Quantifying internal intervertebral disc strains to assess nucleus replacement device designs: a digital volume correlation and ultra-high-resolution MRI study

Frontiers in Bioengineering and Biotechnology

Bioengineering and Biotechnology

Nicoleta Baxan¹  Kay A. Raftery²  George Morgan²  Nicolas Newell²  Axel Moore³  Molly M. Stevens³  Saman Tavana⁴  Tamanna Rahman⁴  Thomas P. Schaer⁵  Nigel Smith⁶  Jonathan Bull⁷ 

[1] Biological Imaging Centre, Central Biomedical Services, Imperial College London, London, United Kingdom;Faculty of Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom;Department of Bioengineering, Imperial College London, London, United Kingdom;Department of Bioengineering, Imperial College London, London, United Kingdom;Department of Materials and Institute of Biomedical Engineering, Imperial College London, London, United Kingdom;Department of Bioengineering, Imperial College London, London, United Kingdom;Department of Mechanical Engineering, Biomechanics Group, Imperial College London, London, United Kingdom;Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, United States;Division of Surgery and Interventional Science, University College London, Stanmore, United Kingdom;Neurosurgery, BARTS Health NHS Trust, London, United Kingdom;

关键词: nucleus replacement surgery;    IVD strains;    digital volume correlation;    nuclectomy;    nucleus replacement device;   

DOI  :  10.3389/fbioe.2023.1229388

 received in 2023-05-26, accepted in 2023-09-15,  发布年份 2023

来源: Frontiers

【 摘 要 】

Introduction: Nucleus replacement has been proposed as a treatment to restore biomechanics and relieve pain in degenerate intervertebral discs (IVDs). Multiple nucleus replacement devices (NRDs) have been developed, however, none are currently used routinely in clinic. A better understanding of the interactions between NRDs and surrounding tissues may provide insight into the causes of implant failure and provide target properties for future NRD designs. The aim of this study was to non-invasively quantify 3D strains within the IVD through three stages of nucleus replacement surgery: intact, post-nuclectomy, and post-treatment.Methods: Digital volume correlation (DVC) combined with 9.4T MRI was used to measure strains in seven human cadaveric specimens (42 ± 18 years) when axially compressed to 1 kN. Nucleus material was removed from each specimen creating a cavity that was filled with a hydrogel-based NRD.Results: Nucleus removal led to loss of disc height (12.6 ± 4.4%, p = 0.004) which was restored post-treatment (within 5.3 ± 3.1% of the intact state, p > 0.05). Nuclectomy led to increased circumferential strains in the lateral annulus region compared to the intact state (−4.0 ± 3.4% vs. 1.7 ± 6.0%, p = 0.013), and increased maximum shear strains in the posterior annulus region (14.6 ± 1.7% vs. 19.4 ± 2.6%, p = 0.021). In both cases, the NRD was able to restore these strain values to their intact levels (p ≥ 0.192).Discussion: The ability of the NRD to restore IVD biomechanics and some strain types to intact state levels supports nucleus replacement surgery as a viable treatment option. The DVC-MRI method used in the present study could serve as a useful tool to assess future NRD designs to help improve performance in future clinical trials.

【 授权许可】

Unknown   
Copyright © 2023 Rahman, Tavana, Baxan, Raftery, Morgan, Schaer, Smith, Moore, Bull, Stevens and Newell.