How to Perform Standing Lateral Oblique Radiographs of the Equine Pelvis

Radiography of the equine pelvis is indicated where physical examination or other localizing diagnostic techniques, such as intra-articular analgesia or nuclear scintigraphy, localize an abnormality to that region. Radiography techniques currently employed for diagnosis of pelvic fractures or abnormalities of the coxofemoral joints are ventrodorsal radiographs obtained with the horse under general anesthesia and ventrodorsal radiographs obtained in the standing sedated horse. As well as complications related directly to anesthesia, horses with suspected pelvic fractures may be subject to additional risks when radiographs are obtained under general anesthesia because of the potential for fracture displacement and subsequent lacerations of the internal iliac arteries during the induction or recovery period. A ventrodorsal radiograph, obtained in the standing sedated horse, requires the X-ray machine to be placed ventral to the abdomen and the cassette to be placed dorsal to the sacrum. This technique may potentially create a significant scattered-radiation hazard to involved personnel. It may also present considerable risk to the equipment in fractious horses, because safe handling of the cassette, centering of the X-ray beam, and collimation of the X-ray beam can all be difficult. Recently, the usefulness of standing lateral oblique radiographs of the equine pelvis in the diagnosis of hindlimb lameness has been shown. The purpose of this paper is to describe how to perform this technique safely in practice and to highlight the clinical situations in which it may be useful.