Biomechanical Effects of Thoracic Flexibility and Stiffness on Lumbar Spine Loading: A Finite Element Analysis Study.

Autor: Morimoto M; Department of Orthopedic Surgery, Tokushima University Graduate School of Medicine, Tokushima, Japan; Departments of Bioengineering and Orthopaedics, Engineering Center for Orthopaedic Research Excellence, University of Toledo, Toledo, Ohio, USA. Electronic address: masa_m_089034@yahoo.co.jp., Tripathi S; Departments of Bioengineering and Orthopaedics, Engineering Center for Orthopaedic Research Excellence, University of Toledo, Toledo, Ohio, USA., Kodigudla M; Departments of Bioengineering and Orthopaedics, Engineering Center for Orthopaedic Research Excellence, University of Toledo, Toledo, Ohio, USA., Motohashi E; Department of Orthopedic Surgery, Tokushima University Graduate School of Medicine, Tokushima, Japan., Fujitani J; Department of Orthopedic Surgery, Tokushima University Graduate School of Medicine, Tokushima, Japan., Goel VK; Departments of Bioengineering and Orthopaedics, Engineering Center for Orthopaedic Research Excellence, University of Toledo, Toledo, Ohio, USA., Sairyo K; Department of Orthopedic Surgery, Tokushima University Graduate School of Medicine, Tokushima, Japan.
Jazyk: angličtina
Zdroj: World neurosurgery [World Neurosurg] 2024 Apr; Vol. 184, pp. e282-e290. Date of Electronic Publication: 2024 Jan 26.
DOI: 10.1016/j.wneu.2024.01.112
Abstrakt: Objective: To determine the effects of thoracic stiffness on mechanical stress in the lumbar spine during motion.
Methods: To evaluate the effect of preoperative thoracic flexibility, stiff and flexible spine models were created by changing the material properties of ligaments and discs in the thoracic spine. Total laminectomy was performed at L4/5 in stiff and flexible models. A biomechanical investigation and finite element analysis were performed preoperatively and postoperatively. A hybrid loading condition was applied, and the range of motion (ROM) at each segment and maximum stress in the discs and pars interarticularis were computed.
Results: In the preoperative model with the stiff thoracic spine, lumbar disc stress, lumbar ROM, and pars interarticularis stress at L5 increased. In contrast, as the thoracic spine became more flexible, lumbar disc stress, lumbar ROM, and pars interarticularis stress at L5 decreased. All L4/5 laminectomy models had increased instability and ROM at L4/5. To evaluate the effect of thoracic flexibility on the lumbar spine, differences between the stiff and flexible thoracic spine were examined: Differences in ROM and intervertebral disc stress at L4/5 in flexion between the stiff and flexible thoracic spine were respectively 0.7° and 0.0179 MPa preoperatively and 1.5° and 0.0367 MPa in the L4/5 laminectomy model.
Conclusions: Biomechanically, disc stress and pars interarticularis stress decrease in the flexible thoracic spine. Flexibility of the thoracic spine reduces lumbar spine loading and could help to prevent stress-related disorders.
(Copyright © 2024. Published by Elsevier Inc.)
Databáze: MEDLINE
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