Table 3.
Femoral microarchitecture assessed by μCT of 1- and 3-mo-old male conditional Dmp1-Cre+/−;RbpjκΔ/Δ null mice (RbpjκΔ/Δ) and RbpjκloxP/loxP controls of the same sex (Control)
| 1 Month |
3 Months |
|||
|---|---|---|---|---|
| Males | Control | RbpjκΔ/Δ | Control | RbpjκΔ/Δ |
| Trabecular bone | ||||
| Bone volume/tissue volume (%) | 4.9 (3.7–6.5) | 4.7 (3.3–5.0) | 8.5 (6.7–13.1) | 8.2 (7.3–12.6) |
| Trabecular separation (μm) | 201 (179–231) | 190 (188–278) | 200 (181–213) | 212 (204–219)* |
| Trabecular number (1/mm) | 5.0 (4.3–5.6) | 5.3 (3.6–5.3) | 4.9 (4.6–5.3) | 4.6 (4.5–4.8) |
| Trabecular thickness (μm) | 20 (20–22) | 21 (20–23) | 33 (31–41) | 34 (33–41) |
| Connectivity density (1/mm3) | 207 (71–386) | 136 (94–175) | 225 (198–281) | 206 (162–253) |
| Structure model index | 3.1 (3.0–3.2) | 3.1 (2.9–3.2) | 2.3 (2.0–2.5) | 2.4 (2.0–2.7) |
| Density of material (mg HA/cm3) | 893 (865–907) | 899 (867–916) | 933 (929–940) | 922 (906–936)* |
| Cortical bone | ||||
| Bone volume/tissue volume (%) | 87.9 (87.6–88.8) | 87.1 (86.2–87.6) | 88.6 (87.5–91.1) | 89.0 (87.2–90.0) |
| Cortical thickness (μm) | 88.5 (80.0–90.0) | 83.0 (80.0–87.0) | 145.0 (129.0–173.0) | 142.5 (128.0–162.0) |
| Periosteal perimeter (mm) | 4.1 (4.0–4.4) | 4.3 (4.3–4.4) | 4.3 (4.2–4.6) | 4.6 (4.3–4.8) |
| Endosteal perimeter (mm) | 3.4 (3.3–3.7) | 3.6 (3.6–3.7) | 3.2 (3.1–3.3) | 3.4 (3.3–3.5)* |
| Total area (mm2) | 1.3 (1.3–1.5) | 1.5 (1.4–1.5) | 1.5 (1.4–1.7) | 1.7 (1.5–1.9) |
| Bone area (mm2) | 0.39 (0.36–0.45) | 0.41 (0.39–0.43) | 0.66 (0.58–0.81) | 0.70 (0.61–0.85) |
Values are medians (minimum and maximum values for each parameter); n = 3–6. μCT was performed on femurs from Dmp1-Cre+/−;RbpjκΔΔ and control RbpjkloxP/loxP littermates.
*
Significantly different from controls by Mann-Whitney U-test, P < 0.05.