Unfortunately, the filly remained lame after 30 days of stall rest and a follow-up exam included an ultrasound evaluation of the stifle joint. The ultrasound exam revealed significant changes along the lateral trochlear ridge which were not fully appreciated on the radiographic exam. In Figure 3, the lateral and medial trochlear ridge are displayed. The bony surfaces of the trochlear ridges appear as a bright white lines and the cartilage as thin black lines that follow the contour of the bony surface. Any disruption of the bony surface/cartilage will appear as a mix of disrupted white lines and black pockets. In Figure 3, the image on the left is of the lateral trochlear ridge and there is clearly disrupted bone and cartilage along the bony surface.