Findings at exploratory tympanotomy for conductive hearing loss.

INTRODUCTION Despite advances in imaging and other diagnostic tests, it is often impossible to establish with confidence a pre-operative diagnosis in a patient with a conductive hearing loss. METHODS We studied a series of 340 exploratory tympanotomies for conductive hearing loss carried out by a single surgeon. RESULTS The most common operative diagnosis was otosclerosis (n = 164, 48.2 per cent). Ossicular discontinuity was found more commonly than previously reported (n = 103, 30.3 per cent). A small but significant number of patients were found to have cholesteatoma (n = 7.2 per cent). CONCLUSIONS This information is of value when discussing potential findings at surgery for conductive hearing loss. While otosclerosis is the commonest finding in such cases, a significant number of patients have defects of the ossicular chain.