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Objective Exploring the effect of spinal cord decellularized scaffold on spinal cord defects and observing the behavior and regeneration of rats after operation. Methods The spinal cords of 30 SD rats were treated with 3% Triton X-100 and 2% sodium deoxycholate on oscillator. The cell residue and the spatial structure of the tissue were compared before and after treatment, in order to understand the tissue structure of the stent itself. 90 SD rats were randomly divided into control group, simple injury group and stent transplantation group. Excision of the spinal cord 9-10 segments in the simple injury group and the stent graft group the acellular scaffold was transplanted to the stent graft group. Behavioral scores were observed postoperatively. At 4, 8, and 12 weeks, the spinal cords of the injured part of the rats were taken for HE staining and immunofluorescence detection of nerve regeneration-related proteins. Results After decellularization of the spinal cord, the nerve cells and axons were completely removed, and the extracellular matrix of the spinal cord was preserved. Scanning electron microscopy revealed that the scaffold retained a certain porous network scaffold structure. In the experiment of decellularized scaffold in vivo, the Basso-Beattie-Bresnahan(BBB) score showed that the recovery of hindlimb motor function in rats with decellularized scaffolds was better than that in rats with simple injury. HE staining showed that the decellularized scaffold could fill the defect of the spinal cord segment and accelerate the repair process of the injured spinal cord. Immunofluorescence showed that there was a certain axonal regeneration in the injured part of the stent transplantation group. Conclusion The spinal cord decellularized scaffold retains the extracellular matrix and has a certain spatial structure, which can accelerate the process of spinal cord defect repair to a certain extent, and has a certain promoting effect on nerve regeneration.
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<p><b>OBJECTIVE</b>To analyze the causes of delayed union or nonunion of the ulna after intramedullary nailing in pediatric forearm fractures.</p><p><b>METHODS</b>From February 2005 to February 2010,5 patients with forearm fractures who were treated with titanium elastic nailing (TEN) were identified to fulfill the criteria of having developed a delayed union or nonunion of the ulna. The causes of delayed union or nonunion were investigated according to mechanism of injury, fracture location, treatments methods and postoperative management. All patients were male and the age was 3 to 14 years old with an average of 9.4 years. All fractures were located on the mid-third part of forearm. Two cases had a re-fracture. Among them, 3 cases caused by high-energy injury and 2 cases by falling down. Open reduction were performed in 4 cases while the other one was treated with closed reduction. Four patients were immobilized in an above-elbow cast, postoperatively.</p><p><b>RESULTS</b>All patients were followed up from 7 to 19 months with an average of 11.4 months. There were 4 delayed union and 1 nonunion. Three patients healed after the removal of the nail and avoidance of weight-bearing. Two patients healed by replacing another fixation. No patients had soft-tissue irritation or nail-entry-site infections.. The clinical effect was evaluated according to Daruwalla and Price scores with 3 excellent and 2 good of the results.</p><p><b>CONCLUSIONS</b>Using titanium elastic nailing for the treatment of pediatric both-bone forearm fractures is a good method. However,strict indication selection should be followed to avoid delayed union or nonunion.</p>