Background: Percutanneous transphyseal intramedullary Metaizeau pin fixation was proven to be effective on diaphyseal displaced fracture of the forearm in children. This kind of pin is not available in VietNam. Objectives: To determine if K wire can replace Metaizeau pin relating to the treatment. Method: Experiment 3 mm K wire and Metaizeau are pulled until they are failed.