Figure 1.
Lumbar spines (L1-L5) collected from fresh cadavers were used for biomechanical tests in the current study (a); Bony endplate was exposed by removing the soft tissue (b); After removing the posterior elements and endplate preparation, each lumbar vertebra was placed at the fixture of the material testing system and then the axial compression test was conducted under the displacement control mode (c).
Figure 2.
The central region of endplate removed in this study was defined as the rectangular area surrounded by two vertical lines (A, B) and two horizontal lines (C, D) which pass through the quarter-points of the x-axis and y-axis across lumbar endplate surface respectively.
Figure 3.
As shown in the load-displacement of the lumbar vertebrae, the compressive strength at the first significant decrease of slope of the load displacement curve was the failure load and the stiffness was the slope of linear region of load-displacement curve.
Figure 4.
Scatter plots showing relationship between BMD and failure load in subgroup A, B and C.
Figure 5.
Scatter plots showing relationship between BMD and stiffness in subgroup A, B and C.
Figure 6.
The mean failure load and standard deviation of the normal BMD, osteoporotic and serious osteoporotic group.
“*” stands for the presence of statistical difference between the subgroup B and C; “**” stands for the presence of statistical difference between the subgroup A and C; “***” stands for the statistical intergroup difference of subgroup A among the three BMD groups; “****” stands for the statistical intergroup difference of subgroup B among the three BMD groups; “*****” stands for the statistical intergroup difference of subgroup C among the three BMD groups.
Figure 7.
The mean stiffness and standard deviation of the normal BMD, osteoporotic and serious osteoporotic group.
“*” stands for the presence of statistical difference between the subgroup B and C; “**” stands for the presence of statistical difference between the subgroup A and C; “***” stands for the statistical intergroup difference of subgroup A among the three BMD groups; “****” stands for the statistical intergroup difference of subgroup B among the three BMD groups; “*****” stands for the statistical intergroup difference of subgroup C among the three BMD groups.