Traumatic fractures of the sternum – typical distribution and need for subgroups within AO and OTA classification system?

Objective of this study is the morphologic validation of the AO-classification of the sternal bone and particularly define subgroups. Analyzed were all patients of a level I trauma center of a 7-year period with fractures of the sternal bone and the anterior rib cartilage. A total number of n = 124 patients was included. The detailed evaluation of the CT-data recorded anatomical basic data of the rib cage and every fracture with its position, dislocation, fracture pattern (which was classified following the AO). 116 (93.5%) patients showed 134 single fractures of the sternal bone, 48 (35.8%) of the manubrium, 81 (60.4%) of the corpus sterni and 5 (3.7%) of the xyphoid. 16 patients had a dual fracture of manubrium and corpus. Fractures of the corpus were mostly type A-fractures, followed by type B-and C-fractures. Manubrial fractures had the same number of type A- and B-fractures. Subgroups were theoretically defined by the senior author of our group and validated. based on location, dislocation and course of the fracture. Sternal fractures are mostly shown at the corpus. Fractures of the xiphoid are very uncommon. Generally, corpus fractures are simple fractures, the rarer manubrium fractures show more complex fractures, which presumes a high trauma energy. The defined subgroups can help draw conclusion to the trauma mechanism and its potential concomitant injuries.