This is the right ear of a pediatric cochlear implant patient at the time of device replacement.  The implant failed after minor head trauma.  The degree of osteoneogenesis is typical, and removal of the implant requires careful bone removal.  Ideally the implant should be removed without any damage, to optimize the information gained when the failed device is studied by the manufacturer.

The last image shows the cochleostomy before electrode removal.  Generally, there is no bone formation here, and the electrode is easily removed and reinserted.

These images were submitted by Dr. David Armstrong.