Incus Interposition Techniques

Abstract

This report describes a technique of incus interposition which has resulted in a closure of air-bone gaps from 30 dB to 15 dB or less in 69.4% of 216 ears, which have been followed for two to five years after surgery. An analysis of a subgroup of preoperative near normal hearing ears revealed no significant increased postoperative hearing loss, while another subgroup with very wide preoperative air-bone gaps showed significantly less air-bone gap closure at 15 dB (44.0%) than the general group. Preoperative and postoperative hearing tests in another subgroup of ears, in which the posterior ear canal wall was removed at the time of surgery, revealed that there was no significant increased hearing loss when compared with the entire group. This finding would suggest that removal of the posterior ear canal wall per se does not decrease the chances for hearing improvement when this technique is used. A study of the tympanosclerotic ears in this series revealed a postoperative air-bone gap closure of 15 dB or less in 58.5%. Failure to achieve adequate air-bone gap closure was most frequently caused by middle ear atelectasis (24.0%), on an allergic basis (52.0%), while graft malposition was infrequent (2.8%) and resorption or rejection of autografts or banked ossicles was not observed.