Prosthetics For Pets

When Polar, a two-year-old Golden Retriever born with paralyzed rear legs contracted osteomyelitis and needed to have a back leg amputated, his owner Pamela Patton of Paradise, Pennsylvania wanted to have an artificial leg made for the dog.


When Polar, a two-year-old Golden Retriever born with paralyzed rear legs contracted osteomyelitis and needed to have a back leg amputated, his owner Pamela Patton of Paradise, Pennsylvania wanted to have an artificial leg made for the dog. She turned to the veterinary surgeons at the Matthew J. Ryan Veterinary Hospital at the University of Pennsylvania in Philadelphia, PA for advice.

For the first time during amputative surgery on an animal, David Diefenderfer VMD Ph.D a Research Associate at the Department of Clinical Studies at the university’s school of veterinary medicine, had a certified prosthetist orthotist on hand in the operating theater to fit a post-operative prosthetic so that the dog would be able to walk immediately afterwards. Thereafter, the medical team had the opportunity to customize and fit a permanent artificial leg.

The operation was a great success.

“Polar has no trouble getting around the house or outside,” says Patton. “Fortunately, we live in a ranch-style home because the only thing he can’t do himself is climb up stairs. Coming down is fine.”

The tables have turned; When it comes to the latest surgical and technological innovations in prosthetics and implants, humans are now the research guinea pigs paving the way for new procedures being performed on animals, particularly dogs. And, as a result many canine patients a being given new leash on life.

According to Bonnie Beaver BS, DVM, MS, DACVB of the Department of Small Animal Clinical Sciences Texas A& M University in College Station, Texas, currently the use of this type of prosthetic device on animals is still fairly uncommon.

“It’s a recognized fact that most four-legged animals manage extremely well on three legs,” explains Beaver. “And because of the vast discrepancies in size amongst dog breeds alone, there is no standard apparatus on the market. So for now, this field is controlled by individual veterinary surgeons that have a special interest in a particular case.

“For example a horse that’s undergone an amputation may need another way to bear some of the weight and it would be up to a veterinarian assisted by an orthotist or even an engineer with a special expertise to get together and figure something out.”

“It’s commonplace for a prosthetist orthotist to be on hand during human amputative surgeries,” explains Marty Mandelbaum CEO of M.H. Mandelbaum Orthotic and Prosthetic Services Inc. in Port Jefferson, New York. “Our role is to advise the surgeon of the required length of bone needed after amputation for a prosthesis to fit properly. So being present in the operating room for Polar’s surgery was groundbreaking.

“Often veterinarians amputate at the shoulder or the hip because they do not think about a prosthetic device as an option. It’s a matter of educating veterinarians to leave more length, if possible. If we have the knee joint or the elbow in front that we can grab on to and get the correct suspension, we can produce a pretty useful device.”

In Polar’s case, a month after the operation a caste was made as a forerunner to the final prosthesis. Thereafter, the dog had several checkups to ensure that it was walking comfortably and to make any final adjustments.

Unlike humans, a dog has to wear the device all the time and the owner must change the sock under the device and clean the limb on a daily basis.

The lifespan of typical canine prosthesis is one to four years. They are made so that they can be adjusted for minimal growth and obviously have to be remade if the patient is a young puppy that still has to grow. Costs range between $800 and $3,000.

According to Mandelbaum, many animals that suffer the loss of a limb from trauma or cancer could be good candidates for an artificial limb.

While it’s obviously best for the initial measuring and caste to be done in-house by a certified prosthetic orthotist, Mandelbaum says any veterinarian can take a caste and send it to an orthotic facility. The resulting device will probably conform to 70 per cent accuracy and can be modified and adjusted further.

Currently at North Carolina State University College of Veterinary Medicine in Raleigh North Carolina, surgeons are developing a new prosthetic technique known as osseo-integrated implants.

The first operation was performed on a cat and involved inserting a thin steel shank into the femur and allowing bone to grow around it in the same way it does around a hip replacement socket. The next step is to place a cosmetic prosthetic over the exposed steel pin.

If proved consistently successful, this method could in future replace the current leg devices that have to be strapped on to the patient.

