[Conventional x-ray after shoulder prosthesis].

Three types of shoulder prostheses are commonly used to cover the different indications of shoulder joint replacements: classical modular, inverse and cup. The modular prosthesis can replace the glenoid as well as the humeral head components. Exact visualization of the interface between the glenoid component and bone (or cement-bone interface) is necessary to detect osteolysis, which is relatively common. Therefore, it is mandatory to make true AP and axial projections. When describing the humeral component, the interface between bone and implant must again be considered. Additionally, the position of the humeral head in relation to the glenoid has to be noted. The glenoid component is usually fixed by screws to the bone and an osteolysis is often present at the inferior pole of the glenoid component due to prosthesis bone notching. If the implants are modular devices (classic modular prosthesis, inverse shoulder prosthesis) there is the possibility of dissociation of components and any suspicion of this should be reported. In case of reporting the conventional x-ray of cup prosthesis, the bone implant interface should be mentioned. Again the position of the humeral head to the glenoid requires attention. In all types of prostheses, dislocation of the glenohumeral joint is obvious and has to be addressed in the medical report.