This study aims to investigate the regional variations of trabecular morphological parameters and mechanical parameters of the femoral head,as well as to determine the relationship between trabecular morphological and...This study aims to investigate the regional variations of trabecular morphological parameters and mechanical parameters of the femoral head,as well as to determine the relationship between trabecular morphological and mechanical parameters.Seven femoral heads from patients with fractured proximal femur were scanned using a micro-CT system.Each femoral head was divided into 12 sub-regions according to the trabecular orientation.One 125 mm^3 trabecular cubic model was reconstructed from each sub-region.A total of 81 trabecular models were reconstructed,except three destroyed sub-regions from two femoral heads during the surgery.Trabecular morphological parameters,i.e.trabecular separation（Tb.Sp）,trabecular thickness（Tb.Th）,specific bone surface（BS/B V）,bone volume fraction（BV/TV）,structural model index（SMI）,and degree of anisotropy（DA） were measured.Micro-finite element analyses were performed for each cube to obtain the apparent Young＇s modulus and tissue level von Mises stress distribution under 1%compressive strain along three orthogonal directions,respectively.Results revealed significant regional variations in the morphological parameters（P〈0.05）.Young＇s moduli along the trabecular orientation were significantly higher than those along the other two directions.In general,trabecular mechanical properties in the medial region were lower than those in the lateral region.Trabecular mechanical parameters along the trabecular orientation were significantly correlated with BS/BV,BV/TV,Tb.Th,and DA.In this study,regional variations of microstructural features and mechanical properties in the femoral head of patients with proximal femur fracture were thoroughly investigated at the tissue level.The results of this study will help to elucidate the mechanism of femoral head fracture for reducing fracture risk and developing treatment strategies for the elderly.展开更多
目的:应用Micro-CT评价Runx2基因修饰的骨髓间充质干细胞(MSC)静脉移植促进兔坏死股骨头修复效果。方法:24只大耳白兔经缺血性股骨头坏死造模4周后随机分为4组,A组静脉移植1×107个Runx2基因修饰的MSC,B组静脉移植1×107个Runx2...目的:应用Micro-CT评价Runx2基因修饰的骨髓间充质干细胞(MSC)静脉移植促进兔坏死股骨头修复效果。方法:24只大耳白兔经缺血性股骨头坏死造模4周后随机分为4组,A组静脉移植1×107个Runx2基因修饰的MSC,B组静脉移植1×107个Runx2 si RNA修饰的MSC,C组单纯植入1×107个MSC,D组静脉植入等量生理盐水,细胞移植后2、4、6、8周取出股骨头标本行Micro-CT检测,评价股骨头坏死修复情况。结果:2周后各组动物股骨头关节面模糊,骨密度降低,骨小梁数量及厚度均下降,骨小梁结构紊乱,但组间差异不明显;4、6周后,A、B、C组动物股骨头内骨密度和骨小梁结构未明显变化,但可见修复反应,而D组动物股骨头内骨小梁结构破坏进一步加剧;8周后,D组动物股骨头关节面塌陷,骨小梁严重缺失形成较大空洞,A、B、C组股骨头可见明显修复反应,关节面完整度、关节面下骨密度、骨小梁体积及数量、骨小梁连续性表现为A>C>B>D组。结论:MSC静脉移植可有效治疗股骨头坏死,且过表达Runx2基因修饰后能有效提升MSC移植后的治疗效果。展开更多
基金supported by the National Natural Science Foundation of China(Nos.11322223,11432016,81471753 and 11272134)the 973 Program(No.2012CB821202)
文摘This study aims to investigate the regional variations of trabecular morphological parameters and mechanical parameters of the femoral head,as well as to determine the relationship between trabecular morphological and mechanical parameters.Seven femoral heads from patients with fractured proximal femur were scanned using a micro-CT system.Each femoral head was divided into 12 sub-regions according to the trabecular orientation.One 125 mm^3 trabecular cubic model was reconstructed from each sub-region.A total of 81 trabecular models were reconstructed,except three destroyed sub-regions from two femoral heads during the surgery.Trabecular morphological parameters,i.e.trabecular separation（Tb.Sp）,trabecular thickness（Tb.Th）,specific bone surface（BS/B V）,bone volume fraction（BV/TV）,structural model index（SMI）,and degree of anisotropy（DA） were measured.Micro-finite element analyses were performed for each cube to obtain the apparent Young＇s modulus and tissue level von Mises stress distribution under 1%compressive strain along three orthogonal directions,respectively.Results revealed significant regional variations in the morphological parameters（P〈0.05）.Young＇s moduli along the trabecular orientation were significantly higher than those along the other two directions.In general,trabecular mechanical properties in the medial region were lower than those in the lateral region.Trabecular mechanical parameters along the trabecular orientation were significantly correlated with BS/BV,BV/TV,Tb.Th,and DA.In this study,regional variations of microstructural features and mechanical properties in the femoral head of patients with proximal femur fracture were thoroughly investigated at the tissue level.The results of this study will help to elucidate the mechanism of femoral head fracture for reducing fracture risk and developing treatment strategies for the elderly.
文摘目的:应用Micro-CT评价Runx2基因修饰的骨髓间充质干细胞(MSC)静脉移植促进兔坏死股骨头修复效果。方法:24只大耳白兔经缺血性股骨头坏死造模4周后随机分为4组,A组静脉移植1×107个Runx2基因修饰的MSC,B组静脉移植1×107个Runx2 si RNA修饰的MSC,C组单纯植入1×107个MSC,D组静脉植入等量生理盐水,细胞移植后2、4、6、8周取出股骨头标本行Micro-CT检测,评价股骨头坏死修复情况。结果:2周后各组动物股骨头关节面模糊,骨密度降低,骨小梁数量及厚度均下降,骨小梁结构紊乱,但组间差异不明显;4、6周后,A、B、C组动物股骨头内骨密度和骨小梁结构未明显变化,但可见修复反应,而D组动物股骨头内骨小梁结构破坏进一步加剧;8周后,D组动物股骨头关节面塌陷,骨小梁严重缺失形成较大空洞,A、B、C组股骨头可见明显修复反应,关节面完整度、关节面下骨密度、骨小梁体积及数量、骨小梁连续性表现为A>C>B>D组。结论:MSC静脉移植可有效治疗股骨头坏死,且过表达Runx2基因修饰后能有效提升MSC移植后的治疗效果。
