April 2018

The future is now— Implications of 3D technology for orthoses

Shutterstock.com 560236789

2018 is shaping up as a breakthrough year for 3D printing in orthoses, as the industry moves from promise to reality. Experts agree: Three-dimensional printing will deliver custom clinical products, designed for individual patients at an affordable price.

By Keith Loria

3D printing is still a young technology for orthoses, and has great potential to change the way orthoses are designed and produced, say experts and specialists in the field.

The technology opens the possibility of adding value to the complete digitalization of analysis, design, and manufacture, said Blake Norquist, director of North American sales and business development for RS Print, a Paal-Beringen, Belgium–based company. He noted that combining digitized gait analysis and 3D printing may provide new standards and frameworks for experts based on objective, scientifically proven data.

One of the big game-changing aspects of this digitalization, Norquist noted, is the translation of data from objective analysis into a design that is then manufactured digitally. Expert involvement in the analysis and conversion toward design remains crucial, he said, adding, “[After] that point, the manufacturing becomes completely unbiased and reproducible.”

Gordon Styles, president and CEO of Star Rapid, a manufacturing company of 3D-printed medical applications based in Guangdong Province, People’s Republic of China, explained that 3D printing allows for orthoses manufacturers to respond quickly to requests for custom-made parts needed for rehabilitation. With this technology, he indicated, it is simple to create tailored supports, such as an insole, using high-resolution medical scans of a patient’s foot to determine arch and pressure points. By creating 3D computer-aided design (CAD) models from these scans, highly accurate sizes and shapes are built with very tight tolerances. This helps ensure optimal fit for the patient to support weak joints and limbs.

Moreover, according to Styles, 3D printing is being used to create patient-specific supports and braces, designed to enhance outcomes owing to their ability to create intricate lattice structures that can be used to create lightweight yet strong parts. “This ultimately makes orthoses more comfortable for patients,” he said. “If there is a requirement for a strong and durable brace, metal 3D printing often provides a stronger support than conventional methods.”

Clinical implications of 3D printing of orthotic devices include new possibilities of customization that have not been available with traditional methods.

The evolution

Computer-aided design of foot orthoses emerged in 1989. This method allowed creation of a digitized model of a foot, which would be sent to a laboratory to be milled from a block of plastic. Use of CAD models for orthoses was slow to evolve because equipment cost was high. With the emergence of 3D-printing machines, however, it has become easier to meet growing customer demand for highly customized parts.

Jay Raju, president of Cura BioMed, Inc., Morristown, New Jersey, noted that early 3D manufacturers offered products that did not necessarily provide the same value given by current solutions. The negatives, he added, far outweighed marginal benefits, and there was a wave of launches that never took off. One of the primary challenges, Raju said, has been the use of an entry-level printing technology called fused-deposit molding, which is “good for making prototypes but not great for industrial-level production.” Next-generation 3D printing companies have adopted a new manufacturing process that uses the more advanced selective laser sintering (SLS), which is used in other cutting-edge markets, such as the aerospace industry.

Because SLS technology incurs high fixed and operating costs, Raju added, it is not generally used for manufacturing orthoses. “But by marrying SLS technology with a robust supply chain from scan to design to manufacture to finishing, companies are now creating commercially viable products.”

With this convergence of supply chain and 3D technology, there should be a change in the functional orthotics market. Star Rapid’s Styles shared that, today, 3D CAD models are quite accurate and the cost of plastic 3D printing is relatively low, making this method better than standard methods, such as milling from a plastic block.

Commentary: We’re in a time of mass production of customized orthoses

3D printing is an accessible manufacturing option. Any other approach is just wrong.

By Chris Lawrie, MSc

As an engineer, I printed my first automotive part in 1989 and my first pair of insoles in 2010. It took until 2017 for the stars to align, however: 3D printing technology capable of printing a pair of shells quickly, in materials that meet the demands of the foot, at a production price point that means 3D printing is no longer just a premium offering.

