Management of glenoid bone loss in primary and revision reverse total shoulder arthroplasty; [Behandlung von Glenoiddefekten bei inverser Schultertotalprothese bei Primär- und Revisionsindikation]

Background: The indications for reverse shoulder arthroplasty have grown dramatically during the past decade. In a relevant proportion of cases, there are accompanying significant glenoid bony defects. Objectives: We aimed to review and summarize the current literature on the management of glenoid defects in reverse shoulder arthroplasties and to describe our approach. Results: Currently, there are no treatment algorithms based on a specific classification system of glenoid defects in reverse shoulder arthroplasty published in the peer-reviewed literature. The authors distinguish between defects that are centric (contained), eccentric (uncontained). The literature mostly describes biological reconstruction of the defect by an autograft, with only a few allograft cases reported. Furthermore, it is unclear whether the procedure can be performed in a one- (glenoid defect reconstruction and implantation of reverse shoulder) or two-stage approach. We prefer a one-stage procedure if there is sufficient fixation of the central peg of the metaglene and good locking screw fixation in the native scapula. In advanced defects, specific glenoid base plates with a longer peg are necessary. In the literature and in our experience, the complication rate for this indication is not higher than with reverse arthroplasties without glenoid defects. Metal-augmented glenoid base plates are a possible alternative to biological reconstruction. Conclusion: Glenoid defects concomitant with reverse shoulder arthroplasties represent a significant percentage of surgically difficult-to-treat patients. It is critical to distinguish between the different types of glenoid defects and to adjust the surgical procedure to the individual defect. In the majority of cases, a one-stage procedure is possible by using specific glenoid base plate designs. © 2017, Springer Medizin Verlag GmbH.