Model of steroid-induced avascular necrosis of the femoral head:Analysis of different construction techniques

ABSTRACT

BACKGROUND:

To construct a normal animal model of femoral head necrosis contributes to the research of the pathogenesis of femoral head necrosis, which can provide theoretical basis for the prevention and treatment of femoral head necrosis.

Thirty-six New Zealand white rabbits were randomly divided into model group (n=21) and control group (n=15). The rabbits in the model group were injected with 10μg/kg lipopolysaccharide daily and continuous for 2 days, and then injected with 25 mg/kg dexamethasone daily for 3 days continuously. The rabbits in the control group were injected with the normal saline at the same volume. RESULTS AND

After 4 weeks, the X-ray film of the rabbit in the model group showed the joint gaps were widened, the density was increased, the articular subchondral bone mineral density was increased, the femoral head was flat, trabecular bone was fuzzy, the boundaries between subchondral bone and cancel ous bone was unclear, and the patchy high-density areas were observed in the femoral head with shortened femoral neck. The bone mineral density of partial femoral head was measured with dual-energy X-ray absorptiometry, and found that the bone mineral density of femoral head and the bone mineral content of the model group were significantly lower than those of the control group (P<0.05). Histological section observation showed that the bone cel lacuna was empty and shal ow, fat cel s were increased and vascular thrombosis was observed, meanwhile, the osteonecrosis rate and lacunae rate of the survival animals were significantly higher than those in the control group. Dexamethasone combined with lipopolysaccharide can effectively construct the model of steroid-induced avascular necrosis of the femoral head.