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Objective To investigate the preliminary clinical result of thoracolumbar fracture combined with posterior ligamentous complex injuries repaired by posterior transpedicular screw fixation.Methods A retrospective review was performed on 22 patients with thoracolumbar flexion-distraction fracture combined with posterior ligamentous complex injuries treated with transpedicular screw fixation from July 2008 to March 2013.There were 16 males and 6 females with mean age of 39 years (range,23-62 years).After medically stable,posterior pedicle screw fixation was performed under intravenousinhalational anesthesia.According to the degree of fracture displacement and types of ligament injury,posterolateral bone grafting or intervertebral fusion at the level of injury was conducted.Vertebral height restoration,Cobb' s angle and American Spinal Injury Association (ASIA) score were reviewed preoperatively,at postoperative 3 days and at the last follow-up.Results All the patients were operated on smoothly.There were no complications during operation.All the patients were followed up for 5-51 months (mean,26.5 months).Fracture reductions were satisfied with the closure of vertebral posterior element.Mean anterior vertebral height and Cobb' s angle improved by 20.6％ and 10.60°respectively after operation (P ＜0.01).Eight patients with neurological dysfunction showed some recovery after operation with the mean sensory score improved by 20.7％ (P ＜ 0.05) and mean motor function score improved by 30.9％ (P ＜ 0.0l).All bone grafts were healed,without pain,loosening or breakage in the fixation system.Conclusions Posterior pedicular screw fixation attains good short-term outcome for thoracolumbar flexion-distraction fracture combined with posterior ligamentous complex injuries.The surgery provides satisfactory reduction and instant spinal three-column stability for the unstable spine fracture.Sufficient bone graft is the guarantee to permanent stability.
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Objective To assess the effect of bone defect repair using the recombinant of adenovirus-mediated hBMP2 and hVEGF165 genes transfer of BMSCs with porous nano-hydroxyapatite/polyamide 66 (n-HA/PA66).Methods Sixty male adult New Zealand rabbits were assigned to groups A,B and C according the completely random design,with 20 rabbits per group.Bone defect of 15 mm in length was made in the middle segment of bilateral radii in rabbits.In Group A,the defects were filled with nothing on the left side in blank controls (Group A1) and with n-HA/PA66 material alone on the right side (Group A2).In Group B,the defects were filled with hVEGF165/BMSCs/n-HA/PA66 on the left side (Group B1) and hBMP2/BMSCs/n-HA/PA66 on the right side (Group B2).In Group C,the defects were filled with BMSCs/n-HA/PA66 on the left side (Group C1) and hBMP2/hVEGF165/BMSCs/n-HA/PA66 on the right side (Group C2).Radiological analysis,HE staining,and Masson coloration were performed 2,4,8 and 12 weeks after operation.Results Radiographs,HE staining and Masson staining taken 8 weeks after cell transplantation showed large amount of new cartilage grown into the defect area and massive bony tissue formation around the margin in Group C2.At postoperative 12 weeks,Group C2 showed transplants were surrounded by outer bone tissues with superior bone repair effect to other groups (P ＜ 0.05).Number of vessels in Group C2 increased compared with that in other groups (P ＜ 0.05).Number of vessels was greater in Group B1 than in Group B2 (P ＜ 0.05),and both were greater than those in Groups A2 and C1 (P ＜ 0.05).Moreover there was no significant difference between Groups A2 and C1 (P ＞0.05).Conclusion hBMP2/hVEGF165 genes transferred BMSCs seeded on porous n-HA/PA66 can contribute to osteogenesis during the repair of rabbit radius defect.
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BACKGROUND:Bone marrow mesenchymal stem cells are considered as commonly used seed cells to construct tissue-engineered for repair of bone and cartilage defects. It is of great significance for cytology and tissue engineering experiments to study the common problems existing in the basic operation and how to avoid these problems in a timely manner. OBJECTIVE:To summarize the common problems existing in the process of operation in order to provide reliable methods about separation, culture and identification of bone marrow mesenchymal stem cells for beginners and researchers. These can reduce or avoid some errors and problems during operation. METHODS:Sixteen New Zealand white rabbits were selected as experiment objects, and bone marrow mesenchymal stem cells were separated from rabbits by iliac puncture, purified and augmented by using density gradient centrifugation combined with adherent culture method. Then cellmorphology was observed by inverted phase contrast microscope, growth curve detected by MTT method and cellphenotype identified by flow cytometry. RESULTS AND CONCLUSION:We encountered some problems in the process of separation and culture, when we operated the first five rabbits. After careful y summarizing and analysis of the reasons, the operation was successful y completed on the rest 11 rabbits. Bacteria pol ution and cellaging were not found in the process of cellculture. What is more, the cells at passage 3 appeared with high-expression of CD29, and CD44, but low expression of CD14 and CD34. The cellgrowth curve showed that the proliferation activity of cells at passages 3 and 5 was higher than that at passage 10. Although the technology of separation, culture and identification of bone marrow mesenchymal stem cells is mature, the failure wil be happen if we do not pay attention to the details of operation. By strictly carrying out normal operations, we can get high purity of bone marrow mesenchymal stem cells, which lays a good foundation for celland animal experiments in the future.
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ObjectiveTo employ the vascular endothelial growth factor (VEGF165) gene transfected rabbbit osteoplast to combine with the porous nano-hydrxyapatite crystal (n-HA)/polyam ide 66(/PA66) so as to evaluate the osteogenesis and rapid revascularization early after repair of the rabbit radius bone defects with the tissue-engineered bone (n-HA/PA66/osteoplast/VEGF165).MethodsThe animal models of bilateral radius bone defects were created in 56 New Zealand white rabbits that were then randomly divided into Group A and Group B.In Group A, the animals were implanted with n-HA/PA66on the left bone defects (Group Al) and with n-HA/PA66/VEGF165 composite materials on the right bone defects (Group A2). In Group B, the animals were implanted with n-HA/PA66/osteoplast/VEGF165 composite materials on the left side (Group B1) and with n-HA/PA66/osteoplast on the right side (Group B2).Gross, digital radiography, histological sections, vessel count and scanning electron microscopy (SEM) were performed at 2, 4, 8 and 12 weeks after operation.ResultsThe osteogenesis and revascularization in Group B1 was superior to that in the other groups at each time point, with statistical difference (P ＜0.05).The revascularization and osteogenesis in Groups B1 and B2 was far better than that in Groups A1 and A2, with no statistical difference between Group A1 and Group A2.ConclusionsThe new tissue-engineered bone (n-HA/PA66/osteoplast/VEGF165) has a perfect osteogenetic effect and can promote rapid revascularization and the bone healing in the early stage after repair of the bone defects.