Department of Anatomy, Gifu University Graduate School of Medicine, Gifu, Japan.
Osteoporos Int. 2010 Apr;21(4):627-36. doi: 10.1007/s00198-009-0993-z. Epub 2009 Jun 19.
We investigated age- and gender-related variation of both cortical and trabecular microstructure in human femoral neck. We found that age-related change of cortical porosity is more noticeable than that of trabecular parameter. Our data may help to gain more insight into the potential mechanism of osteoporotic femoral neck fractures.
Variations in the microstructure of cortical and trabecular bone contribute to decreased bone strength. Age- and gender-related changes in cortical and trabecular microstructure of femoral neck is unclear. The aim of this study was to identify three-dimensional (3D) microstructural changes of both cortical and trabecular bone simultaneously in human femoral neck with age and gender, using micro-computed tomography (micro-CT). We hypothesized that there would be differences in age-related changes of cortical and trabecular bone for both women and men.
We used 56 femoral necks of 28 women and men (57-98 years of age) from a Japanese population. The subjects were chosen to give an even age and gender distribution. Both women and men were divided into three age groups: middle (57-68 years), old (72-82 years), and elderly (87-98 years) groups. We examined cortical bone specimen from the inferior sector of femoral neck and trabecular bone specimen from the middle of femoral neck using micro-CT and 3D bone analysis software.
Cortical thickness (Ct.Th) decreased by 10-15%, cortical porosity (Ca.V/TV) almost doubled, and canal diameter (Ca.Dm) increased by 65-77% between the middle-aged and elderly groups for both women and men. The trabecular bone volume fraction (BV/TV) decreased by around 20%; trabecular thickness (Tb.Th), trabecular number (Tb.N), and connectivity density (Conn.D) decreased; and trabecular separation (Tb.Sp) and structure model index (SMI) increased with age for both women and men. As compared with women, men had higher Ct.Th and BV/TV and lower Ca.V/TV and Ca.Dm among three age groups. There was a significant inverse correlation between Ca.V.TV and BV/TV for both women and men.
Our findings indicate that Ct.Th and BV/TV decreased, and Ca.V/TV and Ca.Dm increased in femoral neck with age for both women and men. The most obvious age-related change is the increase of Ca.V/TV. The decrease of BV/TV with age is more noticeable than that of Ct.Th. This is the first study that has provided both cortical and trabecular microstructural data simultaneously in a Japanese sample. These data may help us to gain more insight into the potential mechanism of osteoporotic femoral neck fractures.
本研究旨在利用微计算机断层扫描（micro-CT）技术同时检测并比较不同年龄段男性和女性股骨颈皮质骨和松质骨的三维（3D）微观结构变化，以明确年龄及性别对股骨颈皮质骨和松质骨微观结构的影响。我们假设男女两性的皮质骨和松质骨的年龄相关性变化存在差异。
本研究纳入了 56 例（男女各 28 例）年龄在 57-98 岁的日本人群股骨颈标本。将研究对象按照年龄分为中年组（57-68 岁）、老年组（72-82 岁）和高龄组（87-98 岁）。采用 micro-CT 和 3D 骨分析软件对股骨颈下区皮质骨样本和股骨颈中部的松质骨样本进行检测。
与中年组相比，男女两性的皮质厚度（Ct.Th）分别下降了 10-15%、皮质孔隙率（Ca.V/TV）几乎增加了 1 倍、管腔直径（Ca.Dm）增加了 65-77%；男女两性的松质骨体积分数（BV/TV）均下降了约 20%，松质骨厚度（Tb.Th）、松质骨数量（Tb.N）和连接密度（Conn.D）下降，而松质骨分离度（Tb.Sp）和结构模型指数（SMI）增加。与女性相比，男性在 3 个年龄组中皮质厚度（Ct.Th）和 BV/TV 较高，皮质孔隙率（Ca.V/TV）和管腔直径（Ca.Dm）较低。男女两性的皮质孔隙率（Ca.V/TV）与 BV/TV 呈显著负相关。
本研究结果表明，男女两性的股骨颈皮质骨和松质骨均随年龄增长而发生变化，表现为皮质厚度（Ct.Th）和 BV/TV 下降、皮质孔隙率（Ca.V/TV）和管腔直径（Ca.Dm）增加。年龄相关性变化最明显的是皮质孔隙率（Ca.V/TV）的增加。与皮质厚度（Ct.Th）相比，BV/TV 随年龄下降更为明显。这是首次在日本人群中提供同时包含皮质骨和松质骨微观结构数据的研究，这些数据可能有助于深入了解骨质疏松性股骨颈骨折的潜在机制。
