South African goose gets a prosthetic leg

8 April 2015

It took a network of very smart people, some cutting edge technology and a true blue animal lover to give a new lease on life to a goose.

Together they produced a prosthetic leg, designed using CAD and produced on a 3D printer, for Ozzie the goose. Ozzie’s leg was broken shortly after it hatched, explains Sue Burger. Burger, who lives in Kibler Park, Johannesburg, is a well- known animal lover who is called on to save and rehabilitate many rescued animals, from spiders to reptiles – she even has a caiman, a small alligator native to Central America.

“The previous owners think the mother stood on the gosling’s leg and broke it. They thought it would heal, but it did not. By the time the goose, which is five or six months old, came to me, the leg had grown very crooked and the goose could not walk,” Burger says. It had also developed badly from compensating for its missing leg, with a crooked back and a bow leg.

“The vet amputated the leg just below the knee. Ozzie would compensate and use its wing as a crutch, but broke the tip of its wing. Its whole body was crooked and because of this, it could not reach the oil gland near its tail. It could not spread the oil over its feathers, and so was not waterproof.”

Homemade solution

Burger tried to fashion a leg for her goose, using an empty toilet roller and tape, but her efforts were not successful. Neighbourly advice to approach RSG radio station led to interest from a variety of people who wanted to help.

Watch Ozzie walk with its prosthetic leg:

Chief among those was Philip van der Walt, whose company, BunnyCorp, uses new technology to develop products that people need. “We are a rapid product development company,” he says of the company, which is in Vereeniging, in southern Gauteng.

“Prosthetic limbs for animals are available overseas, but they are very expensive. We believed there was no reason we could not design and make one here. We used CAD to digitally design a prosthetic leg for Ozzie, and then called on our network to get it going.”

BunnyCorp’s mission is to make things cheaper and faster. It designs many prosthetics for humans, and applied its expertise to the goose’s needs. All the partners worked for free. “So far only a few cases around the world has been recorded where people made custom prosthetics for a bird using 3D printing but nothing in South Africa as far as we know,” says Van der Walt.

Partners

As well as BunnyCorp, which undertook the 3D design, the network comprises 3D Printing Systems, which contributed materials; the J-Lee Inc unit Hybrid Advanced Geometries, which offered use of 3D printers and its workshop, as well as technical help; and Centre for Rapid Prototyping and Manufacturing (CRPM) from the Central University of Technology in Bloemfontein, which will do the final 3D print of the leg.

Ozzie received its prosthetic leg on Easter Friday, and has been learning to use it since then.

It did experience some confusion with the sudden appearance and feel of the artificial limb, Burger says. It will need physical therapy, but is actually walking on the leg. The team is keeping an eye on the goose’s progress and this first leg to see how Ozzie does before CRPM prints the permanent leg.

“We are doing a few experiments and are going for a second fitting on 8 April,” says Van der Walt. “Once we have the perfect leg, the final design will be made by CUT using very high end machinery and materials.”

The prototype leg is made of ABS plastic, but the final one will be made of polyamide, or nylon. It will probably be covered in rubber to give it more flexibility. The nylon is expected to last “forever”, but the rubber coating is expected to need replacing after a few years.

“The nice thing about 3D printing the prosthetic is that we can just reprint the part that needs to be replaced,” Van der Walt says.

Watching brief

Over the past few days, Burger has been watching her bird and is aware of what needs improvement. “With the new leg, there will be some traction on the toe and some rubber under the foot to help Ozzie walk on a smooth surface,” she says.

When Ozzie first arrived on her doorstep, it could not walk at all, and spent its time in a hammock – essentially sitting in a blanket with its legs hanging out of two holes cut in it. Burger did a lot of aquatherapy with the goose, helping it to build its strength. She also feeds it a varied and appropriate diet so it has managed to bulk up a bit, although it is still small for its age.

“Philip is trying to do something here to help disabled animals. I am so grateful to him and to everyone for their help. It has given me much faith in humanity,” she adds.

BunnyCorp is also working on facial reconstruction design for children with facial deformities, as well as a socket for a child who has a prosthetic leg. This will mean greater comfort and ease of use for the child.

When it comes to this technology, South Africa is on a par with the rest of the world, Van der Walt adds.

Once Ozzie has its final leg and is able to move and behave like a normal goose, Burger plans on keeping it exactly where it is now – under her watchful and loving eye.