An animal model of femoral head osteonecrosis induced by a single injection of absolute alcohol: An experimental study

BACKGROUND The lack of an experimental animal model that can reliably mimic all stages of osteonecrosis of the femoral head has hindered progress toward the successful prevention and treatment of the disease. MATERIAL/METHODS A goat model of osteonecrosis of the femoral head (ONFH) was established and observed from the early to the intermediate-to-late stage of mechanical failure. Absolute alcohol was injected slowly into the center of bilateral femoral heads in 12 adult Small Tail Han goats. Postoperatively, the femoral heads were harvested and examined using macrostructural and histological analyses and radiographic and MRI examinations at weeks 4, 8, 12, and 25. RESULTS Macrostructural and radiographic examinations revealed that the contour of both femoral heads was deformed slightly at 12 weeks, but a contour deformation with joint space narrowing was observed at 25 weeks. Histologically, a strong concordance with the natural history of ONFH in humans was found. The present model demonstrated bone trabeculae, marrow necrosis, a reconstruction deficiency and destruction of the microcirculation. CONCLUSIONS Among quadrupedal models, the goat model of ONFH, which is induced by a single injection of absolute alcohol, may be suitable and valuable for the evaluation of various therapeutics and side effects in the treatment of ONFH.