Table 2.
Trabecular and Cortical Bone Properties in Male TH and SWR Mice at 8 and 17 Weeks of Age (Mean ± SD)
| 8 Weeks of Age |
17 Weeks of Age |
Pstrain | Pstrainage | |||
|---|---|---|---|---|---|---|
| SWR | TH | SWR | TH | |||
| n | 8 | 8 | 10 | 10 | ||
| Distal femur (trabecular) | ||||||
| Tb.N, per mm | 6.73 (0.66) | 3.98 (0.2)a | 3.95 (0.66) | 2.76 (0.33)a | <.0001 | <.0001 |
| Tb.Th, mm | 0.052 (0.002) | 0.047 (0.001)a | 0.051 (0.003) | 0.053 (0.004) | NS | .0003 |
| Tb.Sp, mm | 0.143 (0.020) | 0.250 (0.014)a | 0.262 (0.048) | 0.366 (0.045)a | <.0001 | NS |
| SMI | 1.75 (0.23) | 3.02 (0.08)a | 2.18 (0.15) | 3.13 (0.25)a | <.0001 | <.0001 |
| Cortical porosity, % | 12.04 (3.15) | 7.49 (0.63) | 6.77 (0.32) | 5.14 (0.97) | <.0001 | .0104 |
| Cortical thickness, mm | 0.080 (0.008) | 0.100 (0.008)a | 0.102 (0.007) | 0.111 (0.007) | <.0001 | <.0001 |
| Midshaft femur (cortical) | ||||||
| BA/TA, % | 44.5 (1.9) | 50.4 (2.2)a | 49.5 (3.3) | 56.5 (3.3)a | <.0001 | NS |
| Cortical thickness, mm | 0.180 (0.010) | 0.193 (0.005)a,b | 0.186 (0.015) | 0.218 (0.016)a,b | <.0001b | .0334b |
| Imax, mm4 | 0.201 (0.030) | 0.174 (0.020) | 0.175 (0.023) | 0.205 (0.022) | NS | .0016 |
| Imin, mm4 | 0.115 (0.013) | 0.087 (0.012)a | 0.098 (0.005) | 0.102 (0.011)c | .0016 | <.0001 |
| pMOI, mm4 | 0.316 (0.043) | 0.262 (0.031) | 0.273 (0.028) | 0.307 (0.030) | NS | .0004 |
| Fifth lumbar vertebra (trabecular) | ||||||
| BV/TV, % | 32.5 (2.4) | 27.3 (1.9)a | 28.7 (4.2) | 25.0 (2.5)a | <.0001 | NS |
| Tb.N, per mm | 5.41 (0.26) | 5.03 (0.24) | 4.90 (0.53) | 4.86 (0.18) | NS | NS |
| Tb.Th, mm | 0.056 (0.002) | 0.057 (0.001) | 0.055 (0.002) | 0.054 (0.003) | NS | NS |
| Tb.Sp, mm | 0.192 (0.011) | 0.190 (0.013) | 0.209 (0.023) | 0.197 (0.009) | NS | NS |
| Conn.D, per mm | 340.9 (23.1) | 220.6 (25.0)a | 250.7 (33.7) | 200.2 (17.2)a | <.0001 | .0003 |
| SMI | 0.055 (0.280) | 0.766 (0.218)a | 0.478 (0.437) | 0.965 (0.228)a | <.0001 | NS |
Abbreviation: NS, not significant. Trabecular parameters included BV/TV (percentage), Tb.Th (micrometers), Tb.Sp (micrometers), Tb.N (1/millimeter), Conn.D (1/cubic millimeters), and SMI. Cortical parameters included total cross-sectional area, cortical bone area, and medullary area (TA, BA, and MA, square millimeters); BA/TA (percentage), cortical thickness (micrometers), and area moments of inertia (Imax, Imin, and pMOI, millimeters to the fourth power).
Bold text indicates significant difference from SWR (P < .05, two way ANOVA and Fisher's PLSD).
No longer significant after body mass adjustment.
Statistically significant after body mass adjustment.