We report a case of traumatic dislocation of the stapes without disruption of the ossicular chain.
An 8-year-old boy visited our clinic because of left-sided hearing impairment. Pure tone audiography showed average conductive hearing loss of 50dB. Stapedial dislocation was suspected by temporal bone CT. Exploratory tympanotomy revealed that the stapes was dislocated inf eriorly with its footplate fused with the bony promontory wall. Both malleo-incudal and incudo-Stapedial joints were intact. The oval window was closed with thin scar tissue being covered by intact mucosa. When the superstructure of the stapes was removed and the overlying tissue of the oval window was incised, outflow of perilymph was observed. With the placement of a 4.5mm-long teflon wire piston, his hearing improved to 13dB on average, without particular complications. Although the history of head trauma he experienced was not severe enough to explain the dislocation of the stapes, a mechanical cause was more likely in this case than a congenital anomaly because there were no anomalies in his middle ear or any other parts of his body.