Histological Analysis of Articular Cartilage

The knee samples were fixed in 4% paraformaldehyde at 4 °C for 24 h and then decalcified in 10% EDTA (pH 7.4) for 3 weeks. Subsequently, the joint tissues (the medial femoral condyle) were embedded in paraffin and the 5 μm of the paraffin-embedded tissues were stained using hematoxylin–eosin staining (HE), Masson’s trichrome staining (Masson) and alcian blue staining(Alcian blue). Slides were examined using an optical microscope equipped with a digital CCD camera (Olympus, Japan). The severity of the degradation of the articular cartilage was scored according to the Osteoarthritis Research Society International (OARSI) scoring system as previously described[25 (link)].