Prediction of Development of Scapular Notching Following Reverse Total Shoulder Arthroplasty

The Specific Aims are: * Determine the relationship between lateral glenoid offset and the development of scapular notching following reverse TSA * Determine the ability of 3-D preoperative planning tools to define areas of scapular bony impingement on kinematic simulated shoulder range of motion that predict the development of scapular notching * Compare the precision and accuracy of plain radiographs (2-D) versus CT (3-D) for measurement of scapular notching and postoperative implant position following reverse TSA (2-D versus 3-D) * Determine the implant and anatomic factors that best correlate with clinical outcome following reverse TSA by retrospective analysis