Table 1.
Age-Adjusted Comparison of Postmenopausal Women With and Without Specific Vertebral Deformities (Semiquantitative Assessment) With Respect to Five Predictor Variable Categories and Percentage Differences (Δ%) Relative to Women With No Deformity
| Variable (units) | No deformity (n = 90) | Mild (grade 1) deformity only (n = 142) | Δ% | Any severe (grade 2–3) deformity (n = 51) | Δ% |
|---|---|---|---|---|---|
| Bone density | |||||
| Lumbar spine (LS) aBMD (g/cm2) | 1.12 ± 0.16 | 1.09 ± 0.18† | −3 | 1.04 ± 0.17** | −7 |
| Femoral neck aBMD (g/cm2) | 0.88 ± 0.15 | 0.84 ± 0.12† | −5 | 0.79 ± 0.09*** | −10 |
| Total radius aBMD (g/cm2) | 0.61 ± 0.08 | 0.59 ± 0.09†† | −3 | 0.55 ± 0.10** | −10 |
| LS total vBMD (mg/cm3) | 185 ± 38 | 170 ± 35**,††† | −8 | 149 ± 28*** | −19 |
| LS trabecular vBMD (mg/cm3) | 146 ± 32 | 133 ± 29**,††† | −8 | 115 ± 21*** | −21 |
| Distal radius trabecular vBMD (mg/cm3) | 139 ± 42 | 132 ± 41†† | −5 | 108 ± 42*** | 22 |
| Distal radius cortical vBMD (mg/cm3) | 870 ± 65 | 861 ± 67 | −1 | 845 ± 82 | −3 |
| Bone geometry (lumbar spine) | |||||
| Cross-sectional area (cm2) | 10.3 ± 1.1 | 10.5 ± 1.3 | 2 | 10.7 ± 1.5 | 4 |
| Endocortical area (cm2) | 8.58 ± 1.05 | 8.85 ± 1.24 | 3 | 9.08 ± 1.29* | 6 |
| Cortical area (cm2) | 1.76 ± 0.24 | 1.71 ± 0.25 | −3 | 1.65 ± 0.28* | −6 |
| Apparent cortical thickness (mm) | 1.68 ± 0.26 | 1.58 ± 0.24**,† | −6 | 1.48 ± 0.26*** | −12 |
| Bone microstructure (distal radius) | |||||
| Trabecular bone volume/total volume (%) | 0.12 ± 0.04 | 0.11 ± 0.03†† | −8 | 0.09 ± 0.03*** | −25 |
| Trabecular number (1/mm) | 1.64 ± 0.38 | 1.55 ± 0.39† | −5 | 1.38 ± 0.43*** | −16 |
| Trabecular thickness (µm) | 70.0 ± 11.2 | 70.5 ± 11.4†† | 1 | 64.5 ± 10.4* | −8 |
| Trabecular separation (Tb.Sp, µm) | 605 ± 308 | 638 ± 306† | 5 | 770 ± 403** | 27 |
| Tb.Sp distribution (µm) | 301 ± 231 | 346 ± 302† | 15 | 453 ± 389** | 51 |
| Connectivity density (1/mm3) | 3.06 ± 1.07 | 2.89 ± 1.07†† | −6 | 2.36 ± 1.00*** | −23 |
| Structure model index | 2.32 ± 0.39 | 2.35 ± 0.37†† | 1 | 2.57 ± 0.28*** | 11 |
| Cortical thickness (mm) | 0.82 ± 0.21 | 0.78 ± 0.20 | −5 | 0.71 ± 0.21** | −13 |
| Bone strength (lumbar spine) | |||||
| Overall compressive strength (N) | 5528 ± 1898 | 4952 ± 1565*,†† | −10 | 4089 ± 1344*** | −26 |
| “Cortical” strength (N) | 2976 ± 717 | 2796 ± 711†† | −6 | 2486 ± 702*** | −16 |
| Trabecular strength (N) | 2852 ± 1289 | 2493 ± 956*,†† | −13 | 1931 ± 675*** | −32 |
| “Homogenized” trabecular strength (N) | 3912 ± 1609 | 3466 ± 1241*,†† | −11 | 2853 ± 1072*** | −27 |
| Strength per unit density (N · cm3/mg) | 31.5 ± 4.9 | 30.9 ± 4.7††† | −2 | 28.2 ± 5.2*** | −10 |
| AP bending stiffness (kNm/rad) | 2.39 ± 0.85 | 2.22 ± 0.78† | −7 | 1.94 ± 0.73** | −19 |
| Load to strength (ϕ, lumbar spine) | |||||
| Upright standing | 0.08 ± 0.03 | 0.09 ± 0.03*,††† | 12 | 0.12 ± 0.05*** | 50 |
| 45-Degree forward flexion | 0.35 ± 0.12 | 0.39 ± 0.14*,††† | 11 | 0.50 ± 0.22*** | 43 |
| 90-Degree forward flexion | 0.39 ± 0.13 | 0.44 ± 0.16*,††† | 13 | 0.58 ± 0.26*** | 49 |
| 90-Degree forward flexion while lifting 10 kg | 0.55 ± 0.18 | 0.61 ± 0.21††† | 11 | 0.81 ± 0.36*** | 47 |
*
p < .05
**
p < .01
***
p < .001 age-adjusted p values for each group compared with women with no deformities.
†
p < .05
††
p < .01
†††
p < .001 age-adjusted p values for those with grade 1 deformities compared with women with grade 2–3 deformities.