FIG 4. A, Posttraumatic conductive hearing loss in a 20-year-old man. Axial view only shows a partial view of the stapes superstructure.

B, Coronal reformation in the plane of the oval window. The stapes superstructure is visible in the ovale window niche.

C, Oblique axial view in the plane of the stapes superstructure. The anterior and posterior stapes crura are interrupted, and the stapes appears posteriorly displaced.

D, Drawing the S-line perpendicular to the footplate and intersecting its midportion highlights the posterior displacement of the stapes arch. Surgical exploration confirmed the fracture of the anterior and posterior stapes crura. The continuity of the ossicular chain was restored with a PORP prosthesis.

E, Oblique axial view of the contralateral ear. The S-line crosses the stapes head and the long process of the incus.