Frequency-Specific Analysis of Hearing Outcomes Associated with Ossiculoplasty Versus Stapedotomy.

ABSTRACT

OBJECTIVE: Surgery on the ossicular chain may impact its underlying mechanical properties. This study aims to investigate comparative differences in frequency-specific hearing outcomes for ossiculoplasty versus stapedotomy. METHODS: A retrospective chart review was conducted on subjects who underwent ossiculoplasty with partial ossicular replacement prosthesis (PORP) or laser stapedotomy with self-crimping nitinol/fluoroplastic piston, and achieved closure of postoperative pure tone average air-bone gap (PTA-ABG) ≤ 15 dB. 45 PORP and 38 stapedotomy cases were included, with mean length of follow-up of 7.6 months. RESULTS: The mean change in PTA-ABG was similar for the 2 procedures (-17.9 dB vs -18.1 dB, P = .98). Postoperative ABG closure for stapedotomy was superior at 1000 Hz (8.9 dB vs 13.9 dB, P = .0003) and 4000 Hz (11.8 dB vs 18.0 dB, P = .0073). Both procedures also had improved postoperative bone conduction (BC) thresholds at nearly all frequencies, but there was no statistical difference in the change in BC at any particular frequency between the 2 procedures. CONCLUSION: Both procedures achieved a similar mean change in PTA-ABG. Stapedotomy was superior to PORP at ABG closure at 1000 Hz and at 4000 Hz, with 1000 Hz the most discrepant. The exact mechanism responsible for these changes is unclear, but the specific frequencies affected suggest that differences in each procedure's respective impact on the native resonant frequency and mass load of the system could be implicated.