PSI - Issue 28

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2020) 000–000

www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 28 (2020) 1727–1732

1st Virtual European Conference on Fracture Studying the Bulging of a Lumbar Intervertebral Disc: A Finite Element Analysis Hassan Mansour Raheem a,b * , Mohanad Aljanabi b

a Mechanical Department, Faculty of Engineering, University of Kufa, Najaf, 54001, Iraq b Ministry of Oil, Midland Refineries Company, Karbala Refinery, Karbala, 56001, Iraq

© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo Abstract The nucleus pulposus is a crucial compartment of the intervertebral disc. Low back pain is usually connected to the disc situation, how healthy the disc is, and it is also associated with the nucleus pulposus condition. Besides, the bulging (deformation) at the disc plays a vital role in patients suffering from disc degeneration. Increasing bulging causes to increase shear stresses at the annulus fibrosus and eventually leads to surgical intervention if classical treatments do not alleviate the pain. Therefore, knowing the behavior of bulging in the intervertebral disc helps to prevent severe damage to the disc and contributes to finding a feasible treatment for damaged discs. In this study, a three-dimensional finite element (FE) model was used to investigate the bulging in the lumbar disc due to changing the nucleus pulposus status. The model resembles the overall anatomic geometry of the human spinal functional unit of the lumbar region, but without the posterior element. The findings showed that bulging direction in the disc agrees with literature data and removing the nucleus pulposus significantly affects the response of the disc. © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo Keywords: Finite element modeling; Bulging; Axial compression loads; Nucleus pulposus; Lumbar region 1. Introduction The intervertebral disc (IVD) primarily serves as a mechanical cushion permitting controlled motion between vertebral segments of the spinal column. The healthy disc is a unique, mixed structure, comprised of three component tissues: the nucleus pulpous (NP), the annulus fibrosus (AF) and two vertebral end-plates (Raheem, Bay, and Rochefort 2019). The end-plates thus act to attach adjacent vertebrae to the IVD. The spinal disc may be displaced or damaged

____________ * Corresponding author. Tel.: +964-781-793-7099 E ‐ mail address: enghas25@gmail.com (H. Raheem).

2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 10.1016/j.prostr.2020.10.148