ABSTRACT
BACKGROUND: In lumbar spondylolisthesis patients with severe osteoporosis, screw is easily loose and pul s out during reposition, or loss of reduction and internal fixation failure easily occur after repair. Therefore, it is very important to elevate the intensity of pedicle screw fixation during repair. At present, few studies concern application of bone cement screw enhancement technology in lumbar spondylolisthesis patients with osteoporosis. OBJECTIVE: To investigate the clinical value of augmented pedicle screw with polymethylmethacrylate for lumbar spondylolisthesis accompanied with osteoporosis. METHODS: From June 2009 to June 2011, 27 patients suffering from lumbar spondylolisthesis accompanied with osteoporosis were included in this retrospective study. These patients received augmented pedicle screw with polymethylmethacrylate. The levels of disability and pain were evaluated by Oswestry Disability Index and visual analog scale. The internal fixation and fusion were evaluated by radiological findings. Al complications were recorded. RESULTS AND CONCLUSION: Al cases were fol owed up for 15-37 months. Oswestry Disability Index and visual analog scale scores were significantly better in final fol ow-up than that pre-treatment (P < 0.05). Imaging results revealed that bone cement tightly connected to bone interface. The position of screw and bone cement was good. Symptomatic bone cement leakage was not found. No fixation failure was detected during final fol ow-up. Al patients achieved interbody fusion. These results suggested that polymethylmethacrylate bone cement could increase the gripping force of the pedicle screw in osteoporotic vertebral body. It is safe and effective to treat spondylolisthesis accompanied with osteoporosis with augmented pedicle screws. Satisfactory fixation stability and interbody fusion can be obtained.
ABSTRACT
[Objective]To investigate the compatibility of tissue and cell in the three-dimensional porous bioactive glass/recombine human Bone Morphogenetic Protein-2 (BG /rhBMP2)materialscaffolds and provide a reference for improving the constitution of composite material.[Method]The material of BG and BG/rhBMP2 were cultured in vitro with rabbit osteoblasts respectively. The morphology and adhesion were examined by inverted microscope and scanning electron microscope, and the cell proliferation was detected by MTT assay. The composite materialscaffold were embeded in rabbit's muscle and incisions were observed. The specimens were harvested in 2, 4, 8 and 12 weeks respectively and examined by histology to evaluate the tissue response.[Result]The results showed the cells on BG and BG /rhBMP2 were good adhension and activity, the two materialscaffolds had no apparent inflammatory reaction in vivo. MTT assay showed the number of the cells in each group were significantly increased along with the culture time prolonged. The number of cells in the BG and rhBMP2 group was higher than that of the control group at different intervals, with a significant difference. The number of cells in the BG/rhBMP2 was not evidently higher than that of the BG with a significant difference.[Conclusion]The porous composite materialscaffold of BG/rhBMP2 has good biocompatibility with the hope to wide use in bone tissue engineering.
ABSTRACT
Objective To investigate the growth of rabbit osteoblast on the composite bioactive glass material scaffolds and to explore the experimental methods of optimized material scaffolds in bone tissue engineering. Methods The mesenchymal stem cells(MSCs) were separated and cultured from rabbit thigh marrow,and they were induced and differentiated into osteoblast by the revulsant.The change of typical appearance of the MSCs was investigated under microscope.The cytological characteristics of the MSCs were observed through cells activity and immunohistochemistry method.The osteoblast was cocultured with three various bioactive glasses respectively.The compatibility between the various bioactive glasses and osteoblast was compared by observation of the changes of the cells.Results The MSCs were successfully induced and cultured in the presence of the osteoblast revulsant.After inducement,these cells displayed osteoblast-like morphology.The bioactive glass composite scaffolds supported the attachment of cultured rabbit osteoblast.These cells proliferated faster on scaffolds with higher poriness of 90.20% and 94.50% than with lower poriness of 75.90%.Conclusion It is feasible to use bioactive glass composite scaffolds with proper poriness for bone tissue engineering.