Type 2 ossiculoplasty: prognostic determination of hearing results by middle ear risk index.

Purpose: The aims of this study were to investigate the prognostic impact of middle ear risk index on the postoperative hearing results in cases with type 2 ossiculoplasty; to compare the middle ear risk index results among primary, staged, and revision cases; and to compare the results of the prostheses used in ossicular reconstruction.

Material And Methods: Records of 293 patients who had canal wall up tympanomasteidectomy and type 2 ossiculoplasty due to chronic otitis media between November 1995 and November 2007 were reviewed retrospectively.

Results: The mean preoperative air-bone gap was 32.6 dB, and it decreased to 15.2 dB after a mean follow-up period of 26.8 months postoperatively. The mean change of air-bone gap was 17.4 dB. Postoperative air-bone gap was 20 dB or less in 79% of the cases. The patients with dry perforations were in the low-risk group, and 91% of them had an air-bone gap of 20 dB or less. This value was 86% in the ones with intact malleus. The patients who had primary surgery were found in moderate risk group, whereas staged and revision groups were in the high-risk group. The air-bone gap was 20 dB or less in 84%, 78%, and 59%, respectively, of those groups. The difference between the primary and the revision groups reached a statistical significance.

Conclusions: We had the best ossicular reconstruction results with glass ionomer cement, whereas the worst results were obtained with allograft partial ossicular replacement prostheses. We determined that risk-reducing factors such as dry ear, minimal ossicular chain defect, and intact malleus were important to have successful results. The middle ear risk index is a valuable tool for the surgeon to judge the risks and the probability success of the procedure as well as to make a good patient selection.