that fits right onto a patient’s bone and that is what guides the surgeon, helping him make the cuts in precisely the right places,” Burnell said. “I think this is the major advancement in instrumentation that we’ve seen over the last several years. The marriage of 3-D printing and imaging is allowing us to use a patient’s own imaging—their own anatomy—to design a jig that will fit directly onto that patient’s bone and have the implant fit properly. One couldn’t exist without the other; it’s really both of those innovations together that have really allowed this advancement to occur.”
One-half of that couple, though, is thriving quite well on its own. Three-dimensional printing has proven itself a robust and versatile technology in recent years, responsible for such novelties as a bone fracture healing cast, ceramic/polymer bone scaffold, prosthetic limbs, synthetic tissues, and anatomical practice models (for surgery).
However, the technology still is relatively new and has yet to attain a true foothold in the medtech arena. Consequently, much of its use has been relegated to the academic and experimental realm (with the exception of hearing aids and dental braces): Doctors like Nicola Bizzotto, M.D., an orthopedic and trauma surgeon at the University of Verona Hospital (Italy), and Jason L. Koh, M.D., chairman of orthopedic surgery at NorthShore University HealthSystem in Evanston, Ill., have taken advantage of 3-D printing to create replicas of damaged joints or fractures. The practice models enable clinicians to simulate complex fixes/surgeries, and help them determine the best technique and equipment for a particular procedure.
Nevertheless, the technology is making some headway in the commercial market. A research team at the BIOMED Research Institute in Belgium, for example, successfully implanted the first 3-D-printed titanium mandibular prosthesis in June 2011. The implant was made by using a laser to successively melt thin layers of titanium powders.
Oxford Performance Materials Inc. of South Windsor, Conn., has perhaps had the most commercial success with 3-D printed implants, developing three FDA-cleared products over the last three years. The company made medical history with its first FDA-approved device, a polyetherketone ketone (PEKK) cranial plate designed to fill voids in the skull from trauma or disease. The plate successfully was implanted in 2013.
That triumph prompted the company to expand the printing technology to other bones, culminating in last summer’s FDA clearance of Oxford’s OsteoFab patient-specific facial device, a customizable implant for facial reconstruction. Finally, in July this year, Oxford received the regulatory green light for its SpineFab VBR Implant system, a load-bearing polymer device for long-term implantation.
Oxford’s SpineFab device is a vertebral body replacement intended for use in the thoracolumbar regions of the spine to replace a collapsed, damaged, or unstable vertebral body due to tumor or trauma. The company promises to 3-D print the SpineFab VBR System implants in 48 sizes using only biocompatible polymer and laser light.
The company is manufacturing the implants utilizing its OsteoFab process, which combines 3-D printing technology with the firm’s proprietary OXPEKK powder formulation to print orthopedic and neurological implants. The result, according to executives, is a “beneficial set of attributes, including radiolucency, bone-like mechanical properties, and bone on-growth characteristics.”
“This fundamental change in how surgical tools, equipment, and implants can be made has the potential to be significantly disruptive to the industry,” said Fred Hamlin, senior engineer in the Medical Technology division at United Kingdom-based Cambridge Consultants Ltd.
Conservative Change
Disruption is not a prerequisite for great innovation, though. Some of the most important orthopedic advancements over the last decade have improved surgical techniques and implants, but haven’t necessarily revolutionized the industry in the same way as 3-D printing.
Consider, for instance, knee replacements that allow the components to move inside the knee. The plastic insert rotates on a post, enabling the knee’s rotation to be determined by the muscular forces around the joint.
In the broad spectrum of innovation, such a product is certainly not radical. Yet there are numerous advantages that make this a truly great invention: The knee assumes the rotation that best fits the patient’s need and therefore is not limited by the surgeon’s personal choice. Furthermore, allowing the liner to rotate decreases the stress placed on the plastic, which could, in turn, boost the plastic’s longevity. Short and intermediate term study data have shown no difference between knee replacements with moveable components and those with a fixed bearing.
