Radiographic analysis of shoulder anatomical arthroplasty

Arthroplasty is the standard treatment for advanced shoulder osteoarthritis. Modern prostheses designs have modular features whose size, shaft/head and body morphology can be adjusted. Total Shoulder Arthroplasty (TSA) provides better results. A complete X-ray follow-up is essential to assess the results and evaluate the survival rates of a shoulder prosthesis. Antero-posterior at 40 degrees in both internal and external rotation (true AP view) and axillary view are recommended to assess the following parameters: orientation and translation of the humeral component, offset, size and height of the humeral head, acromio-humeral distance, distribution and fixation of the cement, stress shielding and cortical resorption, radiolucent lines, subsidence and tilt, glenoid wear and "bone stock", prostheses instability, glenoid component shift. Shoulder hemiarthroplasty can lead to glenoid wear; the true AP film at 40 degrees of internal rotation provides the best profile of gleno-humeral joint to depict glenoid erosion. Shift of the glenoid component in TSA is identified as tilting or medial migration on true AP and axillary views in the early postoperative period (1-2 months) and at minimum of 2 years. An exhaustive radiographic analysis remains essential to monitor the prosthetic implant and detect early and late complications or risk factors of prosthetic loosening.