Ectopic osteogenesis and scaffold biodegradation of tissue engineering bone composed of chitosan and osteo-induced bone marrow mesenchymal stem cells in vivo / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Chitosan (CS) scaffolds combined with osteogenically induced bone marrow mesenchymal stem cells (BMSCs) have been proved to be promising substitutes for repairing bone defects. Nevertheless, the bone-forming and scaffold-biodegrading processes are seldom studied. This study aimed to determine the osteogenic ability of CS/osteo-induced BMSC composites by observing the bone-forming process and explore the relationship between bone formation and scaffold biodegradation.</p><p><b>METHODS</b>The CS/osteo-induced BMSC composites (CS+cells group) and the CS scaffolds (CS group) were, respectively, implanted into SD rat thigh muscles. At 2, 4, 6, 8, and 12 weeks postoperatively, the rat femurs were scanned by CT, and the CT values of the implants were measured and comparatively analyzed. Subsequently, the implants were harvested and stained with hematoxylin and eosin and Masson trichrome, and the percentages of bone area, scaffold area, and collagen area were calculated and compared between the two groups.</p><p><b>RESULTS</b>The imaging results showed that the densities of implants of the two groups gradually increased along with time, but the CT values of implants in the CS+cells group were much higher than in the CS group at the same time point (P < 0.05). The histological results showed that the de novo bone and collagen formed in the pores of the scaffolds and gradually increased since 2 weeks postoperation in both groups, and the scaffold gradually degraded along with the boneforming process. However, the comparative analysis results showed that the CS+cells group gained more de novo bone and collagen formation and had less scaffold than the CS group at the same time point (P < 0.05).</p><p><b>CONCLUSION</b>The CS/osteo-induced BMSC composites are excellent bone tissue engineering substitutes, and the scaffold biodegradation is accordant with the bone formation.</p>

Proximal femoral anatomical locking plate for treatment of ipsilateral femoral shaft and neck fractures / 中华创伤杂志

ObjectiveTo study the clinical effect of the proximal femoral anatomical locking plate in the treatment of ipsilateral femoral shaft and neck fractures.Methods A retrospective study was done on 10 patients with ipsilateral femoral shaft and neck fractures treated with proximal femoral anatomical locking plate in our hospital from February 2009 to February 2011.After treatment,the outcome was assessed regularly by fracture union as was seen on serial radiographs and clinical function was estimated by Friedman and Vyman System.ResultsAll patients were followed up for 6-24 months ( average 16 months).All the fractures were healed within 2.5-4 months (average 3 months) in the femoral shaft and within 4-9 months (average 6 months) in the neck,respectively.According to Friedman and Vyman System,the overall clinical result was good in eight patients and fair in two,with excellent rate of 80％ (8/10).No osteonecrosis of the femoral head and fixation failure were observed during the followup. Conclusion Proximal femoral anatomical locking plate internal fixation is an effective treatment method for ipsilateral femoral shaft and neck fractures.