Design of a novel lateral mass screw–plate system for the treatment of unstable atlas fractures: a finite element analysis

Abstract Background Osteosynthesis of unstable atlas fractures preserves joint motion and therefore has a distinct advantage over a range of treatment procedures. To prevent the potential disadvantages associated with osteosynthesis, a new atlas lateral mass screw–plate (LMSP) system has been design...

Full description

Bibliographic Details
Main Authors: He-Gang Niu, Jing-Jing Zhang, Yi-Zhu Yan, Cheng-Kun Zhao, Kun Yang, Yin-Shun Zhang
Format: Article
Language:English
Published: BMC 2024-02-01
Series:Journal of Orthopaedic Surgery and Research
Subjects:
Online Access:https://doi.org/10.1186/s13018-024-04582-6
_version_ 1827326749163126784
author He-Gang Niu
Jing-Jing Zhang
Yi-Zhu Yan
Cheng-Kun Zhao
Kun Yang
Yin-Shun Zhang
author_facet He-Gang Niu
Jing-Jing Zhang
Yi-Zhu Yan
Cheng-Kun Zhao
Kun Yang
Yin-Shun Zhang
author_sort He-Gang Niu
collection DOAJ
description Abstract Background Osteosynthesis of unstable atlas fractures preserves joint motion and therefore has a distinct advantage over a range of treatment procedures. To prevent the potential disadvantages associated with osteosynthesis, a new atlas lateral mass screw–plate (LMSP) system has been designed. However, the biomechanical role of using the LMSP system in atlas internal fixation is not known. The aim of this study was to compare the biomechanical stability of a new LMSP with traditional posterior screw and rod (PSR) fixation techniques on the occipitocervical junction (C0–C2) through finite element analysis. Methods A nonlinear C0–C2 finite element model of the intact upper cervical spine was developed and validated. The unstable model using the PSR system was then compared with the model using the LMSP system for fixation. A vertical load of 40 N was applied to the C0 to simulate head weight, while a torque of 1.5 Nm was applied to the C0 to simulate flexion, extension, lateral bending, and axial rotation. Results The range of motion of both systems was close to the intact model. Compared with the LMSP system model, the PSR system model increased flexion, extension, lateral bending, and axial rotation by 4.9%, 3.0%, 5.0%, and 29.5% in the C0–C1 segments, and 4.9%, 2.7%, 2.4%, and 22.6% in the C1–C2, respectively. In flexion, extension, and lateral bending motion, the LMSP system model exhibited similar stress to the PSR system model, while in axial rotation, the PSR system model exhibited higher stress. Conclusions The findings of our study indicate that the two tested system models provide comparable stability. However, better stability was achieved during axial rotation with the LMSP system, and in this system, the maximum von Mises stress was less than that of the PSR one. As the atlantoaxial joint functions primarily as a rotational joint, the use of the LMSP system may provide a more stable environment for the joint that has become unstable due to fracture.
first_indexed 2024-03-07T14:49:59Z
format Article
id doaj.art-dafc104a7b5a4016926e3f197eceeafd
institution Directory Open Access Journal
issn 1749-799X
language English
last_indexed 2024-03-07T14:49:59Z
publishDate 2024-02-01
publisher BMC
record_format Article
series Journal of Orthopaedic Surgery and Research
spelling doaj.art-dafc104a7b5a4016926e3f197eceeafd2024-03-05T19:45:48ZengBMCJournal of Orthopaedic Surgery and Research1749-799X2024-02-0119111010.1186/s13018-024-04582-6Design of a novel lateral mass screw–plate system for the treatment of unstable atlas fractures: a finite element analysisHe-Gang Niu0Jing-Jing Zhang1Yi-Zhu Yan2Cheng-Kun Zhao3Kun Yang4Yin-Shun Zhang5Department of Orthopedics, The First Affiliated Hospital of Anhui Medical UniversityDepartment of Orthopedics, The First Affiliated Hospital of Anhui Medical UniversityDepartment of Orthopedics, The First Affiliated Hospital of Anhui Medical UniversityDepartment of Orthopedics, The First Affiliated Hospital of Anhui Medical UniversityDepartment of Orthopedics, The First Affiliated Hospital of Anhui Medical UniversityDepartment of Orthopedics, The First Affiliated Hospital of Anhui Medical UniversityAbstract Background