Objective　To monitor KBD prevalence rate in Changdu of Tibet.Methods　The aged 7～12 year children are tested with X- ray and epidemiological investigation.Results　Xizang are still high yet,the 3 of 4 porints X-rates are more than 20% and the highest one is 55.34%.Conclusions　The Changdu is the severest point of KBD in our country.

Objective To explore the effects of flavonoids of Rhizoma Drynariae on the formation of blood vessels in the induced membrane by Masquelet technique. Methods Seventy-two SD rats were randomly divided into 4 groups,namely model group,and high-,middle-and low-dose drug groups,18 rats in each group. Rat model of critical- sized femoral defect was built,and then polymethyl methacrylate (PMMA)bone cement spacer was inserted into the bone defect to induce the formation of membrane. From the first day after surgery , the rats in high-,middle-and low-dose drug groups were given gastric gavage of 0.44,0.22,0.11 g·kg-1·d-1 of Rhizoma Drynariae flavonoids, respectively, and the rats in the model group were given the same volume of normal saline. After 6-week medication,the pathologic features of bone cement- induced membrane were observed by Haematoxilin-Eosin(HE)staining,the contents of transforming growth factor(TGF)-β1 and vascular endothelial growth factor(VEGF)proteins in the induced membrane were tested by enzyme-linked immunosorbent assay (ELISA),and the mRNA levels of TGF-β1 and VEGF in the induced membrane were determined by real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Results More blood vessels in the induced membrane of the high-dose group were found than those of the other groups under the light microscope. The protein and mRNA expression levels of TGF-β1 and VEGF in the induced membrane of the 3 drug groups were much higher than those of the model group(P < 0.05). Except for the VEGF mRNA expression level, the changes of other indexes were dose-dependent. Conclusion Flavonoids of Rhizoma Drynariae are effective on enhancing the protein and mRNA expression levels of TGF-β1 and VEGF in the induced membrane, and can accelerate the vascularization,which promotes the reconstruction of bone defect.

Treatment of large bone defects caused by trauma, osteomyelitis, and tumors has been a major challenge in clinical. In the past, there have been many ways to repair and reconstruct the large bone defects. However, there is a long period of treatment, high technical requirement and complications such as ununion. After Masquelet reported the induced membrane technology in 2000, the technique was widely used in treatment of trauma, osteomyelitis, and large bone defects caused by tumors. It has been obtained good results. It has the advantages of short course, high healing rate, easy operation and easy to master. The induced membrane has unique structural characteristics and biological characteristics. There are many kinds of osteogenic factors that are included in the membrane, such as vascular endothelial growth factor, and morphogenetic protein-2, transforming growth factor-β1, etc. These osteogenic factors contribute to accelerate bone healing. With the development of induced membrane technology. The technology of Reamer Irrigator Aspirator technology, engineering tissue technology and internal fixation is used in clinic.It can provide bone source, promote bone defect reconstruction, improve long-term limb function and reduce complications.This paper retrospectively summarizes the experimental research and clinical progress of Masquelet technique in the treatment of large bone defects.