Glenoid component loosening occurs more commonly than the humeral component and is one of the most frequent complications requiring revision surgery. Radiographic signs of loosening are progressive and extensive widening of interfaces between bone-cement, bone-prosthesis or cement prosthesis. Fragmentation or fracture of cement. Migration or subsidence of prosthetic components. Comparison with the initial baseline and early radiographs must be made. The failures of the prosthetic glenoid arthroplasty can be due to the glenoid or humeral prosthetic components, to the seat, to the fixation, to the failure of the glenoid bone and to the balanced management of the eccentric load (avoid "rocking horse effect").