The conventional method for glenoid version measurement. The figures describe the conventional measuring method for glenoid version described by Friedman et al. The glenoid line is defined as the line connecting the anterior and the posterior rim of the glenoid (blue line). The scapular axis is defined as the line connecting the root of the scapular spine and the center of the glenoid line (red solid line). Glenoid version (α) is calculated as the angle between the glenoid line and the line perpendicular to the scapular axis (red dashed line). (A) The conventional method for measuring a normal shoulder. The scapular body shape appears flat. The glenoid shows 6.2° retroversion. (B) The conventional method for another normal shoulder. The scapular body shape is round. The glenoid shows 8.9° anteversion. The conventional method is sensitive to the scapular body shape that varies widely between patients. (C) The conventional method for measuring an arthritic shoulder. The scapular body is waving. CT arthrograms are used to measure glenoid version, and the glenoid has 28.3° retroversion. The intermediate line is selected as the glenoid line in the Walch classification B2 glenoid.