Sonography of the hip joint in puppies as a screening method for hip dysplasia

Hip sonography has been established in human medicine for 20 years and is the preferred imaging method for the diagnosis of hip development disorders (hip dysplasia) among babies in the first weeks of life. A standardised examination method is used in which both quantitative (angle of bone alpha and angle of cartilage beta) and qualitative parameters are determined. The hip is typified using standard values. In comparison to human medicine, dysplasia of the hip joint in dogs is diagnosed at a much later age, whereby standardised x-ray examination is used as part of the official screening process. The animal to be examined has already reached the age of 12 months, or 13 to 18 months in the case of large and heavy breeds. Sonographic examinations were carried out on 78 hip joints in 38 dead and one living German Shepherd puppy (1 day - 8 weeks old). In order to show sonoanatomy and sonomor-phological development, 24 hip joints were prepared and examined ultrasonically in water. It is generally possible to identify anatomical features sonographically from the first day of life onwards. Unlike in human babies, the hip joint of a puppy ossifies relatively quickly. The ossification centre of the fe-mur head must be seen as a limiting factor in this respect since its structures can only be seen distally up to 8th week. A standardised sonographic examination with the corresponding findings has been developed and described in detail. In this connection the ossified shape of the hip socket, the cartilaginous overlap of the acetabular cavity and the looseness of the joint are determined objectively For this pur-pose both angle alpha and angle beta as well as the distraction value are fixed as an index. The first reference values and maturity curves have been determined.