Anteroposterior (A) and lateral (B) radiographs of forearm in 2-year-old boy demonstrate an aneurysmal bone cyst. Anteroposterior (C) and lateral (D) radiographs after extended curettage and grafting with a calcium sulfate/calcium phosphate bone graft substitute. Anteroposterior (E) and lateral (F) radiographs 1 year later demonstrate remodeling of the graft material with no sign of cyst recurrence.