Investigation of the coupling quality of partial prostheses at the stapes head

Introduction The success of partial ossicular chain reconstructions in cases of conductive hearing loss depends on many factors. One important factor is the coupling between the prosthesis and the stapes head. Prostheses with different forms of attachment to the stapes are available, namely clip and bell type PORP. The coupling to the stapes head was never explicitly investigated previously. We present a standardized method to assess the quality of the prosthesis-stapes connection. The coupling quality of different prostheses is compared using measurements on a specimen model.

Methods This study delineated six groups categorized by prosthesis types, employing 12 temporal bones to create a reconstructed ossicular chain model. The model comprised stapes and inner ear of the specimen, various prostheses and a standardized mechanical excitation at the prosthesis head. Multiple-points measurements were conducted using LDV along the sound transfer direction. This methodology enabled the assessment of vibrational magnitude loss from the prosthesis to the stapes and the determination of sound distortion in sound transmission.

Results Among the six groups assessed, significant magnitude loss in sound transmission through the coupler interface was observed only between two groups at 0.3-0.7 kHz band. Moreover, there is no significant variation in sound distortion between prosthesis types across all frequencies.

Conclusion The proposed measurement method enables an explicit and comparable examination of the prosthesis coupling to the stapes head. The coupling mechanism does indeed determine the quality but not sound transmission. The transmission is uniformly good across all groups. But in terms of postoperative dislocation risk the clips from Kurz and Medel offer better stability.

Funding information CSC

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Artikel online veröffentlicht:
19. April 2024