| Objective:The micromechanical physical environment has been confirmed to have an effect on the osteogenic behavior of bone cells.Therefore,the research team used Micro-CT and pathological examination techniques to partition the osteoporotic femoral head,and then used scanning electron microscopy and nanoindentation techniques.The micromorphology and mechanical parameters of different regions of the femoral head(normal zone,osteopenia,osteoporosis zone)were characterized and extracted.The differences in bone surface morphology and mechanical properties of different regions were compared to improve the patients with osteoporosis.The refinement of microphysical factors on the surface of different parts of the femoral head explores the pathogenesis of osteoporosis caused by physical factors such as bone micro-morphology,and provides a basis for the preparation of bone repair materialsMethods:1.Collection of human femoral bone samples;2.Human femoral head specimen processing;3.Micro-CT and pathological examination techniques for the division of the femoral head;4.Nanoindentation scanning and data analysis;5.Extraction and analysis of SEM image parametersResult:1.Micro-CT of different regions of the osteoporotic femoral head showed that the trabecular bone in the normal area was continuous,the thickness was uniform,and the gap was normal;the trabecular bone in the osteopenia area was occasionally broken,the thickness was uneven,the arrangement was scattered,and the gap was enlarged;In the loose area,the trabecular bone fracture is obvious,the thickness of the trabecular bone is obviously uneven,the arrangement is scattered,and the gap is increased.Pathological examination of different regions,the normal trabecular bone structure is intact,the thickness is uniform,and the inflammatory cells infiltration of the trabecular bone can be seen;the trabecular thickness of the ossification is uneven,the fracture is irregular and the arrangement is irregular,and the trabecular bone between the focal bones See granulation tissue hyperplasia,with peripheral inflammatory cell reaction;osteoporotic area trabecular thickness is uneven,trabecular bone fracture disorder,partial bone tissue degeneration and necrosis,fibrous tissue hyperplasia and granulation tissue hyperplasia between focal trabecular bone.2.The nanoindenter measures the hardness and elastic modulus of different parts of the osteoporotic femoral head:the elastic modulus of the normal zone is 10.110±6.88Gpa,the osteopenia zone is 9.175±7.30Gpa,the osteoporosis zone is 9.66±4.10Gpa;the normal zone The hardness was 0.347±0.161Gpa,the osteopenia area was 0.295±0.141 Gpa,and the osteoporosis area was 0.366±0.188Gpa.There was no significant difference in the elastic modulus and hardness between normal area,osteopenia and osteoporosis area(P>0.05).3.Scanning electron microscopy to characterize the morphology of different regions of the osteoporotic femoral head:SEM image of normal area SEM image of mineralized collagen on the surface of trabecular bone is uniform,flat and compact.The bone mineralized collagen fiber bundles are arranged regularly and tend to be better;The collagen fibers(MCF)in the osteopenia area are arranged in a bundle,the fiber orientation is relatively uniform,and there is no obvious fiber disorder.The diameter of the mineralized collagen fiber bundle is thinner than the normal area Occasionally,the collagen fiber breaks and shrinks the area,and the collagen fibers in different directions are cross-like arrangement;In the osteoporosis area,the mineralized collagen fiber bundles were uneven in thickness and disordered in distribution,and there was no obvious fork-like arrangement.The gap of the mineralized collagen fiber bundles was larger than that in the osteopenia reduction zone.4.Scanning electron microscopy to characterize the surface topography parameters of different regions of osteoporotic femoral head:The normalized mineralized collagen fiber bundle fiber diameter(915 ± 307)nm,fiber tendency(37.9 ± 25.8)°,fiber number(22±4);The diameter of the mineralized collagen fiber bundle in the osteopenia region is(1077±358)nm,the fiber tends to be(43.0 ± 20.1)°,and the number of fibers is(18 ± 3);The mineralized collagen fiber bundles in the osteoporotic zone have a diameter of(1282±349)nm,a fiber orientation(31.4 ±19.2)°,and a fiber number(16 ± 2).There were significant differences in the diameter of mineralized collagen fibers in the three regions of normal area,osteopenia,and osteoporosis(p<0.001).There was a statistically significant difference between the two groups(p<0.05).There were significant differences in the trend of mineralized collagen fibers in three different regions of normal area,osteopenia and osteoporosis(p<0.05).There was statistical significance between the two groups and the junction group and the necrotic group.P<0.05),there was no significant difference between the normal group and the junction group,the normal group and the necrotic group(P>0.05).There were significant differences in the number of mineralized collagen fibers in the normal area,osteopenia area and osteoporosis area(p<0.05).Comparison between normal group and border group,normal group and necrosis group.There was statistical significance(P<0.05).There was no significant difference between the junction group and the necrotic group(P>0.05).5.Scanning electron microscopy to characterize the surface topography parameters of different subgroups of osteoporotic femoral heads are:There was a statistically significant difference between the middle-aged group and the old group in the normal group(P<0.05).There was a statistically significant difference between the middle-aged group and the elderly group in the osteoporosis area.P<0.05);There was significant difference between the male and female groups in the normal group(P<0.05).There was significant difference between the male and female groups in the osteoporosis area(P<0.05);the difference in the remaining indicator groups was not statistically significant.Conclusion:1.The femoral head of patients with osteoporosis was examined by Micro-CT scanning and pathology.The osteoporotic femoral head was divided into normal area,osteopenia area and osteoporosis area.2.The mechanical properties and load-displacement curves of different regions of osteoporotic femoral head were obtained by measuring the divided areas by nanoindentation technique.3.The SEM micromorphology of bone tissue in different regions of osteoporotic femoral head was performed,and the bone microscopic morphology images of different regions were obtained.The morphological differences of bone morphology in different regions were analyzed.4.The SEM image of bone tissue was extracted by the morphology parameter extraction process established in the early stage of the experimental group.The fiber diameter of the osteoporotic area was thicker than that of the bone reduction area and the normal area,while the fibers in the osteoporotic area tend to be arranged in disorder.The number of fibers in the normal area is larger than that in the osteopenia and osteoporosis areas.The fiber tendencies of different regions in the middle-aged and elderly groups were significantly different.There were significant differences in fiber diameters between the male and female groups.5.The results of this study help to understand the mechanism of physical factors in the pathogenesis of osteoporosis,and establish a database of human femoral head micromorphology parameters to provide a basis for bone repair materials. |
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