It’s a fact: Today, labs can have shells made for a price that is comparable to shells manufactured by direct-milling polypropylene or positives. Scanners are off-the-shelf items that can, with the right app, give us results that make casting an insanely poor choice. Design software (such as FITFOOT360) can give you complete clinical control over a custom, print-ready device, and you can, case by case, choose whether to mill or print a shell or a positive. I describe this digital mass-customization process as simply “capture–design–make.”

What’s the key to us introducing 3D printing into our foot-health community (for good, this time)? It’s producing a device that is better clinically while being believable to both clinicians and patients; after all, 3D printing it is just another way of making something. Any strategy that presents 3D printing as a premium product or high technology is dated and flawed; it simply maintains the low-volume, high-price strategy that has slowed the evolution of 3D printing, in all markets, over the past 30 years. The recent move by Hewlett-Packard to promote the democratization of printed materials has enabled entrepreneurial companies (such as iOrthotics and FIT360) to capitalize on a wholesale approach to designing and manufacturing 3D-printed insoles. As a result, 3D-printed insoles are already the preferred choice of many labs worldwide.

This is an exciting time in the world of 3D printing—a time that we will all benefit from, as our colleagues in the dental world did nearly a decade ago. As you invest in new technology for rapidly capturing the human form to precisely represent a prescription, please, consider a digital process: from capturing the human form instantly, to creating a custom 3D prescription in seconds, to choosing the ideal “make” option for you, whether form, mill, or print.

To sum up, for the first time in this industry, 3D printing is an accessible manufacturing option. Be careful, however: Do not assume that you need to offer space-age printed devices to your customers… Some entrepreneurs have been here before, and have failed.

Chris Lawrie, MSc (Engineering Business Management), is chief executive officer of FIT360 Ltd (www.ff360-sw.com), developers of software, including FITFOOT360, for use by manufacturers of digital custom insoles.

Clinical implications

3D printed foot orthoses are designed and manufactured using the latest digital technologies and require limited manual intervention. Industry experts say that this not only guarantees clinical accuracy of the product, required by clinicians for their patients, but also ensures that orthoses are of consistent quality, durability, and flexibility.

From a clinical perspective, Raju stated, the orthoses produced by 3D printing will deliver all the clinical modifications needed, while also making the insoles more flexible, durable, and ultra-light compared with co-poly– or carbon-based competing products. This may broaden the range of choices in shoe type and lifestyle available to patients.

Raju offered an example of how a 3D-printed orthosis can aid in correcting a pronated foot, in which the hind foot is directed into excessive valgus and impairs efficient heel strike and toe off in the gait cycle, causing calf pain and fatigue. The 3D-printed insoles have built-in hind-foot corrections specific to the patient’s deformity to permit a stable, neutral hind foot during the gait cycle.

Andrei Vakulenko, chief business development officer at Artec 3D, Luxembourg, believes the clinical implications of using 3D scanning and 3D printing are limitless. Following the creation of personalized 3D medical solutions, such as prosthetics, back braces, and even something as intricate as an ear, orthopedists are finding an industry that is constantly creating and improving the software and expanding the tools available for the seamless creation of both ready-made and custom orthoses.

For instance, Vakulenko said, the Robotics and Multibody Mechanics research group at Vrije Universiteit Brussel (University of Brussels) has, as one of its projects, a lower body–powered exoskeleton, built using the Artec Eva 3D scanner. The design uses a tightly fitting orthotic device for the user’s leg that is created by 3D-scanning of the limb. This process replaces the use of uncomfortable, messy plaster molds to capture the shape of a limb; the molds are then shipped to a manufacturer.

“The precise 3D scan is used to digitally model an orthosis that can be 3D printed,” Vakulenko said. “Once printed, the orthotic is reinforced with carbon fibers and epoxy composite. Creating this form-fitting interface between the user and device ensures less energy is lost by the exoskeleton’s actuators and mechanical components that are built around it.”

Bruce E. Williams, DPM, DABFAS, director of gait analysis studies at the Weil Foot & Ankle Institute, Chicago, Illinois, said the potential for 3D-printed devices is huge because of the ability to control segmental stiffness in a way that has never been done before. “There are huge benefits to being able to control specific segmental elements in an orthotic. This cannot be achieved with traditional polypropylene devices,” he said. “The ability to stiffen the medial arch, create more flexibility in the medial or lateral columns has huge benefits for athletes and even day-to-day patients.”

