Evaluation and management of osteochondral lesions of the knee.

Osteochondral lesions of the knee is a common disorder in adolescents, although it may present in children and adults. Despite the fact that the disorder was discovered more than a century ago, no specific causes have been identified, although relationships with ischemia, irregular ossification of epiphyseal cartilage, genetic influences, trauma, and endocrine disorders have been postulated. Taking a thorough history and performing a thorough physical examination will facilitate diagnosis of this condition. Radiographic and magnetic resonance imaging are useful diagnostic tools that aid in the evaluation. A comprehensive knowledge of the relevant anatomy and clinical progression of osteochondral lesions allows for a better understanding of the classification systems and, ultimately management of this disorder. The size, location, and stability of the lesion, as well as the patient's age, are crucial in determining optimal treatment. The spectrum of injury ranges from small, stable lesions, which can be treated nonoperatively, to unstable or displaced lesions, which may require surgical management. Surgical options include drilling of subchondral bone, curettage and microfracture, refixation of detached lesions, autologous osteochondral autograft procedures (eg, mosaicplasty, osteochondral autograft transfer system), autologous chondrocyte implantation, and osteochondral allograft resurfacing. This article provides a basic approach to the evaluation and management of osteochondral lesions, as well as indications for surgery.