Table 4.

Mechanical strength of femurs from 12 week, WT and OPN−/− mice

Parameter	WT	OPN−/−
Rigidity (Nmm/[mm/mm2])	909 ± 70	1308 ± 92a
Ultimate moment (Nmm)	28.8 ± 3.4	47.3 ± 2.0a
Ultimate normalized displacement (mm/mm2)	0.042 ± 0.003	0.047 ± 0.003
Energy (Nmm∗ (mm/mm2)	0.456 ± 0.12	1.1 ± 0.08a
Cross sectional moment of inertia (mm4)	0.161 ± 0.010	0.191 ± 0.008b
Elastic modulus (GPa)	5.7 ± 0.19	7.1 ± 0.62c
Ultimate periosteal tensile stress (MPa)	116.1 ± 9.5 (n = 4)	170.7 ± 7.9a (n = 18)

Left femora from WT and OPN−/− mice were used for biomechanical testing. Four point bending tests were conducted using a materials testing machine as described in the MATERIALS AND METHODS. Data shown are means ± SE. 

^a p < 0.005; 

^b p < 0.05; 

^c p < 0.02.