Treatment of thoracolumbar fracture with pedicle screws at injury level: a biomechanical study based on three-dimensional finite element analysis
Autor: | Zhaoming Chu, Qinliang Li, Hu-sheng Zhang, Xiu-Zhong Li, Jinchuan Chen, Peng Shang, Ming Chen, Ru-Jie Qin, Yi Liu |
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Rok vydání: | 2012 |
Předmět: |
musculoskeletal diseases
Male medicine.medical_specialty medicine.medical_treatment Bone Screws Finite Element Analysis Kyphosis Thoracic Vertebrae Stress (mechanics) Fracture Fixation Internal Fracture fixation Fractures Compression medicine Internal fixation Humans Orthopedics and Sports Medicine Stress concentration Orthodontics Lumbar Vertebrae Cobb angle business.industry Biomechanics Middle Aged equipment and supplies musculoskeletal system Compression (physics) medicine.disease Surgery Biomechanical Phenomena surgical procedures operative Spinal Fractures Stress Mechanical business |
Zdroj: | European journal of orthopaedic surgerytraumatology : orthopedie traumatologie. 23(7) |
ISSN: | 1432-1068 |
Popis: | The aim of this study was to investigate the biomechanical mechanisms of treatment of thoracolumbar compression fracture with pedicle screws at injury level based on a three-dimensional finite element method. We constructed one three-dimensional finite element model of T11-L1 in a patient with a compression fracture of the T12 vertebral body(anterior edges of vertebral body were compressed to 1/2, and kyphosis Cobb angle was 18.6°) fixed by four pedicle screws and another model fixed by six pedicle screws at the injured vertebrae, and then assigned different forces to the two models to account for axial compression, flexion, extension, left lateral bending, and rightward axial rotation by Ansys software. After different loading forces were applied to the models, we recorded stress measurements on the vertebral pedicle screws, as well as the maximum displacement of T11. The stress distribution suggested that stress concentration was appreciable at the root of the pedicle screws under different loading modalities. Under axial compression, flexion, extension, left lateral bending, and rightward axial rotation load, the stress for the superior screw was significantly greater than the stress for the inferior screw (P < 0.05). The stress in the six pedicle screw fixation model was significantly decreased compared to the four screw interbody fusion model (P < 0.05), but the maximum displacement of T11 between two models under different loadings was not statistically different. The use of pedicle screws at injured vertebral bodies may optimize internal fixation load and reduce the incidence of broken screws. |
Databáze: | OpenAIRE |
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