Ultrasonography of the Canine and Equine Stifle Joint - Correlation with Humans

Abstract

The gross anatomy and physiology of the knee are similar in people, dogs and horses. However, evolution, way of life and the use of horses and dogs means that the detailed anatomy, physiology and disease processes have altered with time. In dogs, cranial cruciate ligament injury (30%), degenerative joint disease (17%) and patellar ligament injury (17%) are the most frequently encountered disease processes, while in horses, osteochondrosis and subchondral cysts (52%), medial collateral ligament injury (28%), patellar ligament injury (23%), degenerative joint disease (23%) and medial meniscus lesions (19%) are more frequently reported. In addition the technological possibilities and the cooperation of the patient are different between human and veterinary medicine. In people, ultrasonography of the knee is easy to perform and gives lots of information, but it has inferior diagnostic capabilities compared to MRI. In dogs, the small size of the joint and large variation between breeds are responsible for the limited use of knee ultrasonography. In horses, ultrasonography of the knee is risky and time-consuming but is currently the only practical alternative to radiography. There is a lack of ultrasonographic reference values in the dog and horse compared to people. Veterinary radiologists have to define normal variants and reference values in young and adult animals to improve the objectivity, and thus the quality, of knee ultrasonography.