Temporal bone fractures are mostly due to high-energy head trauma with high rates of concurrent intracranial and cervical spine injury and belong to the wider spectrum of lateral skull base trauma.
Temporal bone fracture is thought to occur in ~20% (range 14-22%) of all calvarial fractures. They have a prevalence of 3% of all trauma patients in one series 1).
Fracture of the petrous temporal bone is usually classified according to the main orientation of the fracture plane and/or involvement of the otic capsule.
Temporal bone fracture is described relative to the long axis of the petrous temporal bone, which runs obliquely from the petrous apex posterolaterally through the mastoid air cells. Using this plane, fractures may be classified as follows:
longitudinal fractures
transverse fractures
mixed fractures
Given that the temporal bone represents the most complex bone structure in the human body, containing a multitude of vital neurovascular structures, variable clinical presentations may arise from such fractures, ranging from asymptomatic courses to serious consequences, such as conductive and/or sensorineural hearing loss, vascular and/or cranial nerve injury as well as Cerebrospinal fluid fistula.
It is suggested by the Battle sign (post-auricular ecchymosis) and bleeding from the external auditory canal. As the fracture can sometimes involve the ossicles, inner ear and facial nerve, symptoms such as hearing loss, vertigo, balance disturbance, or facial paralysis may be present.
Head computed tomography with a petrous temporal bone fine slice (≤1 mm) multiplanar bone window reformats is the imaging modality of choice. Aside from the fracture lucency itself, which may be subtle on thicker slices or some planes, there may be secondary imaging features that, while less specific, raise concern in the setting of trauma for temporal bone fracture
in the temporomandibular joint glenoid fossa
in the intracranial cavity (pneumocephalus)
in the soft tissues of the infratemporal or temporal fossae
in the mastoid air cells
in the middle ear
in the external auditory canal
Isolated temporal bone fractures usually have a good outcome in children, but in some cases they can be fatal or have permanent sequelae. Long term follow up is recommended 2).
Delayed-onset or incomplete facial paralysis almost always resolves with conservative management, including the use of tapered-dose corticosteroids.
facial nerve involvement
ossicular chain disruption
otic capsule involvement
vertigo and sensorineural hearing loss
cerebrospinal fluid (CSF) disruption
Traumatic cerebrospinal fluid otorrhea
Traumatic cerebrospinal fluid rhinorrhea
post-traumatic cholesteatoma
perilymphatic fistula
Facial function following temporal bone fractures should be evaluated in the emergency room. If facial motion is noted at any time after the injury, surgical intervention is rarely indicated. Prophylactic antibiotics should be considered in temporal bone fractures when CSF fistulae are present. Surgical closure of a CSF fistula is indicated if it persists for > 7-10 days 3).