Role of magnetic resonance imaging and clinical criteria in predicting successful nonoperative treatment of osteochondritis dissecans in children.

Magnetic resonance imaging (MRI) offers promise as a noninvasive method to determine the potential of an osteochondritis dissecans (OCD) lesion to heal without surgical intervention. The purpose of this study was to compare the value of MRI, plain radiographs, and clinical findings in predicting the success of nonoperative treatment of juvenile OCD lesions. Twenty-seven lesions in 24 patients (mean age 12.2 y) with OCD of the distal femur diagnosed based on MRI were identified. A radiologist or orthopaedist, blinded to the clinical status of the patients, correlated the MRIs with patient outcome. MRIs were assessed for lesion size, location, and four criteria evaluating signal intensity changes and articular surface defects to determine lesion stability. Older, more skeletally mature patients with at least one sign of instability on MRI were most likely to have nonoperative treatment fail. Nonoperative treatment failed most often in patients with large lesions in weightbearing areas, as seen on lateral radiographs. However, location based on anteroposterior radiographs was not statistically significant for predicting treatment outcome. Although no single factor was uniformly predictive of successful nonoperative treatment, younger, skeletally immature patients with no MRI criteria of instability were most amenable to nonoperative treatment.