Inter-Observer Agreement in Radiographic Diagnosis of Coxofemoral Joint Disease in a Closed Cohort of Four-Month-Old Rottweilers

SIMPLE SUMMARY: Canine hip dysplasia is an important orthopedic disorder in veterinary medicine. In addition to body weight, fat intake, rapid growth, and hormonal changes, heredity is one of its underlying factors. Diagnosis of hip dysplasia under one year of age would help veterinarians to plan proper preventive/therapeutic methods and exclude dysplastic dogs from breeding programs to reduce the incidence of the disease in future generations. Therefore, having an accurate method for the early diagnosis of dysplastic dogs is an important subject, and a limited number of screening methods are used globally. Assessment of the accuracy of these methods can be examined with intra- and inter-observer studies. In this study, we aimed to assess the inter-observer agreements of the eight radiographic parameters from four different radiographic projections between five experienced observers (two of them certified scrutineers for canine hip dysplasia) to evaluate the reproducibility of the protocols. In our study, high inter-observer agreements were recorded for measurable values such as angle measurements, whereas the results of the subjective grading were low. Thus, it can be deduced that quantitative parameters are reliable values and a combination of these values with other screening programs such as clinical examinations might increase the accuracy of the examinations. ABSTRACT: Canine hip dysplasia is a complex and multifactorial disease. The early diagnosis of dysplastic dogs under one year of age helps veterinarians to plan proper preventive/therapeutic methods. Having an accurate screening method increases the chance of the early detection of dysplasia. The goal of our study was to assess the inter-observer reliability of eight radiographic parameters in four-month-old Rottweilers. Radiographs of the 28 Rottweilers were investigated by five experienced observers. The radiographs were taken in ventrodorsal view with extended legs, frog-leg ventrodorsal view, distraction view, and dorsal acetabular rim view. Four quantitative parameters such as Norberg angle (NA), distraction index (DI), dorsal acetabular rim slope (DARS), and center edge angle (CEA) and four qualitative parameters such as sclerosis of the cranial acetabular rim (SCAR), location of the center of the femoral head (LCFH), grading of the degenerative joint disease (GDJD), and grading of the dorsal acetabular rim (GDAR) were evaluated. High inter-observer agreements were recorded for quantitative values, whereas the inter-observer agreement of the qualitative parameters was low. It can be deduced that the evaluated quantitative parameters are reliable, and a combination of these methods with clinical examinations might increase the accuracy of the examinations.