COMP and osteochondritis dissecans: In order to elucidate the molecular bases of OCD development, several investigations have focused on the study of the different biochemical changes that may appear during joint diseases, as well as the distribution pattern of main matrix molecules (Type II collagen, cartilage oligomeric matrix protein, large-aggregate proteoglycans, fibronectin, cartilage matrix protein and biglycan) following the development of early lesions resulting in necrosis of the epiphyseal cartilage [4].