June 01, 2007
Canine hip dysplasia (CHD) is a heritable, developmental orthopedic disease which results in an abnormal formation of the hips leading to varying degrees of laxity (i.e. looseness) of the hip joints followed by inflammation, damage to the cartilage and arthritis. The amount of arthritis that develops can range from mild with no clinical signs to severe with crippling effects.
CHD is a difficult disease to prevent because it often goes undiagnosed in an individual used for breeding and this disease is then passed on genetically to the offspring thereby perpetuating the disease in the gene pool. Breeders have used radiographic techniques (i.e. OFA and PennHIP) in order to select individuals for breeding that have no radiographic signs of hip dysplasia. The PennHIP technique can be performed at a much earlier age (i.e. 4 months) and is superior in evaluating for passive hip laxity compared to OFA evaluation. This allows the PennHIP technique to be used as an early detection test for hip laxity, which has a strong correlation with the risk of development of hip arthritis later in life.
The early assessment of a dogís risk of developing hip arthritis is ideal not only from the standpoint of removing affected individuals from the gene pool but also providing the opportunity for utilizing preventative treatments in individuals at risk before arthritis has already developed. Dogs should be screened for hip dysplasia at 12 to 16 weeks of age in order to be a possible candidate for preventative treatments. A veterinarian, in addition to completing a full orthopedic exam, should perform a PennHIP evaluation to determine the passive laxity of the hip joints that are then correlated to the petís risk of developing hip arthritis later on in life. Dogs that have excess laxity of the hip joints, whether they are currently showing clinical signs or not, are at risk of developing hip arthritis in the future.
Treatment options for hip dysplasia depend on the age of the individual, orthopedic exam findings, and radiographic changes (i.e. degree of laxity and arthritis) at the time of the evaluation. Conservative management is an option for all patients diagnosed with hip dysplasia and consists of dietary recommendations (i.e. slow growth rate and/or achieve lean body weight), moderation in activity, and medications (i.e. cartilage supplements, adequan injections, and non-steroidal anti-inflammatory drugs). Conservative management does not stop the progression of arthritis but rather ameliorate the signs of the disease. Unfortunately, it is not possible to exactly predict which patients will go on to develop severe debilitating arthritis with conservative management. When the conservative management of severe hip dysplasia fails then salvage surgical procedures such a total hip replacement or femoral head and neck excision can be performed.
It would be preferable to prevent the arthritis from developing in the first place rather than treat the arthritis after it occurs. Two surgical procedures intended to prevent or at least greatly diminish the degenerative process in dogs with hip dysplasia are the triple pelvic osteotomy (TPO) and the juvenile pubic symphysiodesis (JPS).
The TPO procedure is performed in dogs less than a year of age without radiographic evidence of severe hip laxity or arthritis. This surgical procedure is invasive and involves performing three separate osteotomies of the pelvis, lateral rotation of the dorsal acetabular rim over the femoral head and securing the ilial osteotomy with a bone plate. The goal of the surgery is to improve the congruency of the hip joint and thereby decrease joint laxity, and prevent future osteoarthritis. This procedure is performed on one hip at a time and is not without potential complications including infection, implant failure, sciatic nerve injury, and pelvic canal narrowing.
The newer JPS procedure involves destroying the pubic symphyseal growth plate using electrocautery and results in an improved coverage of the femoral head by the acetabulum as the rest of the pelvis continues to grow. The JPS procedure is performed in dogs between 12-20 weeks of age. The advantages of the JPS over the TPO procedure are a much less invasive surgery, shorter anesthesia time, less costly, both hips treated with one surgery, and the procedure has minimal risk of complications.
The JPS procedure can be effective in preventing degenerative changes in the hip joints however the difficulty resides in being able to identify patients at an early enough age that would benefit the most from this procedure. At the Wisconsin Veterinary Referral Center we recommend having your petís hips screened at 12-16 weeks of age to determine the risk of developing hip arthritis in the future. This would provide you with the option of choosing a surgical procedure such as the JPS for your pet with the intent of preventing future hip arthritis and improving their quality of life.
Jeffrey Meinen, DVM, DACVS - Wisconsin Veterinary Referral Center (WVRC) is the Midwestís leader in veterinary specialty and emergency care. Open 24 hours/7 days a week, WVRC is staffed by full-time emergency veterinarians and specialists in Emergency/Critical Care, Surgery, Cardiology, Anesthesia/Pain Management, Medical Imaging, Dermatology, and Internal Medicine. WVRC is located one half mile south of I-94, Exit 294 in Waukesha. For more information visit www.wiwvrc.com.
Nothing found in the guestbook.