Reverse shoulder arthroplasty.

The reverse shoulder arthroplasty emerged as a potential solution for those patients who could not be managed effectively with a conventional total shoulder arthroplasty. Grammont revolutionized the design by medializing and distalizing the center of rotation and utilizing a large convex glenoid surface and concave humeral component with a neck-shaft angle of 155°. This design has been highly successful in cuff deficient shoulders, and indications continue to broaden. Many mid-term studies have improved upon the early encouraging results. Long-term studies are starting to emerge, demonstrating good survivorship, but progressive functional and radiographic deterioration continue to be concerning. Careful patient selection and attention to appropriate technique are required to reduce the current high rate of complications. New prosthesis designs are continuing to develop to address some of these limitations.