The Scientific Committee of the Department of Surgery and Radiology at the Faculty of Veterinary Medicine, Cairo University approved this retrospective study protocol before the investigation. Thus, this protocol may encourage veterinarians and clinical practitioners to utilize it in an attempt to prevent the breeding of dogs without consideration of normal hip conformation at the time of breeding. Our long-term goal is to evaluate the effectiveness of the FCI after adding these modifications to develop an appropriate assessment protocol that, when applied to a selective breeding strategy using German Shepherd Dog parents with phenotypically normal coxofemoral joints at the time of assessment, lowers the prevalence of hip dysplasia among offspring. In the present study, we hypothesize that the AFH coverage, cranial acetabular edge steepness, and IA in dysplastic joints will differ from normal or near normal joints. To overcome the possible interbreed variability, both recent and current studies performed on Labrador Retrievers and German Shepherd Dogs, respectively, were carried out without combining the 2 populations. 21 Therefore, our main objective is to develop a similar scoring system for the coxofemoral joint of German Shepherd Dogs to develop quantitative measures that, when combined with the FCI score, would potentially enhance the accuracy of the scoring process. 17– 20 Instead, the modified-FCI scoring system recently established in Labrador Retrievers provided morphometric criteria for each score to quantify the extent of lateral and dorsal AFH coverage, the steepness of cranial acetabular edge, and the IA in normal, near normal, and dysplastic joints.

Existing selective breeding strategies, using conventional radiographic procedures such as the NA, have not significantly lowered the CHD levels. The current study is the first to evaluate the CE and acetabular index angles for each hip joint independently and assess the degree of dorsal AFH coverage and the inclination angle (IA) in German Shepherd Dogs with normal and dysplastic hip joints. Furthermore, the previously estimated CE and acetabular index angles in the veterinary literature depended on both the right and left coxofemoral joints, because a line is drawn between the femoral head centers. Unlike human anteroposterior pelvic radiographs, canine VD pelvic radiographs are taken in the dorsal recumbent position hence, a midsagittal or transverse axis may not be effective for measuring the CE or acetabular index angle. 9 Measurement of the acetabular index angle relies on the use of the transverse planes drawn in the supine position in humans and the dorsal recumbent position in dogs. 9 On the other hand, the acetabular index angle is used to measure the steepness of the weight-bearing surface of the cranial acetabulum (the thick bone of the cranial acetabular edge) in humans 8 and dogs. However, these investigations relied on the contralateral hip joint to measure the CE angle using the long axis of the pelvis (the axis perpendicular to a line connecting the FH centers) 16 or using the midsagittal axis. 6, 7, 14, 15 Two reports identified the CE 9, 16 and acetabular index 9 angles on the extended VD pelvic radiographs in dogs.

In humans, the center edge (CE) and acetabular index angles measured on the anteroposterior view are used to independently assess the degree of lateral AFH coverage and the steepness of the cranial acetabular edge, respectively, for each hip joint. 12, 13 However, this technique considers both coxofemoral joints.

11 The Norberg angle (NA) is a commonly used radiographic measurement in dogs to quantify the degree of lateral acetabular femoral head (AFH) coverage. 2, 6– 9 An extended ventrodorsal (VD) view of the pelvis, first introduced in the 1960s by Riser, 10 is still used to examine the canine coxofemoral joint, according to the Fédération Cynologique Internationale (FCI), the Orthopedic Foundation for Animals, and the British Veterinary Association and the Kennel Club. 4, 5 A variety of radiographic measurements have been utilized in both adult humans and dogs to assess hip dysplasia. 1, 2 The disease is prevalent in large-breed dogs that grow rapidly, 3 including German Shepherd Dogs, Labrador Retrievers, and Boxers. Canine hip dysplasia (CHD) is a developmental disorder of the coxofemoral joint accompanied by joint laxity and incongruity that may develop into coxarthrosis.

Dog normal hip xray