Fig. 6

Osteoid osteoma near a growth plate. An 11–year-old male with a history of surgical removal of an OO on the distal metadiaphysis of the left femur. His symptoms persisted, and follow-up MRI (a, b) and CT (c) showed a residual nidus at the medial femoral margin represented by the intracortical nodule (arrows) and surrounding bone marrow edema (asterisk in b). In a, note that the affected side of the distal femur is longer than the lateral side, resulting in a femoral deformity and length discrepancy of the left lower limb