How 3-D Printing Will Revolutionize Prosthetics

New technology makes replacing limbs easier and cheaper than ever before.

3-D printer rack and pinion.

3-D printing could be the answer for people who are missing body parts – from arms to ears.

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As technology improves, inventions that were once seen as merely science fiction are becoming reality and providing new solutions to health problems. One area of technology revolutionizing health is in the field of prosthetics, where 3-D printing allows doctors and engineers to partner to rebuild limbs faster and cheaper than ever before – especially for children.

3-D printing works by melting thin plastic filament and squeezing it through a nozzle, building up computer-generated renderings layer by layer, says John Rieffel, assistant professor of computer science at Union College in Schenectady, New York, who specializes in 3-D printing. “You can think of a 3-D object as being composed by numerous 2-D slices,” he says. “3-D printers build those slices from the bottom layer up.”

[Read: How Technology Is Transforming Health Care.]

Using these printers, you​ can create almost anything – including body parts, Rieffel says. “3-D printers allow you​ to customize in ways we never could before,” he says. “You can print customized prosthetics specialized for one person. This reduces cost because you produce them to order, instead of mass producing them and then sizing them.”

​For children, 3-D prosthetics have major benefits, Rieffel says. “Children grow really quickly,” he says. “An adult can keep a prosthetic leg designed for them for as long as they want. For children, they grow so often that they need new prosthetics quite often, which can be quite expensive.”

While traditional prosthetics can cost between $5,000 and $50,000, ​​the cost of 3-D printed prosthetics in is the hundreds, with some being produced for what could be considered pocket change. ​

One of Rieffel’s students recently won a​​ scholarship award for a 3-D printed prosthetic she created for children that can stretch and expand with the child it’s outfitted for. “It grows as the child grows,” he says.

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But that’s just one example of how 3-D printing is revolutionizing prosthetics, says ​Thomas Most​, a designer and prosthetics expert with ProofX, a 3-D biomedical printing service in Illinois. One of the most famous examples is the Robohand, which was created to help a 14-year-old boy whose arms were blown off due to war in Sudan,​ and has since helped countless others across the globe. “It’s very simple and very rudimentary,” Most says, “but for $5, you can keep printing a hand like that until he fully develops. Then, once he reaches maturity, you can print a much more ornate and functional one.”

3-D printing is not just about replacing limbs, Most says. For people missing facial parts, like one of their ears, 3-D printing is a godsend. “You can scan the ear they have, make it a mirror image, and then print and cast it to make their other ear,” he says. “That’s the kind of stuff that still impresses me.”

The technology is already widely used for some medical implants, says David Dean​, an associate professor in the plastic surgery department at​ The Ohio State University, who has worked extensively with 3-D printers. "Old cranial implants were hard to get right," he says. "If they didn't fit right, you could block blood vessels or even cause seizures."

With the advent of 3-D printing, those are problems of the past, as major hospitals and printing labs can print implants to the correct fit faster than ever before. "These implants can be manufactured and shipped out [to hospitals] the same day," he says.

In Dean's view, 3-D printing will soon become the norm for all prosthetics. "There’s going to be a revolution coming," he says. "You’ll be seeing 3-D printed hip and knee replacements become standard before long."

However, it may still be several years before 3-D printed prosthetics are mainstream, Most says. The biggest hurdle is getting major orthotics companies to get on board. But as 3-D printing becomes cheaper, manufacturers will be forced to adapt. “When the companies realize this technology can hurt their wallet if they don’t utilize it, that’s when they’ll take notice.”

[Read: Op/Ed: Hospital of the Future Will Be a Health Delivery Network.]

And the technology is only going to get better, Rieffel says. He likens 3-D printing to the advent of personal computers. “Computers used to be giant machines that filled rooms. Now they’re in our pockets,” he says. “Today, instead of 3-D printers only being for schools and corporations, you can go to Home Depot and pick one up.”

In the future, people might even be able to print prosthetics in their living rooms, Rieffel says. “You’ll be able to go online and download existing models for prosthetics, and then print them at home.”

But the most exciting part about the technology is that no one knows where exactly it will go, Rieffel says. “3-D printing isn’t a technology that exists by itself,” he says. “If you partner it with 3-D scanning, what you’ve created is a 3-D Xerox machine.”

We’re already seeing the early stages of that type of technology, Rieffel adds. There are apps, like 123D Catch, that let you take 40 or more pictures of an object with your smartphone or tablet​ ​from different angles. The data is then used to produce a 3-D printable model. “The possibilities are endless,” Rieffel says. “These printers have a ton of potential.”