Imaging the Elbow

Canine elbow dysplasia is characterized by either fragmented medial coronoid process, ununited anconeal process, osteochondrosis , and/or elbow incongruity. An accurate diagnosis can be difficult due to limitations in performing and interpreting common imaging modalities. Radiography remains the most cost-effective, least invasive, and efficient of the diagnostic imaging tests available to private practitioners, but the complexity of the elbow joint and an inability to directly assess cartilage pathology makes it only a piece in a complete diagnostic work-up. Four orthogonal views should be evaluated to ensure accuracy and complete assessment of the elbow. Nuclear scintigraphy can be used to localize an inflamed joint, but it is not specific for cause or severity. Computed tomography (CT) and magnetic resonance imaging (MRI) provide detailed information on the canine elbow. CT can evaluate the entire joint, including complex views of the radial head and medial coronoid process, and can be used to judge joint congruency. MRI is superior for imaging soft tissues, including articular cartilage, cartilage–bone interfaces, and bone marrow lesions. However, MRI is limited by expense, availability, and the potential lack of distinction between cartilage of the humerus and that of the radius and ulna.

COMMENTARY: This review article clearly defines canine elbow disease and implications for imaging, and does an excellent job of comparing the most common modalities available. Advanced imaging helps more clearly define disease of the canine elbow by providing a detailed anatomic view of the joint and disease process. However, limitations include expense, lack of availability, requirement for general anesthesia, and lack of data supporting the clinical relevance of images. More research is needed to determine proper positioning, as well as correlations between histopathology and images with clinical lameness, the need for intervention, and prognosis.

Diagnostic imaging of canine elbow dysplasia: A review. CR Cook, JL Cook. VET SURG 38:144-153, 2009.