Infuence of the Radius of Curvature and Residual Stresses on Pedicular Spinal Implant Rods
Autor(a) principal: | |
---|---|
Data de Publicação: | 2021 |
Outros Autores: | , , |
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 |