Figure 1.

Histology of the knee joint. (A–D) To confirm the OA progression, histological sections were stained with Safranin O at 1, 2, and 4 weeks after injection of MIA. Anatomical labels of knee joint are shown in D. Scale bar: 1 mm. Loss of cartilage matrix is recognized as smaller or almost no area or lacy appearance (C) of red staining of Safranin, as shown with dotted line. This change occurred from 1 week after injection of MIA. The arrows in B and C show osteophytes. (E) μCT images of the knees of rat of the sham group (left) and MIA group (right) 4 weeks after injection. The upper panels are three-dimensional reconstruction images and the lower panels are the sagittal plane images. MIA group showed irregular surface and destroyed cartilage.