Traumatic ossicular disruption with isolated fracture of the stapes suprastructure: comparison with incudostapedial joint dislocation

CONCLUSION: More severe high frequency hearing loss, especially at 8 kHz, occurs with fracture of the stapes suprastructure (SSF) compared with isolated incudostapedial joint dislocation (ISD). Successful hearing gain can be achieved in the speech range with appropriate ossicular reconstruction.

OBJECTIVES: Traumatic SSF is a rare consequence of head trauma. This study aimed to demonstrate the characteristic features of SSF compared with traumatic ISD.

METHODS: Eighteen patients who suffered from conductive hearing loss after head trauma and were operated from 2000 to 2012 were enrolled. Eight and 10 patients were confirmed to have a traumatic SSF (SSF group) and ISD (ISD group), respectively. The etiology of ossicular disruption, preoperative CT scan of the temporal bone, and intraoperative findings were retrospectively reviewed. Pre- and postoperative hearing was analyzed by both pure tone averages and thresholds at each frequency (0.5-8 kHz).

RESULTS: The most common etiologies in the SSF group were fall (n = 3) and direct ear trauma (n = 3), and for those in the ISD group, the most common etiology was traffic accident (n = 6). CT scan showed no evidence of fracture in the SSF group, whereas findings of ossicular dislocation were found in 70% of patients in the ISD group. Hearing outcomes according to the frequencies demonstrated that pre- and postoperative hearing loss at 8 kHz was more severe in the SSF group than in the ISD group. In a comparison of hearing outcomes at each frequency, the postoperative hearing threshold at 8 kHz was higher than for other frequencies. Postoperatively, 63% of the SSF group and 70% of the ISD group obtained an air-bone gap of within 15 dB.