Relation of the Norberg angle and position of the femoral head centre to the dorsal acetabular edge in evaluation of canine hip dysplasia

Summary

Canine hip dysplasia (CHD) is a locomotive-system disease in dogs, which in many countries is the target of screening programs aimed at reducing the prevalence of CHD among descendants of predisposed dog breeds. Despite the efforts to apply genetic testing or ultrasound diagnostics in diagnosing CHD (as is common in human medicine), the main diagnostic process in veterinary medicine is by radiographic examination. The main two parameters which are used in diagnosing HD are the Norberg angle (NA) and the position of femoral head centre to the dorsal acetabular edge (FHC/DAE). We examined the relationship between these two parameters in the process of the determination of CHD degree by evaluating 225 randomly selected radiographs which were made during the period from 1993 to 2008. The aim of our study was to examine the validity of these two parameters in CHD classification as used in three different classification programs. Using Pearson’s correlation coefficient, the value of which was 0.85 (p <0.05), we observed a positive correlation. Comparing the three scoring systems for CHD evaluation, we found that the final degree of CHD was similar for 78% to 85% of cases using Flückiger’s scoring system versus a modified scoring system of 5 parameters without FHC/DAE. Results were significant.

Keywords

Hip dysplasia - dog - Norberg angle

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