Osteochondritis dissecans in an adult.

Osteochondritis Dissecans in an Adult A 27-year-old student underwent surgical arthroscopy of the left knee with debridement and drilling of an osteochondritis dissecans lesion as a teenager. Approximately 1 year later, some symptoms returned. The intensity of pain was an 8 of 10 at worst and was associated with definite, unpredictable catching sensations. On physical examination, left knee range of motion was 0° to 135°. Point tenderness was localized to the distal aspect of the medial femoral condyle with the knee flexed to 90°. Moderate effusion was observed. Two magnetic resonance imaging (MRI) scans (Figure A, B) and 3 arthroscopy photographs (Figure C-E) are shown (arrow [E], cartilaginous loose fragment). What would you do?