An audit of outcomes of cochlear implantation in patients following temporal bone fracture

Background: Temporal bone fractures may cause a number of pathological changes in the temporal bone, which may influence potential cochlear implantation. In this retrospective study, we examine the impact of previous temporal bone fracture on outcomes and adverse events with cochlear implantation.Methods: Retrospective case series of 14 adult patients with unilateral or bilateral temporal bone fracture undergoing cochlear implantation. Audiological outcomes [consonant-vowel-consonant (CVC) word and phoneme speech perception scores], ongoing implant use and adverse events were recorded. Audiological outcomes were compared to a control group of 1,414 adult patients undergoing cochlear implantation for post lingual deafness. All patients were discussed in the Cochlear Implant Multidisciplinary Meeting prior to implantation. Computed tomography (CT) petrous temporal bone and magnetic resonance imaging (MRI) scans were performed in all patients for workup and operative planning. Results: Successful implantation (phoneme >= 55% with ongoing use) was recorded in 8 of 14 patients (57%). Cochlear implantation in otic capsule violating fractures results in worse CVC phoneme scores than both the control group (mean 33.8% vs. 63.7%, P=0.0005), and the otic capsule sparing group (mean 33.8% vs. 78.8%, P=0.002). There is a statistically significant strong correlation between age at implantation and both CVC word (r=-0.763; P=0.001) and phoneme scores (r=-0.773; P=0.001), with audiological scores reducing with advancing age.Conclusions: Cochlear implantation following temporal bone fracture is safe, and while technical difficulties may be encountered, implantation may provide significant hearing and communication benefits, even when occurring several years post injury. Implantation in the setting of an otic capsule violating fracture may provide poorer audiological outcomes and has higher complication rates.