the new AO classification: preliminary results of the distribution of lateral rib fractures

Objectives Although different types of rib fractures are already well known there is a lack of knowledge about their distribution and localization.

The aim of this study is the morphological validation of the AO classification for lateral rib fractures.

Methods The data basis were all patients with chest wall fractures in a Level-I-Trauma Center from 2010 to 2016 who had at least one rib fracture between tubercle and osteochondral transi-tion.

The detailed analysis of the CT data (total n = 632, subgroup n = 116) included anatomical basic data of the thoracic cage and each rib fracture with location (angle in degrees), dislocation and its fracture pattern, classified according to AO, including the current fracture modifiers.

Results and Conclusion A total number of 617 rib fractures were found, which is an average of 5.3 fractures per pa-tient. Overall 85.58 % simple type A and 14.42 % multifragmentary type B fractures were identified. Their combination resulted in 12.80 % type C fractures.

The distribution of the fractures cranio-caudal showed a significant fracture focus in the middle thorax, as 45.87 % of the fractures were found in ribs 5, 6 and 7. In contrast only 14.59 % of the rib fractures were found in the last four ribs.

The distribution of the fracture localizations in the transversal plane ranged from 24° to 140° with an average of 80° (± 28.2), while 39.22 % of all fractures were found in the range from 40° to 69°.

The results show that there are multiple fracture focuses in the examined collective in vari-ous levels of the thorax. For the evaluated patients - among others - two imposing fracture accumulations were found in the ribs 5-7 and in a range from 40° to 69° concerning fracture localizations.

The results suggest to divide the shaft segment of the ribs into two sectors - the posterol-ateral and the anterolateral one.

The division of the lateral ribs in different sectors is a possible and innovative way to examine the clinical relevance of these findings. As it is assumed that traumatic chest wall injuries often take a clinically severe course, these results should be further investigated.

Stichwörter thoracic trauma, rib fracture, localization

Publication History

Article published online:
15 October 2020