Labyrinthine Ossificans and Cochlear Implantation in a Case of Post Modified Radical Mastoidectomy

Abstract

Labyrinthitis ossificans (LO) is the pathological ossification of the membranous labyrinthine spaces in response to an insult involving the membranous labyrinth or the endosteum of the otic capsule. The exact pathogenesis remains unclear, with proposed mechanisms including metaplastic and osteoplastic new bone formation. LO progresses through acute, fibrotic, and ossifying phases. Early diagnosis is essential for hearing preservation, timely cochlear implantation, and appropriate surgical planning, as progressive ossification may necessitate modified implantation techniques. Grade II labyrinthitis ossificans is characterized by replacement of 25–50% of the membranous labyrinth by new bone or fibrous tissue. This report describes a patient presenting with hearing loss who successfully underwent cochlear implantation following modified radical mastoidectomy despite Grade II labyrinthitis ossificans.