Comparison of four in vitro test methods to assess nucleus pulposus replacement device expulsion risk.

Autor: Rahman T; Department of Bioengineering Imperial College London London UK.; Biomechanics Group, Department of Mechanical Engineering Imperial College London London UK., Kibble MJ; Department of Bioengineering Imperial College London London UK., Harbert G; Department of Bioengineering Imperial College London London UK., Smith N; Division of Surgery and Interventional Science University College London Stanmore UK., Brewer E; Department of Biomedical Engineering Rowan University Glassboro New Jersey USA., Schaer TP; Department of Clinical Studies New Bolton Center University of Pennsylvania School of Veterinary Medicine Kennett Square Pennsylvania USA., Newell N; Department of Bioengineering Imperial College London London UK.
Jazyk: angličtina
Zdroj: JOR spine [JOR Spine] 2024 Apr 23; Vol. 7 (2), pp. e1332. Date of Electronic Publication: 2024 Apr 23 (Print Publication: 2024).
DOI: 10.1002/jsp2.1332
Abstrakt: Background: Nucleus replacement devices (NRDs) are not routinely used in clinic, predominantly due to the risk of device expulsion. Rigorous in vitro testing may enable failure mechanisms to be identified prior to clinical trials; however, current testing standards do not specify a particular expulsion test. Multiple methods have therefore been developed, complicating comparisons between NRD designs. Thus, this study assessed the effectiveness of four previously reported expulsion testing protocols; hula-hoop (Protocol 1), adapted hula-hoop (Protocol 2), eccentric cycling (Protocol 3), and ramp to failure (Protocol 4), applied to two NRDs, one preformed and one in situ curing.
Methods: Nucleus material was removed from 40 bovine tail intervertebral disks. A NRD was inserted posteriorly into each cavity and the disks were subjected to one of four expulsion protocols.
Results: NRD response was dependent on both the NRD design and the loading protocol. Protocol 1 resulted in higher migration and earlier failure rates compared to Protocol 2 in both NRDs. The preformed NRD was more likely to migrate when protocols incorporated rotation. The NRDs had equal migration (60%) and expulsion (60%) rates when using unilateral bending and ramp testing. Combining the results of multiple tests revealed complimentary information regarding the NRD response.
Conclusions: Adapted hula-hoop (Protocol 2) and ramp to failure (Protocol 4), combined with fluoroscopic analysis, revealed complimentary insights regarding migration and failure risk. Therefore, when adopting the surgical approach and animal model used in this study, it is recommended that NRD performance be assessed using both a cyclic and ramp loading protocol.
Competing Interests: Thomas P. Schaer was involved in research support as Principal Investigator and the patenting of the hydrogel‐based technologies for ReGelTec, Inc. and Johnson and Johnson DePuy‐Synthes. Additionally, Thomas P. Schaer is a paid consultant and stock supplier for ReGelTec, Inc. Nigel Smith was involved in the development and patenting of hydrogel‐based technologies for Synthes Spine as Director of Non‐Fusion Technologies. Nigel Smith and Erik Brewer were involved in the development and patenting with ReGelTec Inc. of the Hydrafil™ Injectable hydrogel for minimally invasive treatment for treating degenerative disk disease. Nigel Smith and Erik Brewer are current shareholders of ReGelTec Inc. (https://regeltec.com/) that is active in the clinical evaluation of Hydrafil™. Additionally, Erik Brewer receives research funding from ReGelTec, Inc.
(© 2024 The Authors. JOR Spine published by Wiley Periodicals LLC on behalf of Orthopaedic Research Society.)
Databáze: MEDLINE
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