AO classification (adapted from Tscherne)
The AO classification of fracture wound severity provides a grading system for injuries of each of the skin (I), muscles and tendons (MT), and neurovascular (NV), each of which is divided into five degrees of severity.
It is designed to provide a unique, unequivocal definition of any injury and thereby, allows accurate comparison of cases.
A full understanding of the severity of an open fracture requires consideration of each of these elements.
This very detailed classification is designed to be used in conjunction with the AO/OTA Fracture and Dislocation Classification.
This comprehensive classification is better suited for research than routine clinical use, but it should remind the clinician that a thorough evaluation of each of the included tissues is essential for an adequate understanding of a fracture wound.