The printing of prostheses and orthopedic products is definitely one of the most promising markets in the world of 3D printing. As shown by 3DPI’s increased recent coverage on initiatives by Gyrobot, e-NABLE, Nicolas Huchet and Bionico (and many more) it continues to pick up steam. Even, or actually, especially at a desktop 3D printing level. It seems that many professional prostheses manufacturers, who were previously using traditional methods, may now be switching to 3D printers. Marco Avaro, a biomedical engineering in the Friuli region of Italy, is the latest to do so, by acquiring a €2,300 DeltaWASP 2040 system and cutting prostheses production times from 8 to 2 hours.
Perfectly reproducing a limb that can be used on a patient and knowing that it will fit exactly drastically reduces the time for development of the prosthesis, thus allowing the manufacturer greater speeds to market. Meanwhile, the patient is gifted with a reduction in stress, the number of required visits, and waiting time. Avaro and the Del Bene orthopedic laboratory decided to try using 3D printing to create parts of the prostheses produced by the company and, to their surprise, found they could manufacture as many as two perfectly rendered implants a day.
Several months earlier, Avaro had begun to explore the possibilities offered by 3D printing, initially facing several challenges in tailoring the technology for his specific needs. But then, he found WASP’s delta robotic arm would be able to easily produce objects that were empty inside. For Marco, it was the turning point. “I believed strongly in this technology,” he says, “and when I turned to WASP, I found the perfect machine for my work.”
From the start, he was able to produce high quality prostheses. “The printer makes a difference. It allows me to make pieces that are very tall, even over 40 centimeters, with a single print. The surface quality is such that we don’t have to do any smoothing. The print speed is also quite high and the delta architecture lets us produce perfect shells, even with very fine walls. There are many other advantages: for example, if we take the case of degenerative diseases, the geometries can become particularly difficult, very asymmetric, and the 3D printer can reproduce exactly what we need.”
Marco Avaro’s is one of the first such initiatives in Italy and it is proving highly effective. Since late November 2014, when Avaro first purchased the DeltaWASP, the Dal Bene laboratory has produced thirty prostheses. “Let me be clear,” says the engineer, “I have not invented anything. I simply apply 3D printing technology. It is the printer itself that allows this very high quality technique. I found it is a highly competitive machine even from a pricing standpoint.”
With a build chamber the shape of a cylinder, measuring 20 cm in diameter and 40 cm tall, DeltaWASP’s smallest pre-assembled Delta’s printing volume is very generous. The 3D printer also assures a good cohesion between layers, which means that it is possible to work with acrylic resins in a vacuum, without the risk that they get on the inside of the hollow prints. Keeping the resin and carbon fiber from getting in between the layers makes the prostheses more resistant over time by limiting stiffness variation. Furthermore, the machine’s heated plate and partially enclosed body practically eliminate the risk of deformation during printing.
“Prints made with DeltaWASP 20×40 have passed the finite elements method (FEM) tests. This means that it is possible for us to produce structures that are just as tough and considerably lighter,” says Avaro. “If that were not enough, the advantages are also aesthetic, something that is fundamental in a prosthesis. We can polish the product until it shines, using special acrylic resins and lacquers. Consequently, wearing it becomes more comfortable.”
Among all of these clear advantages of 3D printing as a manufacturing method for custom orthopedic prostheses, the DeltaWASP’s speed may be the determining factor. “For a tibial prosthesis, I used to need eight hours. Now, I only need two. I have the possibility to make prostheses for people who practice specific disciplines, such as mountain climbing or sky run. That gives me great satisfaction. I finish the prosthesis; I hand it over and I never have to intervene to fix it again. Physical therapists who deal with the rehabilitation are even amazed at what we can do. Avaro says that meeting WASP and its 3D printing technologies has changed his life. It has likely changed those of his customers as well.
