DEFINING CLINICALLY-RELEVANT VALUES FOR DEVELOPMENTAL SPINAL STENOSIS: A LARGE SCALE MRI STUDY Authors: Jason Pui-Yin Cheung 1 , MBBS(HK), Dino Samartzis 1 , DSc Hideki Shigematsu 2 , M.D. Kenneth Man-Chee Cheung 1 , M.D. Affiliations: 1 Department of Orthopaedics and Traumatology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong SAR, China 2 Department of Orthopaedics Surgery, Nara Medical University, Kahihara, Nara, Japan Corresponding author: Kenneth Man-Chee Cheung Jessie Ho Professor in Spine Surgery Head, Department of Orthopaedics & Traumatology The University of Hong Kong Queen Mary Hospital, Pokfulam Road Hong Kong SAR, China Tel: (+852) 2255-4341 Fax: (+852) 2817-4392 Email: cheungmc@hku.hk Ethics approval from local institutional review board achieved. Work supported by grants from Hong Kong Theme-Based Research Scheme (T12-708/12N) and the Hong Kong Area of Excellence programme (AoE/M04/04). *Title Page