Objective To discuss the etiology, cl inical manifestation, imaging, staging, and treatment of bone necrosis of the second metatarsal head, the navicular bone, and the talus so as to provide more information for cl inical appl ication. Methods The related home and abroad l iterature concerning bone necrosis of the second metatarsal head, the navicular bone, and the talus in recent years was reviewed extensively. And the cl inical manifestation, imaging, staging, and treatment were summarized and analyzed. Results Bone necrosis of the second metatarsal head, the navicular bone, and thetalus were more closely related to the particular anatomy; the environmental and genetic factors also lead to such diseases. The cl inical presentation was typically local pain and swell ing around the joint, frequently with restricted joint motion in severe cases. Both radiographs and MRI were used to be the main criteria for diagnosis and staging of these diseases. According to different phases, conservative therapy was effective in treating osteonecrosis at early stage. While surgical treatments such as osteotomy, fixation, and arthrodesis were used in late-stage bone necrosis. Conclusion The current methods of treatment have achieved good effect, but long-term cl inical follow-up is needed and the new surgery should be further studied.
Objective To discuss the method of constructingbiomechanical model of rabbit femur.Methods The sample of rabbit femur was prepared as follows:firstly，femur section images were obtained，then the image wasput into the computer and processed to get the boundary contour line; secondly, through programming the contour line coordinate for modeling was obtained, then the data were put into the model software to find the threedimensional entity model. Results Whole three-dimensional model of rabbit femur was constructed. It simulated actually dissection form of femur. Conclusion The establishment of the model lays a foundation for ascertaining optimal parameter of vibration improving bone minerydensity by finite element analysis.