The word has been used countless times in recent years to describe 3-D printing technology, an innovation spawned from the best imaginations of science-fiction writers (think the replicator from “Star Trek: The Next Generation”) that now is revolutionizing nearly every industry on the planet, from fashion and aerospace to food service and healthcare.
As its name suggests, 3-D printing—also called additive manufacturing—creates objects in successive layers, or three dimensions, its ink serving as substrate and substance in one. Since their late 1980s de-but (around the time the Star Trek replicator fabricated hot Earl Grey tea in seconds), 3-D printers have shrunk both in size and price, enabling professional engineers and amateur hobbyists alike to tinker with designs for nuts, bolts, earbuds, eyeglasses, athletic cleats, jewelry, cremation urns, Star Wars figurines, automobiles, even houses. Today’s printers also boast the ability to create objects in different materials, including plastics, silicone, silver, gold, titanium and other metals, ceramics, wax and food. Future versions could combine materials as well: Massachusetts Institute of Technology researchers, for example, have built a 3-D printer capable of building items with 10 photopolymer substances at once.
Indeed, the word “disruptive” is an appropriate adjective for an advancement as game-changing as 3-D printing. Another suitable adjunct would be lucrative, as the global market for the technology is set to mushroom over the next five years, skyrocketing from $4.5 billion today to $17.2 billion by 2020, according to a recent report from management consulting firm A.T. Kearney. “Although traditional manufacturing will have cost advantages in large-scale production settings for the foreseeable future, 3-D printing’s role will grow in settings where five dimensions are crucial for success, such as prototyping (lead time and speed), personalized medical implants (mass customization), and jet components that require a complex assembly and have high fly-to-buy ratios (new capabilities and waste reduction), the report states.
Healthcare is expected to be one of the fastest-growing sectors within the overall market, expanding at a compound annual growth rate of 20-25 percent over the next half-decade, A.T. Kearney analysts predict. The technology already has made an indelible impact on the industry—3-D printers have created prosthetic limbs for amputees, new faces for trauma victims, and practice models for orthopedic implant surgeons.
Inbal Mazor, vice president of marketing at 3D Systems Inc., a Rock Hill, S.C.-based provider of 3-D digital design and fabrication solutions, spoke with Orthopedic Design & Technology about the technology and its applications in the orthopedic sector. Her conversation with the magazine follows:
ODT: How is the orthopedic industry utilizing 3-D printing technology?
Mazor: 3-D printing is used in several ways today. Polymer printing technologies are used extensively to print patient-matched surgical guides to improve the precision and clinical outcome of surgical procedures. Moreover, plastic 3-D printing technologies are used a lot to build anatomical models that allow the surgeons to better evaluate a case and even practice it before the actual surgery. Metal 3-D printing is used both to manufacture patient-specific implants and to manufacture large series or orthopedic and spinal implants.
ODT: What advantages does the technology provide to orthopedic implants? Are there any disadvantages associated with 3-D printing orthopedic implants?
Mazor: One of the biggest advantages of 3-D printing in orthopedic implants is the inherent geometric freedom of the technology. This not only allows the design of more natural anatomical shapes, it also brings the possibility of designing porous bone replacement scaffolds that can seamlessly be integrated in the implant design. This allows for natural bone ingrowth, ensuring stability of the implant in the long run. Of course, 3-D printing is also the perfect technology to support the ongoing evolution of personalized digital medicine, creating a digital thread starting at the medical imaging process, over treatment planning, implant design, patient communication and ending with the digital manufacturing of a personalized implant and instrumentation. The shape freedom of 3-D printing brings some new challenges for implant designers and manufacturers. Designers and manufacturers need to take into account the cleaning requirements of the instruments and implant in the design phase, since the unlimited geometric freedom can create more challenging cleaning demands.
ODT: What challenges does the orthopedic industry face in using 3-D printing to its advantage? How can the industry overcome these challenges?
Mazor: Standardization of 3-D printing is still an ongoing process. Regulatory agencies are getting more familiar with 3-D printing technologies today, but will probably impose some 3-D printing–specific requirements on medical device manufacturers until globally accepted standards are adopted and recognized by the regulatory authorities. A 3-D printing user must take into consideration the designed geometry, but also the fact that an actual material is being produced at the same time, with its corresponding required mechanical and physical properties. Process validation is therefore a crucial aspect of a 3-D printing production plant. The economic benefit of 3-D printing is today obvious in certain application areas, whereas in other areas, productivity of 3-D printing should still be higher in order to achieve lower manufacturing costs compared to classical casting and forging technology. Ongoing and future technology developments will continue to improve 3-D printing productivity and this will gradually result in similar or better economics for 3-D printing technology with respect to classical production methods.
ODT: Are there specific sectors within the orthopedic arena (shoulders, extremities, hips, knees, trauma, etc.) that are better suited to 3-D implants? What makes these sectors better candidates?
Mazor: In general, 3-D printing is most beneficial in producing custom-shape components. Although the productivity is increasing year after year, the actual part volume plays a role in the final manufacturing cost of the implant or instrument. This is less of an issue in patient-specific implant manufacturing but can play a role in the production of large-volume implants like knee joints. Because of the shape complexity and volume of implants, today the spinal industry and small joint orthopedics are perfect candidates for 3-D printed manufacturing. Even though the part volumes of large joint orthopedic implants like hip and knee components result in a higher variable cost per unit, the flexibility, low setup and tooling costs and reduced inventory can already result in economic manufacturing of large joint implants today.
ODT: What kinds of regulatory concerns exist with 3-D printed orthopedic implants?
Mazor: The unlimited geometric freedom, which is one of the biggest advantages of 3-D printing technology, may result in more challenging cleaning processes, since complex geometries and porous scaffold structures are less trivial to clean than a simple solid volume. Since the 3-D printing user does not only produce a three-dimensional shape but also is responsible for the material properties resulting from the production, strict definition and control of the process parameters and thorough process validation of 3-D printing production lines are of high importance.
ODT: What materials—if any—are best suited for 3-D printing orthopedic implants?
Mazor: Today, some of the most used orthopedic materials are available by 3-D printing. Several titanium grades (Grade CP1/2, Ti6Al4V ELI), cobalt-chrome alloys (e.g., ASTM F75) and stainless steel allows (e.g. 316L) are commercially available. Moreover, 3D Systems also offers more exotic materials like tantalum for certain niche applications.
ODT: What factors must manufacturers or designers take into account when creating a 3-D-printed implant?
Mazor: Cleanability of designs is an important consideration when designing and developing implants. Since 3-D printing can be seamlessly combined with classical CNC manufacturing technologies like CNC milling, turning, grinding, electric discharge machining, etc., it is also important to take into account the possible need to add stock material on certain surfaces that may require additional post-processing downstream.
ODT: Does 3-D printing technology have the potential to revolutionize the orthopedic industry? If so, how?
Mazor: We strongly believe that 3-D printing is already revolutionizing the industry today. The benefits of the technology are huge and our expectation is that in the near future a significant part of the orthopedic market will use 3-D printing, both for its volume manufacturing and patient-specific applications. At 3D Systems, we want to be a reliable partner for both 3-D printing newcomers and experienced users in medical manufacturing, a partner for a variety of services from design to manufacturing, either as a service or locally, to software development and planning tools, resulting in state-of-the-art orthopedic implants.