Prosthetics are devices that replace a missing body part. Humans have been using prosthetics for several hundred years, from crude peg legs and hook hands to modern high-tech replacement limbs that can be controlled by existing nerve endings. Surgical replacement of hips and knees have become commonplace. It’s not so surprising then that veterinary surgeons have also become quite skilled in pet prosthetics, and makers are constantly improving the design and materials used to construct these devices.
Dogs, cats and other pets might need a prosthetic replacement for a limb or other body part because of injury, disease or congenital defects. Although prosthetic surgery can be expensive, some insurance policies for pets are now available to cover some or all of the costs. Prosthetic devices are often attached after a pet has had a limb amputated, which may be needed because of cancer, injuries or other causes. Prosthetic devices must be carefully fabricated to fit each pet so that they function flawlessly once attached.
Total hip replacement is available for dogs and cats. The artificial hip joint is composed of a ball to replace the head of the femur and a socket to replace the acetabulum (the concave surface of the pelvis). The surgeon first removes the head of the femur, the socket is implanted, and then the new ball is attached to the femoral stem. The ball is then placed in the socket to create the new joint. Hip replacement may be needed to treat the pain of arthritis or hip dysplasia, which is a looseness of the hip joint that can lead to arthritis. At one time, hip replacement surgery was performed mainly on heavier and larger dogs, but new devices are available for animals as small as five pounds.
Hip replacement can be costly and is performed only at large animal hospitals and veterinary centers. It is an alternative to non-prosthetic surgery known as femoral head osteotomy (FHO), in which a portion of the hip is removed and scar tissue forms a new hip joint. FHO is less successful on older and heavier pets.
Dogs and cats can also get total knee replacements, in which a metal/polyethylene joint replaces the pet’s damaged knee. The most common reason for knee replacement is joint pain from osteoarthritis, although other reasons can include trauma, disease and malformation. The surgeon exposes the side of the knee with an incision and the joint surfaces are replaced. Knee replacements are usually done only after less intrusive treatments fail, and your vet can review with you the various risks and rewards of total knee replacement.
Veterinary surgeons have also been successful installing artificial elbows when a pet has end-stage elbow dysplasia. The prosthetic elbow relieves pain and allows your pet to return to its normal daily activities.
Closely aligned with pet prosthetics are pet orthotics, which are externally applied devices that modify or support a pet’s skeletal and neuromuscular systems. Orthotics are less expensive than prosthetics, because they usually don’t involve surgery. You can find on YouTube many videos of dogs, cats, pigs and other animals that have been fitted with rolling wheelchairs and carts to replace the function of compromised legs and hips. Hip dysplasia and arthritis are common among certain dog breeds, and can making walking quite painful. A canine wheelchair is a cart harnessed to the back of the dog. The wheelchair supports the animal and allows it to use its front legs to pull the cart without engaging its back legs.
Cat wheelchairs are also available, and there are many documented cases of other animals, such as Crisp E. Bacon (a pig), who adapt well to wheelchairs.
Another class of orthotics for pets are braces for knees, ankles, tarsals (lower ankles), elbows and wrists. Stifle or knee braces support dogs with injuries to the Anterior Cruciate Ligament (ACL). Braces help control unwanted motions while supporting desired ones. Braces may be used when surgery is not an option, due to the pet’s age, the required recovery period, the nature of the problem or the costs of treatment.
Tarsal braces help alleviate pain from missing paw pads or toes, fractures, paralysis, knuckling, severe strains, arthritis and dislocation. Elbow braces can correct symptoms such as collapsing, limping, loose joint or inability to bear weight. These braces have a clamshell design and can partially or completely immobilize the joint.
Your veterinarian is an expert on the various options available to owners of pets with damaged limbs and joints. Get all the facts before you decide how to proceed.
Dr. Paul has a strong interest in avian and exotic animal medicine and surgery, as well as small animal internal medicine and surgery.
He has provided services for numerous breeders, kennels, aviaries, and mini zoos.