Introduction to ct interpetation of temporal bone fractures duration. Temporal bone definition of temporal bone by the free. Conductive and mixed hearing loss is more common in longitudinal fractures of the temporal bone or injuries with no identifiable fracture, while transverse. It protects the part of your brain that controls hearing, speech, memory, and behavior. A total of 84 patients with 89 fractures of the temporal bone were examined with high resolution ct hrct a few hours to 21 months after the initial trauma. Consequently pluridirectional tomography has been the method of choice for the. Temporal bone fractures can occur after severe blunt trauma to the head and sometimes involve structures of the ear, causing hearing loss, vertigo, balance disturbance, or facial paralysis.
Temporal bone fractures have been categorized as longitudinal, transverse, and mixed 1,2. In addition to potentially damage to hearing and the facial nerve, associated intracranial injuries, such as extraaxial hemorrhage, diffuse axonal injury and cerebral. Frequently, a nonlinear course and sclerotic margins allow confident identification of these sutures. Involvement of the middle ear causes frequent hemotympanum and ossicular disruption, resulting in. Axial hrct disclosed 63 longitudinal, transverse, 10 complex and 3 atypical fractures. Dysfunctional temporal bone movement impediments to normal temporal bone motion can occur anywhere along the arc of its normal motion. It is the retrospective clinical study and the study took place at tertiary. Average force required to produce temporal bone fracture. The temporal bone is separated from adjacent bones by a number of sutures. Find highquality temporal bone stock photos and editorial news pictures from getty images. Temporal bone fractures can cause various injuries to the middle and inner ear. Approximately 70 to 80% of temporal bone fractures are longitudinal, resulting from a blow to the temporal or parietal region of the skull.
Temporal bone fracture is usually a sequela of significant blunt head injury. It houses many vital structures, including the cochlear and vestibular end organs, the facial nerve, the carotid artery, and the jugular vein. 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. Temporal bone fracture is thought to occur in 20% range 1422% of all calvarial fractures. Categorization of temporal bone fractures should include a descriptor for fracture direction, the presence or absence of labyrinthine involvement, and the segment of temporal bone involved.
Some 15% of temporal bone fractures are produced by blows to the occiput. The longitudinal temporal bone fracture that extended down the length of the bony canal could be seen dearly. The fracture line is parallel to the longitudinal axis of the. Although temporal bone fractures are relatively uncommon, they present many complex diagnostic and therapeutic challenges. A, ct image shows occipitomastoid suture arrowheads. There are a number of openings and canals in the temporal bone through which structures enter and exit the cranial cavity. In 20 cases the fracture involved more than one cranial bone, and the implications of this with regard to nonaccidental injury are discussed. Longitudinal temporal bone fractures radiology reference. Pdf temporal bone fractures can lead to high morbidity andor mortality. Temporal bone fractures merck manuals professional edition. Injuries include rupture of the eardrum and damage to the ossicles the chain of small bones that connects the eardrum to the inner ear, the cochlea the organ of hearing, the vestibular apparatus the organ of balance in the inner ear, or the nerve that controls. The most common cause of a temporal bone fracture was a motor vehicle accident occurring in 4090 44% patients. This patient had a ct scan of the temporal bone, which found a temporal bone fracture. Pdf temporal bone fracture causing superior semicircular.
In addition, it was noted that the incus was dislocated, with the long process projecting laterally and separated from the head of the stapes, with only a fibrous band connecting the drum to the stapes capitulum. Temporal bone fractures can lead to high morbidity andor mortality. A number of medical issues can arise in this part of the skull. The traditional system for classifying temporal bone fractures does so according to their orientation relative to the long axis of the petrous pyramid. Associated trauma to other cranial nerves other than the facial nerve. Temporal bones house numerous nerves, therefore, fracture of the temporal bone carries a risk of concomitant functional deficits.
Some fractures may have characteristics of both patterns. The temporal bone contributes to the lower lateral walls of the skull. Ct scans were carried out in 14 cases and 11 of these showed intracranial haematoma. The fracture line begins in the posterior fossa, at or near the foramen magnum, and crosses the petrous ridge through the internal auditory canal or the otic capsule. In this article, we shall look at the different parts of the temporal bone, their articulations, and any.
These figures form part of a larger study of 90 temporal bone fractures treated over a sixyear period from 1975 through 1981. Typically, the more frequent longitudinal fractures break through. Longitudinal temporal bone fractures are petrous temporal bone fractures that occur parallel to the long axis of the petrous temporal bone. It is important to identify associated complications related to temporal bone trauma that will guide. A 21yearold woman at admission to the trauma center after a motor vehicle accident with loss of consciousness. To compare the traditional and otic capsule classification system of temporal bone fractures for clinical relevance.
Temporal bones also house the internal carotid arteries. Petrous apex fractures tend to involve the iac and cochlea, explaining the higher prevalence of cn vii and viii dysfunction than with nonpetrous apex fractures fig. Five percent of patients with significant head trauma will also sustain temporal. This can lead to a number of serious complications, including damage to hearing, vertigo, facial paralysis due to damage to the facial nerve, and bleeding in the ear as well as bone bruising.
