Animal Experimental Study Of 3D Printed Cervical Porous Metal Mesh Cage

ObjectiveParallel imaging evaluation and histological analysis of animal experiments were performed using a 3D printed cervical vertebrae porous metal mesh cage.The results were compared with the conventional traditional cervical titanium mesh to evaluate the bone graft fusion and porous structural bone ingrowth.Provide theoretical basis for further improved design and preliminary clinical application of the cage.MethodsSelect 12 local hybrid goats,Weight(25±2.0kg),Randomly divided into 2 groups and numbered.Construction of a 3D printing cervical porous metal mesh cage and an ordinary titanium surgical mesh ACCF animal model.After the experimental animals were sacrificed in March,the surgical segments were completely removed,and X-ray,CT,Micro-CT and histological examinations were performed.The results of the experimental group and the control group were evaluated by imaging and histological analysis,and statistical analysis was performed to compare the differences.Results1.Successfully constructed animal models of the 3D printing cervical porous metal mesh cage group and the traditional cervical titanium mesh group 6 per group.2.X-ray imaging analysisAnalysis of results using the BSF pseudo joint score table(Table 1).In the experimental group,there were 5 cases of BSF-3,1 case of BSF-2,and 0 cases of BSF-1.In the control group,there were 4 cases of BSF-3,2 cases of BSF-2,and 0 cases of BSF-1.Comparison of the experimental group and the control group,No significant difference,Not statistically significant(p>0.05).3.CT imaging analysisThe results were evaluated using the CT fusion evaluation index of Siepe et al.(Table 2).The experimental group has 4 cases of grade 1,2 cases of grade 2,0 cases of grade 3,and 0 cases of grade 4.The control group has 2 cases of grade 1,3 grades of grade1,1 cases of grade 3,and 0 cases of grade 4.Comparison of the experimental group and the control group,No significant difference,Not statistically significant(p>0.05).4.Micro-CT Imaging analysisThe Micro-CT images of the experimental group and the control group were observed for 3 months.In the experimental group,the trabecular space structure similar to the upper and lower vertebral bodies appeared in the autogenous bone grafting area,and the new bone ingrowth was observed in the central bone grafting area and the titanium alloy trabecular bone structure,and the bone-metal interface was well integrated.In the control group,the trabecular space structure similar to the upper and lower vertebral bodies also appeared in the autogenous bone grafting area,but the new bone in the control group was mainly distributed in the central bone grafting area.There was no bone tissue attachment on the inner plant surface,and the bone-metal interface was not integrated.5.Histological analysisThe Masson staining and Goldner's staining were observed in the experimental group and the control group at 3 months after operation.In the experimental group,fibrous connective tissue and more bone tissue were observed in the central bone grafting area of the plant.The surrounding titanium alloy structure was mostly wrapped with fibrous tissue,and bone tissue was formed around some titanium alloy structures.In the control group,fibrous connective tissue was observed in the central bone-planting area of the plant.There was a small amount of bone tissue in the middle.The bone tissue grew at both ends.The titanium alloy structure was surrounded by fibrous tissue,and the cartilage and bone tissue were formed around the local titanium alloy structure.The total area of bone tissue area/central bone graft area in the central bone grafting area of the experimental group was 27.75±7.13%,and the total area of bone tissue area/central bone grafting area in the central bone grafting area of the control group was 19.25±4.64%.There was no significant difference and no statistical significance(p>0.05).The length of tissue/inner plant integration length/inner plant length of the experimental group was 92±3.55%,and the plant integration length/inner plant total length in the control group was 45.75±13.47%.There was a significant difference between the experimental group and the control group.Statistical significance(p<0.05).It is proved that the bone-metal interface of the 3D printed porous metal mesh cage is well integrated.ConclusionThe 3D printed porous metal mesh cage has better bone graft fusion effect;its porous structure has bone tissue ingrowth and its bone-metal interface is well integrated.