Osteochondritis dissecans of the knee in children.

Osteochondritis dissecans is a term used to describe the separation of an articular cartilage subchondral bone segment from the remaining articular surface. Juvenile osteochondritis dissecans describes an osteochondritis dissecans lesion found in skeletally immature children with a maximum incidence occurring between the ages of 10 and 20. It is found more frequently in children who are active athletically and involved in organized sports and is twice as common in males as in females. Although the etiology of these lesions is unclear, it is believed that repetitive microtrauma may interrupt the already tenuous epiphyseal blood supply in the growing child and contribute to the development of osteochondritis dissecans lesions. Treatment is dependent upon age at presentation, fragment size, fragment location, and fragment stability. Stable lesions in skeletally immature patients are generally amenable to conservative management. Failed conservative management or unstable lesions will more likely require surgical intervention. Lesions in skeletally mature patients have a more unpredictable course and may require surgery. This review article discusses the anatomy, etiology, evaluation, classification, treatment, and expected outcome of osteochondritis dissecans lesions.