Petrous bone fractures and ossicular chain lesions detected by PMCT in burnt bodies

Thermal fractures of the skull or even the complete loss of skull structures can make it extremely difficult or even impossible to assess additional mechanical head trauma in severely burnt bodies. However, as the petrous part of the temporal bone is very dense, it often remains more intact, even when other structures of the head are destroyed. It has been suggested in the past that certain lesions of the petrous bone, particularly transverse fractures, may indicate the presence of mechanical trauma. In this retrospective study, a total of 54 cases comprising 108 petrous bones with thermal damage to the head were examined based on CT data and reports, focusing on the occurrence of longitudinal and transverse petrous bone fractures and auditory ossicle luxation in relation to the degree of burning and mechanical trauma. None of the 44 cases without assumedly present mechanical head trauma displayed a fracture of the petrous bone or dislocation of the ossicular chain. In contrast, four transverse and five longitudinal fractures as well as two ossicle dislocations were seen in the ten cases with mechanical trauma to the head. These results indicate that the presence of petrous bone fractures and auditory ossicle lesions are highly indicative of an additional mechanical trauma - possibly before being burnt - thus demanding further investigations.