The following parameters were determined from the trabecular bone using a direct three-dimensional approach [40]: total bone marrow volume including the trabeculae (TV; mm3), trabecular bone volume (BV; mm3), trabecular bone volume fraction (BV/TV), mean trabecular number (Tb.N; 1/mm), mean trabecular thickness (Tb.Th; mm), and mean trabecular separation (Tb.Sp; mm).
Trabecular bone volume per total volume (BV/TV), mean trabecular thickness (Tb. Th), mean trabecular number (Tb. N, and mean trabecular separation (Tb. Sp) were calculated using Scanco μCT V6.1 software.
Afterwards, a three-dimensional (3D) analysis for the indices including bone volume density (bone volume/tissue volume, BV/TV, %), bone surface density (bone surface/tissue volume, BS/TV, mm−1), mean trabecular thickness (Tb.Th, mm), mean trabecular number (Tb.N, mm−1), and mean trabecular separation (Tb.Sp, mm) was done for the spongy bone [ 14].
Trabecular morphometric traits were computed from binarized images using direct 3D techniques that do not rely on prior assumptions on underlying structures: trabecular bone volume per total volume (BV/TV), mean trabecular thickness (Tb.Th)., mean trabecular number (Tb.N ., and mean trabecular separation (Tb.Sp).
Results showed that mean trabecular separation (Tb.Sp) and number (Tb.N) can be accurately determined at all sites.
There was a trend for the correction factor to linearly increase as volume fraction decreased (p=0.001) and as mean trabecular separation increased (p<0.001).
Structural parameters included the apparent trabecular bone volume fraction (BV/TV), apparent trabecular number (Tb.N), apparent trabecular separation (Tb.Sp), apparent trabecular thickness (Tb.Th), mean trabecular area, mean trabecular perimeter, mean trabecular roundness and mean skeleton length [ 41].
Finally, preliminary data suggest the method to be able to provide information on trabecular bone architecture such as regional mean trabecular plate separation.
Bone volume fraction (BV/TV) of the eight different cube sites (sample) ranged from 0.408 to 0.501 (mean: 0.453); trabecular thickness (Tb.Th) ranged from 158.1 to 185.5 μm (mean: 168.6 μm); and trabecular separation (Tb.Sp) ranged from 179.4 to 233.1 μm (mean: 204.7 μm).
The mean distance between individual trabeculae (trabecular separation) was 0.514 mm in the radius and 0.541 mm in the tibia (Table 9).
(C) Trabecular subchondral bone area (Tb.A) and trabecular separation (Tb.Sp) in subchondral bone.
