3D Printing of Upper-Limb Prosthetics: Present Reality, Future Potential

Home > Articles > 3D Printing of Upper-Limb Prosthetics: Present Reality, Future Potential
By Miki Fairley
Albert Chi

ABOVE: Albert Chi, MD, a trauma surgeon at Johns Hopkins Hospital, Baltimore, makes an e-NABLE hand. BELOW: enlargement of 3D pieces of e-NABLE hand. Photograph courtesy of e-NABLE and Jen Martin Studios.

enlargement of 3D pieces of e-NABLE hand

The use of 3D printing is developing rapidly in a variety of industries, including aerospace, defense, automotive, and, notably, healthcare. At the same time, the technology has brought manufacturing capabilities into offices, homes, classrooms, university laboratories, and small businesses, unleashing a tsunami of creativity and innovation.

"3D printing has been around for decades.... What's new is that 3D printing has reached consumer-friendly price points and footprints, new materials and techniques are making new things possible, and the Internet is tying it all together," according to a 2013 report, 3D Printing and the Future of Manufacturing, by Computer Sciences Corporation, Falls Church, Virginia.

3D printing has ignited interest from the O&P community as well, reflected in research, presentations at professional and scientific conferences, research and development initiatives, and new products on the market. However, a surge of new developments in prosthetics outside the O&P profession has sparked both interest and concern from the O&P community. Although this article focuses on upper-limb prosthetics, we will also look at some innovations in orthotics and lower-limb prosthetics.

Underserved Population Gets a Helping Hand

Stories about high school and university students, engineers, healthcare professionals, and hobbyists creating prosthetic hands for children with amputations or congenital limb deficiencies have been garnering media attention and drawing public curiosity. An interest in helping others is converging with a creative passion for technological innovation fueled by affordable 3D printers, low-cost materials, and opensource, downloadable files for printing. The technology is also promising in meeting O&P needs for humanitarian missions in developing countries or areas hit hard by warfare and natural disasters, says Jeff Erenstone, CPO, Mountain Orthotic and Prosthetic Services, Lake Placid, New York.

Boy with e-NABLE hand on bike

A boy uses his e-NABLE hand to ride his bike.

e-NABLE volunteer and patient

An e-NABLE volunteer assembles a 3D-printed prosthetic hand while the recipient watches. Photographs courtesy of e-NABLE and Jen Martin Studios.

One of the organizations at the forefront is e-NABLE (www.enablingthefuture.org), founded in 2013 by Jon Schull, PhD, a research scientist in the Media Arts Games Interaction Creativity Center at the Rochester Institute of Technology. The worldwide network of volunteers is growing rapidly; Schull estimates it now numbers about 6,300 and is growing by about 1 percent each week, with devices currently provided to at least one recipient in about 40 countries.

Since children outgrow prostheses fast and, being active and energetic, are tough on their devices, the cost of providing traditional prostheses is prohibitive for most families. Thus, the children do without. "And even when they have traditional prostheses, they often reject them," Schull comments.

"With children, we are actually in a sweet spot," he continues. "Cool, superhero designs and toy-like features make them attractive to children; their friends admire the devices too. So there are psychosocial as well as functional benefits."

"When you make it look like a robot hand and give it to an eight-year-old, they're going to be the most popular kid in the class," adds Erenstone, a volunteer with e-NABLE.

e-NABLE: What's Available, What's Coming

Most of the devices e-NABLE volunteers provide are partial hands requiring the recipient to have an intact wrist; however, transradial and even transhumeral devices are being developed or are in beta testing before being released publicly. Several hand recipients and family members are paying it forward by becoming volunteers themselves, making more devices, and some recipients are volunteering as new-device beta testers.

Included on the e-NABLE website is a myoelectric prosthesis for people with transhumeral limb differences, the Limbitless arm, created by a student team at the University of Central Florida (UCF) led by engineering doctoral student Albert Manero. Although the open-source files are available for downloading and the components and materials can be purchased at widely available consumer retailers, the design requires extensive electrical expertise, time, and a more robust printer than most volunteers have, e-NABLE points out. The UCF team has created a nonprofit organization, Limbitless Solutions (www.limbitless-solutions.org), that can provide the prostheses for about $350 in materials cost.

Safety, Regulatory Concerns

The O&P community has voiced concern over the safety of volunteer-designed-and-printed 3D devices that lack the input of professional prosthetists and have not been approved by the U.S. Food and Drug Administration (FDA).

The American Orthotic & Prosthetic Association (AOPA) issued a statement in February that expresses these concerns. "[W]e are intrigued by the emerging 3D technologies outlined in several recent TV, print, and web-based media reports, while noting that in many cases the care featured involves instances that do not fully comply with FDA rules and/or federal or state licensure and accreditation requirements." Schull notes that he shares this concern and that FDA officials have been supportive of e-NABLE's work, as expressed by FDA official Matthew DiPrima during the Science in 3D: 2015 Bioinformatics Festival in January.

The AOPA statement also reflected concern by prosthetists over inaccurate reporting of the cost of traditional upper-limb prostheses.

