Radiologic and Functional Evaluation of Electrode Dislocation from the Scala Tympani to the Scala Vestibuli in Patients with Cochlear Implants

Atypical position of the electrode array. A, The electrode is inserted via cochleostomy (white arrow) and enters the basal cochlear turn from the scala vestibuli (apical, black arrowhead) into scala tympani (basal, white arrowhead). B, In the following course of the basal turn, the electrode array dislocates into the scala vestibuli. C, In the middle turn, the electrode array is clearly identified in the scala vestibuli. D, The insertion depth reaches position 8, which refers to 316°–360°, and the tip shows a kinking at the last electrode element.