The Clarion electrode positioner: Temporal bone studies

Objective: To study the relationship of the Clarion electrode to the modiolus when using an intracochlear positioner. Background: There are theoretical advantages to positioning a cochlear implant electrode in close proximity to the modiolus. This may allow more focused, discrete fields of electrical current, reducing both requirements to achieve threshold and the channel interactions associated with the simultaneous and nonsimultaneous stimulation of closely spaced electrodes. Methods: Ten fresh temporal bones were used to assess the position of the electrode in the scala tympani with the positioner in place. The bones were X-rayed after implantation. The relationship of the electrode to the modiolus was studied by calculating a ratio between the curve assumed by the electrode in relationship to the outer wall of the cochlea. The depth of insertion was evaluated in degrees or number of turns around the modiolus. Results: The electrode was brought closer to the modiolus and a greater depth of insertion was achieved in all cases with the positioner. Conclusion: The intracochlear positioner is capable of bringing the electrode consistently closer to the neural elements within the modiolus.