Idiopathic incus necrosis: Analysis of 4 cases

We evaluated ossicular chain reconstruction in patients with idiopathic incus necrosis who have conductive hearing loss and an intact ear drum. The study included four patients (3 women and 1 man; the ages of the patients were 22, 31, 35, and 56 years, respectively) with unilateral conductive hearing loss, no history of chronic serous otitis media, an intact ear drum, normal middle ear mucosa, and necrosis of the long processes of the incus. On preoperative pure tone audiometry, air-bone gaps were 24, 25, 38, and 33 dB. Bilateral tympanometry and temporal bone computed tomography results were normal. All 4 patients underwent an exploratory tympanotomy. During the operation, the mucosa of the middle ear was normal, with a mobile stapes foot plate and malleus. No evidence of any granulation tissue was found; however, necrosis of the incus long processes was seen. For ossicular reconstruction, we used tragal cartilage between the incus and the stapes in 1 patient; in the other 3 patients, glass ionomer bone cement was used (an interposition cartilage graft also was used in the patients who received the glass ionomer bone cement). In all patients, air-bone gaps under 20 dB were established in the first year after surgery. In the ossicular disorders within the middle ear, the incus is the most commonly affected ossicle. While, the most common cause of these disorders is chronic otitis media, it may be idiopathic rarely. Several ossicular reconstruction techniques have been used to repair incudostapedial discontinuity.