It’s hard to forget Derby, the incorrigible Little-Husky-That-Could that we outfitted with 3D printed prosthetics last December. With flagless determination, Derby was all tail wags and enthusiasm over his first set of prosthetics, which we designed to help him overcome the debilitating impact of his congenitally malformed front paws. In case you missed his story, get the full impact of his amazing transformation with this video.

As many noted when Derby’s story initially came out, the first version of his prosthetics kept him fairly low to the ground. This was a very intentional choice. Derby’s first pair of prosthetics was not only a concept test for the feasibility of the overall design, it also started the process of acclimating Derby to a new elevation. We wanted to give Derby the opportunity to gradually and comfortably adjust to a vertical status quo. Had we skipped this intermediary step and immediately addressed his height in isolation of his ambulatory abilities, his story would have evolved differently. His struggles would have outweighed his successes.

Once we were confident that Derby had adapted to his initial lift, it was time for phase two of our project. Because our first circular “blade” design was so successful, our initial thought was simply to scale the original. What we had not accounted for in this second iteration, however, was that while we managed to elevate Derby to the appropriate height, the results of the scaled design were too ungainly for easy movement. Rather than walk, play and run as he had previously, Derby simply shook his paws, trying to dislodge the oversized impediments we had given him.  

Realizing the task at hand was not as straightforward as polishing off a previous success, it was back to the drawing board to concept a new design. Our goal was to maintain the same adaptive curve at the prosthetic’s point of contact with the ground so Derby could pivot and play as before, while also attempting a knee-like structure to provide the appropriate amount of give for the new height. Our structural reassessment likewise called for a review of our material choice, leading us to select nylon for the right blend of stability and flex. To transform these concepts into real-life functional prosthetics, we then sent our design to one of our Selective Laser Sintering 3D printers, which create lightweight yet durable parts (ICYMI, this is the same technology that New Balance is using to create their new line of high performance running shoes with a 3D printed midsole). Before the day was over, we had our new design in hand and were ready to test them out.

“I can’t imagine tackling this case without 3D printing,” said Tara Anderson, 3D Systems’ project lead for Derby’s prosthetics. “The key to our ability to help Derby was being able to quickly and fluidly move from design to verification to end-use part, and back to design without losing any momentum. We were able to adapt our design to suit Derby’s evolving needs in real-time.”

When we strapped Derby into this new version, we knew we had a winner. Now up to his natural height, Derby took off at a trot, testing out his new legs with his fluffy tail wagging and pink tongue lolling. Derby’s owner, Sherry Portanova, says Derby has adapted beautifully, now sitting and walking like any other dog. “This past year has been amazing for us and for Derby,” she says. “We can’t wait to see what the future holds.”

Although 3D printing has helped Derby achieve a normal dog’s stature, we know he is anything but.

Watch Derby take his new prosthetics for a spin in the video below.