The stemless anatomic shoulder prosthesis

Background and aim: The anatomic shoulder prosthesis offers the opportunity for pain reduction with simultaneous restoration of mobility in advanced osteoarthritis (omarthrosis). While stem-guided implants were used for many years to reconstruct the humeral articular surface, stemless procedures are increasingly available for fixation of the humeral implant. This review aims to analyze the results of stemless anatomic shoulder prostheses. Materials and methods: Presentation of the results of a selective literature search. Results: With correct indication and accurate reconstruction of the anatomy, stemless anatomic shoulder arthroplasty (slTSA) achieves satisfactory results with reliable pain relief and functional improvement. Initial anchorage may be challenging with decreased metaphyseal bone density or may even require conversion to a stem-guided prosthesis. Reasons for prosthesis revision often include rotator cuff failure and loosening of the glenoid component, whereas no humeral-side loosening has been noted in long-term follow-up. Revision surgery of anatomic shoulder prostheses is facilitated if stem revision does not need to be performed. Conclusion: Clinical outcomes of slTSA are comparable to fourth-generation prostheses. Morbidity of revision surgery is successfully reduced by stemless prostheses or convertible platform systems. The conversion rate of platform systems remains unsatisfactory at 70%. Causes of failure of anatomic prostheses are predominantly nonhumeral, so that further development of the glenoid component is required.