Isolated Congenital Incus Anomaly: Report of a Case

Abstract

Congenital ossicular anomalies are often encountered in patients with congenital aural atresia and less frequently in patients with normal external ears. The most common site of isolated congenital ossicular anomalies is the stapes. Isolated congenital incus anomalies are rare. In June 2000, a thirteen-year-old girl visited our department complaining of hearing loss in the right ear since childhood. The external ears were normal. The pure tone audiometry showed 42 dB hearing loss with a 33 dB air-bone gap in the right ear. As the tympanic membrane was elevated during exploratory tympanotomy, the incus was found to be anomalous and resembled a small bar with one end attached to the head of the stapes while the other end was free. Both the malleus and the stapes were normal and mobile. We placed a piece of partial ossicular replacement prosthesis (Xomed 11-56362) onto the head of the stapes. We also inserted a piece of tragal cartilage between the eardrum and the prosthesis in order to prevent early protrusion of the prosthesis. The postoperative hearing gain was 15dB, and there has been no evidence of hearing deterioration over the last 12 months of follow-up.