Nitinol in passive ossicular reconstruction - first preclinical results

Introduction Rigid alloplastic materials are the standard in passive middle ear prostheses. While these materials have good sound transmission properties, they are less suitable for compensating for atmospheric pressure fluctuations. Superelastic materials such as Nitinol could be a valid alternative.

Methods Together with an industrial partner, we developed a Nitinol clip prosthesis equipped with a flexible head plate. The new prosthesis was tested for flexibility and its sound transmission properties were compared with those of a conventional rigid titanium clip prosthesis. Laser Doppler vibrometry was used to measure the sound-induced velocities of the stapes footplate in temporal bones. This characterization was supplemented by measurements of a load cell to test the reversible elasticity of the new prosthesis and by an evaluation of the handling by experienced ear surgeons.

Results The measured velocities of the stapes footplate after acoustic excitation show comparable values for both prostheses in the frequencies from 0.25 to 10 kHz. The tests in the load cell confirmed the flexibility of the nitinol prosthesis. Almost identical material states are achieved after the application of force. In addition, the ear surgeons rated the handling of the new prosthesis as "very positive".

Discussion The newly developed Nitinol clip prosthesis has good transmission properties with reduced rigidity and is thus a step towards physiological ossicular chain reconstruction.

Poster-PDF A-1754.PDF

Bundesministerium fur Wirtschaft und Energie

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Artikel online veröffentlicht:
10. Juni 2020