Stemless versus stemmed anatomic total shoulder arthroplasty: minimum 2- year follow-up of the global ICON and global unite systems

Anatomic total shoulder arthroplasty (TSA) was first introduced by Neer et al. in 1955, primarily for treatment of proximal humerus fractures [ 1 ]. Neer´s initial prothesis design was a stemmed monobloc implant. Over time, TSA has continuously evolved and been refined to better replicate the natural anatomy of the glenohumeral joint [ 2 , 3 ]. With an increase in implantations, humeral complications associated with stemmed protheses became evident. These included fractures, loosening, stress shielding, and periprosthetic fractures [ 4 , 5 ].