3D Printing Orthopedic Solutions — Where are we? An Update.
Author: Dr. Faisal Mirza
Healthcare is rapidly changing and by this, I mean that the technology of delivery and care is advancing faster than the providers, the insurers and the patients can keep up. We are going to be seeing a remarkable transformation over the next few decades that will benefit patients most, and much of this is due to advances in 3D printing.
Now, some of this already exists today. There are prototypes built everyday by manufacturers using this technology for research and development but only a handful have fully embraced this technology in medical device implantation for patients. For example, there are cutting jigs that are designed and printed based off the patient’s individual anatomy that act as guides for the surgeon to define bone margins and planned cuts or alignment principles during orthopedic surgery. Commonly, a CT scan of the patient’s bones and joints is visualized with landmarks identified that plot the proposed positions and cuts the surgeon is going to make to accommodate for the proposed implant. This can theoretically and practically simplify complex procedures in to a ‘paint by numbers’ solution.
Some companies have taken this a few steps further by developing mass-manufactured implants that are 3D printed and patient specific, such as a total knee replacement device. Although some companies may tout these as‘custom, or customized’ implants, they may not be considered‘custom’ according to the FDA. The regulation bar for custom implants is quite different than for patient-specific devices. The patient does indeed have an individualized MRI or CT of their joint which makes it patient-specific, however, the scans are then matched to several computational combinations of implant sizes which are then concatenated in a patient-specific manner to create the 3D printed device from a designated finite number of parts; quite different from creating an exact matching duplicate for the patient’s anatomy. For example, instead of having to select from 2 widths in a size 9 shoe, you are now matched to a shoe size that offers 5 forefoot, 5 midfoot and 5 hindfoot geometries in length width and height in reconstituting the final device to be printed– but it is still a finite number of options available. A true ‘custom’ implant would offer only 1 option (and size terminology becomes irrelevant) for each patient from an infinite possibility of choice based on unique and precise anatomy, which is not the case.
The FDA is very interested in this landscape and has discussed many considerations for companies that desire regulatory due process as well as trying to stay ahead of the tide of applications it foresees (http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm533992.htm). In the case of bone or tissue scaffolds that are designed for bone and tissue reconstruction and healing, the implants may be designed from an average of 100’s or 1000’s of scans by many patients aggregated in to a single simplified model or in limited sizes. Direct scanning of the deficiency and printing of the void with an appropriate filler or device or replacement is not quite there yet. Scaffolds such as vertebral cages as well as meniscus are available in some markets but the science is just barely scraping the surface.
In other situations, complex congenital deformities and mal-united bones can avail advanced computational geometric manipulations to refine the ideal surgical plan preoperatively, even before the patient even enters the operating room. This does not mean that a surgeon should no longer be aware of the patient’s anatomical considerations such as nerves and blood vessels or soft tissues, but it allows much of the thinking time to be spent well advance of surgery, utilizing validated formatting techniques that are FDA approved or cleared (software and or hardware), uponstate of the artcomputational platforms to provide various calculated scenarios. In other words, you can consider many options and risk benefit ratios, not only with the entire surgical team, but with the patient and their caregivers as well, to come up with an optimal strategy of care that is patient-specific, patient-centric, and caregiver-inclusive all in a combined decision-making approach that may be a cut above current standard of care. This may apply not only to the cutting jigs themselves but also in the calculation of where to slice the bone(s) and how many cuts are needed and which orientation would provide optimal re-alignment using mathematical models beyond our human scope.
No longer forged or casted in a blasting hot furnace, or extruded or cut out of molds or sheets of material, computer-generated 3D printed devices will continue to revolutionize the manufacturing industry. In fact, the medical device world has been slower to adapt than other manufacturers mainly due to regulatory process and healthcare protocols but also due to the financing of a novel process, which although may eventually furnish a smaller footprint and cost less, the current capital loss of equipment and facilities may affect bottom line mobilityenough in the short-term to temper progress. Imagine losing or breaking a part of an instrument during surgery — simply print it from a data file directly at the hospital, sterilize it, and use it immediately — Hospitals are just starting to embrace this reality in part already. Now imagine that at a M.A.S.H. center overseas for our troops in need — a mobile 3D printing factory — and yes, Amazon has thought of this already. The evolving health insurance landscape also poses considerable challenge as to who will pay for the newer technological marvels — the innovation paradox unique to healthcare.
There are also evolving teaching tools, not only for residents and faculty at academic centers, but also for community surgeons who want to learn new techniques or become proficient in newer equipment. 3D printing allows planning of surgery but also training. The education industry is bound to reap significant benefits from this new landscape. Being able to understand the anatomy, perceive the deformity compared to normality, appreciate the constraints of the tools and the tissues, visualize the exact procedure step by step and then perform the art step by step off the field before entering the surgical foray is timeless.Steps A to Z in a cerebro-visually appealing tactile interface of science, technology and thought that is directly pragmatic in managing apprehension through modulated learning curves — hopefully to reduce surgical time, improve outcomes and eventually optimize benefit risk ratios. The ability to reduce time from design to prototype is already apparent, but to then compress time from design to implant delivery is coming. Yes, the path is complex with regulatory, legal, scientific,ethical, biomechanical constraints and concerns but it is ripe for blossoming a new paradigm to the surgical experience.
Ultimately, however, the holy grail of surgery is bioprinting of tissues. Parts for the active human race — vulnerable but capable. Instead of replacing a joint, we simply print new cartilage and bone to accommodate for the degeneration, deformity, trauma or cancer. This is on the encroaching horizon no longer in a galaxy far away, but not now.
3D printing is making surgeon’s lives simpler and patient’s lives better.
About the Author
Dr. Faisal Mirza is an orthopaedic surgeon in private practice, OrthoSynthesis, in Silicon Valley where he focuses on surgical and non-surgical restoration of function, preservation of mobility and promotion of musculoskeletal health and regeneration.
His experience spans across biotech industry, drug & device regulation, and academic practice as Medical Director, Global Bone Health Development, Amgen; Medical Officer, Device Regulation and Research, FDA; and Clinical Assistant Professor, Stanford University VA Palo Alto.
Faisal fosters innovation and development of biologics, devices and combination products through his consulting startup, Clarity Synergy. Having trained at the University of Western Ontario and McMaster University in Canada, Dr. Mirza now considers San Francisco home where he lives with his wife and two children. Dr. Mirza is a speaker at #3DHEALS2017.
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