Alteration patterns of trabecular bone microarchitectural characteristics induced by osteoarthritis over time

Figures & data

Figure 1 Micro-computed tomography (μ-CT) scan, 3-D reconstruction, region of interest (ROI) and volume of interest (VOI) selection, and bone microarchitecture analysis in 3-D trabecular bone.

Abbreviations: BV/TV, bone volume/tissue volume; BS/BV, bone surface/bone volume; Tb.Pf, trabecular bone pattern factor; Tb.N, trabecular bone number; Tb.Th, trabecular bone thickness; Tb.Sp, trabecular bone separation.

Figure 2 (A–F) Relative variables of trabecular bone microarchitecture in the tibial epiphysis at weeks 0, 4, and 8 (black bar, control group; white bar, osteoarthritis group).

Notes: *Difference between groups; **difference between weeks, P < 0.05).
Abbreviations: BV/TV, bone volume/tissue volume; BS/BV, bone surface/bone volume; Tb.Pf, trabecular bone pattern factor; Tb.N, trabecular bone number; Tb.Th, trabecular bone thickness; Tb.Sp, trabecular bone separation.

Table 1 Incidence of microarchitectural alterations in each microarchitectural parameter in terms of the individual analysis for control and osteoarthritis groups

	Control (n = 7)		Osteoarthritis (n = 7)
	Number of increases	Number of decreases	Number of increases	Number of decreases
0–4 weeks
BV/TV	7	0	2	5
BS/BV	0	7	7	0
Tb.Pf	0	7	5	2
Tb.N	3	4	7	0
Tb.Th	7	0	0	7
Tb.Sp	0	7	7	0
4–8 weeks
BV/TV	3	4	0	7
BS/BV	4	3	7	0
Tb.Pf	3	4	7	0
Tb.N	2	5	0	7
Tb.Th	3	4	0	7
Tb.Sp	0	7	7	0

Abbreviations: BV/TV, bone volume/total volume; BS/BV, bone surface/ bone volume; Tb.Pf, trabecular bone pattern factor; Tb.N, trabecular number; Tb.Th, trabecular thickness; Tb.Sp, trabecular separation.

Figure 3 Alteration of trabecular bone thickness distribution in the tibial epiphysis at weeks 0, 4, and 8 (vertical axis, trabecular bone thickness, mm; horizontal axis, bone percentage; black bar, control group; white bar, osteoarthritis group).

Notes: *Differences between groups; **difference from 0 to 4 weeks; ***difference from 4 to 8 weeks.
Abbreviations: BV/TV, bone volume/tissue volume; BS/BV, bone surface/bone volume; Tb.Pf, trabecular bone pattern factor; Tb.N, trabecular bone number; Tb.Th, trabecular bone thickness; Tb.Sp, trabecular bone separation.

Figure 4 (A–C) Alteration in trabecular bone separation distribution in the tibial epiphysis at weeks 0, 4, and 8 (vertical axis, trabecular bone separation, mm; horizontal axis, bone percentage; black bar, control group; white bar, osteoarthritis group).

Notes: *Differences between groups; **0–4, difference from 0 to 4 weeks; ***4–8, difference from 4 to 8 weeks.

Table 2 Changes in bone mineral density (vBMD) of control and osteoarthritis groups at 0, 4, and 8 weeks

	Volumetric bone mineral density (g/cm^3)
	Control (n = 7)	Osteoarthritis (n = 7)
0 weeks	0.35 ± 0.04	0.35 ± 0.04
4 weeks	0.48 ± 0.04a	0.45 ± 0.03a
8 weeks	0.47 ± 0.05	0.31 ± 0.05b,*

Notes: Values are mean ± standard deviation;

a significant changes from 0 weeks;

b significant changes from 4 weeks;

* significant difference between control and osteoarthritis groups at 0, 4, and 8 weeks, P < 0.05.

Figure 5 Representative radiological results in osteoarthritic (OA group) and normal (CON group) knee joints at 0, 4, and 8 weeks (white arrowhead, bone erosion and osteophyte formation).

Abbreviations: OA, osteoarthritis; CON, control group.

Figure 6 Representative histological sections of osteoarthritis (OA group) and normal (CON group) knee joints (black arrowheads in the ×20 magnification of the OA section show bone erosion, inflammation, pannus formation, and synovial hypertrophy).

Abbreviations: OA, osteoarthritis; CON, control group.