Rib fracture as a cause of hindlimb lameness in a horse

Abstract

A 2-year-old racing Thoroughbred gelding in training was presented with moderate (6/10) right hindlimb lameness unresponsive to regional anaesthesia of the right hind limb. Gamma scintigraphic examination revealed severe, focal, increased radio-pharmaceutical uptake over the dorsal aspect of the right 18th rib, which had an abnormal contour. Ultrasonographic examination of this area confirmed the presence of a complete, displaced fracture of the proximal aspect of the right 18th rib. Local infiltration with local anaesthetic around the 18th right rib (10ml cranial and 10ml caudal to the fracture site) abolished the right hindlimb lameness. A diagnosis of rib fracture causing moderate ipsilateral hindlimb lameness was made. The horse returned to walking exercise after 12 weeks of rest and was reported to be sound on the same limb 12 months after presentation. Caudal rib fractures should be considered as possible cause of hind limb lameness. Local diagnostic anaesthesia around the fracture site can aid localise the origin of lameness.