Radiographic Diagnosis of Hip Laxity in Rottweilers: Interobserver Agreement at Eight- and Twelve-Months of Age

SIMPLE SUMMARY: Hip laxity is one of the most frequent orthopedic disorders in dogs, and it is one of the main underlying reasons for canine hip dysplasia. Canine hip dysplasia is a progressive disease influenced by inheritance. Veterinarians can take timely preventive/therapeutic measures when hip laxity is diagnosed early, and prevent the participation of dysplastic dogs in breeding programs to reduce the prevalence of the disease. Effective treatment strategies can increase the welfare of dogs by reducing the severity of the disease at older ages. In this study, we aimed to assess the reproducibility of the protocols reported for the radiographic assessment of canine hip dysplasia in 8- and 12-month-old Rottweilers. Five observers investigated eight radiographic parameters at each examination time. According to the results, there were high interobserver agreements at both ages for the measurable parameters, such as the center edge angle (CEA), dorsal acetabular rim slope (DARS), distraction index (DI), and Norberg angle (NA), whereas the observers recorded poor to moderate agreements for the subjective values, such as the grading of the dorsal acetabular rim (GDAR), grading of the degenerative joint disease (GDJD), location of the center of the femoral head (LCFH), and sclerosis of the cranial acetabular rim (SCAR). ABSTRACT: Hip laxity is one of the predisposing factors of canine hip dysplasia. The early diagnosis of hip laxity allows veterinarians to prevent the participation of dysplastic dogs in breeding programs, which could lower the disease’s prevalence due to its genetic background. Furthermore, it allows them to plan preventive/therapeutic procedures for mild/near-normal hips to reduce the symptoms of the disease at older ages. A reliable screening program must be repeatable and reproducible, and intra- and inter-observer studies can help us to determine the best methods. In this study, we aimed to evaluate the radiographic parameters used for the early diagnosis of hip dysplasia in Rottweilers at 8 and 12 months of age with five observers to assess the interobserver agreements. According to our findings, there were high interobserver agreements at both ages for the quantitative values, such as the center edge angle (CEA), dorsal acetabular rim slope (DARS), distraction index (DI), and Norberg angle (NA), whereas we recorded from poor to moderate agreements for the qualitative values, such as the grading of the dorsal acetabular rim (GDAR), grading of the degenerative joint disease (GDJD), location of the center of the femoral head (LCFH), and sclerosis of the cranial acetabular rim (SCAR).