Congenital Incus Fixation to the Fallopian Canal

IMPORTANCE An isolated congenital anomaly of the ossicular chain is a rare finding in an ear that, otherwise, appears clinically normal. The most common congenital ossicular anomaly is fixation of the stapes footplate. The least common congenital ossicular anomaly is isolated incus fixation, with only a few reported in the literature. OBSERVATIONS We describe a woman in her 50s with a long history of left-sided hearing loss and unremarkable neurotologic findings aside from a tuning-fork examination result suggestive of left-sided conductive hearing loss. Intraoperatively, she was found to have isolated fixation of the incus to the fallopian canal. The incus-fallopian canal fixation was separated, and an autologous bone graft was placed between the lenticular process and stapes capitulum to create elevation and prevent refixation. One month postoperatively, an audiogram revealed a nearly complete air-bone gap closure. CONCLUSIONS AND RELEVANCE Patients who present with conductive hearing loss, normal physical examination findings, and an apparent normal radiograph are generally assumed to have otosclerosis. This case illustrates an unanticipated unique anomaly that was surgically corrected by releasing the bony fixation of the incus to the fallopian canal and placing an autologous bone graft at the incostapedial joint.