Assessment of Femoral Trochlear Groove Depth in Canine Cadavers with Normal Stifle Joints Using Ultrasonography with the Joint Positioned at 45°, 90°, and Hyperextension, and Radiography in the Skyline Projection

This prospective, analytical study aimed to measure and compare trochlear groove depth using skyline radiographic projection and ultrasonography at three stifle joint angles and four distinct anatomical regions, as well as to compare these findings with ex vivo measurements obtained using a caliper under the same conditions in canine cadavers without patellar luxation. A total of 67 limbs were evaluated. Ultrasonography demonstrated greater agreement with ex vivo measurements than radiography. Ultrasonographic assessment was considered appropriate for measuring trochlear groove depth with the stifle joint in maximal extension, with the transducer positioned distal to the patella, and at 90° of flexion, with the transducer positioned proximal to the patella.