BACKGROUND Obliteration of the mastoid cavity with S53P4 bioactive glass is becoming a popular method of treatment, allowing most of the problems with the postoperative cavity to be eliminated. In the case of a hearing aid, reconstruction of the posterior wall of the auditory canal is an extremely beneficial procedure and, in the case of the Bonebridge implant, is necessary. After reconstruction, the FMT transducer is covered by bone and bioactive glass and has no contact with the postoperative cavity. The aim of this article is to present a case report. CASE REPORT A 41-year-old male patient with a history of bilateral otitis media with cholesteatoma since childhood had undergone many ear operations since 2001, including radical modified operations and postoperative revisions. There had been ossiculoplasty using own materials and a Kurz TORP prosthesis which gave a short-term hearing improvement for 3 months. The patient underwent tests for implantable devices, which showed a potential significant improvement in hearing and understanding speech. The patient met the audiological criteria qualifying him for the use of an implantable bone conduction device. However, a CT scan of the temporal bone showed that the Bonebridge implant could not be implanted due to insufficient mastoid volume. In order to safely implant the Bonebridge device, it was necessary to first rebuild the posterior wall of the left ear canal. The absolute condition was no inflammation of the ear or leaks for several months. CONCLUSIONS The two-stage surgical procedure as described in this case report can allow the Bonebridge implant to be used in a wider group of patients with previous anatomical limitations.