Review Question - QID 8525

Figures 65a and 65b are the initial radiographs of a 13-year-old boy who sustained an injury to his right knee while playing tackle football. He had immediate pain and the inability to bear weight. Open treatment of the injury was recommended and his postoperative radiograph is shown in Figure 65c. He and his family should be advised that his risk for distal femoral physeal arrest is approximately