Fig. 8From: Practical considerations for determination of scapular internal rotation and its relevance in reverse total shoulder arthroplasty planning3D-CT reconstruction of a patient with advanced kyphoscoliosis. 3D measurement of scapular internal rotation (SIR) is referenced as a perpendicular line to the sagittal axis through vertebra Th1 and the sternum (blue line). With a limited field of view (black rectangle) the standardized CT reference (black dashed line) is used as the transversal axisBack to article page