Fig. 8. There are prominent abnormalities affecting the articular process joint or joints at C6–7 on the lateral radiograph of this horse (A, arrowheads). However, it is not clear whether the findings noted on the lateral view are affecting the left and/or right articular processes. B, C, On the corresponding oblique projections, the osseous remodeling is noted to be markedly more pronounced in left articular processes more than the right. A component of the proliferation represents enthesopathy at the joint capsule attachments and/or fascial plane attachments away from the periarticular margins (B and C, black arrows). Arthrosis of the articular process joints is identified as osteophytosis along the margins on the oblique views (B and C, white arrows) that changes the normal shape of the joint margins. Also identified in this case are changes affecting the subchondral and trabecular bone of the articular process joints. The subchondral bone margins of the articular processes are undulating, with trabecular bone sclerosis (asterisk) present in the caudal facet of the C6 vertebra overlying a region of subchondral bone loss. In comparison, the horse in image D has normal periarticular margins.