Similarly, the disposable arthroscope is a major advancement for both optical quality and patient safety. Single-use scopes help to reduce hospital-acquired infections while providing surgeons with the best optical quality for the procedure.
The overall grandeur of any device, however, is very subjective. Roy K. Aaron, M.D., an orthopedic surgery professor at Brown University’s Warren Alpert Medical School, deems highly cross-linked polyethylene to be the industry’s greatest technological advancement in the last decade. “The polyethylene component of a hip replacement has been greatly strengthened by cross-linking,” said Aaron, who also is director of the Orthopedic Cell Biology Lab at Brown and director of the orthopedic program in Clinical/Translational Research. “It’s made it much more resistant to wear. As a consequence you can use thinner plastic than you were able to use in the past. That means you can use a bigger ball on the femoral component—a bigger head size—and that gives you a larger turning range, which has resulted in a much lower rate of dislocation of the implant.”
For Matityahu, one of the industry’s major achievements was the development of locking plates, an innovation he claims has provided orthopedic surgeons with a better way to fix osteoporotic bones with very low density.
“It sounds simple but it actually has revolutionized what we’re doing,” he told ODT. “Our population in general is getting older and the bone quality in older people may not be very good. Locking plates are flat pieces of metal with holes in it for screws. The metal plate is attached to the bone with screws. Imagine you have a screw that you put into a piece of very soft wood. What happens? It very easily pulls out. The same thing can happen in older patients. How do you fix that? What has been developed is a way to lock the head of the screw to the plate. You have a plate with eight holes and four screws on each side. You can lock the screw heads into the plate, and that creates a fixed angle construct, meaning the screws can’t toggle, they are fixed in space relative to the plate. For those screws to come out, it takes a lot of force. It’s really a better way to fix bones with very low density.”
All Aboard!
Marty McFly’s storyline ended on Oct. 27, 1985, with the destruction of the DeLorean he used to travel through three centuries. As he inspects the damage, Marty’s dear friend (and eccentric scientist) Emmett “Doc” Brown shows up in a time-traveling 1880s-style train.
Before embarking on his next timeless adventure, Doc gives Marty a photo of the two of them at an 1885 festival and reminds him that his future hadn’t yet been written. Marty bids him a fond farewell and watches the train convert into an aerial craft and disappear into eras unknown.
Marty, of course, remains in 1985 to live out his future (with Jennifer by his side, presumably). Had he boarded the train, though, he may have been tempted to swing by the year 2025 to preview the newest technological and medical advancements available to his 57-year-old self (assuming he hasn’t visited the rejuvenation clinic).
A decade from now, scientists and biomedical researchers might have perfected stem cell treatments to reverse the degenerative process in intravertebral discs (perhaps he’ll lick the lower back trouble that afflicted his father). Stem cells might also be used by then to improve the recovery of patients with spinal cord injuries.
There’s also the possibility that doctors could monitor the progress of joint replacement and fracture repair patients via smart implants, providing clinicians with biological and mechanical data from the treated site. “If the patient is not supposed to be walking, and the implant indicates that it is being loaded, that will tell us that the patient is not following directions,” Matityahu said. “Smart implants can give the doctor a much more accurate way of determining whether a fracture is healing the proper way.”
Biomedical engineers likely will still be searching for the ideal biocompatible material to increase implant longevity, and 3-D printing is certain to play an even bigger role in product design and development, perhaps allowing surgeons to complete procedures faster, cheaper and more efficiently.
“I don’t foresee a major change in the way implants look or what they are made of. What I see is a drive to do more of the same operations faster because the system is going to be significantly stressed as the baby boomers start coming through,” Burnell predicted. “Anything that can help expedite the surgical process will be welcomed, whether it be disposable instruments so you don’t have to wait for a set to be cleaned, or custom cut blocks to help speed the intraoperative process up, making sure the implants are in there right so we don’t have to take time to redo ones we’ve already performed. In terms of the next 10 years, most of the innovation is going to come from changing instrumentation and changing load to get things done faster to keep up with demand.”
Unless 3-D printed replacement body parts are perfected by then.