Fig. 4

Histological and microstructural changes in the subchondral bone of the superior articular surface in OA model rats. Representative images from experiments are shown. a Safranin O/fast green-stained sections of the subchondral bone of the tibia. The damaged region of the articular surface is indicated by black arrows. Scale bar = 200 μm. b 2D imaging of the structure of the subchondral bone of the tibia. The damaged region of the articular surface is indicated by white arrows. c 3D imaging of the medial compartment of the subchondral bone of the tibia. Scale bar = 1.0 mm. d Quantitative results based on the OARSI scoring system. e, f Quantitative results of the structural parameters of the tibial subchondral bone, including BV/TV (trabecular BV per TV) and BMD (n = 8, *P < 0.05, **P < 0.01 vs sham)