pathologic lesion affecting articular cartilage and subchondral bone with variable clinical patterns.
Diagnosis may be made radiographically (notch view)
but MRI usually required to determine size and stability of lesion, and to document the degree of cartilage injury.
Treatment may be nonoperative with restricted weight bearing in children with open physis
Surgical treatment may be indicated in older patients (closed physis), lesions that are unstable and patients who have failed conservative management.
juvenile form (open physes)
occurs at age 10-15 while the physis is still open
adult form (skeletal maturity)
knee (most common)
posterolateral aspect of medial femoral condyle (70% of lesions in knee)
capitellum of humerus
mechanism/etiology may be
cause of adult form is thought to be vascular
softening of the overlying articular cartilage with intact articular surface
early articular cartilage separation