Osteochondritis dissecans (OCD) is a condition that develops in joints, most often in children and adolescents. It occurs when a small segment of bone begins to crack and separate from its surrounding region due to a lack of blood supply.| orthoinfo.aaos.org
Active teenagers or young adults who participate in sports sometimes experience pain in the front of the knee, usually underneath the kneecap. This type of pain is not usually caused by a physical abnormality in the knee, but by overuse or inadequate stretching.| orthoinfo.aaos.org