Reverse Shoulder Glenoid Loosening Test Method: an analysis of fixation between two different offset glenospheres

Introduction Recent successes achieved with reverse shoulder arthroplasty (RSA) have led to an expansion of its indications and an increase in the number of commercially available designs in the global marketplace. Despite these development efforts, little guidance exists regarding reverse shoulder test methods and little published data exists regarding reverse shoulder performance standards. At least one of the bench studies published using RSA was performed under idealized bone conditions (e.g. polyurethane bone substitute densities of 30 lb/ft) or were based upon physiologic-irrelevant loading conditions (such as, applying the ASTM 2028 glenoid rocking test which translates a convex humeral head against a concave glenoid to induce edge loading and facilitate the rocking horse mechanism).