Broad Carhart's Notch in Otosclerosis: Postoperative Bone-conduction Changes and Resolution Rates After Stapes Surgery

Monday, October 19, 2026

1:30 PM - 1:36 PM PT

Location: 511AC

Presenting Author(s)

Vanessa J. Zhang

Medical Student
UMass Chan Medical School
Lexington, MA, United States

Co-Author(s)

BW

Brooke Wang, BS

Research Lab Technician I
Massachusetts Eye and Ear Infirmary, United States
Renata M. Knoll, MD

PGY-3 Resident, Otolaryngology–Head and Neck Surgery
Massachusetts Eye and Ear Infirmary / Harvard Medical School
Boston, MA, United States

Senior Author(s)

AR

Aaron K. Remenschneider, MD, MPH, FACS

Staff Neurotologist; Associate Professor of Otolaryngology–Head and Neck Surgery
Boston Children's Hospital
Boston, MA, United States
David H. Jung, MD, PhD, FACS

Associate Professor of Otolaryngology–Head and Neck Surgery
Massachusetts Eye and Ear / Harvard Medical School
Boston, MA, United States

Disclosure(s):

Vanessa J. Zhang:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Introduction: In otosclerosis, the classic “Carhart’s notch” is a bone-conduction (BC) depression near 2 kHz that often normalizes after stapes surgery. Some ears show a broader BC depression extending to adjacent frequencies (“broad Carhart’s notch”); we assessed postoperative BC changes, the rate of broad-notch resolution, and whether air-bone-gap (ABG) closure predicts resolution.

Methods: Retrospective cohort from two tertiary centers (2016–2025). Included primary stapedotomy/stapedectomy ears with a broad-notch pattern on pre-op BC thresholds at 0.5, 1, and 2 kHz and complete pre/post audiometry; clinically anomalous outcomes were excluded. Broad-notch resolution was conservatively defined using within-ear criteria: the 2-kHz asymmetry largely normalizes and the adjacent 1-kHz “shoulder” improves. ABG outcomes (PTA, 2 kHz) and clinical factors (footplate drill-out, side, unilateral vs bilateral otosclerosis, sex, site) were assessed with multivariable logistic regression for broad-notch resolution.

Results: Forty-two ears met criteria (Site A 26; Site B 16). BC improved at 2 kHz and 1 kHz (both p< 0.001), yet broad-notch resolution occurred in only 15/42 (35.7%). ABG closure was common (final ABG-PTA ≤10 dB in 39/42) but did not identify broad-notch resolution (14/15 vs 25/27; p=1.00). In multivariable analysis (AUC ~0.90), bilateral otosclerosis and footplate drill-out were associated with lower odds of broad-notch resolution; other covariates were not significant.

Conclusions: Most ears achieved near-complete ABG closure, but only about one-third demonstrated normalization of the broader BC asymmetry, particularly in bilateral disease or drill-out cases. This may inform preoperative counseling. Ongoing work will add 4-kHz BC and incorporate CT and serial audiograms to clarify mechanisms.