There’s a striking lack of individuals in the developing world who are capable of making good prosthetic limbs. The World Health Organization has previously estimated that as many as 40,000 more trained personnel are needed.

To address the problem, a Canadian professor is leading an effort to use 3-D scanning and printing to create parts for prosthetic legs. While 3-D printed limbs aren’t as good as those handmade by skilled technicians, they could provide a superior alternative to going without a prosthetic, or using a device that an amateur made.

Easy-to-use 3-D scanning and printing technology would enable quick creation of a large pool of people capable of generating prosthetic limbs. The goal is to make a prosthetic about 80 percent as good as what a skilled technician could make by hand.

“We can’t get enough prosthetic technicians, but maybe we can create a semi-automated process that’s maybe not quite as good but will at least serve to increase the access to prosthetics,” said Matt Ratto, a professor at the University of Toronto who leads a lab addressing the social implications of 3-D printing. Ratto’s lab is partnering on the project with the Christian Blind Mission and CoRSU, which provides rehabilitation services for disabled Ugandans.  

Ratto’s team has experimented with using a Microsoft Kinect and other 3-D scanning technology to create a representation of a residual limb in Autodesk, which is 3-D modeling software. A 3-D printer can then be used to print a custom socket, the portion of a prosthetic limb that attaches to the existing limb. The sockets are attached to the main stem and foot of the artificial leg, which are donated in various sizes to CoRSU by organizations such as the Red Cross. Ratto hopes to complete the research in time for his sockets to be used in Uganda in 18 months. His team is counting on inexpensive 3-D scanners emerging on the market in the next six months to speed the process and keep costs down.

Ratto’s lab is in touch with Ugandan doctors to learn about the types of residual limbs they may be dealing with. While amputations in the developed world are generally planned — meaning surgeons can fashion remaining bones and muscles in a way that will support a prosthetic — that’s not the case in Uganda.

“The kind of shapes and things you get out there is much more complex. We need that information to make sure the thing we’re working on will fit there,” Ratto said.

One interesting element of this approach is the use of a new technology despite it being inferior to existing methods. With the traditional, manual process a technician would feel the residual limb and note the density of the flesh and location of any bony outcroppings. This allows the technician to craft a socket that fits better. 3-D scanning only senses the external attributes of the residual limb. But because there’s a shortage of prosthetic technicians, 3-D printing may be finding a place because it can do good-enough work.