The biomechanics of current reverse shoulder replacement options

Reverse shoulder arthroplasty (RSA) has experienced a rebirth in popularity as a surgical procedure starting with the Grammont design. The biomechanics of RSA continues to be studied and better understood, however at the same time there has been rapid development of different prostheses that have taken the geometry of the reverse and made substantial changes, impacting the mechanics of these devices in many ways. Classifying the different styles of design helps surgeons form a working nomenclature to discuss these design parameters and the potential biomechanical consequences of implant selection for patients. This chapter breaks down the RSA into glenoid sided, humeral sided, rotator cuff related and bone quality related components as they relate to biomechanics.