Koerner Septum. The körner's septum (ks), persistent petrosquamosal lamina, is a bony lamina (developmental remnant) that extends from the articular fossa to the mastoid. Körner’s septum (ks) or petrosquamosal lamina is a bony lamina beginning at the articular fossa, extending above the middle ear, and running inferiorly and laterally to the facial.
The koerner septum is a thin bridge of bone which divides the petrous and squamous portion of the mastoid air cells at the level of the mastoid antrum. Körner’s septum (ks) or petrosquamosal lamina is a bony lamina beginning at the articular fossa, extending above the middle ear, and running inferiorly and laterally to the facial.