Dog to Sport New High-Tech Leg

By Tracey Peake

A German shepherd mix named Cassidy now has a chance to walk on all fours again, thanks to a surgical procedure conducted at NC State that has implications for the future of human prosthetics.

During a four-hour procedure last Thursday at the College of Veterinary Medicine, Dr. Denis Marcellin-Little, associate professor of orthopedics, inserted a titanium implant into the bone of Cassidy's missing right hind leg. In three months, after the implant has time to fuse with the bone, Cassidy's missing leg will be fitted with an osseointegrated prosthetic limb. 

Surgeons inserted a titanium implant into Cassidy's leg bone, which will be fitted with a custom-designed prosthetic limb.

Marcellin-Little, and Dr. Ola Harrysson, associate professor of industrial and systems engineering, are pioneers in the area of osseointegration, a process that fuses a prosthetic limb with an animal's (or human's) bones. The result is a custom-designed, limb-sparing prosthesis that behaves more like a natural limb- and a technique that could revolutionize human prosthetics.

"We are assessing how well it will work in cats and dogs at this point, but it's a great start," Marcellin-Little says.

Marcellin-Little and Harrysson began their work on osseointegrated pet prosthetics in 2005 with a cat named George Bailey, who had been born without the lower halves of his hind legs. Harrysson designed and built the limb in collaboration with his students and Marcellin-Little, who performed the surgery. The procedure involved inserting a titanium nail into one of the legs and securing it with screws.

Since then, the collaborators have improved and strengthened the design, and Cassidy's limb surgery was the first such surgery on a dog performed at NC State.

"This research collaboration, along with new technologies, has made it possible for us to custom design and directly fabricate metal prosthetic implants in a timely and economical fashion," Harrysson says. "Ten years ago this process would have taken much longer, cost much more and not been as accurate. We see this process becoming even faster and more cost-effective in the future."

The researchers hope that Cassidy won't be the sole beneficiary of this surgery.

"The implications for this procedure are huge," Marcellin-Little says. "As we gain more experience with the surgical technique and the design of the limbs, we see the possible benefits for humans - implants that allow the prosthetic limbs to attach without chafing or irritation, and limbs with more natural ranges of motion. We believe that this is the future of prosthetics."

Link

• College of Veterinary Medicine