This variation in both local and directional flexibility reflects the biomechanical data from digital, dynamic analysis. “It results in lightweight devices that last longer than traditional orthotics, giving the patient better value for money,” Williams said.

For example, Dr. Williams has made orthoses with decreased stiffness of the lateral column specifically for athletes who have had, or are at high risk of having, a 5th metatarsal fracture. After implementing this modification, the pressures and length of high pressures under the 5th metatarsal decreased markedly and greatly reduced or minimized further risk to these athletes for that type of injury.

Norquist added that from a technical perspective, using 3D printing offers new possibilities of customization that have been impossible with traditional methods. What the clinician has ordered is what is received, fostering a trusting relationship with patients.

Getting results

Photo courtesy of RS Print

The process of using 3D printing can produce high-quality results, and Vakulenko shared that, with constant technological advances and new developments in the tools and materials being used, customized solutions are becoming lighter, more ergonomic, and more cost-effective. In most cases, customized 3D-printed orthoses have the potential to improve on standard methods in terms of accuracy, cost, and procedure. Using 3D scanning to create a model that is then 3D printed delivers the exact data required for sizing the orthosis, creating a perfect fit and a durable solution. Because the process is additive, there is no wasted material when creating parts, eliminating the risk of additional costs.

Williams added that some materials, such as nylon, are largely unbreakable and allow for significant variability in stiffness and flexibility. Norquist agrees: “The choice of the material wasn’t just a lucky guess,” he said. “PA 12 [nylon powder] is a material that lasts far better than, for example, EVA [ethylene vinyl acetate] or cork and leather.”

However, Vakulenko cautioned that, just as with anything else, there is always room for improvement. “3D printing is the best option for personalized orthoses; however, if an orthotic is mass-produced, it will be more cost-effective to do so with a more traditional manufacturing process,” he said. “In addition, 3D printing can be rather slow compared to, for example, milling machines.”

Looking ahead

3D printing is already being used in orthopedics to create implants and in minimally invasive surgery to create small devices, resulting in less tissue damage during operations. With the growth of this technology, most believe that use will be more widespread in the future.

iStockphoto.com 643357494

Although 3D printing for the medical industry is highly practical for the creation of customized devices, Styles noted that, regrettably, using this process for mass production of supports and braces may not become a reality in the near future. Until plastic 3D-printing machines reach commercial speed, he explained, the time needed to create a part will be days, and the size of a finished orthotic is limited to the size of the 3D machine’s print bed—typically smaller than what can be made using computer numerical control machining or custom casting.

Ultimately, Raju explained, the biggest caveat for the 3D-printed orthotics industry is not what technology is being used but, rather, how that technology is married with the entire value chain of production—from design to global supply chain to product pricing to quality control to research and to design and innovation.

One key competitive advantage of 3D printing is that it can be used to manufacture objects with complex geometry, such as an object within another object that cannot be created by any means other than 3D printing. In the long run, 3D printing may eventually replace traditional methods of manufacturing, both mass-produced and customized, in numerous industries.

Vakulenko said that most traditional methods of creating prosthetics are approaching obsolescence, and practicing orthopedists are embracing the new 3D technologies for a much cleaner, faster, and more precise process. “Today, using both high-tech 3D-printing and 3D-scanning technologies opens up a large variety of possibilities and allows for a much more flexible workflow with the use of the cutting-edge systems,” he said. “With the development of highly advanced tools to tailor to the healthcare industry, it is safe to say that we are now witnessing a significant shift in the procedures of the orthotics field.”

Keith Loria is a freelance medical writer.

(Visited 513 times, 6 visits today)

Leave a Reply

Your email address will not be published. Required fields are marked *

Spam Blocker * Time limit is exhausted. Please reload CAPTCHA.

This site uses Akismet to reduce spam. Learn how your comment data is processed.