The purpose of this study was a comparison between the Codman classification (CC) and the Neer classification (NC) based on a data base(cases of multi-center). Simple X rays of 333 shoulders of the data base were investigated. In CC, we defined the type's number clockwise from upward left and judged the fracture in the existence of the fracture line. We examined the relation between NC and C about the flexion angle. Types 2,8,13 and 16 of CC were not included in the data base. There were 4 cases that were impossible to classify by CC, and 27 cases by NC. NC and CC were related as follows: NC Type 1 (CC Types 4,6,7,9,10,11,12,14), 2-II(1.7), 2-III a (1,3,4,5,10,11), 2-III b (4,10,11), 2-III c (1,10,11), 2-IV(1,3,4,9,12), 2-VI a (4,9,12), 3-IV(1,4), 3-V(5), 3-VI a (4), 4(1), 4-VI a (1,12), unclassified (1,3,4,5,6,14,15, unclassified). In the cases of conservative therapy of an NC 2-part fracture, the CC Type 4 had significantly more cases over 120 degrees flexion than Type 11. In the cases of CC Type 4, the cases of less displacement had a significantly better flexion angle. Therefore NC was better if it had more patterns of classification and CC was better if it had a concept of the displacement.
