Total Hip Replacement as a Treatment for Hip Dysplasia in Dogs
Hip dysplasia is a genetic problem that occurs most commonly in dogs that have a mature body weight of more than 30 pounds—though toy breeds and cats occasionally are affected as well.
At VETMED, we recommend orthopedic screening examinations at six to eight weeks of age in at-risk medium, large, and giant breed dogs. At this young age, hips should be evaluated for dysplasia using standard radiographic views, as well as compression/distraction positioning techniques. Hip radiographic examinations for certification by the Orthopedic Foundation for Animals (OFA) for breeding purposes, however, are not performed until dogs are 24 months old or older.
Signs and Symptoms
The clinical signs of hip dysplasia, including lameness and pain, can be evident in dogs as early as three to six months of age. Symptoms initially can be as subtle as intermittent hind-limb stiffness, reluctance to stand when lying down or sitting, decreased activity level or decreased endurance when playing, a change in the stride of the hind legs, “bunny hopping,” or frequent sitting episodes. Oftentimes puppies with hip dysplasia are simply characterized as “inactive” or “laid back.” In some cases, symptoms may not develop until the pet is middle-aged or older.
Young dogs (usually under 12 months of age) that do not have radiographic degenerative joint disease (DJD) may be candidates for a pelvic osteotomy procedure that reconstructs the pelvis and allows the acetabulum (hip socket) to have greater coverage of the femoral head.
For dogs diagnosed with radiographic degenerative joint disease—or for those whose conservative hip pain treatment strategies were unsuccessful or medication is needed over an extended period of time (more than one month)—total hip replacement (THR) is an option.
Other indications for a THR include hip luxations, arthritis secondary to malunions, fractures, and avascular necrosis. We do not typically recommend salvage procedures, such as femoral head ostectomy (FHO) in dogs that have uncomplicated hip dysplasia and would be good candidates for total hip replacement.
Why Consider a THR?
A THR is performed to improve quality of life by providing pain relief, improving hip function and allowing the patient to return to an active lifestyle. The modular, prosthetic hip replacement system used today has three main components: the femoral stem, the femoral head, and the acetabulum. These components, which are made of cobalt chrome, stainless steel or titanium, and ultra-high-molecular-weight polyethylene, are available in multiple sizes allowing for a custom fit.
In 96 to 98% of THR cases, dogs have good to excellent results and return to normal function. About 30 to 50% of patients have both hips replaced, and the minimum time interval between surgeries is six weeks.