Table 3 Mean (±SD) of the baseline and follow-up scans, mean (±SD) of both measurements, root-mean-square precision error (CV%RMS) for stiffness, apparent stiffness, average von Mises stress, and failure load from 3 different FE models at the distal tibia in postmenopausal women
Tibia (n = 32) | First scan | ± SD | Second scan | ± SD | Mean | ± SD | CV%RMS | |
|---|---|---|---|---|---|---|---|---|
Single Tissue Model (STM) | ||||||||
Stiffness | (kN/mm) | 172.7 | ± 33.7 | 173.1 | ± 34.1 | 172.9 | ± 33.7 | 3.7 |
Apparent Modulus | (MPa) | 1896.8 | ± 375.2 | 1908.3 | ± 374.3 | 1902.5 | ± 372.0 | 4.0 |
Average von Mises Stress | (MPa) | 66.6 | ± 5.8 | 66.8 | ± 5.4 | 66.7 | ± 5.1 | 4.8 |
Failure Load | (kN) | 8.746 | ± 1.570 | 8.761 | ± 1.587 | 8.754 | ± 1.571 | 2.7 |
Dual Tissue Model (DTM) | ||||||||
Stiffness | (kN/mm) | 316.1 | ± 60.9 | 317.2 | ± 61.8 | 316.6 | ± 61.0 | 3.4 |
Apparent Modulus | (MPa) | 3477.5 | ± 685.3 | 3500.6 | ± 685.3 | 3489.1 | ± 680.7 | 3.8 |
Average von Mises Stress | (MPa) | 120.6 | ± 10.2 | 120.9 | ± 9.4 | 120.7 | ± 9.3 | 3.8 |
Failure Load | (kN) | 7.256 | ± 1.345 | 7.267 | ± 1.360 | 7.261 | ± 1.345 | 2.9 |
Cortical Bone | ||||||||
Average von Mises Stress | (MPa) | 166.4 | ± 5.4 | 166.6 | ± 5.6 | 166.5 | ± 5.5 | 0.8 |
% Minimum Load Carried | (%) | 41.5 | ± 9.1 | 41.9 | ± 9.7 | 41.7 | ± 9.4 | 3.5 |
% Maximum Load Carried | (%) | 61.6 | ± 9.9 | 61.8 | ± 10.2 | 61.7 | ± 10.0 | 2.1 |
Trabecular Bone | ||||||||
Average von Mises Stress | (MPa) | 97.9 | ± 11.6 | 97.8 | ± 11.4 | 97.9 | ± 10.8 | 5.9 |
% Minimum Load Carried | (%) | 58.5 | ± 9.1 | 58.2 | ± 9.7 | 58.3 | ± 9.4 | 2.6 |
% Maximum Load Carried | (%) | 38.4 | ± 9.9 | 38.2 | ± 10.2 | 38.3 | ± 10.0 | 3.5 |
Scaled E-BMD Model | ||||||||
Stiffness | (kN/mm) | 118.7 | ± 27.8 | 118.7 | ± 27.5 | 118.8 | ± 27.6 | 2.1 |
Apparent Modulus | (MPa) | 910.6 | ± 223.7 | 912.8 | ± 224.9 | 911.7 | ± 224.0 | 1.8 |
Average von Mises Stress | (MPa) | 16.7 | ± 3.3 | 16.8 | ± 3.2 | 16.7 | ± 3.2 | 2.0 |
Failure Load | (kN) | 3.558 | ± 0.802 | 3.556 | ± 0.797 | 3.557 | ± 0.797 | 2.5 |