Abstract
Lesions of the patellar ligament (PL), most commonly deriving from direct trauma, are rare in dogs. The resulting injury can be a complete or partial laceration depending on the quantity of torn colla-gen fibers. Information obtained from imaging evaluation is of great value to the clinical approach towards PL injuries because subsequent treatment options are affected by the distinction between complete or partial tears. Imaging diagnosis of PL damage in veterinary practice commonly relies on radiographic examination through the recognition of indirect signs such as “patella alta”, bone frag-ments at the level of patellar or tibial insertion and a soft tissue opacity at cranial aspect of the joint. In humans patients, ultrasound and magnetic resonance imaging have been described as useful di-agnostic tools for the assessment of normal and pathologic ligaments. In particular these techniques provide more detailed information on partial PL tears compared to radiographs and computed to-mography. Unfortunately, specific comparative data regarding the evaluation of PL rupture in dogs with different imaging modalities is lacking in veterinary literature. This paper, aims, therefore, to describe and compare the radiographic, ultrasonographic, CT and MRI imaging findings of partial PL tear in a dog and discuss the role of these techniques in the diagnostic utility of this condition.

Key words: Key words: Patellar ligament, dog, ultrasound, computed tomography, magnetic resonance imaging.