Reversed shoulder prostheses are used for the treatment for glenohumeral arthritis associated to rotator cuff muscle deficiency. The glenoid component is fixed with peripheral screws, which provide the primary stability that is crucial for the long-term osteo-integration of the prosthesis. The number of screws and their position is not clear yet. The goal of this project is analyze the effect of these two parameters on the stability of the glenoid component. From micro-CT images of the scapula and the relationship between compressive screw force and bone quality, an optimizing algorithm will have to be developed in MatLab to estimate different screw positions.