THE INTRAOSSEOUS BLOOD-SUPPLY OF THE CANINE RADIUS - IMPLICATIONS FORHEALING OF DISTAL FRACTURES IN SMALL DOGS

The intraosseous vascular anatomy of the radius was studied in 12 pair s of canine cadaver Limbs. Six pairs of specimens were obtained from s mall-breed dogs (less than 6 kg) and six pairs were obtained from larg e-breed dogs (Is to 30 kg). All specimens were studied after arterial injection with India ink. Samples were fixed, frozen, then sectioned a nd processed using a modified Spalteholz technique. In all specimens, the intraosseous blood supply arose from the nutrient artery with its associated branches and the metaphyseal arteries. In small-breed dogs, there was decreased vascular density at the distal diaphyseal-metaphy seal junction compared with large-breed dogs. The reduced vascularity corresponded to the region associated with a poor prognosis for fractu re healing in small-breed dogs. This regional association suggests tha t a decreased vascular supply in the distal radius may contribute to a higher frequency of delayed union and nonunion in smaller dogs. (C) C opyright 1997 by The American College of Veterinary Surgeons