Fracture of the ischium in an eight‐year‐old Arabian gelding: A diagnostic challenge

Abstract

Summary Proximal hindlimb lameness remains a diagnostic challenge despite modern imaging techniques. In the case described here, a fracture of the ischium produced false negative results on initial ultrasound and scintigraphy examinations, despite a 14 day delay from onset of clinical signs to the time of the nuclear bone scan. However, the history and clinical examination were strongly suggestive of a pelvic injury and this was only confirmed by the use of a novel radiographic technique. False negative findings from diagnostic imaging can, and do, occur, even with high sensitivity techniques such as nuclear bone scans used after an appropriate delay period. Therefore, equal weighting should be given to all facets of a lameness investigation, including the history and clinical examination, while remembering the limitations of any imaging modalities used.

Effect of displaced versus non‐displaced pelvic fractures on long‐term racing performance in 31Thoroughbred racehorses

“…16 Fracture displacement or callus formation can be observed using ultrasound, in the majority of cases, whereas nondisplaced fractures are difficult to identify. [17][18][19] Therefore, the combination of scintigraphy and ultrasound enabled diagnosis in most cases of pelvic fracture in this study. Standing radiography of the pelvis was used in this study to determine coxofemoral joint involvement in some cases, because of the difficulty of assessing acetabular involvement using ultrasound alone.…”

“…Scintigraphy is commonly used to identify pelvic fractures, but it is rarely possible to determine if a fracture is displaced using this technique . Fracture displacement or callus formation can be observed using ultrasound, in the majority of cases, whereas non‐displaced fractures are difficult to identify . Therefore, the combination of scintigraphy and ultrasound enabled diagnosis in most cases of pelvic fracture in this study.…”

Imaging begins with a physical examination

“…In the paper, Fracture of the ischium in an eight-year-old Arabian gelding: A diagnostic challenge (Driver and Nagy 2008), the authors bring attention to the difficulties faced by equine clinicians trying to diagnose the cause of lameness in the axial skeleton of the horse. Nuclear scintigraphy remains the most common imaging modality used when searching for the cause of lameness in the back, pelvis or hips.…”

“…The novel transrectal radiographic technique was not performed because the horse was a yearling. The sacrum and the tuber sacrale are much more superficial structures and therefore appear much blacker than normal because the contrast has been enhanced to see the IRU in the deeper structures of the coxofemoral joint. As noted by Driver and Nagy (2008), the diagnosis of fractures in this region can be very difficult . Fig 1: Photograph of a horse with severe atrophy of the muscles on the right side of the pelvis.…”

“…In the paper by Driver and Nagy (2008), the authors chose nuclear scintigraphy in light of a history consistent with an acute fracture. However, when there was no focal IRU normally associated with an acute fracture, the authors were forced to rethink their approach.…”