The neer classification for fractures of the proximal humerus: A narrative review

In 1970 Charles Sumner Neer, II (b.1917) published his classification system for fractures of the proximal humerus. The authors present the Neer classification and its modifications in a historical context, review the literature on observer agreement and consider comments from leading shoulder surgeons. One of the most eagerly discussed aspects of the classification system has been the low inter- and intraobserver agreement reported in more than a dozen studies. Systematic training seems, however, to improve agreement to an acceptable level, especially among specialists. The authors discuss current attempts to improve the Neer classification and the features of a satisfying classification for proximal humeral fractures. The classification of displaced fractures of the proximal humerus remains a challenge in clinical orthopedics and research.