Not Full-Fledged Prostheses

Perhaps related to the safety and regulatory concern is a distinction that is not well-understood by the media and general public, that the volunteer-printed 3D devices are not actually fully functional prostheses, according to their producers. Schull is quick to point out the limitations of the partial hand devices. As noted on e-NABLE's website, the devices produced from its designs should be seen as tools and not as fully functional prosthetic devices. They aid children in doing simple tasks such as holding a water bottle while holding a snack in the other hand, using two hands to ride a bicycle, or catching a ball. The website warns that the devices cannot hold more than a few pounds of weight and the grip strength isn't strong enough to play on monkey bars, work bicycle brakes, do handstands, or do similar activities. Volunteers and recipients are informed about the limitations.

UL prosthetic cover from UNYQ

Erenstone mentions that his discussions with Schull helped add insight to e-NABLE on the value and necessity of involving professionally trained prosthetists in the development and application of the devices. Schull is eager to reach out to the O&P community. He and Erenstone presented a morning general session at the recent AOPA National Assembly on "The Brave New World of 3D Printed Devices: Challenges and Opportunities" along with an afternoon workshop for attendees to try their hand at 3D printing. Schull also presented at the International Society for Prosthetics and Orthotics (ISPO) Canada Symposium General Session on October 2.

"We are eager to collaborate with and include professionals among our volunteers, as well as among our advisors," Schull says. "The goal is to develop new opportunities and to create new options for users as well as professionals. I'm very aware that we can only serve a very small percentage of the people who need assistive devices, prostheses, or orthoses. Prosthetists and orthotists are an essential part of the healthcare ecosystem in deciding which cases need what kinds of systems." He continues, "We would really like to work with the O&P community; there's a place for all of these solutions. It is not our purpose to undermine the very valuable profession that makes what we do possible and does what we can't do."

False Picture for Policymakers, Public?

Some O&P clinicians and other interested parties have expressed concern over the image generated by media coverage that seems to equate a 3D-printed prosthetic hand that has relatively simple technology and limited function with the function, strength, and durability of a complex, professionally designed, fabricated, and fitted upper-limb prosthesis, plus greatly inflating the costs of professionally provided prostheses.

"As prosthetists, we feel very confident with socket fit, material properties, and working with patients," points out Gerry Stark Jr., MSEM, CPO/L, FAAOP, senior upper limb clinical specialist, Otto Bock HealthCare, Austin, Texas. "All of these competencies are still extremely valuable and relevant with 3D printing. Basically, 3D printing could be considered as a sophisticated and novel form of technology to aid in the fabrication process. My feeling is that the prosthetist is still critical in managing this patient-client relationship to implement and optimize this technology." Stark continues, "What greatly concerns prosthetists is that some policymakers are making the misguided assumption that amputees can bypass the fitting process. There is this technologically naive notion that patients could simply have their residual limb measured, scanned, and the file sent to a fabrication center. The patient would then receive a fully functional and durable prosthesis much more cheaply than through a prosthetist. However, there will always need to be a trained prosthetic professional available to fit and optimize this new technology."

Other prosthetic professionals have weighed in on public forums, such as the OANDP-L listserv. Many of their comments could be summed up as, "People will think we're ripping off the public."

girl with 3D-printed scoliosis brace

A girl wears the 3D-printed UNYQ Scoliosis Brace, with a distinctive aesthetic pattern. Photograph courtesy of UNYQ.

William Layman, CPO, BOCO, BOCP, co-owner with his wife Sharon Layman, CFOM, COF, CMF, of Innovative Orthotics & Prosthetics of Louisiana, Kenner, says, "Therefs a lot of misleading information out there on the costs of traditional prosthetic devices and in claims about what the [3D-printed prosthetic hands created by volunteers and others] can do." Layman is a proponent of 3D printing's potential, and has been developing a 3D-printed prosthetic leg with good results. Layman also owns Innovative Digital Manufacturing of Louisiana, Kenner, which produces a wide variety of 3D-printed products.

3D Printing in Education

"The Enable Community Foundation is developing a repository of data and experiences gained by those involved in the volunteer printing process and is becoming a center for research on several topics," Schull says. "We would welcome the opportunity to pursue collaboration with professional prosthetists and orthotists."

Director of Programs Maria Esquela describes the e-NABLE Educators' Exchange and the e3STEAM initiative. "They give formal and informal educators a chance to develop something together or develop it and share with others, teach others, and create makerspaces." Author's note: Makerspaces are creative spaces, sometimes called hackerspaces or fablabs, where people gather to create and learn.

girl receives her 3D-printed prosthetic hand

A girl receives her new 3D-printed prosthetic hand from volunteers at the Prosthetists Meet Printers conference. Photograph courtesy of e-NABLE and Jen Martin Studios.

The National Commission on Orthotic and Prosthetic Education (NCOPE) notes in its report on the 2015 Educational Summit, "3D printing may eventually offer a convenient means of producing devices, but the appropriate application of emerging technology will depend on well-qualified practitioners. Such technologies are opportunities for-not threats to-the profession."

