Are suspensory ligaments important for middle ear reconstruction?

Journal Article · 24 August 2021 · PLoS ONE

DOI: https://doi.org/10.1371/journal.pone.0255821 · OSTI ID:1909575

Brister, Eileen Y. ^[1]; Withnell, Robert H. ^[2]; Shevchenko, Pavel ^[3]; Richter, Claus-Peter  ^[4]

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1. Northwestern Univ., Chicago, IL (United States). Feinberg School of Medicine; Indiana Univ., Bloomington, IN (United States)
2. Indiana Univ., Bloomington, IN (United States)
3. Argonne National Lab. (ANL), Lemont, IL (United States). Advanced Photon Source (APS)
4. Northwestern Univ., Chicago, IL (United States). Feinberg School of Medicine; Hugh Knowles Center, Evanston, IL (United States)

As the resolution of 3D printing techniques improves, the possibility of individualized, 3-ossicle constructions adds a new dimension to middle ear prostheses. In order to optimize these designs, it is essential to understand how the ossicles and ligaments work together to transmit sound, and thus how ligaments should be replicated in a middle ear reconstruction. The middle ear ligaments are thought to play a significant role in maintaining the position of the ossicles and constraining axis of rotation. Paradoxically, investigations of the role of ligaments to date have shown very little impact on middle ear sound transmission. We explored the role of the two attachments in the gerbil middle ear analogous to human ligaments, the posterior incudal ligament and the anterior mallear process, severing both attachments and measuring change in hearing sensitivity. The impact of severing the attachments on the position of the ossicular chain was visualized using synchrotron microtomography imaging of the middle ear. In contrast to previous studies, a threshold change on the order of 20 dB across a wide range of frequencies was found when both ligaments were severed. Concomitantly, a shift in position of the ossicles was observed from the x-ray imaging and 3D renderings of the ossicular chain. These findings contrast with previous studies, demonstrating that these ligaments play a significant role in the transmission of sound through the middle ear. It appears that both mallear and incudal ligaments must be severed in order to impair sound transmission. The results of this study have significance for middle ear reconstructive surgery and the design of 3D-printed three-ossicle biocompatible prostheses.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1909575
• Journal Information: PLoS ONE, Journal Name: PLoS ONE Journal Issue: 8 Vol. 16; ISSN 1932-6203
• Publisher: Public Library of ScienceCopyright Statement
• Country of Publication: United States
• Language: English