Estrogen deficiency accelerates LFJ subchondral bone resorption. (A) Representative TRAP staining images show abnormal bone remodeling in subchondral bone marrow in OVX and OVX+ Veh-treated groups (magnification 600×). (B) Increased osteoclasts are shown in subchondral bone cavities (green arrow head; magnification 1000×). (C and D) Quantitative evaluation of osteoclasts in LFJ subchondral bone. Key: *P < 0.05, (N.S.) not significant.