Sessions and presentations on 3D printing are beginning to appear in professional conferences, and some of the O&P schools accredited by NCOPE and the Commission on Accreditation of Allied Health Education Programs (CAAHEP) are adding information about 3D printing to their programs.

children at Prosthetists Meet Printers conference

Some of the children at the Prosthetists Meet Printers conference enjoyed helping to make the 3D-printed hands. Photograph courtesy of e-NABLE and Jen Martin Studios.

The program for the 15th ISPO World Congress held June 22-25 in Lyon, France, included this note: "In addition to the continuous improvements that are seen in the P&O devices...this year there is a new area of development- 3D or additive printing technologies. These are extremely suited to make personally adapted devices."

Prosthetic Design Inc. (PDI), Clayton, Ohio, is working with Century College and Baker College in developing a 3D session for their O&P technician programs, according to Brad Poziembo, LP. "We're building a printer for Baker College; they'll be training their [student] technicians on the printer." The PDI printer can make sockets much faster than traditional fabrication and thus provide accelerated training, he adds. PDI has successfully evolved a tough, durable 3D-printed lower-limb prosthetic socket from technology developed at Northwestern University, Poziembo says. "I can scan and fit the patient in the same day. They can go out for lunch, come back in about an hour and a half, and I can have the socket ready for them."

New Developments in Lower-Limb Prosthetics, Orthotics

At an intersection where aesthetics, industrial design, and O&P meet, some developments in 3D-printed orthoses and lower-limb prosthetic covers show off 3D printing's ability to showcase the user's individuality.

In 2012, 3D Systems, Rock Hill, South Carolina, acquired Bespoke Innovations, San Francisco, noted for lower-limb prosthetic fairings created by industrial designer Scott Summit. UNYQ, San Francisco, is collaborating with 3D Systems to commercialize 3D Systems' prosthetic fairings, braces, and casts. UNYQ is partnering with Ottobock, Duderstadt, Germany, to provide lower-limb cosmetic fairings made from various materials depending on user choice. UNYQ is also releasing 3D-printed upper-limb prosthetic fairings this month.

In the orthotic realm, UNYQ has launched a limited release of a 3D-printed scoliosis orthosis developed by 3D Systems. The brace achieved a similar level of curve correction as the Boston Brace but was overwhelmingly favored by the children and teens for its attractive appearance, according to an unpublished pilot study conducted at UCSF Benioff Children's Hospital, Oakland, California, by 3D Systems' personalized medical device team working in collaboration with James Policy, MD, of Stanford University and Robert Jensen, CPO, Laurance Orthopedic, Oakland.

woman with custom lowerlimb covering

Erenstone's client poses with her daughter, showing off the Rosie the Riveter design on her custom lower-limb covering. Photograph courtesy of Jeff Erenstone.

"Something that is missing in our industry has been personalization [reflecting the user's personality and individual aesthetic style], and we have not really embraced the digital revolution like [some other healthcare-related industries]," says UNYQ CEO and Cofounder Eythor Bender. "In the next five years, 3D printing will change our industry in many ways. At UNYQ we are working with the O&P industry in maximizing [its] potential."

Erenstone has launched a new company, Create Prosthetics, Lake Placid, and developed some prosthetic covers. "We have exclusive use of a flexible material-not like brittle plastic that will crack if you hit something," he explains. "It's much more durable and conforms to the leg. We're going to specialize by doing cool aesthetics. We recently had a war veteran who wanted Rosie the Riveter on her prosthetic cover, so that's what we did. We can make flesh-colored covers too, but it's fun to make covers that express [the patients'] interests."

Now and the Future

Although 3D printing is beginning to make an impact in O&P, the emphasis at this point seems to be more on potential than current use. "I think it's close but not quite there yet in terms of durability and being cost competitive and time competitive with traditional methods of producing structural O&P devices," says Jim Colvin, director of research and development, WillowWood, Mt. Sterling, Ohio. WillowWood has investigated 3D printing and is currently working on a project. "Materials and processes need to improve, but I think it's just a matter of time before the technology advances to the point of being commercially viable for mainstream O&P devices."

"There are some limitations in 3D printing," says Sam Hale, CPO, director of prosthetics, Fillauer Companies Inc., Chattanooga, Tennessee. "There is a lack of durability and [there is] structural weakness. There are ways to strengthen the material, but it's expensive. However, we're watching developments and using the technology that is available whenever possible."

"I see the field continuing to embrace 3D printing, at whatever level, because it's definitely here to stay," says Tracy Slemker, CPO/L, FAAOP, president and founder of Dayton Artificial Limb, Ohio, and PDI.

"How we manufacture the orthosis or prosthesis is secondary to the management of the care of the patient," says Dennis Clark, CPO, president, Clark & Associates Prosthetics and Orthotics and O&P1, Waterloo, Iowa. "Every time we come up with a new way of measuring or manufacturing, people say, 'They make it so easy that anybody can do it.' All the techniques in fabrication just allow us to focus on our job, which is to manage prosthetic and orthotic care, with the goal of improving the function, health, and quality of life of the patients we serve."

Miki Fairley is a freelance writer based in southwest Colorado. She can be contacted via e-mail at .