Individual computer assisted 3D planning for placement of auricular prosthesis anchors in combination with an implantable transcutaneous bone conduction hearing device in atresia patients

Background

Simultaneous implantation of the Bonebridge (BB), a semi-implantable, active, transcutaneous bone conduction hearing device and anchors for auricular prosthesis may be challenging, as both implants contain magnets and compete for the narrow space in the designated implantation area.

Methods

A preoperative planning tool was used, which allowed to freely adjust the floating mass transducer (FMT) of the BB in an individual 3D computer model of the skull (“virtual surgery”) for finding optimal implant positions for both, the FMT and the anchors for the auricular prosthesis. The magnetic interaction between the anchors and the FMT was measured by application of static magnetic forces. Retrospective chart analysis was conducted with focus on surgical and audiological outcome.

Results

Between 2014 and 2016, 5 ears in 4 patients (3 males, 1 female; age range 17-51 years, all with a history of multiple failed attempts of ear reconstruction) were treated with the BB with simultaneous planning of auricular prosthesis. In one of these patients, anchors were already in situ. The individual preoperative planning was considered extremely beneficial for an optimal placement of bone anchors in combination with the BB. Audiological data showed clear benefit of hearing after 3 and >11 months. No adverse interactions between the magnetic prosthesis anchors and the FMT were found. In two patients, revision surgery was indicated due to skin inflammation or wound healing problems.

Conclusion

Preoperative 3D planning benefits the implantation of the Bonebridge in combination with magnetic anchors for auricular prostheses.

Publication History

Article published online:
24 May 2022