Table 2 Comparison of bone structure and biomechanical properties in no-DMARD-, methotrexate-, and bDMARD-treated PsA patients
|  | No DMARDs (N = 79) | Methotrexate (N = 34) | bDMARDs (N = 52) | p value a/b |
|---|---|---|---|---|
Finite element analysis | ||||
 Stiffness (kN/mm), (mean ± SD) | 45.2 ± 13.7 | 46.7 ± 14.2 | 52.1 ± 15.0 b | −/0.012 |
 Failure load (N), (mean ± SD) | 2154 ± 621 | 2242 ± 645 | 2473 ± 704 b | −/0.012 |
Bone parameters | ||||
 Volumetric bone mineral density | ||||
  Dtotal mg HA/cm3, (mean ± SD) | 290 ± 54 | 299 ± 63 | 320 ± 44 b | −/0.001 |
  Dtrab, mg HA/cm3, (mean ± SD) | 156 ± 39 | 166 ± 40 | 174 ± 36 b | −/0.005 |
  Dmeta, mg HA/cm3, (mean ± SD) | 214 ± 38 | 222 ± 39 | 236 ± 35 b | −/0.001 |
  Dinn, mg HA/cm3, (mean ± SD) | 116 ± 41 | 127 ± 43 | 132 ± 40 b | −/0.026 |
  Dcomp, mg HA/cm3, (mean ± SD) | 817 ± 57 | 817 ± 72 | 831 ± 43 | −/− |
  Meta/Inn, %, (mean ± SD) | 1.9 ± 0.5 | 1.9 ± 0.8 | 2.0 ± 0.8 | −/− |
 Bone microstructure | ||||
  BV/TV, %, (mean ± SD) | 0.13 ± 0.03 | 0.14 ± 0.03 | 0.15 ± 0.03 b | −/0.005 |
  Tb.N, 1/mm, (mean ± SD) | 1.99 ± 0.35 | 2.05 ± 0.36 | 2.12 ± 0.32 b | −/0.022 |
  TbTh, mm, (mean ± SD) | 0.065 ± 0.010 | 0.067 ± 0.011 | 0.069 ± 0.010 b | −/0.030 |
  Tb.Sp, mm, (mean ± SD) | 0.47 ± 0.18 | 0.44 ± 0.10 | 0.42 ± 0.11 b | −/0.010 |
  Tb.1/N.SD, mm, (mean ± SD) | 0.21 ± 0.16 | 0.19 ± 0.08 | 0.19 ± 0.13 b | −/0.017 |
  Ct.Th, mm, (mean ± SD) | 0.71 ± 0.16 | 0.73 ± 0.18 | 0.80 ± 0.15 b | −/0.001 |
 Bone area | ||||
  Cross-sectional area (mean ± SD) | 321 ± 76 | 335 ± 88 | 325 ± 80 | −/− |