Congenital ossicular anomalies

Congenital ossicular anomalies include abnormalities of either one isolated ossicle or a combination of more than one. We report our patients with this condition and relate the findings to Cremers' classification.

Chart records of patients with congenital ossicular anomalies who received exploratory tympanotomies from 1993 to 2001 were collected. The pre-operative hearing assessment, operative findings, reconstructive types and post-operative hearing results were reviewed retrospectively.

Seventeen cases of ears that underwent exploratory tympanotomy were included in this study. The stapes was the most frequently involved ossicle. Six patients (35.3%) had isolated stapes anomalies, 8 (47%) had incus and stapes anomalies, and all of the remaining patients had anomalies in all 3 ossicles. According to Cremers' proposed classification, the distribution of our cases was as follows: 3 in Class 1, 6 in Class 2, 5 in Class 3, and 3 in Class 4. In 13 cases, the affected ears also underwent reconstructive procedures, including 6 stapedotomies, 6 ossiculoplasties, and 1 labyrinthotomy. The post-operative hearing improvement in air conduction was 28.7 dB.

Patients with congenital ossicular anomalies often present with associated middle and inner ear abnormalities. Some patients could benefit from ossicular reconstruction. Cremers' classification is useful in categorizing the operative findings and the reconstruction. The status of the stapes may be a reference for other associated middle ear anomalies.