Measurement of intraspecimen variations in vertebral cancellous bone architecture

A three-dimensional technique was developed for the quantification of the n umber and cross-sectional geometry of individual trabeculae oriented along a given direction. As an example application, the number of vertical and ho rizontal trabeculae and their respective cross-sectional geometry were dete rmined for a set of six vertebral cancellous bone specimens (L3-L4 female v ertebral bodies; age range 39-63 years). Three-dimensional optical images a t a spatial resolution of 20 mu m were obtained using an automated serial m illing technique. The thickness distributions were generally right skewed. The mean true thickness for both the vertically and horizontally oriented t rabeculae showed a strong relationship with volume fraction (vertical: r(2) = 0.86; p < 0.05; horizontal: r(2) = 0.80; p < 0.05), and mean trabecular thickness (Tb,Th,) (vertical: r(2) = 0.81; p < 0.05; horizontal: r(2) = 0.7 2; p < 0.05). The horizontal trabeculae were greater in number and were thi nner than the vertical trabeculae, The coefficient of variation of the intr aspecimen vertical trabecular thicknesses ranged from 25% to 42%, and showe d a weak, albeit insignificant, positive correlation with volume fraction ( r(2) = 0.46). The findings demonstrated substantial intraspecimen variation s exist in trabecular thickness that are not related to volume fraction. Fu rther studies are recommended to determine the potential role of such intra specimen variations in architecture on biomechanical properties. (C) 1999 b y Elsevier Science Inc. All rights reserved.