Osteochondritis dissecans (OCD) is an inflammatory pathology of the bone and cartilage. OCD is most commonly seen in adolescents, particularly those who play sports that require throwing or repetitive upper limb motions (e.g., baseball).

OCD occurs when a piece of bone and cartilage near the elbow breaks off, essentially causing it to die due to the lack of blood supply. The end result of OCD in the elbow is damaged cartilage which causes pain and discomfort when engaging in physical activity.