When it comes to hip, knee and elbow implants in dogs, veterinary medicine has once again benefited for extensive research done on humans. Total hip replacement surgery is now a commonplace option for dogs, allowing them to live pain-free, active and mobile lives.

Because canine hip dysplasia is the leading genetic health problem in many dog breeds and the most common skeletal disease seen by veterinarians, prosthetic implants are now one of the medical management options taught in every basic surgery course at veterinary schools around the country.

Randy Boudrieau DVM. Diplomate ACVS, Professor of Surgery at the Cummings School of Veterinary Medicine Tufts University in Grafton, Mass. is a pioneer in this field and actively involved in on-going research studies regarding cement-less implants being done by the Canine Implant Retrieval Program under the auspices of the BioMotion Foundation, a nonprofit orthopedic research laboratory in West Palm Beach, Fla.

Boudrieau says that while cemented implants are still considered to be the “gold standard”, the new technology has many potential advantages.

“When doing cemented implant surgery, surgeons have to be very concerned with their environment because there is a high potential for infection. Cement-less implants are a simpler process from the standpoint of not putting in so much hardware and surgeons can work in a less than ideal environment. Personally, I think they are nevertheless technically more demanding because it’s such a precision operation.”

According to Melinda Harman, Director of Research of the Canine Implant Retrieval Program, cementless hip implants, has been available to dogs since the late Nineties.

“Cemented implants have been known to crack and loosen over time. To date, our studies have shown that cement-less implants overcome this problem. By studying hip implants in dogs that have lived out their natural lives, researchers have been able to gather valuable information and pass it on to Kyon, the Swiss-based company that manufacturers the majority of canine hip implants available on the market. In turn, this knowledge is used to further improve both the implant and the surgical procedure involved in their placement.

“Kyon has also taken on the role of educator,” says Harman. “The company is training surgeons through a worldwide program of presentations at veterinary conventions and specialized workshops.

“Veterinary medicine is not as specialized as human medicine and veterinarians are required to know a lot about various different fields. Consequently, once a veterinarian has concluded a training course, they are able to perform the surgery with confidence. Any veterinarian in the United States can apply to attend a training workshop.”

While Bourdrieu’s forté is hip implants, veterinary surgeons at Iowa State University have focused their research on canine knee and elbow replacements with the ultimate goal of making these implants which considerably reduce pain from arthritis totally cement-less too.

According to Harman, while it is essential to veterinary practitioners are aware of the latest surgical options and state of the art technology available for animals, it’s equally important to educate pet owners so that they are aware of all the choices available.

“In the same way that magazine and television advertisements about the latest human drugs and surgical techniques always add the tag line that patients should seek further information from their doctor, pet owners should be educated and made aware of options related to their pets so that they can talk to their veterinarian,” says Harman.

Thanks to the media, pet owners are becoming more aware of Neuticles, the testicular implant designed to give neutered pets a more “masculine” look.

According to inventor Gregg Miller, he gets daily emails from people claiming they would have not neutered their pet if not for Neuticles.

“Consequently I feel Neuticles play an important role in helping to control the pet population,” he says.

To date, more than 150 000 implants have been fitted worldwide. While the recipients are mainly dogs, Miller now has a range of implants that range in softness and size to fits cats as well as horses and bulls. The implants are FDA approved and are inserted at the time of neutering. Prices range from $79 to $400 a pair.

“It’s like changing a light bulb,” explains Miller. “It takes less than three minutes and veterinarians charge around $60 in additional to the neutering fee. The animal doesn’t know anything has changed but the owner feels his pet has retained his identify in the dog park.

Miller’s company also makes silicone eye implants for animals that have lost an eye and would otherwise have a sunken lopsided face and also a micro-thin ear implant to correct drooping or sagging ears.

However despite the advantages regarding pet over population, many veterinarians remain skeptical about testicular implants.

According to Alan Schulman, DVM, Diplomate ACVS, a surgeon with special training in orthopedic, neurologic, and reconstructive surgery at the Animal Medical Center of Southern California in Los Angeles, California, it’s translates into owners projecting their own anthropomorphic concerns on to the pet.

“ If we take this seriously, then what about the female pet population? This is such a politically correct country; we are overlooking any female feelings with regard to them being “fully female.” If there are Neuticles, why aren’t their Ovacles?”


This article is from Veterinary Practice News

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