Appearance of the sacroiliac joint in ventrodorsal radiographs of the normal canine pelvis

Radiology of the canine sacroiliac (SI) joint was investigated by obtaining ventrodorsal radiographs of cadaveric pelves and bone specimens (n = 40) marked with solder wire or radiopaque paint to demonstrate the orientation of the sacroiliac joint in various radiographic views. In the following retrospective radiographic study (n = 94 survey sacroiliac joint radiographs), central projections of the sacrum were noted to ease identification of the dorsal, middle and ventral joint components, whereas angled projections of the sacrum had advantages when assessing the cranial joint components. Radiographic assessment was already successful in juvenile dogs older than 5 months. Failure in tracing the outlines of the joint space of the sacroiliac joints is not consistent with alteration of the SI joint. Rather, it was felt that alterations would have assisted in identifying the contours of the SI joints because of an increase in mineralization.