Osteochondritis Dissecans is a painful medical condition within a joint of the body in humans or animals, in which fragments of cartilage or bone have become loose within a joint, leading to pain and inflammation. These fragments are sometimes referred to as "joint mice" due to a squeaking sound sometimes resulting from the joint. Specifically, OCD is a type of osteochondrosis in which a lesion has formed within the cartilage layer itself, giving rise to secondary inflammation. It has a complex etiology, and can be caused by genetic, hormonal, environmental and nutritional factors.
Anyone can get osteochondritis dissecans but it happens more often in boys and young men 10 to 20 years old, while they are still growing. Osteochondritis dissecans is being diagnosed more often in girls as they become more active in sports.