Int J Med Sci 2012; 9(9):816-824. doi:10.7150/ijms.4882

Research Paper

Development of a Clinically Relevant Animal Model for the Talar Osteonecrosis in Sheep

Chao-Fan Yuan1,*, Jun-Lin Wang2,*, Yong-Quan Zhang1, Xiao-Kang Li1, Yi Li1, Su-Hua Wu1, Zhi-Yong Zhang3✉, Zheng Guo1✉

1. Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi'an, China;
2. School of Stomatology, Fourth Military Medical University, Xi'an, China;
3. Department of Plastic and Reconstructive Surgery, Shanghai 9th People's Hospital, Shanghai Key Laboratory of Tissue Engineering, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
* The authors have contributed equally to this paper as co-first authors for this article.

This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) License. See for full terms and conditions.
Yuan CF, Wang JL, Zhang YQ, Li XK, Li Y, Wu SH, Zhang ZY, Guo Z. Development of a Clinically Relevant Animal Model for the Talar Osteonecrosis in Sheep. Int J Med Sci 2012; 9(9):816-824. doi:10.7150/ijms.4882. Available from

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There are a lot of reports and reviews about osteonecrosis of the talus (ONT), yet reports about the animal model of ONT to evaluate proper therapeutic approaches are rarely heard. In our study, a novel animal model was established. Pure ethanol was injected into the cancellous bone of sheep's talus. Macroscopic observation, X-ray, CT and histology were performed at two, four, 12 and 24 weeks postoperatively. It was revealed that the trabeculae of talar head began to change their structure after two weeks postoperatively compared to the normal talus. The ONT was obvious at the end of the fourth week, and their outstanding feature was the damage of trabeculae bone and formation of cavities. CT scans and pathological changes of the subjects all showed characteristics of the early stage of osteonecrosis, also the sections of the specimens confirmed necrosis of tali. By 12 weeks, the phenomenon of necrosis still existed but fibrous tissue proliferated prominently and bone reconstruction appeared in certain area. Most specimens (3/4) got late stage necrosis which presented as synarthrosis in X-ray and mass proliferation of fibrous tissue in histology at the end of 24 weeks. The novel animal model of ONT was successful, and it is inclined to deteriorate without any intervention. The study provides us a new way to evaluate various treatments on ONT in laboratory, which may eventually pave way to clinical applications.

Keywords: Animal model, Osteonecrosis of the talus, Ethanol, Injection.