Table 3 Spearman’s rank correlation coefficients (r with respective p-value) of FEM-based ACM, BMD, and trabecular bone microstructure parameters of the formalin-fixed and frozen vertebrae at baseline, 3 and 6 month follow-up with failure load (FL) as determined after six months. Correlation coefficients were not significantly different for the two preservation methods as compared by using the Fisher Z transformation (p > 0.05)
| Â | Â | Â | FL [N] | |
|---|---|---|---|---|
| Â | Preservation | Baseline | 3Â month follow-up | 6Â month follow-up |
FEM-based ACM [N/mm2] | frozen (n = 6) | 0.94 (p = 0.005) | 0.99 (p < 0.001) | 0.99 (p < 0.001) |
FEM-based ACM [N/mm2] | formalin (n = 6) | 0.94 (p = 0.005) | 0.94 (p = 0.005) | 0.94 (p = 0.005) |
BMD [mg/cm3] | frozen (n = 6) | 0.99 (p < 0.001) | 0.99 (p < 0.001) | 0.99 (p < 0.001) |
BMD [mg/cm3] | formalin (n = 6) | 0.89 (p = 0.019) | 0.93 (p = 0.008) | 0.89 (p = 0.019) |
app. BV/TV | frozen (n = 6) | 0.94 (p = 0.005) | 0.93 (p = 0.008) | 0.89 (p = 0.019) |
app. BV/TV | formalin (n = 6) | 0.94 (p = 0.005) | 0.89 (p = 0.019) | 0.89 (p = 0.019) |
app. TbN [mm−1] | frozen (n = 6) | 0.94 (p = 0.005) | 0.89 (p = 0.019) | 0.89 (p = 0.019) |
app. TbN [mm−1] | formalin (n = 6) | 0.94 (p = 0.005) | 0.89 (p = 0.019) | 0.89 (p = 0.019) |
app. TbSp [mm] | frozen (n = 6) | −0.94 (p = 0.005) | −0.89 (p = 0.019) | −0.89 (p = 0.019) |
app. TbSp [mm] | formalin (n = 6) | −0.94 (p = 0.005) | −0.89 (p = 0.019) | −0.89 (p = 0.019) |
app. TbTh [mm] | frozen (n = 6) | 0.94 (p = 0.005) | 0.99 (p < 0.001) | 0.94 (p = 0.005) |
app. TbTh [mm] | formalin (n = 6) | 0.94 (p = 0.005) | 0.94 (p = 0.005) | 0.89 (p = 0.019) |
FD | frozen (n = 6) | 0.94 (p = 0.005) | 0.94 (p = 0.005) | 0.93 (p = 0.008) |
FD | formalin (n = 6) | 0.89 (p = 0.019) | 0.89 (p = 0.019) | 0.89 (p = 0.019) |