Abstract
Objectives Comparison of PennHIP and a novel method to diagnose hip laxity, called the Vezzoni
modified Badertscher distension device technique.
Methods In a total of 10 dogs, it was first assessed whether the distraction index (DI) from
the PennHIP evaluation center could be reproduced by two individual observers. In
the next two steps, the DI measurements made by the individual observers and the PennHIP
evaluation center were compared with the laxity index (LI) measured on the Vezzoni
modified Badertscher distension device view. Finally, the interobserver agreement
of the DI, LI and Norberg angle was assessed and compared with classification criteria.
Results The results were similar for the first three comparisons: there was no evidence for
bias, the relation between DI and LI was linear and the variability was small. A comparison
of the interobserver agreement showed that the measurement variability for the NA
was substantial, while the reproducibility for the DI and LI was equal.
Clinical Significance While the standard ventrodorsal hip extended radiograph is most commonly used for
diagnosis and screening of canine hip dysplasia, it lacks sensitivity to diagnose
laxity. To improve the identification of hip joint laxity, distraction-based radiographic
techniques are helpful. The Vezzoni modified Badertscher distension device technique
allows for a reliable in-house evaluation of canine hip joint laxity.
Keywords
canine hip dysplasia - laxity - PennHIP - Vezzoni modified Badertscher distension
device
