Digital analysis of ulnar trochlear notch sclerosis in Labrador retrievers.

Objectives: To compare ulnar trochlear notch bone radiopacity in Labrador retrievers with and without fragmented medial coronoid process using quantitative analysis of film density on digitised radiographs.
Methods: Mediolateral view elbow radiographs from Labrador retrievers (n=34) aged between six and 18 months were obtained and digitised. Images from dogs with an arthroscopic diagnosis of fragmentation of the medial coronoid process (n=17) were compared with that of a control population (n=17), and this data subject to statistical analysis.
Results: A statistically significant relationship between the presence of increased trochlear notch radiopacity and a fragmented medial coronoid process was identified. Fractional analysis of this area shows the region of greatest difference in radiopacity between normal and fragmented medial coronoid process cohorts to be in the trochlear region of the medial coronoid process of the ulna. A decrease in radiopacity values in the dysplastic group versus the normal cohort was observed for the region of the proximo-caudal ulnar trochlear notch.
Clinical Significance: An increase in ulnar trochlear notch radiopacity is a finding associated with fragmentation of the medial coronoid process in Labrador retrievers.