Hearing loss in pediatric temporal bone fractures: Evaluating two radiographic classification systems as prognosticators.

INTRODUCTION

Temporal bone fractures (TBF) are traditionally classified by their angle of fracture relative to the petrous ridge, and more recently by whether or not they violate the otic-capsule. This study compared rates of hearing loss (HL) and signs of otologic dysfunction among fracture types of both classification systems, within the pediatric population.

METHODS

Pediatric patients were retrospectively characterized from a previously identified cohort of TBF patients, diagnosed from 2000 to 2014. CT scans were reviewed and TBFs were classified first as longitudinal (L), transverse (T) or mixed (M), and then as otic-capsule sparing (OCS) or otic-capsule violating (OCV). Medical records were reviewed, and rates of HL and presenting signs were compared among L, T and M fractures, and OCS and OCV fractures.

RESULTS

Forty-three patients with 47 TBFs met the inclusion criteria. Eighteen, 4 and 25 TBFs were classified as L, T and M fractures, respectively. Thirty-three and 9 were classified as OCS, and OCV, respectively. Among 24 cases of HL: 20, 3, and 1 were conductive HL (CHL), sensorineural HL (SNHL) and mixed HL, respectively. Two cases of SNHL were found among OCV fractures, with none in OCS fractures (estimated difference 0.22; 95% confidence interval 0.01-0.60). Similar rates of CHL were found across L, T and M fractures (range 36-50%), and across OCV and OCS fractures (range 42-44%). Hemotympanum was the most common presenting sign, found in 68% of TBFs and 80% of CHL cases. There were no significant differences in the incidence of signs or symptoms between fracture types.

CONCLUSIONS

In our cohort, both the traditional and otic-capsule radiographic classification systems failed to predict the incidence of CHL and other otologic signs in the pediatric population. Though OCV fractures conferred an increased risk for developing SNHL, we found a lower incidence than anticipated given violation to the bony labyrinth.