Preoperative high-resolution computed tomography and three-dimensional reconstruction of the ossicular chain in conductive hearing loss with an intact tympanic membrane: a retrospective imaging-surgical case series

Abstract Background The structural cause of conductive hearing loss may remain uncertain when the tympanic membrane is intact. This study examined how high-resolution computed tomography (HRCT), multiplanar reformation (MPR), and three-dimensional (3D) ossicular reconstruction contributed to the integrated preoperative assessment and reconstruction planning. Methods We retrospectively reviewed 33 consecutive patients (35 operated ears) treated between June 2018 and August 2024. All patients underwent audiologic testing, temporal-bone HRCT with physician-directed post-processing, and exploratory tympanotomy. Ossicular reconstruction was performed when technically feasible and considered safe. Operative findings served as the anatomic reference. Correspondence between the integrated preoperative diagnostic impression, based on clinical, audiologic, and CT findings, and the principal operative diagnosis was summarized at the patient level. Preoperative and 3-month hearing thresholds were compared in the 33 reconstructed ears. Results Eight ears were diagnosed with otosclerosis, and all had an immobile stapes footplate at surgery; the other operative diagnoses were congenital ossicular anomalies in 25 ears and traumatic ossicular discontinuity in 2 ears. The integrated preoperative diagnostic impression agreed with the principal operative diagnosis in 32 of 33 patients (97.0%; 95% Wilson confidence interval [CI], 84.7–99.5%). The discordant lesion was a fibrous incudostapedial connection. Mean air-conduction pure-tone average improved from 65.4 ± 14.0 to 31.9 ± 9.2 dB HL (mean paired improvement, 33.5 dB; 95% CI, 28.2–38.9), and mean air-bone gap decreased from 40.9 ± 13.1 to 12.1 ± 7.3 dB (mean paired closure, 28.8 dB; 95% CI, 24.0-33.6; both P < 0.001). Mean bone-conduction threshold improved by 4.7 dB (95% CI, 1.7–7.7; P = 0.003). A postoperative air-bone gap < 20 dB was achieved in 28 ears (84.8%). Conclusions In this selected surgical series, CT provided anatomic information for the integrated preoperative assessment and helped anticipate possible reconstruction requirements. The 97.0% patient-level correspondence reflects the combined clinical, audiologic, and imaging impression and should not be interpreted as the diagnostic accuracy of CT alone. Stapes fixation and fibrous ossicular connections may remain occult on CT.