PennHIP Radiographs Now Offered at Best Friends Animal Hospital
In addition to offering OFA hip radiographs (x-rays), Best Friends Animal Hospital now also offers PennHIP hip radiographs! Many believe that PennHIP is the most accurate screening method for canine hip dysplasia.
What is Canine Hip Dysplasia?
The hip joints are ball and socket joints (socket = acetabulum of the hip, and ball = head of the femur) and each dog has two hip joints. Dysplasia means abnormal development, so hip dysplasia means abnormal development of the hip joints. If the ball and socket joint is irregular or loose, this leads to much more motion in the hip joint. The body responds to this excess motion by attempting to stabilize the joint by laying down new bone. What results are sloppy joints with extra bone (arthritis) formation. Eventually, these hips become a source of chronic pain and decreased quality of life. Hip dysplasia is the most commonly inherited orthopedic disease and affects large breeds more severely than small breed dogs. Once a dog is diagnosed with hip dysplasia, efforts at slowing the progression of pain and arthritis can be attempted, but the development of arthritis/degenerative joint disease is inevitable. Surgical correction (FHO - Femoral head Ostectomy or total hip replacement) is expensive and may not return the dog to function.
The best way to prevent hip dysplasia is to choose breeding dogs with "tight" hips to reduce the incidence of this inherited condition.
What are PennHIP Radiographs?
Dr. Gail Smith at the University of Pennsylvania developed a method to assess hip laxity, the key factor in the development of canine hip dysplasia. PennHIP is a not-for-profit program wholly owned and operated by the University of Pennsylvania. Veterinarians have to attend advanced training, obtain special equipment, and pass the certification process before they can take PennHIP radiographs.
For the radiograph procedure, the dog's muscles are completely relaxed by administering sedation or general anesthesia. For the PennHIP screening, three separate radiographs are taken. The first radiograph is the Distraction Radiograph where the dog's hind legs are positioned in a neutral, weight bearing orientation using a special device to reveal the dog's inherent joint laxity. Second is the Compression Radiograph where the dog's hind legs are positioned in the same neutral position as the distraction radiograph but the femoral heads (balls of the femur) are gently seated in to the acetabula (hip sockets). This view can help identify critical anatomic landmarks of the hip and determine how well the femoral head fits into the acetabulum. Finally we take the Hip-Extended Radiograph where the dog's legs are placed in extension. PennHIP uses this view to identify radiographic signs of hip arthritis also known as Degenerative Joint Disease (DJD). While the hip-extended view can detect existing arthritic changes, it often conceals hip laxity thereby giving a false impression of joint tightness. The PennHIP method uses the amount of joint laxity revealed in the distraction view to tell if the dog is susceptible to develop hip dysplasia and will likely show radiographic evidence of hip arthritis later in life.
After taking the three radiographs, we electronically submit them to the University of Pennsylvania for specialized evaluation. We receive a report consisting of the following three key parts:
- Distraction Index - or measurement of hip laxity; expressed as a number between zero and one.
- Arthritis - evaluation if arthritis is present.
- Breed Laxity Profile Ranking - a ranking of your dog based on his/her breed and their distraction index.
What is the difference in PennHIP vs. OFA Radiographs?
Many veterinarians believe that PennHIP is a more accurate predictor of hip dysplasia in the dog. An article comparing the two methods of hip evaluation is titled "Evaluation of the relationship between Orthopedic Foundation for Animals' hip joint scores and PennHIP distraction index values in dogs." A video with Dr. Smith explaining the article is also available. Another advantage to PennHIP is that puppies can be screened as early as 16 weeks of age, as opposed to 2 years with OFA radiographs. This allows breeders to best choose their breeding stock and allows veterinarians to advise pet owners on lifestyle adjustment and preventative strategies to minimize the pain and progression of the disease.
How can I find a Certified PennHIP Veterinarian?
Veterinarians have to attend advanced training, obtain special equipment, and pass the certification process before they can take PennHIP radiographs. Best Friends Animal Hospital is a certified PennHIP location. If you live in another state, you may locate a certified PennHIP veterinarian anywhere in the world by visiting PennHIP's Locator Tool.
For more information, visit the PennHip Website or call us at 406-255-0500 to schedule your dog's evaluation.
