Table 1 Flexural properties of wild-type and MMP13ocy−/− femurs

From: Osteocyte dysfunction promotes osteoarthritis through MMP13-dependent suppression of subchondral bone homeostasis

 

Posterior compression, 2 months (n = 9)

Posterior compression, 4 months (n = 8–9)

Flexural propertities

WT

MMP13ocy−/−

WT

MMP13ocy−/−

Bending stiffness/(N·mm−1)

83.63 ± 9.14

82.85 ± 6.00

112.24 ± 13.40

110.26 ± 9.64

Yield load/N

7.94 ± 1.71

8.07 ± 1.03

9.31 ± 1.97

11.26 ± 1.40*

Ultimate load/N

16.79 ± 2.21

15.11 ± 1.24#

19.02 ± 2.08

18.24 ± 1.63

Postyield displacement/mm

0.56 ± 0.22

0.60 ± 0.27

0.54 ± 0.37

0.38 ± 0.13

Work to fracture/N-mm

7.98 ± 1.87

7.86 ± 3.09

8.24 ± 3.30

6.55 ± 1.85

Bending modulus/GPa

10.97 ± 1.60

12.50 ± 2.56

15.31 ± 1.07

15.50 ± 3.26

Yield stress/MPa

107.94 ± 19.20

124.38 ± 30.27

132.45 ± 25.56

162.75 ± 32.98#

 

Anterior compression, 2 months (n = 3–9)

Anterior compression, 4 months (n = 8–9)

 

WT

MMP13ocy−/−

WT

MMP13ocy−/−

Bending stiffness/(N·mm−1)

78.65 ± 10.82

67.03 ± 1.04

100.77 ± 6.70

94.25 ± 9.42

Yield load/N

8.65 ± 1.22

9.28 ± 2.29

11.08 ± 1.09

10.73 ± 1.50

Ultimate load/N

13.25 ± 1.65

13.61 ± 1.67

17.12 ± 1.34

15.64 ± 1.35*

Postyield displacement/mm

0.95 ± 0.56

1.00 ± 0.50

0.31 ± 0.10

0.37 ± 0.19

Work to fracture/N-mm

8.91 ± 2.32

9.16 ± 2.40

5.09 ± 1.50

5.27 ± 2.01

  1. Femurs from wild-type and MMP13ocy−/− mice were broken with either anterior or posterior side in compression. In general, structural and tissue material properties were stronger in posterior (physiological) compression than anterior compression and get stronger with age. Ultimate load tended to be lower in MMP13ocy−/− bones than wild-type bones, particularly in 4-month-old samples broken in anterior compression. MMP13ocy−/− bones also had lower stiffness in this test configuration. Values are presented as mean ± SD. *P < 0.05 between genotypes, #P < 0.065 between genotypes by unpaired t test
Back to article page