Orthotics and prosthetics in veterinary rehabilitation
In veterinary school, I was taught that animals do well on three legs. While it is true that many of them adapt amazingly well, this is functional adaptation—not necessarily the highest quality of life. During the time I spent in general practice, I came to expect—even accept—that limited mobility, limb breakdown and chronic neck or back pain were consequences of limb amputation. I thought that cast-related wounds were unavoidable and that dogs with cranial cruciate ruptures would be uncomfortable for the remainder of their lives without surgical stabilization. But I was seeing dogs with mobility issues every day, and it seemed there should be something more I could do to help them run, chase balls and harass squirrels again.
Rehabilitation moves to the forefront
Over the past decade, there has been a tremendous increase in our understanding of physical fitness for both people and animals. We now know that optimal movement and mobility can significantly impact the physical and mental health of our patients. Canine rehabilitation has moved to the forefront of modern veterinary medicine with the advent of the American College of Veterinary Sports Medicine and Rehabilitation. With this new paradigm comes the idea that using mechanical appliances to improve the mobility and functionality of impaired patients is no longer the purview of human medicine alone.Veterinarians have a history of creating assistive devices from things at hand, using everything from plywood to low temperature thermoplastics and aluminum rods to PVC pipe. As our understanding of the intricacies of quadruped mobility and biomechanics has grown, so have the variety and sophistication of these devices. Now they incorporate veterinary-specific hinges, composite plastics, titanium, carbon fiber and specialty foam liners. Veterinary orthotics and prosthetics (V-OP) is evolving into a new specialty.
Orthoses (braces) are defined as any medical device attached to the body to support, align, position, immobilize, prevent or correct deformity; assist weak muscles or control and improve function. They are not a replacement for surgery, but complementary. Orthoses can be used as preoperative or postoperative solutions or even as alternatives to surgery. In cases in which surgery must be delayed, they can provide interim support, protect a limb and minimize disuse atrophy. Postoperatively, orthoses can provide a safe, effective and dynamic alternative to casting. Orthoses can also be used when surgery is not an option such as in patients that are poor candidates for anesthesia or have comorbidities or advanced age or if finances are an issue for the owner. These patients are seen daily in veterinary clinics everywhere, and until the advent of V-OP, there were no options to offer them.
The structural consequences of a missing limb or limb segment are now being recognized, in part through the efforts of rehabilitation therapists who understand the biomechanics of locomotion. Reestablishing a quadruped structure should be the goal whenever possible. Prostheses, like orthoses, are readily accepted by veterinary patients with congenital limb deformities as well as by those requiring an elective level amputation. In human medicine, amputation at the hip for a catastrophic ankle injury would be unthinkable, but elective level amputation is a recent development in veterinary medicine. Why amputate an entire limb if only the distal segment is not salvageable? When a friend of mine lost the lower half of her leg in an accident, her surgeons did everything they could to save her knee. Why don't we do this for dogs? Lack of awareness or knowledge? These reasons are no longer tenable in this era of V-OP.
There are many advantages afforded by orthoses and prostheses. Simply put, they offer treatment options where none existed before. They can improve quality of life and functional independence, preventing premature decisions to euthanize. Patients can return to an active lifestyle that curtails obesity and associated comorbidities. Biomechanics can be improved, decreasing secondary or compensatory pain. Cast-related wounds with associated pain and expense can be prevented. This is particularly notable given that in a recent retrospective study,1 cast-related injuries were shown to occur in 63 percent of casted patients at a cost that in some cases actually exceeded that of the original orthopedic procedure.