Hip Dysplasis is a genetically inherited disease of hip joints that results in hip joint laxity. This laxity causes cartilage damage, scar tissue formation around the joint, and eventual arthritis. Most dogs with hip dysplasia develop arthritis before one year of age. The arthritic process will continue to worsen as the dog ages. The lameness associated with hip dysplasia is variable. Some dogs never display lameness, while others can be severely affected. Mild cases of hip dysplasia can be treated medically, while more severe cases are best treated surgically. Surgical procedures are usually divided into corrective procedure and salvage procedures.
Corrective procedures are procedures that are designed to be performed in young dogs before arthritis develops. As this usually occurs before one year of age, early detection is essential. Essential diagnostics include both joint palpitation and radiographs. Corrective procedures work by decreasing the laxity in the hips caused by hip dysplasia. They do not completely normalize the dogs, and some arthritis will still develop post surgery. However, when these procedures are performed before significant joint degeneration occurs, the vast majority of dogs will go through life with little to no lameness. The two corrective procedures currently in common use are Pubic Symphsiodesis and Triple Pelvic Osteotomy.
Pubic Symphysioded is is a surgical procedure that results in fusion of the two halves of the pelvis. This is performed using an electroscalpel on the pubic symphysis. Fusion of the symphysis will cause the hip sockets to rotate outward as the dog grows, improving joint stability. Dogs must be less than four to five months of age to benefit from this procedure.
Triple Pelvic Osteotomy (TPO) surgery involves making three cuts on each side of the pelvis so the portion that contains the hip socket is detached. That bone segment is then rotated outward until joint stability is achieved. The bone is then secured in this new position with a bone plate that will hold the bone in place until healing is complete. TPO surgery is only success arthritis yet. Typically, only young dogs less than one year of age candidates for this procedure.
Developed by Dr. W. Bruce in Australia (who is not board certified) TTO is the newest of the dynamic stabilization techniques. Similar to TPLO and TTA, it Salvage procedures are those surgeries performed to treat dogs that have already developed arthritic changes. These include Femoral Head Ostectomy and Total Hip Replacement.
FHO removes the head and neck of the femur (the portion of the upper leg bone that articulates with the pelvis, which minimizes the discomfort from hip arthritis. The body reacts by forming a false joint. Although this procedure does compromise hip function, it can relieve a significant amount of pain and restore quality of life. Its main advantage over hip replacement is that it is less expensive. Cats and small breed dogs generally do well with FHO. Large breed dogs generally do less well with FHO. Results in large breed dogs are less consistent, and are best if combined with aggressive physical therapy.
THR is the Treatment of choice for larger dogs with significant hip arthritis. Following complete healing, most dogs return to a near normal gait and normal level of activity. During THR, both the femoral and pelvic portions of the hip are replaced with prosthetic devices. There are many different types of hip replacement available, including both cemented bone in-growth systems and cement less systems that have biological advantage for bone vitality.