Radiographic and ultrasonographic examinations of the horse’s stifle, in presence of flattening of the lateral trochlear ridge and effusion of articular compartments: the effect of the X-ray tube positioning in the detection of flattening in the lateromedial view variations and effect of agonistic effort in highlighting subtle ultrasonographic findings

Different radiographic projections for views considered as lateromedial were examined and divided in groups. Using a method based in the Pythagorean Theorem, the distance between lateral and medial femoral condyles borders was calculated and then proportionally corrected to the diaphyseal thickness. Five categories for each axis were created and compared. Results show that radiographs with an X-Ray tube positioning within the ±5% from an exact lateromedial view in the X Axis, are statistically more effective to reveal flattenings (p<0.05).Synovial effusion is a sign of synovitis and even though it can be accompanied by pain, in sound horses can be present also. Ultrasonographic measurements were carried on the medial femorotibial recess and lateral femoropatellar recess of sound horses used in competition to see if the ultrasound scan could reveal an influence of the size of these recesses in presence or absence of subtle lesions. Two different gallop activities were compared. In racetrack gallop flat racers, the side with most biomechanical stress (inner circle) showed to have larger measurements in the presence of subtle lesions (p<0.05) for the right lateral femoropatellar recess.When comparing two isolated populations of horses radiographically, sBs and Sardinian horses, no statistical differences were found between the presence or absence of lateral trochlear ridge flattenings in the lateral femoral ridge in the present study (p>0.05).