Cortical bone loss is an early feature of nonradiographic axial spondyloarthritis

Table 3 Bone microstructure in patients with nonradiographic axial spondyloarthritis with short and longer disease duration and in healthy control subjects

	axSpA < 2 yr (n = 46)	axSpA > 2 yr (n = 55)	Control subjects (n = 50)	axSpA < 2 yr vs. axSpA > 2 years vs. control subjects	axSpA < 2 yr vs. control subjects	axSpA < 2 yr vs. axSpA > 2 yr	axSpA > 2 yr vs. control subjects
Bone geometry
Total bone area, mm²	317 (114)	349 (94)	326 (116)	0.060	0.322	0.023	0.136
Ct. area, mm²	59 (18)	61 (22)	65 (23)	0.068	0.032	0.703	0.066
Tb. area, mm²	250 (95)	277 (88)	254 (83)	0.068	0.628	0.041	0.062
Volumetric bone mineral density
Total BMD, HA/cm³	317 (49)	309 (75)	334 (61)	0.096	0.170	0.423	0.036
Ct. BMD, HA/cm³	833 (62)	814 (65)	846 (78)	0.012	0.096	0.167	0.004
Tb. BMD, HA/cm³	173 (44)	175 (47)	183 (68)	0.571	0.289	0.564	0.610
Tb. meta BMD, HA/cm³	233 (38)	234 (51)	243 (61)	0.561	0.294	0.728	0.465
Tb. inn BMD, HA/cm³	132 (47)	135 (52)	141 (72)	0.618	0.359	0.464	0.753
Bone microstructure
BV/TV, %	14.4 (3.7)	14.6 (3.9)	15.2 (5.7)	0.575	0.288	0.564	0.628
Tb. N, mm^− 1	2.12 (0.30)	2.05 (0.41)	2.11(0.42)	0.534	0.739	0.263	0.480
Tb. Th, μm	68 (15)	71 (15)	72 (17)	0.244	0.171	0.120	0.946
Tb. Sp, μm	410 (66)	423 (107)	410 (104)	0.677	0.956	0.480	0.424
Inhomogeneity, μm	165 (41)	178 (48)	169 (47)	0.351	0.575	0.149	0.399
Ct. Th, μm	775 (160)	759 (235)	840 (160)	0.015	0.050	0.245	0.007
Ct. Po, %	2.0 (1.46)	2.8 (1.72)	2.2 (1.57)	0.064	0.373	0.020	0.157

Abbreviations: BMD Bone mineral density, SpA Spondyloarthritis, Ct. Cortical, Tb. Trabecular, Tb. meta Bone mineral density peripheral trabecular density adjacent to cortex, Tb. inn Bone mineral density central medullary trabecular density, BV/TV Trabecular bone volume, Th Thickness, Sp Separation, Po Porosity
Bone geometry, microstructure, and volumetric BMD by high-resolution peripheral quantitative computed tomography at the ultradistal radius. Results are median (IQR)
Bold indicates significant differences (p < 0.05)

ISSN: 1478-6362