Advanced preclinical testing of a design-optimized ceramic bearing for a cervical total disc replacement
Lucia Kölle, Gregory Pryce, Andrew R. Beadling, Michael Bryant, Richard M. Hall, Stephen J. Ferguson, Benedikt Helgason
Abstract
Arthroplasty in the cervical spine is performed using Total Disc Replacement (TDR) implants. This study investigates the safety and tribology of a design-optimized ceramic TDR bearing.
Introduction
Neck pain is a common physical complaint, from which over 300 million people suffered for more than three months in 2015 [1]. When myelopathy, radiculopathy and/or neurological deficits cannot be treated conservatively within a reasonable timeframe, surgical intervention may be considered.
Materials and methods
In the present study, the safety and tribology of a ceramic ball-in-trough TDR bearing [9] intended for the lower cervical spine, particularly the C6/C7 level, are investigated.
Results
The radial clearance of the samples was 0.24 ± 0.05 mm (mean ± SD) compared to 0.07 mm in the optimized design. Further geometrical measurements and how they relate to the optimized geometry are provided in Fig 2 and Table 2.
Discussion
The aim of the present study was to investigate whether a computationally optimized ceramic bearing for a TDR would perform adequately in terms of function and safety, also under test conditions for which it was not optimized.
Conclusion
This study indicates that the computationally optimized ceramic TDR bearing is safe and can perform adequately, even under loading conditions for which it was not optimized. We report methods and results to investigate tribology and subluxation of cervical TDRs.
Citation: Kölle L, Pryce G, Beadling AR, Bryant M, Hall RM, Ferguson SJ, et al. (2026) Advanced preclinical testing of a design-optimized ceramic bearing for a cervical total disc replacement. PLoS One 21(2): e0339851. https://doi.org/10.1371/journal.pone.0339851
Editor: Amitava Mukherjee, VIT University, INDIA
Received: September 8, 2025; Accepted: December 14, 2025; Published: February 5, 2026
Copyright: © 2026 Kölle et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the manuscript and its Supporting Information files.
Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreements No 812765 and No 956004.
Competing interests: The authors declare no conflict of interest. Michael Bryant and Andrew R. Beadling do not have any conflict of interest, but have the following declarations: Michael Bryant and Andrew R. Beadling are in receipt of research funding from Zimmer-Biomet and MatOrtho. Michael Bryant is furthermore in receipt of research funding from DePuy-Synthes. For transparency, Stephen J. Ferguson would like to state that he is a co-founder and minority shareholder of the ETH Spin-Off CustomSurg AG.
