A Novel Tabletop Plane-Based Scapular Coordinate System Improves the Reproducibility of Preoperative Three-Dimensional Measurements in Reverse Total Shoulder Arthroplasty

Background/Objectives: Accurate three-dimensional (3D) assessment of glenoid morphology depends on the coordinate system used for measurement. Conventional landmark-based coordinate systems may be affected by observer-dependent variability in identifying the scapular landmarks. This study aimed to compare the reproducibility of a novel anterior scapular plane (ASP) coordinate system with that of the conventional surgical scapular plane (SSP).