| Objective:1.The individualized intercellular β-tricalcium phosphate prosthesis for the experimental study of bone defects in New Zealand rabbits was designed and manufactured by computer aided technique and 3D Plotting rapid prototyping technology.2.The dimensions and internal microstructures of the 3D model were measured to clarify the accuracy of the printing.The effect of the dimensional accuracy of the experimental material on the bone repair results was investigated.3.The interstitial β-tricalcium phosphate and autogenous bone composite osteogenesis tissue engineering bone repair and no treatment of intercellular bone repair body at the same time implantation of New Zealand rabbits in the large radius of bone defect model,compared with the same environment under the two The effect of bone restorations on the repair of large segment of bone defects and the effect of bone grafting on the degradation of materials.Method:1.Three-dimensional measurement of the bilateral radius of the New Zealand white rabbits and the three-dimensional design of the personalizedβ-tricalcium intertrochanteric bone repair scaffold:Reconstruction and measurement of the radial data of 6 New Zealand white rabbits with CT scan were performed with mimics10.01 software.Based on this data,we designed a 15mm,wide and high corresponding bone defect repair model in soliworks software and save the file in STL format.2.Computer-aided simulation of the operation of the New Zealand white rabbits with radial bone defects:NX-Imagewarer software in the use of separation,regional division and other operations in the distance from the New Zealand white rabbit elbow at 30mm to cut off a large length of 15mm long bone defect,the New Zealand white Three-dimensional model of large segmental bone defect in rabbits.A large segment of the bone defect model designed in the Soliworks software was introduced into the Imageware 13.2 software and simulated into the bone defect model.3.The rabbits of New Zealand white rabbits were implanted into the interstitial β-tricalcium intertrochanteric bone repair scaffolds and randomly implanted with New Zealand rabbits.In New Zealand rabbits,under the general anesthesia,Cut the bilateral lateral radius,and with high-speed grinding in the bilateral radial to create a large length of 15mm long bone defect,random implantation of autologous bone between the interstitial bone repair and treatment of bone repair Into the matching with the radial bone defect,and the bone prosthesis and stump fit.4.The specimens were examined by X-ray examination,HE staining,Masson staining and Micro-CT scanning at the corresponding time points at 4 weeks,8 weeks and 12 weeks.The results were Statistical Analysis.Results:1.The diameter of the middle radius of the New Zealand white rabbits was 4 ± 1.2mm,and the length was 15mm,width and height were 5mm,the pore size was 3mm,the hole spacing was 2.4mm,and the internal structure was 400μ m.Three-dimensional model of segmental restorations.2.The interstitial β-tricalcium phosphate interstitial bone scaffolds were prepared by 3D printing technique with length of 15 ± 0.83mm,width and height of 5mm ± 0.65,hole spacing:pore size = 0.8.The interstitial structure provides a space for filling the bone in the scaffold,providing a model basis for in situ osteogenesis experiments.The results of scanning electron microscopy(SEM)show that the microporous structure of the scaffold is reasonable and the interconnection rate is high.3.During the operation,the bone scaffold was well matched with the radius defect area,indicating that the individual design of New Zealand white rabbits’ large segment of bone defect was accurate.4.The repairing speed and repair intensity of bone grafts were significantly better than those without bone grafts.1)4 weeks,8 weeks,12 weeks after the blank control group were not seen in the radius of the repair,the stump of the bone marrow cavity closed,part of the fusion with the ulna;2)postoperative X-ray found with the passage of time,implanted 3)postoperative micro-CT scan and defective three-dimensional reconstruction and bone density measurements found that bone reconstruction process,the implantation of new bone creeping replacement more smoothly.4)The results of HE staining showed that the number of neovascularization in the bone graft group and the non-grafted group was consistent with that reported in the literature[26].The HE staining results showed that the new bone of the bone graft group More than 12 weeks postoperatively HE staining found almost all of the bone graft material degradation,new bone mass increased significantly,some of the material has been completely replaced by newborn bone;not bone graft material most of the degradation,new bone mass less bone even.Masson staining showed that more blue-stained nasal bone tissue was seen in the implantation group at 4 weeks,8 weeks and 12 weeks after operation,and bone mass increased with the increase of time,but only the blue-stained collagen Fiber and a small amount of new bone tissue,bone graft repair effect was significantly better than the control group.Conclusion:1.The CAD design technique is used to design the bone defect model and the personalized bone repair body with high precision,practicality and repeatability,and can simulate the process of surgical repair,improve the success rate of surgical repair and avoid the waste of medical resources.2.CAD precision design combined with 3D printing technology to prepare 3D printing personalized intercellular β-tricalcium phosphate interstitial bone stent,its porosity,high connectivity,high matching accuracy,and the defect area is closely fit,is conducive to long bone cells Into and proliferating.3.3D printing personalized interstitial bone scaffold composite bone graft can slow down the rate of degradation of the stent,can better improve the speed of bone defect repair,for the clinical solution to large segment of bone defect repair problems provide a new way to explore.In the shortcomings,the current 3D graphics stent is still in a number of defects,such as sintering after shrinkage,shrinkage rate and material degradation speed control difficulties,the lack of experimental experiments to support large animals. |
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