The interscalar septum is a thin bony plate that separates each turn of the cochlea 1.
It radiates from the modiolus laterally to the spiral ligament 2. Vessels (venules, arterioles and capillaries) run within the septum through bony canals 2.
Partial absence of the interscalar septum is a relatively common developmental anaomly that does not interfere with normal cochlear function 3.
Absence of the interscalar septum is associated with cochlear incomplete partition.