1. Copyright © 2013 Lippincott Williams & Wilkins. Unauthorized commercial reproduction of this slide is prohibited Supplemental PowerPoint Slides In vivo analysis of insertional torque during pedicle screwing using cortical bone trajectory technique Keitaro Matsukawa, M.D.,1* Yoshiyuki Yato, M.D.,1 Takashi Kato, M.D.,1, Hideaki Imabayashi, M.D.,1 Takashi Asazuma, M.D.,2 and Koichi Nemoto, M.D.1 Affiliations: 1Department of Orthopaedic Surgery, National Defense Medical College, Tokorozawa, Saitama, Japan 2Department of Orthopaedic Surgery, National Hospital Organization, Murayama Medical Center, Tokyo, Japan

2. Key Points 1)The mean maximum insertional torque using the CBT technique is about 1.7 times higher than the traditional technique (p < 0.01). 2)Positive linear correlations between maximum insertional torque and BMD were found in both techniques. 3)The correlation coefficient between insertional torque and BMD of the traditional screws (r = 0.63, p < 0.01) was higher than that of the CBT screws (r = 0.59, p < 0.01).