Plain radiography displays only 17%30% of temporal bone fractures 4, 5. Vertigo, dizziness, and tinnitus after otobasal fractures. The longitudinal fracture type is more common 80%90% of temporal bone fractures and results from temporoparietal impact. In this locationspecific classification system, a stronger correlation be tween petroustype fractures and the presence of snhl, facial nerve injury, and cerebrospinal fluid csf leak was identified. The middle ear consists of the tympanic cavity and. Temporal bone fractures may be complicated by intracranial haemorrhage, c. Deck and b r blenkinsop and e mandul\an\e farkas, journalthe canadian journal of neurological sciences. Temporal bone fracture causing superior semicircular canal dehiscence. Pdf a study of temporal bone fractures researchgate. Radiographic classification of temporal bone fractures. B, from more cranial slice than a, ct image shows anterior part of suture arrowhead. Temporal bone fractures were previously classified as longitudinal or transverse. They are the thickest skull base bones and require a great force to fracture.
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. A temporal bone fracture generally requires very strong forces to the skull that occur either laterally or in an anterior or posterior ear direction. The criteria for ct scan following head injury in general, and temporal bone fracture in particular are discussed. Temporal bone fractures were historically divided into three main categories, longitudinal, in which the vertical axis of the fracture paralleled the petrous ridge, horizontal, in which the axis of the fracture was perpendicular to the petrous ridge, and oblique, a mixed type. In other cases, knowledge of normal anatomy is required to prevent misinterpretation as fractures. Pertinent physical findings, occurring alone or in combination, were a hemotympanum, bleeding from the. You have two temporal bones, one on each side of your head. Temporal bone fractures are best classified as either otic capsule sparing or otic capsule disruptingtype fractures, as such classification correlates well with risk of concomitant functional. However, for the precise topographic analysis of the course of the fracture, additional coronal hrct. Involvement of the middle ear causes frequent hemotympanum and ossicular disruption, resulting in conductive hearing loss.
A temporal bone fracture can involve none or all of these structures. Temporal bone fractures are subdivided into petrous apex and nonpetrous apex fractures. A, an axial noncontrastenhanced computed tomographic scan of the bone window shows a complex fracture of the right occipital bone and temporal bone, and mastoid air cells extending into the right side of the cavity. Resident manual of trauma to the face, head, and neck. To access free multiple choice questions on this topic. Longitudinal fractures make up 70 to 90% of temporal bone fractures, and transverse fractures make up 10 to 30%. It contains the middle and inner portions of the ear, and is crossed by the majority of the cranial nerves. Temporal bone fractures have been classified by orientation with respect to the long axis of the petrous portion of the temporal bone. Temporal bone fractures introduction the temporal bone is the most complex bone in the human body trauma of the intratemporal structures cochlear and vestibular end organs facial nerve carotid artery jugular vein trauma of the extratemporal structures other cranial nerves vi abducens, ix glossopharyngeal, x vagus. These impediments could stop motion completely at a certain point, disallowing left temporal bone axis of rotation right temporal bone figure 1 normal temporal bone motion left and right temporal bones move in sync. The temporal bone is the bone that goes around your ear, in your skull. The lower portion of the bone articulates with the mandible, forming the temporomandibular joint of the jaw. Introduction to ct interpetation of temporal bone fractures. The temporal bones are a pair of bilateral, symmetrical bones that constitute a large portion of the lateral wall and base of the skull.
It is important to note whether fractures involve the otic capsule or brain parenchyma by reference to the long axis of the petrous temporal bone ie in the plane of the ear canal, 80% of temporal bone fractures are longitudinal from lateral blows and 20%. Nur aini jusoh introduction the temporal bone is the most complex bone. This will diagnose temporal bone fractures and associated intracranial pathology. While the temporal bone is relatively thick, blunt trauma can cause a fracture of this bone. Motor vehicle accidents are the cause of 31% of temporal bone fractures.
They are highly irregular bones with extensive muscular attachments and articulations with surrounding bones. A large volume of force is required to fracture the temporal bone. Imaging of temporal bone trauma geisel school of medicine. Anatomy and inflammatory and neoplastic processes1 from a clinicalradiologic standpoint, there are a limited number of structures and disease entities in the temporal bone with which one must be familiar in order to proficiently interpret a computed tomographic or magnetic resonance imaging study of the temporal bone. Download premium images you cant get anywhere else.
All patients were seen at beaumont hospital, the national tertiary referral centre for neuro. A comparison of temporal bone fracture classification. Some structures are discussed in more detail with emphasis on related pathology. The most common complications of temporal bone fractures are facial nerve injury, cerebrospinal fluid csf leak, and hearing loss. Either of a pair of bones forming part of the sides and the base of the skull. We present eight cases seen in a 12 month period in which a temporal bone fracture. Setting university trauma center and department of otolaryngologyhead and neck surgery. Temporal bone fractures mitchell jay ramsey, md, lt colonel, mc, usa although temporal bone fractures are relatively uncommon, they present many complex diagnostic and therapeutic challenges. Accurate early diagnosis is important to enable adequate investigation and prompt treatment of any complications. The diagnosis of a temporal bone fracture was established by axial hrct in almost every case. Temporal bone fractures and their complications springerlink.
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