Total reverse shoulder arthroplasty: European lessons and future trends.

In the late 1980s, Grammont introduced a new reverse total shoulder arthroplasty (TSA), with a hemisphere directly attached to the glenoid surface and with medial positioning of the center of rotation to overcome former shortcomings. Over the past few years, results from several mid- and long-term clinical studies of this new TSA have demonstrated that unexpectedly good functional outcomes and pain relief (Constant-Score, 60-69) could be achieved, even in patients with progressive superior migration, joint destruction, and rotator cuff deficiency. In all these studies, however, limited range of passive internal rotation and no improvement in active external rotation capacity were reported. In addition, glenoid erosion ("inferior glenoid notching") was reported in all these studies as a frequent phenomenon, occurring in 10% to 42%. The clinical impact of inferior notching is the subject of controversy, and its correlation with glenoid component loosening is not clear. In addition, rates of perioperative and postoperative complications (eg, dislocations, infections, hematomas, fractures) seem to be higher with this new TSA than with the conventional TSA. Improvements in prosthesis design and implantation technique (eg, easier and more reproducible surgical technique) should contribute to better range of motion, lower complication rates, and a lower frequency and lesser amount of inferior glenoid notching.