Roger Härtl1, Ai-Min Wu2. 1. Department of Neurological Surgery, Weill Cornell Medicine Center for Comprehensive Spine Care, New York-Presbyterian Hospital, Weill Cornell Brain and Spine Institute, New York, NY, USA (Email: roger@hartlmd.net). 2. Department of Spine Surgery, Zhejiang Spine Surgery Centre, The Second Affiliated Hospital and Yuying Children's Hospital of the Wenzhou Medical University, The Second School of Medicine Wenzhou Medical University, The key Orthopaedic Laboratory of Zhejiang Province, Wenzhou 325000, China. (Email: aiminwu@wmu.edu.cn).