Distinct Tissue Mineral Density in Plate- and Rod-like Trabeculae of Human Trabecular Bone.
Trabecular bone quality includes both microstructural and intrinsic tissue mineralization properties. However, the tissue mineralization in individual trabeculae of different trabecular types and orientations has not yet been investigated. The aim of this study was to develop an individual trabecula mineralization (ITM) analysis technique to determine tissue mineral density (TMD) distributions in plate- and rod-like trabeculae, respectively, and to compare the TMD of trabeculae along various orientations in micro-computed tomography (μCT) images of trabecular bone samples from the femoral neck, greater trochanter, and proximal tibia. ITM analyses indicated that trabecular plates, on average, had significantly higher TMD than trabecular rods. In addition, the distribution of TMD in trabecular plates depended on trabecular orientation with the lowest TMD in longitudinal plates and the highest TMD in transverse plates. Conversely, there was a relatively uniform distribution of TMD among trabecular rods, with respect to trabecular orientation. Further analyses of TMD distribution revealed that trabecular plates had higher mean and peak TMD, whereas trabecular rods had a wider TMD distribution and a larger portion of low mineralized trabeculae. Comparison of apparent Young's moduli derived from micro-finite element models with and without heterogeneous TMD demonstrated that heterogeneous TMD in trabecular plates had a significant influence on the elastic mechanical property of trabecular bone. In conclusion, this study revealed differences in TMD between plate- and rod-like trabeculae and among various trabecular orientations. The observation of less mineralized longitudinal trabecular plates suggests interesting implications of these load-bearing plates in bone remodeling. The newly developed ITM analysis can be a valuable technique to assess the influence of metabolic bone diseases and their pharmaceutical treatments on not only microstructure of trabecular bone but also the microarchitectural heterogeneity of tissue mineralization.
Bone Bioengineering Laboratory, Department of Biomedical Engineering, Columbia University, New York, NY, USA.
Ji
J
Wang
Musculoskeletal Quantitative Imaging Research Group, Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA.
Galateia J
GJ
Kazakia
Bone Bioengineering Laboratory, Department of Biomedical Engineering, Columbia University, New York, NY, USA.
Bin
B
Zhou
Bone Bioengineering Laboratory, Department of Biomedical Engineering, Columbia University, New York, NY, USA.
X Tony
XT
Shi
Bone Bioengineering Laboratory, Department of Biomedical Engineering, Columbia University, New York, NY, USA.
X Edward
XE
Guo
D000368:Aged; D015519:Bone Density; D016723:Bone Remodeling; D001842:Bone and Bones / Q000000981:diagnostic imaging* / Q000473:pathology; D055119:Elastic Modulus; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000502:physiology; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000502:physiology*; D020342:Finite Element Analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000473:pathology; D013977:Tibia / Q000000981:diagnostic imaging / Q000502:physiology; D055114:X-Ray Microtomography
INDIVIDUAL TRABECULA MINERALIZATION; INDIVIDUAL TRABECULA SEGMENTATION; MICRO-COMPUTED TOMOGRAPHY; TISSUE MINERAL DENSITY