Coronal shear fractures of the distal humerus in children and adolescents: proposal for a modified classification

PURPOSE: Coronal shear fractures (CSF) of the capitulum and trochlea humeri are rare injuries during growth age. No systematic, prospective analysis of the classification, procedure, and outcome has yet been found in the literature. MATERIALS AND METHODS: Based on the results of a multicentre study of CSF in growing patients, we propose a redesign of the AO Paediatric Comprehensive Classification of Long-Bone Fractures (PCCF) for children and adolescents. We also assessed inter-rater agreement consistency with the modified classification and calculated the intra-class correlation coefficient (ICC) and its 95% confident interval (CI). RESULTS: A detailed classification has been proposed that refers to the location of the fragment, the extent to which the trochlea is involved, and the distinction between single and multiple fracture injuries. This modified AO classification distinguishes between five types of injury (13-E/3.1I - 13-E/3.1IV and 13-E/3.2), replacing the current code 13r-E/8.1. Inter-rater reliability using this modified classification was moderate (ICC 0.452 (95% CI 0,284; 0,661). This is more accurate than all previous classifications tested for CSF. CONCLUSION: A revised classification of coronal shear fractures of the distal humerus in children and adolescents is required. Our proposed classification considers the various types of this injury and their implications for treatment. Cross-sectional imaging is necessary for any classification to be applied successfully, since plain radiographs do not provide sufficiently precise information.