Practical Matters: Early screening and the role of DARthroplasty as an intervention in young dogs with hip dysplasia

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Dec 01, 2008


David Luck, DVM
For too long, many veterinarians who have diagnosed hip dysplasia in young patients have informed the owners that the consequences will have to be dealt with later in life, when signs of osteoarthritis develop. When this time comes, we treat the pain associated with osteoarthritis with medications, we advise weight loss, and, for owners who can afford it, we recommend a total hip replacement.

DIAGNOSTIC EVALUATION IN PUPPIES


Figure 1: Comprehensive Hip Wellness Program for Large-Breed Puppies
A proactive hip wellness program, on the other hand, would attempt to modify the course of dysplasia toward normalcy at an early age, which might result in little if any osteoarthritis during the course of the affected animal's life. This comprehensive hip wellness program would ideally begin by evaluating 4-month-old puppies of breeds susceptible to dysplasia. These puppies would be sedated or anesthetized and examined for a positive Ortolani sign. If an Ortolani sign is present, confirm joint laxity with a radiographic examination (PennHIP), or possibly an ultrasonographic examination. These procedures can be easily accomplished as part of an early-age wellness diagnostic examination (Figure 1). Hip laxity identified in puppies < 5 months old might benefit from juvenile pubic symphysiodesis.1-3


2. A ventrodorsal hip-extended pelvic radiograph of a young dog reveals subluxation of the femoral head (solid white arrow), little if any dorsal rim of the acetabulum (solid black arrow), early osteoarthritic changes (dashed arrow), and shallow acetabuli (dotted arrows).
For puppies examined later in adolescence, from 6 to 12 months of age, the same diagnostic evaluations should be performed. Puppies in this age group showing laxity may benefit from one of two procedures: triple pelvic osteotomy (TPO) or dorsal acetabular rim arthroplasty (DARthroplasty). For patients that do not qualify for a TPO procedure because of a lack of dorsal acetabular rim, excessive subluxation of the femoral head, or beginning osteoarthritic changes,4 DARthroplasty may be appropriate (Figure 2).5