# Audiometric and vestibular outcomes following temporal bone fractures: a retrospective analysis of a major trauma center cohort in China

## TL;DR

This study shows that the integrity of the otic capsule strongly influences long-term hearing and balance outcomes in patients with temporal bone fractures.

## Contribution

The study provides novel long-term prognostic data on audiometric and vestibular recovery in temporal bone fracture patients based on otic capsule status.

## Key findings

- Otic capsule violating fractures showed no functional hearing recovery or return to normal hearing within 24 months.
- Otic capsule sparing fractures had 90.4% functional hearing recovery and 38.5% return to normal hearing.
- OCV fractures had five-fold higher complication rates, including cerebrospinal fluid leak and meningitis.

## Abstract

Temporal bone fractures form a major skull-base injury subset, yet prognostic data—drawn chiefly from short-term Western cohorts—remain sparse. This study therefore investigated long-term audiometric and vestibular outcomes by otic-capsule integrity to refine recovery estimates and treatment efficacy.

We conducted a retrospective cohort study of 1,871 adults with traumatic temporal bone fractures treated at a Level I trauma center in China (2014–2023). Patients were stratified by otic capsule status: sparing (OCS, n = 1,617) vs. violating (OCV, n = 254). Primary outcomes included pure tone audiometry and Dizziness Handicap Inventory scores assessed over 24 months. Statistical analysis employed mixed-effects models, Kaplan-Meier survival analysis, and propensity score matching. Two a priori hearing endpoints were used: “normal hearing” (PTA ≤25 dB HL) and “functional hearing recovery” (≥30 dB improvement from baseline).

Baseline hearing impairment was significantly worse in OCV patients (84.6 ± 8.7 vs. 45.1 ± 8.5 dB HL, p < 0.001). At 24-month follow-up, functional hearing recovery (≥30 dB improvement) occurred in 90.4% of OCS patients, whereas 0% of OCV patients reached this threshold; return to normal hearing (PTA ≤25 dB HL) was observed in 38.5% of OCS patients and 0% of OCV patients. Multivariable analysis identified OCV fracture as the strongest predictor of severe hearing loss (OR 4.89, 95% CI: 3.42–6.99, p < 0.001). Complication rates were five-fold higher in OCV patients (31.5 vs. 6.1%, p < 0.001), including cerebrospinal fluid leak (13.8 vs. 2.0%) and meningitis (4.3 vs. 0.7%). Propensity-matched analysis demonstrated surgical benefit, with 7.6 dB hearing improvement compared to conservative management (p = 0.001).

Otic capsule integrity represents the primary determinant of recovery following temporal bone fractures. OCV fractures demonstrate profound, persistent deficits with minimal recovery potential, while OCS fractures show excellent recovery prospects. These findings provide crucial prognostic information for patient counseling and treatment planning in temporal bone trauma management.