Review Question - QID 220048

A 12-year-old female soccer player is brought to the office by her parents with atraumatic, vague left knee pain that is activity-related and started about 3 months ago. The patient has not tried anything up to this point, and her pain has slowly worsened, leading to an antalgic gait with recurrent knee effusions. Plain radiographs demonstrate age-appropriate, open physes, and an MRI scan shows a stable 0.5 cm x 0.5 cm OCD lesion in the left medial femoral condyle. She begins conservative treatment, including restricted weight-bearing and bracing. What characteristics warrant initial nonoperative management?