VASCULAR CHANGES IN THE FEMUR AND TIBIA OF CORTISONE-TREATED RABBITS: A MICROANGIOGRAPHIC STUDY

Abstract

The development of avascular necrosis of the femoral head is associated with high-dose cortisone therapy. To study the effect of high-dose cortisone therapy on blood supply of the femoral head, the diaphysis of the femur, tibia, kidney, and liver, microangiography was performed in 24 steroid-treated adult Japanese white rabbits. Weekly doses of 2.5 mg/kg of methylprednisolone acetate were given. Rabbits were killed after 2 and 4 days, and 1, 2, 4 and 6 weeks. Vascular changes were observed on X-ray films after microangiography and decalcification of bone. Five rabbits of the control group received no drugs.
The nutrient arteries of the femoral head, femur and tibia were not stained extensively from proximal thick vessels to distal small vessels of capillary size at 2 to 4 weeks. Formation of numerous small arteries was seen at that time. At 6 weeks, nutrient arteries had formed again, and the vascular pattern was normalized. These findings were also observed in the kidney and liver. These results suggest that the blood supply by nutrient arteries was impaired owing to the effect of high-dose cortisone. Similar changes were observed in the kidney and liver. Vascular impairment probably occurs systemically and might produce bone ischemic changes leading to avascular necrosis.