longitudinal temporal bone fractures
Longitudinal temporal bone fractures are petrous temporal bone fractures that occur parallel to the long axis of the petrous temporal bone. Although more current classifications of the extent of temporal bone fractures focus on the integrity of the otic capsule rather than the fracture orientation, description of fractures in terms of longitudinal or transverse or mixed orientation is still common and useful in conveying the fracture anatomy.
Epidemiology
Longitudinal fractures represent the majority (70-90%) of all petrous temporal bone fractures. Periauricular swelling and retroauricular ecchymosis (Battle sign) are common, and almost all have otorrhagia.
Pathology
Mechanism
Longitudinal temporal bone fractures typically originate from the squamous temporal bone with the inferior propagation of the fracture line through the mastoid into the lateral wall of the middle ear, passing behind, through, or in front of the external auditory canal and ends in middle cranial fossa adjacent to the foramen spinosum and foramen lacerum.
Depending on the force of impact, the fracture line may extend, deviated by the strong petrous bone, through the anteromedial wall of the middle ear. Involvement of the otic capsule is rare, but the fracture line can involve the squamous part of the temporal bone and/or the parietal bone.
Complications
- tympanic membrane rupture
- ossicular injury including incudostapedial joint dislocation
- conductive hearing loss
- facial paralysis (~25%)
- pneumocephalus
- herniation of temporal lobe through fracture
- perilymphatic fistula