Does bilateral otosclerosis make pre-operative bone conduction more inaccurate?

Area of Science:

• Otolaryngology
• Audiology
• Surgical Outcomes

Background:

• Otosclerosis, a condition affecting the middle ear, can impact hearing.
• The Carhart effect describes a change in bone conduction thresholds after stapes surgery.
• Assessing pre-operative bone conduction accuracy is crucial for surgical planning.

Purpose of the Study:

• To determine if bilateral otosclerosis increases the inaccuracy of pre-operative bone conduction measurements.
• To compare the Carhart effect in unilateral versus bilateral otosclerosis.

Main Methods:

• Retrospective analysis of 745 ears undergoing stapedectomy for otosclerosis (2013-2020).
• Comparison of pre- and post-operative bone conduction audiograms in unilateral (U1), first-side bilateral (B1), and second-side bilateral (B2) otosclerosis.
• Evaluation of bone conduction change magnitude within and between groups.

Main Results:

• Significant pre- to post-operative bone conduction changes occurred in all groups (P <0.05).
• The greatest change was observed in the unilateral otosclerosis (U1) group.
• No statistically significant difference in bone conduction change was found between unilateral and bilateral otosclerosis groups (P=0.37).
• The most pronounced change occurred at 2000 Hz across all groups, but differences between unilateral and bilateral cases were not significant (P=0.36).

Conclusions:

• This study suggests pre-operative bone conduction accuracy is similar for unilateral and bilateral otosclerosis.
• There is no evidence that bilateral otosclerosis leads to a more inaccurate assessment of bone conduction.
• Reliable post-operative bone conduction assessment methods are needed, independent of cochlear reserve assumptions.