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, in addition, the individual anatomy of the scapula requires a specific fixation for each patient. A relationship between compressive screw force and bone quality has already been found using micro-CT images of cadaveric scapulae, however, this technique is not suitable for routine interventions. The goal of this project was to adapt the existing algorithm to conventional computer tomography scans in order to be used during the pre-operative planning of reverse shoulder arthroplasty.