Osteosynthesis of unstable atlas fractures preserves joint motion and therefore has a distinct advantage over a range of treatment procedures. To prevent the potential disadvantages associated with osteosynthesis, a new atlas lateral mass screw–plate (LMSP) system has been designed. However, the biomechanical role of using the LMSP system in atlas internal fixation is not known. The aim of this study was to compare the biomechanical stability of a new LMSP with traditional posterior screw and rod (PSR) fixation techniques on the occipitocervical junction (C0–C2) through finite element analysis. Methods A nonlinear C0–C2 finite element model of the intact upper cervical spine was developed and validated. The unstable model using the PSR system was then compared with the model using the LMSP system for fixation. A vertical load of 40 N was applied to the C0 to simulate head weight, while a torque of 1.5 Nm was applied to the C0 to simulate flexion, extension, lateral bending, and axial rotation. Results The range of motion of both systems was close to the intact model. Compared with the LMSP system model, the PSR system model increased flexion, extension, lateral bending, and axial rotation by 4.9%, 3.0%, 5.0%, and 29.5% in the C0–C1 segments, and 4.9%, 2.7%, 2.4%, and 22.6% in the C1–C2, respectively. In flexion, extension, and lateral bending motion, the LMSP system model exhibited similar stress to the PSR system model, while in axial rotation, the PSR system model exhibited higher stress. Conclusions The findings of our study indicate that the two tested system models provide comparable stability. However, better stability was achieved during axial rotation with the LMSP system, and in this system, the maximum von Mises stress was less than that of the PSR one. As the atlantoaxial joint functions primarily as a rotational joint, the use of the LMSP system may provide a more stable environment for the joint that has become unstable due to fracture.https://doi.org/10.1186/s13018-024-04582-6Atlas fracturesOpen reduction and internal fixation (ORIF)Cervical spineBiomechanicsFinite element analysis
spellingShingle He-Gang Niu
Jing-Jing Zhang
Yi-Zhu Yan
Cheng-Kun Zhao
Kun Yang
Yin-Shun Zhang
Design of a novel lateral mass screw–plate system for the treatment of unstable atlas fractures: a finite element analysis
Journal of Orthopaedic Surgery and Research
Atlas fractures
Open reduction and internal fixation (ORIF)
Cervical spine
Biomechanics
Finite element analysis
title Design of a novel lateral mass screw–plate system for the treatment of unstable atlas fractures: a finite element analysis
title_full Design of a novel lateral mass screw–plate system for the treatment of unstable atlas fractures: a finite element analysis
title_fullStr Design of a novel lateral mass screw–plate system for the treatment of unstable atlas fractures: a finite element analysis
title_full_unstemmed Design of a novel lateral mass screw–plate system for the treatment of unstable atlas fractures: a finite element analysis
title_short Design of a novel lateral mass screw–plate system for the treatment of unstable atlas fractures: a finite element analysis
title_sort design of a novel lateral mass screw plate system for the treatment of unstable atlas fractures a finite element analysis
topic Atlas fractures
Open reduction and internal fixation (ORIF)
Cervical spine
Biomechanics
Finite element analysis
url https://doi.org/10.1186/s13018-024-04582-6
work_keys_str_mv AT hegangniu designofanovellateralmassscrewplatesystemforthetreatmentofunstableatlasfracturesafiniteelementanalysis
AT jingjingzhang designofanovellateralmassscrewplatesystemforthetreatmentofunstableatlasfracturesafiniteelementanalysis
AT yizhuyan designofanovellateralmassscrewplatesystemforthetreatmentofunstableatlasfracturesafiniteelementanalysis
AT chengkunzhao designofanovellateralmassscrewplatesystemforthetreatmentofunstableatlasfracturesafiniteelementanalysis
AT kunyang designofanovellateralmassscrewplatesystemforthetreatmentofunstableatlasfracturesafiniteelementanalysis
AT yinshunzhang designofanovellateralmassscrewplatesystemforthetreatmentofunstableatlasfracturesafiniteelementanalysis