INNOVATIVE IMAGING TECHNIQUES TO ENHANCE THE QUALITY OF YOUR PRACTICE
Fig. 2. A, the affected hindlimb is placed on a hoof jack or block to flex the stifle to 90°. B, in this position, the operator can easily image the femoral condyle and assess the best trajectory for needle entry to the SBC. Note the SBC is visible on the ultrasound screen.
the MFC becomes more superficial and can be easily evaluated using standard linear transduc- ers (Fig. 3). To obtain a parasagittal image, the transducer is placed in long axis, proximal to the tibial crest and axial to the middle patellar liga- ment. The ultrasound transducer is directed ap- proximately 45° in a craniodistal to caudoproximal direction to image the medial condyle and SBC. The probe is then rotated 90° to obtain transverse images of the condyle and the SBC. The femoral condyle is more rounded in the transverse plane
than the parasagittal plane. In a normal MFC, the articular margin is a smooth, convex bone surface with a thin layer of overlying anechoic cartilage. The SBC is often a concave disruption of this smooth contour and may be associated with thickening of the cartilage layer around the cloaca (Fig. 4). By obtaining images in 2 planes, it is possible to judge the contour and size of the cloaca and articular surface. This allows the formation of a plan for needle trajectory, saving valuable time in the surgically prepared patient.
Fig. 3. A, in the standing position, the weight-bearing medial condyle is not accessible to ultrasound imaging (arrow). B, by flexing the stifle joint 90°, the medial condyle becomes superficial and easily identifiable on ultrasound examination (arrow).
