A locked knee in an adolescent boy: resolving meniscal pathology in young athletes.

A young athlete presenting with a locked knee is an uncommon occurrence in most outpatient clinics. Locked knees in children are primarily caused by meniscal tears, a discoid meniscus, or osteochondritis dissecans. When diagnosing meniscal tears, the history, physical examination, MRI, and/or arthroscopy are used to support a definitive diagnosis.