Best MJ, Aziz KT, Wilckens JH, et al. - This research was undertaken to ascertain the incidence of primary reverse and anatomic total shoulder arthroplasty in the United States and to explore changes in age and gender-based procedure rates. They further ascertained the incidence of hemiarthroplasty. Researchers distinguished over 508 thousand cases of primary reverse and anatomic total shoulder arthroplasty and shoulder hemiarthroplasty from 2012 to 2017 using nationally representative data along with United States Census data. They examined trends in incidence for each procedure and estimated gender-adjusted and age-adjusted procedure rates. In the United States, the incidence of primary reverse and anatomic total shoulder arthroplasty has elevated substantially between 2012-2017 while the incidence of hemiarthroplasty has reduced.