Estrogen deficiency induces severe LFJ cartilage degradation. (A) Staining LFJ with HE, safranin O/Fast green and terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) in different groups. Chondrocyte clusters (black arrow head), hypertrophic chondrocytes (blue arrow head), osteocyte lacunaes (green arrow head) and apoptotic chondrocytes(yellow arrow head) are seen in OVX and OVX+ Veh-treated groups (magnification 400×). (B) Quantitative evaluation of LFJ cartilage degeneration in different groups. Cartilage erosion is labeled with double-headed arrows (magnification 600×). (C) Quantitative evaluation of LFJ chondrocytes apoptosis in different groups (magnification 600×). Key: **P < 0.01, ***P < 0.001, (N.S.) not significant.