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1. Longitudinal Injuries

Longitudinal injuries are much more common and account for 70–90

percent of fractures. They follow a course through the external auditory

canal (EAC) and TM, progressing along the axis of the petrous apex,

following the path of least resistance, which often involves aerated

regions, foramina, and suture lines. Longitudinal injuries classically

result from a blow to the temporal parietal region. They are frequently

associated with a CHL, and may have an associated facial nerve injury

in the perigeniculate region. Figure 6.2 illustrates the path of a longitu-

dinal and transverse fracture relative to the long axis of the petrous

bone. Figure 6.3 represents the radiologic appearance of a longitudinal

fracture. This patient sustained a fracture in a motor vehicle accident

and had complete facial paralysis, requiring decompression.

Figure 6.2

Superior view of the left temporal bone

in isolation. This image illustrates the

long axis of the temporal bone and the

course of longitudinal (red dashed

line) and transverse (blue-dashed line)

patterns of fractures. The petrous

portion of the temporal bone is seen

best in this view. It houses the otic

capsule, internal audiotry canal, petrous

carotid, and portions of the facial nerve

and forms the petrous apex.

Figure 6.3

Axial view of the left temporal bone, with

longitudinal fracture (red dotted line)

extending through the petrous apex into the

sphenoid.