Orthopedic Surgery
A newer medical approach to the treatment of degenerative arthritis secondary to hip dysplasia involves the use of products called polysulfated glycosaminoglycans or PSGAGs. PSGAGs are naturally occurring components of the joint cartilage and increase joint fluid production. Although results are preliminary and no controlled studies in dogs have been performed, there have been several reported successes with these compounds in selected cases.
When should a patient receive conservative management as opposed to specific surgical treatment? The answer depends on the age of the dog, the intended use of the dog, the degree of arthritis, the severity of the lameness and the financial capability of the owner. Approximately 50-60% of the patients may respond to conservative therapy over a long period of time. The remaining 40-50% will require surgical treatment. Unfortunately, there is no way to predict into which category any one particular dog will fall.
Three surgical procedures are currently used in the treatment of hip dysplasia. In young patients with minimal evidence of arthritis, a stabilizing reconstruction of the hip joint is recommended. This involves reconstructing the joint congruency and stopping the subluxation and laxity that lead to severe arthritis. This technique centers around the Triple Pelvic Osteotomy. It has been established as a reliable, predictable mode of treatment in those cases which meet the case selection criteria.
Once the patient (usually adult) has radiographic evidence of degenerative arthritis, it is no longer a candidate for a triple pelvic osteotomy procedure. Over time, many of these dogs will become less responsive to analgesic medications and surgical therapy should be considered. There are two procedures available.
1) Removal of the femoral head and neck (excision arthroplasty, femoral head & neck excision, FHNE)
2) Total hip replacement
Femoral head excision works well for dogs under 30 lbs and those with unilateral dysplasia. It is less satisfactory for dogs over 50 lbs, particularly when performed bilaterally. This is a salvage procedure for those owners who cannot afford the cost of a total hip replacement, but need an alternative to constant medication and debilitating pain.
Introduced in 1976, the Total Hip Replacement has become the only treatment available that provides normal hip joint function once advanced arthritis is present. With this technique, the femoral head and neck are replaced with a cobalt chrome, or titanium, component and the acetabulum is replaced with a plastic cup prosthesis. A five year follow up study of 221 total hip replacements revealed an overall success rate of 91%. Total hip replacement can be done on both hips, although many dogs (80-90%) do very well with one side replaced.
