Kim Do-Gyoon, Hunt Christine A, Zauel Roger, Fyhrie David P, Yeni Yener N
Bone and Joint Center, Department of Orthopaedics and Rehabilitation, Henry Ford Hospital, 2799 West Grand Boulevard, Detroit, MI 48202, USA.
Ann Biomed Eng. 2007 Nov;35(11):1907-13. doi: 10.1007/s10439-007-9363-1. Epub 2007 Aug 10.
Cancellous centrum is a major component of the vertebral body and significantly contributes to its structural strength and fracture risk. We hypothesized that the variability of cancellous bone properties in the centrum is associated with vertebral strength. Microcomputed tomography (micro-CT)-based gray level density (GLD), bone volume fraction (BV/TV), and finite element modulus (E) were examined for different regions of the trabecular centrum and correlated with vertebral body strength determined experimentally. Two sets of images in the cancellous centrum were digitally prepared from micro-CT images of eight human vertebral bodies (T10-L5). One set included a cubic volume (1 per vertebral centrum, n = 8) in which the largest amount of cancellous material from the centrum was included but all the shell materials were excluded. The other set included cylindrical volumes (6 per vertebral centrum, n = 48) from the anterior (4 regions: front, center, left, and right of the midline of vertebra) and the posterior (2 regions: left and right) regions of the centrum. Significant positive correlations of vertebral strength with GLD (r (2) = 0.57, p = 0.03) and E (r (2) = 0.63, p = 0.02) of the whole centrum and with GLD (r (2) = 0.65, p = 0.02), BV/TV (r (2) = 0.72, p = 0.01) and E (r (2) = 0.85, p = 0.001) of the central region of the vertebral centrum were found. Vertebral strength decreased with increasing coefficient of variation of GLD, BV/TV, and E calculated from subregions of the vertebral centrum. The values of GLD, BV/TV, and E in centrum were significantly smaller for the anterior region than for the posterior region. Overall, these findings supported the significant role of regional variability of centrum properties in determining the whole vertebral strength.
松质骨中心是椎体的主要组成部分，对其结构强度和骨折风险有显著影响。我们假设松质骨中心特性的变异性与椎体强度相关。基于微计算机断层扫描（micro-CT）的灰度密度（GLD）、骨体积分数（BV/TV）和有限元模量（E）在小梁骨中心的不同区域进行了检测，并与实验测定的椎体强度相关联。从八个人体椎体（T10-L5）的micro-CT图像中数字制备了松质骨中心的两组图像。一组包括一个立方体体积（每个椎体中心1个，n = 8），其中包含来自中心的最大量松质材料，但排除所有外壳材料。另一组包括来自椎体中心前部（4个区域：椎体中线的前部、中部、左侧和右侧）和后部（2个区域：左侧和右侧）区域的圆柱形体积（每个椎体中心6个，n = 48）。发现椎体强度与整个中心的GLD（r(2)=0.57，p = 0.03）和E（r(2)=0.63，p = 0.02）以及椎体中心区域的GLD（r(2)=0.65，p = 0.02）、BV/TV（r(2)=0.72，p = 0.0）和E（r(2)=0.85，p = 0.001）呈显著正相关。椎体强度随着从椎体中心子区域计算的GLD、BV/TV和E的变异系数增加而降低。椎体中心前部区域的GLD、BV/TV和E值明显小于后部区域。总体而言，这些发现支持了中心特性的区域变异性在确定整个椎体强度中的重要作用。
