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).
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).
The mean trabecular number in the radius was 1.73/mm and in the tibia it was 1.65/mm (Table 7).
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].
In OA group, bivariate correlation analysis showed App BV/TV (r=−0.559), mean trabecular area (r=−0.940), mean trabecular perimeter (r=−0.574), mean skeleton length (r=−0.529) were associated with Euler number.
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].
There was no significant difference between the two groups in apparent trabecular number, mean trabecular area, mean trabecular perimeter, mean skeleton length, total skeleton length, energy, absolute value, inverse difference, angular second moment and other parameters (p > 0.05).
Results showed that mean trabecular separation (Tb.Sp) and number (Tb.N) can be accurately determined at all sites.
In OP group, apparent trabecular separation (Tb.Sp), inertia, absolute value and contrast were positively correlated with Euler number, whereas apparent trabecular number (Tb.N), mean trabecular area, inverse difference and inverse different moment were negatively correlated.
Mean (SD) bone volume fraction (25.1 (6) %), trabecular number (1.69 (0.26) mm-1), trabecular thickness (0.17 (0.03) mm), and degree of mineralisation (695.39 (39.83) mg HA/cm3) were higher in the superior region.
