Table 4.

Correlation coefficient of linear regression between the subchondral microstructure and biomechanical properties in the OA, OP and NC groups.

Microstructure	OA (n = 13)		OP (n = 17)		NC (n = 8)
	Stiffness	Failure Load	Stiffness	Failure Load	Stiffness	Failure Load
Standard micro-CT
BV/TV (%)	0.95∗∗	0.98∗∗	0.89∗∗	0.86∗∗	0.84∗∗	0.74∗
Tb.N (1/mm)	0.92∗∗	0.93∗∗	0.56∗	0.52∗	0.58	0.46
Tb.Th (mm)	0.67∗	0.69∗∗	0.69∗∗	0.68∗∗	0.65	0.65
Tb.Sp	−0.83∗∗	−0.85∗∗	−0.48	−0.46	−0.28	−0.17
SMI	−0.89∗∗	−0.91∗∗	−0.90∗∗	−0.91∗∗	−0.92∗∗	−0.88∗∗
Conn.D (1/mm3)	0.82∗∗	0.85∗∗	0.29	0.24	0.38	0.26
ITS-based micro-CT
aBV/TV (%)	0.98∗∗	0.97∗∗	0.90∗∗	0.87∗∗	0.90∗∗	0.84∗∗
pBV/TV (%)	0.96∗∗	0.97∗∗	0.87∗∗	0.84∗∗	0.92∗∗	0.84∗∗
rBV/TV (%)	0.80∗∗	0.85∗∗	0.17	0.15	−0.57	−0.6
pTb.N (1/mm)	0.82∗∗	0.83∗∗	0.58∗	0.53∗	0.87∗∗	0.82∗
rTb.N (1/mm)	0.86∗∗	0.88∗∗	0.08	0.04	0.55	0.47
pTb.Th (mm)	0.88∗∗	0.88∗∗	0.70∗∗	0.68∗∗	−0.34	−0.34
rTb.Th (mm)	0.31	0.37	0.13	0.16	−0.91∗∗	−0.91∗∗
pTb.S (mm2)	0.37	0.36	0.36	0.39	−0.62	−0.61
rTb.l (mm)	0.66∗	0.71∗∗	0.09	0.14	−0.89∗∗	−0.88∗∗
R–R Junc.D (1/mm3)	0.67∗	0.72∗∗	−0.18	−0.21	0.24	0.15
R–P Junc.D (1/mm3)	0.95∗∗	0.96∗∗	0.50∗	0.44	0.78∗	0.68
P–P Junc.D (1/mm3)	0.87∗∗	0.88∗∗	0.54∗	0.49∗	0.79∗	0.71
μFEA
Stiffness (kN/mm)	1	0.987∗∗	1	1∗∗	1	0.98∗∗
Failure Load (MPa)	0.99∗∗	1	1∗∗	1	0.98∗∗	1
OARSI	−0.29	−0.24	−0.22	−0.22	−0.33	−0.42

∗p < 0.05.

∗∗p < 0.01.

a = axial; BV = bone volume; Conn.D = connenctivity density; CT = computed tomography; ITS = ; NC = normal control; OA = osteoarthritis; OP = osteoporosis. p = plate; P–P Junc.D = plate–plate junction density; r = rod; R–P Junc.D = rod–plate junction density; R–R Junc.D = rod–rod junction density; SMI = structure model index; Tb.l = trabecular length; Tb.N = trabecular number; Tb.S = trabecular surface area; Tb.Sp = trabecular separation; Tb.Th = trabecular thickness; TV = total volume.