Photomicrographs of sections stained with picrosirius-hematoxylin and analyzed by bright-field microscopy under polarized light (D-F and J-L). A-F: Control group; G-L: treated group. Specimens were collected 7 (A, D, G, and J), 21 (B, E, H, and K) and 35 (C, F, I, and L) days after experimental injury. (*) Original cartilage; (→) collagen fibers; (▸) blood vessels. Bar, 50 μm.