Imaging description

Patients with temporal bone fractures usually have severe intracranial injuries as well, and temporal bone fractures may be difficult to diagnose on head CT due to insufficient resolution provided. Free air in the posterior fossa, middle cranial fossa adjacent to the mastoid, infratemporal fossa, and temporomandibular joint should prompt a search for temporal bone fracture.

The temporal bone region is anatomically complex, containing many important and vital vascular, nervous, and sensorineural structures including internal carotid artery, middle meningeal artery, sigmoid sinus, jugular bulb, cranial nerves V, VI, VII, and VIII, and the otic capsule containing sensitive sensorineural organelles and the membranous inner ear [1].

The traditional classification of temporal bone fractures indicates the relationship of the fracture line with the long axis of the petrous portion of the temporal bone. A newer classification describes temporal bone fractures on the basis of whether the otic capsule is involved or spared [2]. Otic-capsule-violating fractures involve the labyrinth, causing injury to the cochlea, vestibule, or semicircular canals, and are more commonly associated with complications such as sensorineural hearing loss, CSF otorrhea, and facial nerve injury. Otic-capsule-sparing fractures are more commonly associated with intracranial injuries such as epidural hematoma and subarachnoid hemorrhage. However, this classification was not considered significantly better than the traditional system in predicting the likelihood of sustaining specific injuries from fracture of the temporal bone [3].