ABSTRACT
Tibial fracture is one of the most commonly encountered fractures in small animals that requires particular attention and care. Bone pins were made from bovine long bones treated by 3% hydrogen peroxide and sterilized by ethylene oxide. Ten mixed breed dogs were osteotomized at tibial mid shaft under general anesthesia. In 5 dogs the fractures were immobilized by bone pins and in other 5 dogs they were fixed using the conventional metal pins. 50 days after surgery, 883 mg/kg urographin was injected into the femoral artery and radiography was performed during urographin injection. Angiography of the healthy leg was performed simultaneously as a control study. Analysis of data revealed that there was no significant difference in arterial diameter of popliteal, proximal cranial tibial, distal cranial tibial, caudal tibial, cranial branch of saphenous, caudal branch of saphenous, main saphenous and proneal arteries between two groups. There was, however a significant increase [P<0.05] in the diameter of these arteries between each group as compared with the control study. The number of vessels in callus region was not significantly different between the two groups but it was significantly increased in each group as compared with the control study. By intramedullary pinning, the medullary and metaphyseal blood supply impair. However, periosteal and extraosseous blood supplies are the major sources for callus nutrition. Medullary blood supply regenerates parallel to intramedullary pins after 10-28 days postoperatively. After this period, extraosseous and periosteal arteries supply the fracture callus predominantely. This study proved that both bovine bone pins and metal pins had similar influences on extraosseous blood supply