Malleus ankylosis: a clinical, audiometric, histologic, and surgical study of 123 cases.

OBJECTIVE: Malleus ankylosis is a cause of conductive hearing loss that can be difficult to assess, particularly in association with otosclerotic stapes fixation. The aim of this study is to seek the clinical and audiometrical features unique to this pathology.

STUDY DESIGN: The study design was a review of malleus ankylosis cases and an analysis of functional results after ossiculoplasty.

SETTING: The study was performed at Jean Causse Clinic in France.

PATIENTS: The authors reviewed a series of 123 ears in 112 patients who underwent surgery for incudo-mallear ankylosis from January 1991 to September 1997.

INTERVENTION: The surgical technique depends on the type of pathology encountered. In case of associated stapedial fixation, a stapedotomy with vein graft interposition and reconstruction with a total prosthesis will be performed during a same step.

MAIN OUTCOME MEASURES: Clinical evaluation, preoperative and postoperative audiometrical evaluation, operative findings, histologic examination, and postoperative functional results.

RESULTS: In our series, a postoperative air-bone gap smaller than 10 dB was obtained in 77% of cases. These results confirm the possibility of managing both pathologies in a single surgical step.

CONCLUSION: Incudo-mallear ankylosis remains an unusual pathology but should be systematically assessed during surgery and preferably after separation of the incudo-stapedial joint. A preoperative diagnosis is difficult to ascertain; some audiometrical features allow a suspicion. In this series, it is shown that otosclerosis can be responsible for ankylosis as seems to be confirmed by the two cases presented in this study.