Craniofacial malformation caused by premature fusion of cranial suture of infants has a serious impact on their growth. The purpose of skull remodeling surgery for infants with craniosynostosis is to expand the skull and allow the brain to grow properly. There are no standardized treatments for skull remodeling surgery at the present, and the postoperative effect can be hardly assessed reasonably. Children with sagittal craniosynostosis were selected as the research objects. By analyzing the morphological characteristics of the patients, the point cloud registration of the skull distortion region with the ideal skull model was performed, and a plan of skull cutting and remodeling surgery was generated. A finite element model of the infant skull was used to predict the growth trend after remodeling surgery. Finally, an experimental study of surgery simulation was carried out with a child with a typical sagittal craniosynostosis. The evaluation results showed that the repositioning and stitching of bone plates effectively improved the morphology of the abnormal parts of the skull and had a normal growth trend. The child’s preoperative cephalic index was 65.31%, and became 71.50% after 9 months’ growth simulation. The simulation of the skull remodeling provides a reference for surgical plan design. The skull remodeling approach significantly improves postoperative effect, and it could be extended to the generation of cutting and remodeling plans and postoperative evaluations for treatment on other types of craniosynostosis.
In order to investigate the possibility of porous hydroxyapatite ceramics (HAC) in the repair of skull bone defect, twenty-four rabbits were used. The bone defect model was created by operation to obtain a defect in parietal bone in a size of 1 cm x 1 cm. Filled the defect with HAC and methyl-methacrylate-syrene copolymer (MMAS) to fill the defect as control. At 1st, 2nd and 3rd months after operation, behavior of the rabbits was observed and then these animals were sacrificed and specimens were examined under microscope. Results showed as follows: after operation, behavior of all animals were normal. By histological examination, it was found that in HAC group, there were granulation tissue, fibrous tissue and newly formed vessels grew into the pores and the osteoblasts formed osseous trabeculae. There was no inflammatory cell infiltration. In the MMAS grafted asea, there was formation of fibrous membrane. It suggested that HAC might be a good material for bone substitute in repair of skull bone defect.
OBJECTIVE: To determine whether culture expanded bone marrow derived mesenchymal stem cells (MSCs) in combination with beta-tricalcium phosphate(beta-TCP) can repair critical cranial defects in New Zealand rabbits. METHODS: In group A(n = 20), MSCs from homogeneous rabbits were isolated and expanded in vitro and then implanted onto the pre-molded porous beta-TCP. The MSCs-beta-TCP complexes were implanted into rabbit critical cranial defects. In group B (n = 10), The defects were repaired with beta-TCP only. In group C(n = 4), the defects were left un-repaired. Samples were extracted 6 and 12 weeks after operation for histological, histochemical and immunohistochemical analysis. RESULTS: In group A, bone-like tissue formation could be seen on the surface of the implants. Microscopic analysis demonstrated certain degradation of beta-TCP and extensive new bone filling in rich extracellular matrix after 6 weeks. The cells were stained positively for type I collagen. After 12 weeks, the bioceramics had almost completely degraded and abundant bone formation could be seen in the whole defects. In group B, marginal bone ingrowth was observed after 6 weeks and the number of osteoblasts increased significantly after 12 weeks. However, no new bone formation could be detected in the middle of the material. In group C, only a small quantity of new bone formation was found along the margin of defects. CONCLUSION: Transplantation of MSCs with beta-TCP can serve as an example of a cell-based treatment for bone regeneration in skeletal defects.
Objective To investigate the clinical application of self-cranial bone powder in one stage cranioplasty．Methods From October 1999 to December 2002,self-cranial bone powder and medical adhesive were used to repair the skull defect, for one stage cranioplasty, caused by operations on cranium in 128 casesof severe dangerous craniocerebral injury, acute intracranial hematome, sick skull and intracranial tumor．The bone growth was observed by CT or X-ray examination 3-24 months after replantation of cranioplasty．Results The decompression and cranioplasty were performed simultaneously, the time prolonged 5-10 minutes than that of routine, the appearance of repaired cranial bone was normal, without concavity and convexity. After 12 months of operation, the replanted bone merged with the normal bone completely, with normal appearance. The operation successful rate was 96.1%(123/125) without any complication. Only fivecases were not better in growing because of less bone powder, but withoutcerebral pulse and defective syndrome. All the cases did not need secondary cranioplasty．Conclusion The effect of cranioplasty with self-cranial bone powder effect is good in taking shape. This new method can avoid the traditional secondary cranioplasty for skull defect and complications．
Objective To evaluate repair of critical-sized cranialdefect with tissue engineered bone fabricated by coral, bone mesenchymal stem cells(MSCs) and sustainedly released recombinant human bone morphogenetic -protein 2 (rhBMP-2) by collagen. Methods Three scaffolds of rhBMP-2+coral,collagen+rhBMP-2+coral and MSCs+collagen+rhBMP-2+coral were fabricated. Forty New Zealand rabbits were made the models of critical-sized defects and divided into5 groups according to different implants: group Ⅰ, auto-ilium; group Ⅱ,coral; group Ⅲ, rhBMP-2+coral; grop Ⅳ, collagen+rhBMP-2+coral; and group Ⅴ,MSCs+collagen+rhBMP-2+coral. Repair of bone defect was evaluated after 8 and 16 weeks of implantation by gross obeservation, X-ray,HE staining and Masson’s trichrome staining. Results Repair ofbone defect in group Ⅴ was similar to that in group Ⅰ, andwas better than that in group Ⅳ; and group Ⅲ was worse. The gross appearance showed that defect region filled with bony tissue which had similar strength to adjacent bone and formed bone union with surrounding bone. The X-ray result displayed high radiopacity(80.45%±2.52% in the 16thweek). Histological observation showed new lamellar bone tissue and with few pore blank area. However, only transpasent fibrous tissue filled the defect in group Ⅱ. Conclusion Collagen may be a suitable sustained release system for rhBMP-2. And MSCs may have important effect on enhancing repair of bone defect. Tissueengineered bone fabricated by MSCs+collagen+rhBMP-2+coral may be a useful material for bone defect repair.
In order to repair cartilage defect in joint with transplantation of cryopreserved homologous embryonic periosteum, 30 rabbits were used and divided into two groups. A 4 mm x 7 mm whole thickness cartilage defect was made in the patellar groove of femur of each rabbit. The homologous embryonic rabbit skull periosteum (ERSP), preserved in two-step freezing schedule, was transplanted onto the cartilage defect of joints of one group and autogenous periosteal graft was done in the joint defect of the other group. The knees were not immobilized, following operation and 16 weeks later, the newly formed tissue in the defects were assessed by gross observation, histochemical examination and biochemical analysis. The results showed that new hyaline-like cartilage was formed in the cryopreserved ERSP grafted knee, and had no significant difference from that of the knee receiving autogenous periosteal graft, but had significant difference from that of the fresh ERSP grafted knee and the non-grafted knee. Furthermore, the new hyaline-like cartilage had the biochemical characteristics of a fibrous cartilage. The conclusion was that this method might be feasible to repair articular cartilage defects.