Table 2.

Basic information about the included animal studies

Author	Year	Imaging tool and indicator	Animal and modeling method	Evaluation time	Result	Conclusion	Relevance
Xiao et al. [26]	2019	Micro-CT: BV/TV; BS/TV; Tb.N; Tb.Th; Tb.Sp; SMI; BMDtv	C57BL/6 J mice Female a total of 40, 10 per group OVX	12 weeks	OVX can cause vertebral trabecular thinning, cartilage endplate ossification, and angiogenesis	OVX can cause disc degeneration	Positive correlation
Xiao et al. [27]	2018	Micro-CT: BMDtv; BV/TV; Tb.N; Tb.Th; Tb.Sp; Tb.Pf; CONN.D; SMI; Po.N(cl); PO(op); Po.V(tot)	C57BL/6 J mice female a total of 30, 15 per group OVX	12 weeks	A large number of osteoclasts appeared in the subchondral bone and cartilage endplates in the OVX group, and the expression of OSX, OPN, and VEGF in the endplates was elevated	OVX induces vertebral osteoporosis and endplate osteochondral remodeling, promoting angiogenesis and increased porosity of the osteochondral surface	Positive correlation
Li et al. [28]	2016	Micro-CT: build the 3D images to show the bottom of L4 vertebrae and top of L5 vertebrae, evaluate the newly formed bone marrow cavities	Opg KO mice	8, 12, 24 weeks	New bone formation in endplate cartilage and increased VEGF-A, CD31, VE-cadherin, CD34, IL-1β, and TNF-α protein expression in endplate of Opg knockout mice	Increased expression of neovascularization and inflammatory cytokines in the lumbar disc of Opg knockout mice	Positive correlation
Zhong et al. [29]	2016	DEXA: BMD MRI: Pfirrmann grading system Micro-CT: BV/TV; Tb.N; Tb.Th; Tb.Sp; SMI	rhesus monkey female a total of 12, 6 per group OVX + PYM injection	12 months	PYM injection caused disc degeneration, which was more pronounced when combined with OVX. Endplate calcification was more severe in the OVX + PYM group, and endplate vascularization was lower than in the other groups	Osteoporosis can lead to accumulation of calcification in the endplate and reduced vascularization	Positive correlation
Ding et al. [30]	2014	Micro-CT: BV/TV; SMI; Tb.N; Tb.Th; Tb.Sp; Mdtv	SD rats female a total of 52 OVX + CMS	12, 18, 24 weeks	The CMS-OVX group showed cartilage endplate wear at 12 weeks postoperatively and in situ calcification at 18 and 24 weeks postoperatively	CMS combined with OVX causes more severe cartilage endplate damage than OVX alone. The cartilage endplates wear early and calcify in situ later	Positive correlation
Zhang et al. [31]	2012	DEXA: BMD	SD rats female a total of 100, 50 per group natural aging	22, 28 months	Indicators of osteoporosis are negatively correlated with indicators of disc degeneration	Osteoporosis was negatively correlated with disc degeneration	Negative correlation
Wang et al. [32]	2004	DEXA: BMD	SD rats female a total of 30, 10 per group OVX	6 months	There was a significant negative correlation between the bone mineral density and Grade II discs in the OVX rats	Cartilage endplate degeneration as a possible causative factor for disc degeneration	Negative correlation