Sensorineural hearing loss in posttraumatic incus dislocation.

In 34 posttraumatic incus dislocations, the initial sensorineural hearing loss (primary) after the trauma and that 11 years after trauma (late) were analyzed. Primary hearing loss measurements following the trauma showed that 53% of patients had sensorineural hearing loss of more than 10 dB for at least one of the frequencies from 1,000 to 4,000 cps, 18% for more than 30 dB. For late hearing loss after the trauma, the corresponding percentages were 50% and 15%, respectively. No reliable progression of the posttraumatic sensorineural hearing loss was found, although a few exceptions were seen. It may be concluded that sensorineural hearing loss is not a progressive disorder of the inner ear.