Infuence of the Radius of Curvature and Residual Stresses on Pedicular Spinal Implant Rods

Detalhes bibliográficos
Autor(a) principal: Masiero, Lucas Verdan
Data de Publicação: 2021
Outros Autores: Habib, Anderson Závoli, Aliaga, Luis César Rodríguez, Lima, Lucas Venâncio Pires de Carvalho
Tipo de documento: Artigo
Idioma: por
Título da fonte: Vetor (Online)
Texto Completo: https://periodicos.furg.br/vetor/article/view/12880
Resumo: Pedicle rods are used in spinal implants in order to stabilize and correct deformities. In several clinical applications, pedicle rods are molded (cold forming) at the time of surgery, in order, for example, to provide sagittal alignment to the patient. However, the normative test related to these implants (ASTM F1717-04) evaluates the straight configuration (without conformation). The present work seeks to verify the influence of such bending on the rods’ stress state, affecting the implant lifespan. In this work, two effects are evaluated: the influence of the new geometries (by varying radii of curvature) and the influence of residual stresses resulted from bending. The influence of geometry was investigated using finite element modeling using ANSYS Mechanical APDL software. The influence of residual stresses was estimated based on a simplified model proposed by the balance of moments for a circular cross-section. It was found that both effects are significant. For the geometric effects, the rod closest to the point of force application resulted on a lower tractive tension in the posterior part of the implant, while for residual stresses, the effect was the opposite. Greater bending increased in tensile stresses. The present work results point out that it would bebeneficial to use precast pedicle rods in such a way that the manufacturing processes would minimize their residual stresses.
id FURG-7_6a55b91b3df2e1e80ee28d48e373acdf
oai_identifier_str oai:periodicos.furg.br:article/12880
network_acronym_str FURG-7
network_name_str Vetor (Online)
repository_id_str
spelling Infuence of the Radius of Curvature and Residual Stresses on Pedicular Spinal Implant RodsInfluência do Raio de Curvatura e Tensões Residuais em Hastes de Implantes Pediculares na Coluna VertebralPedicular ImplantsFinite ElementsResidual StressesImplantes PedicularesElementos FinitosTensões ResiduaisPedicle rods are used in spinal implants in order to stabilize and correct deformities. In several clinical applications, pedicle rods are molded (cold forming) at the time of surgery, in order, for example, to provide sagittal alignment to the patient. However, the normative test related to these implants (ASTM F1717-04) evaluates the straight configuration (without conformation). The present work seeks to verify the influence of such bending on the rods’ stress state, affecting the implant lifespan. In this work, two effects are evaluated: the influence of the new geometries (by varying radii of curvature) and the influence of residual stresses resulted from bending. The influence of geometry was investigated using finite element modeling using ANSYS Mechanical APDL software. The influence of residual stresses was estimated based on a simplified model proposed by the balance of moments for a circular cross-section. It was found that both effects are significant. For the geometric effects, the rod closest to the point of force application resulted on a lower tractive tension in the posterior part of the implant, while for residual stresses, the effect was the opposite. Greater bending increased in tensile stresses. The present work results point out that it would bebeneficial to use precast pedicle rods in such a way that the manufacturing processes would minimize their residual stresses.Hastes pediculares são utilizadas em implantes na coluna vertebral com o objetivo de estabilizar e corrigir deformidades. Em diversas aplicações clínicas, as hastes são dobradas (conformação a frio) no momento da cirurgia, a fim de, por exemplo, fornecer ao paciente um bom alinhamento sagital. Entretanto, o teste normativo que avalia estes implantes (ASTM F1717-04) o faz numa configuração de haste reta (sem conformação). O presente trabalho buscaverificar a influência de tal dobra no estado de tensões da haste, que pode reduzir a vida útil do implante. Neste trabalho dois efeitos são avaliados: a influência de novas geometrias (pela variação de diferentes raios de curvatura) e a influência das tensões residuais provenientes da flexão. A influência da geometria foi averiguada por meio de modelagem em elementos finitos utilizando o software ANSYS Mechanical APDL. A influência das tensões residuais foi estimada a partir de um modelo simplificado, proposto por equilíbrio de momentos para uma haste de seção circular. Verificou-se que ambos os efeitos são influentes. Para os efeitos geométricos, quanto mais a haste se aproxima doponto de aplicação da força (por causa da conformação), menor a tensão trativa na parte posterior do implante. Para as tensões residuais o efeito é contrário, quanto maior o dobramento, maiores são as tensões trativas no mesmo local. Os resultados do presente trabalho apontam que seria benéfico o emprego de hastes pediculares pré-conformadas de forma que os processos de fabricação minimizem as tensões residuais presentes nestas.Universidade Federal do Rio Grande2021-04-22info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://periodicos.furg.br/vetor/article/view/1288010.14295/vetor.v30i1.12880VETOR - Journal of Exact Sciences and Engineering; Vol. 30 No. 1 (2020); 49-59VETOR - Revista de Ciências Exatas e Engenharias; v. 30 n. 1 (2020); 49-592358-34520102-7352reponame:Vetor (Online)instname:Universidade Federal do Rio Grande (FURG)instacron:FURGporhttps://periodicos.furg.br/vetor/article/view/12880/8679Copyright (c) 2021 VETOR - Revista de Ciências Exatas e Engenhariasinfo:eu-repo/semantics/openAccessMasiero, Lucas VerdanHabib, Anderson ZávoliAliaga, Luis César RodríguezLima, Lucas Venâncio Pires de Carvalho2021-08-05T21:46:16Zoai:periodicos.furg.br:article/12880Revistahttps://periodicos.furg.br/vetorPUBhttps://periodicos.furg.br/vetor/oaigmplatt@furg.br2358-34520102-7352opendoar:2021-08-05T21:46:16Vetor (Online) - Universidade Federal do Rio Grande (FURG)false
dc.title.none.fl_str_mv Infuence of the Radius of Curvature and Residual Stresses on Pedicular Spinal Implant Rods
Influência do Raio de Curvatura e Tensões Residuais em Hastes de Implantes Pediculares na Coluna Vertebral
title Infuence of the Radius of Curvature and Residual Stresses on Pedicular Spinal Implant Rods
spellingShingle Infuence of the Radius of Curvature and Residual Stresses on Pedicular Spinal Implant Rods
Masiero, Lucas Verdan
Pedicular Implants
Finite Elements
Residual Stresses
Implantes Pediculares
Elementos Finitos
Tensões Residuais
title_short Infuence of the Radius of Curvature and Residual Stresses on Pedicular Spinal Implant Rods
title_full Infuence of the Radius of Curvature and Residual Stresses on Pedicular Spinal Implant Rods
title_fullStr Infuence of the Radius of Curvature and Residual Stresses on Pedicular Spinal Implant Rods
title_full_unstemmed Infuence of the Radius of Curvature and Residual Stresses on Pedicular Spinal Implant Rods
title_sort Infuence of the Radius of Curvature and Residual Stresses on Pedicular Spinal Implant Rods
author Masiero, Lucas Verdan
author_facet Masiero, Lucas Verdan
Habib, Anderson Závoli
Aliaga, Luis César Rodríguez
Lima, Lucas Venâncio Pires de Carvalho
author_role author
author2 Habib, Anderson Závoli
Aliaga, Luis César Rodríguez
Lima, Lucas Venâncio Pires de Carvalho
author2_role author
author
author
dc.contributor.author.fl_str_mv Masiero, Lucas Verdan
Habib, Anderson Závoli
Aliaga, Luis César Rodríguez
Lima, Lucas Venâncio Pires de Carvalho
dc.subject.por.fl_str_mv Pedicular Implants
Finite Elements
Residual Stresses
Implantes Pediculares
Elementos Finitos
Tensões Residuais
topic Pedicular Implants
Finite Elements
Residual Stresses
Implantes Pediculares
Elementos Finitos
Tensões Residuais
description Pedicle rods are used in spinal implants in order to stabilize and correct deformities. In several clinical applications, pedicle rods are molded (cold forming) at the time of surgery, in order, for example, to provide sagittal alignment to the patient. However, the normative test related to these implants (ASTM F1717-04) evaluates the straight configuration (without conformation). The present work seeks to verify the influence of such bending on the rods’ stress state, affecting the implant lifespan. In this work, two effects are evaluated: the influence of the new geometries (by varying radii of curvature) and the influence of residual stresses resulted from bending. The influence of geometry was investigated using finite element modeling using ANSYS Mechanical APDL software. The influence of residual stresses was estimated based on a simplified model proposed by the balance of moments for a circular cross-section. It was found that both effects are significant. For the geometric effects, the rod closest to the point of force application resulted on a lower tractive tension in the posterior part of the implant, while for residual stresses, the effect was the opposite. Greater bending increased in tensile stresses. The present work results point out that it would bebeneficial to use precast pedicle rods in such a way that the manufacturing processes would minimize their residual stresses.
publishDate 2021
dc.date.none.fl_str_mv 2021-04-22
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv https://periodicos.furg.br/vetor/article/view/12880
10.14295/vetor.v30i1.12880
url https://periodicos.furg.br/vetor/article/view/12880
identifier_str_mv 10.14295/vetor.v30i1.12880
dc.language.iso.fl_str_mv por
language por
dc.relation.none.fl_str_mv https://periodicos.furg.br/vetor/article/view/12880/8679
dc.rights.driver.fl_str_mv Copyright (c) 2021 VETOR - Revista de Ciências Exatas e Engenharias
info:eu-repo/semantics/openAccess
rights_invalid_str_mv Copyright (c) 2021 VETOR - Revista de Ciências Exatas e Engenharias
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Universidade Federal do Rio Grande
publisher.none.fl_str_mv Universidade Federal do Rio Grande
dc.source.none.fl_str_mv VETOR - Journal of Exact Sciences and Engineering; Vol. 30 No. 1 (2020); 49-59
VETOR - Revista de Ciências Exatas e Engenharias; v. 30 n. 1 (2020); 49-59
2358-3452
0102-7352
reponame:Vetor (Online)
instname:Universidade Federal do Rio Grande (FURG)
instacron:FURG
instname_str Universidade Federal do Rio Grande (FURG)
instacron_str FURG
institution FURG
reponame_str Vetor (Online)
collection Vetor (Online)
repository.name.fl_str_mv Vetor (Online) - Universidade Federal do Rio Grande (FURG)
repository.mail.fl_str_mv gmplatt@furg.br
_version_ 1797041761776828416

Registros relacionados