Temporal bone fractures: traditional classification and clinical relevance.

OBJECTIVES/HYPOTHESIS: The objectives were to evaluate the clinical relevance of traditional temporal bone radiographic descriptors and to investigate the efficacy of an alternative fracture classification scheme.

STUDY DESIGN: Retrospective consecutive case series.

METHODS: Charts and computed tomography scans representing 155 temporal bone fractures at a level I trauma center were reviewed. Fracture types were correlated with clinical presentation and outcomes.

RESULTS: The traditional classification system (i.e., longitudinal, transverse, or mixed) correlated poorly with clinical findings such as facial nerve weakness and cerebrospinal fluid leakage. It also had limited utility in predicting conductive hearing loss and sensorineural hearing. An alternative schema distinguishing petrous from nonpetrous involvement demonstrated better correlation with these measures. Cerebrospinal fluid leak was 1.1 times more common in transverse than in longitudinal fractures but was 9.8 times more common in petrous than in nonpetrous fractures. Similarly, facial nerve injury more strongly correlated with fractures through the petrous temporal bone than did the other fracture types. Sensorineural hearing loss did not correlate with the transverse fracture classification but was significantly more prevalent in petrous fractures. Likewise, conductive hearing loss did not correlate with longitudinal fractures but was four times more common in the "middle ear" subcategory of nonpetrous fractures.

CONCLUSION: Traditional temporal bone fracture descriptions correlate poorly with clinical findings. However, simply distinguishing petrous from nonpetrous involvement demonstrates significant correlation with the occurrence of serious sequelae of temporal bone fractures. Subcategories of mastoid and middle ear involvement further refine this classification schema to correlate with minor complications. This simple, radiographically based scheme better focuses clinical resources and attention toward more likely sequelae.