A novel Nitinol-Clip in partial ossicular reconstruction – first results from temporal bone experiments

Ossicular chain replacement using clip prosthesis is one of the common reconstruction options in middle ear surgery. A further development of the currently available prostheses should contribute to the optimization of the hearing structure and the intraoperative handling. Therefore, two new clip prostheses were developed, each with different nitinol plates.

Methods:

In temporal bone experiments, the sound transmissions of the new nitinol plate prostheses with a modified plate were compared with a standard prosthesis (Clip prosthesis type Dresden). For this purpose, the acoustic stimulation was carried out via the ear canal. The measurable variable was the sound-induced vibrations of the stapedial footplate. In addition to the vibration transmission, the deformation behavior of the prosthetic plate under static pressure load was investigated. For this purpose, the deflection was measured at the edge of the prosthetic plate when impressing a point force. As a control, the deflection of a rigid surface was measured.

Results:

The measured accelerations of the footplate after acoustic excitation show almost identical values in the frequencies 0.25 to 10 kHz for both nitinol plate prostheses. Both in the analysis of the absolute values and in the relative representation of measurements with an intact ossicle chain, there are no clear differences compared to the currently used clip prosthesis (type Dresden). In the measurements of the deformation behavior, a significantly higher flexibility of the new prostheses was shown.

Conclusion:

The newly developed nitinol plate prostheses show good transmission properties of the acoustic stimulus with reduced rigidity and thus increased flexibility compared to the currently available clip prosthesis in a temporal bone model.

Publication History

Publication Date:
18 April 2018 (online)