Due to the new personalised resection guide technique developed with Slovenian technology, the determination of the optimal bone cuts, best anatomical axis and glenoid position in the available bone stock upon the preoperative 3D-CT joint model, is easier and more precise. Our goal is the most optimal bone fixation of the glenoid implant in the available bone stock, without stressing the primary on its retroversion and rather adapts the humerus head retroversion, which has been the primary rule for resection in the conventional technique. Due to this 3D preoperative model, we can create resection guides with optimum fits to the bony surface of the patient’s bone and determine the exact intraoperative bone cuts, the shape and size of the bony transplant, as well as the optimal positioning of the EP, which enables the best stability and kinematic of the prosthesis. The postoperative 3D-CT EP positioning has been analysed by comparing the planned and performed resections and the final joint biomechanics. The results showed an easier, quicker and more precise procedure, with less postOP-3D-CT mechanical axis outliers. Due to the optimal bone fit and the combined retroversion of both components, we expect optimal biomechanics, functions and prolonged EP survival.