Fig. 3

Right proximal humeral fracture of a 78-year-old woman. The humeral head is anteriorly dislocated and completely isolated from the other segments, while the fragmented tuberosities remain attached to the shaft. This fracture is often categorized as a 2-part fracture of the anatomical neck, but it is mostly grouped as 3-part or 4-part fractures according to the conventional Neer classification. Although the number of displaced segments is 2, the fracture is regarded as a 4-part fracture with the modified classification in all trials. a Antero-posterior and scapular-Y views of plain radiographs. b Anterior and lateral views of 3-dimensional CT reconstructions