miun.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Modeling of fractured clavicles and reconstruction plates using CAD, finite element analysis and real musculoskeletal forces input
Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Technology and Management, Mechanical Engineering and Mathematics.
2013 (English)In: WIT Transactions on Biomedicine and Health, WIT Press, 2013, 235-243 p.Conference paper, Published paper (Refereed)
Abstract [en]

This study focuses on the treatment options for clavicle fractures, more specifically the cases with a need for internal fixation: non-unions and some complex fractures. Enhancing the understanding of the loading of the bone and fixation device enables treatment options to be improved. The aim of the study was to develop a method for the realistic simulation of stresses and displacements in the bone and fixation device and to use this method to make comparisons between a conventional reconstruction plate and a customized plate, designed from patient-specific computed tomography (CT) data. In an earlier study, a finite element (FE) mesh of the clavicle geometry was created from CT data, subjected to muscle forces and other boundary conditions from a multibody musculoskeletal model and imported into the FE solver. In this study, a solid 3D model of the same clavicle geometry was created and the mesh was replaced by the solid model to make the FE-model more suitable for the comparison of different plates. An LCP Reco-Plate 3.5 straight, 6 holes (by Synthes) was compared with a customized plate which was designed to follow the anatomy of the bone. The LCP-Reco plate has tapered reconstruction segments throughout the plate to allow for the plate reshaping during surgery. The customized plate was designed without such segments and with a lower width than the LCP plate. The two different plates showed stresses and displacements of similar magnitudes. The customized plate had a more even stress distribution while the LCP plate had higher stress concentrations in the middle of the plate and on the edges of the tapered reconstruction segments. To the authors' best knowledge, this is the first FE model of a clavicle bone with plate and it may, upon further development, serve as a useful instrument for improved clavicle fixation.

Place, publisher, year, edition, pages
WIT Press, 2013. 235-243 p.
Series
WIT Transactions on Biomedicine and Health, ISSN 1743-3525 ; 17
Keyword [en]
Bone plate, CAD, Clavicle, Finite element analysis, Modeling
National Category
Biomedical Laboratory Science/Technology
Identifiers
URN: urn:nbn:se:miun:diva-19364DOI: 10.2495/BIO130211Scopus ID: 2-s2.0-84878022216ISBN: 9781845647063 (print)OAI: oai:DiVA.org:miun-19364DiVA: diva2:643126
Conference
10th International Conference on Modelling in Medicine and Biology, BIOMED 2013; Budapest; Hungary; 24 April 2013 through 26 April 2013; Code 97013
Available from: 2013-08-26 Created: 2013-06-19 Last updated: 2014-09-15Bibliographically approved
In thesis
1. On customization of orthopedic implants - from design and additive manufacturing to implementation
Open this publication in new window or tab >>On customization of orthopedic implants - from design and additive manufacturing to implementation
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This doctoral thesis is devoted to studying the possibilities of using additive manufacturing (AM) and design based on computed tomography (CT), for the production of patient-specific implants within orthopedic surgery, initially in a broad perspective and, in the second part of the thesis focusing on customized clavicle osteosynthesis plates. The main AM method used in the studies is the Electron Beam Melting (EBM) technology. Using AM, the parts are built up directly from 3D computer models, by melting or in other ways joining thin layers of material, layer by layer, to build up the part. Over the last 20 years, this fundamentally new way of manufacturing and the rapid development of software for digital 3D reconstruction of anatomical models from medical imaging, have opened up entirely new opportunities for the design and manufacturing of patient-specific implants. Based on the information in a computed tomography (CT) scan, both digital and physical models of the anatomy can be created and of implants that are customized based on the anatomical models.

 

The main method used is a number of case studies performed, focusing on different parts of the production chain, from CT-scan to final implant, and with several aims: learning about the details of the different steps in the procedure, finding suitable applications, developing the method and trying it out. The first study was on customized hip stems, focusing on the EBM method and its special preconditions and possibilities. It was followed by a study of bone plates, designed to follow the patient-specific bone contour, in this case a tibia fracture including the whole production chain. Further, four cases of patient-specific plates for clavicle fracture fixation were performed in order to develop and evaluate the method. The plates fit towards the patient’s bone were tested in cooperation with an orthopedic surgeon at Östersund hospital. In parallel with the case studies, a method for finite element (FE) analysis of fixation plates placed on a clavicle bone was developed and used for the comparative strength analysis of different plates and plating methods. The loading on the clavicle bone in the FE model was defined on a muscle and ligament level using multibody musculoskeletal simulation for more realistic loading than in earlier similar studies. 

 

The initial studies (papers I and II) showed that the EBM method has great potential, both for the application of customized hip stems and bone plates; in certain conditions EBM manufacturing can contribute to significant cost reductions compared to conventional manufacturing methods due to material savings and savings in file preparation time. However, further work was needed in both of the application areas before implementation. The studies on the fracture fixation using patient-specific clavicle plates indicated that the method can facilitate the work for the surgeon both in the planning and in the operating room, with the potential of a smoother plate with a better fit and screw positioning tailored to the specific fracture (paper VI). However, a large clinical trial is required to investigate the clinical benefit of using patient-specific plates. The FE simulations showed similar stress distributions and displacements in the patient-specific plates and the commercial plates (papers III to VI).

 

To summarize: the results of this thesis contribute to the area of digital design and AM in patient-specific implants with broad basis of knowledge regarding the technologies used and areas in which further work is needed for the implementation of the technology on a larger scale. Further, a method has been developed and initially evaluated for implementation in the area of clavicle fracture fixation, including an approach for comparing the strength of different clavicle plates.

Place, publisher, year, edition, pages
Sundsvall, Sweden: Kopieringen, Mid Sweden University, 2014. 60 p.
Series
Mid Sweden University doctoral thesis, ISSN 1652-893X ; 191
Keyword
Patient-specific implants, Additive manufacturing, Electron beam melting, Multibody musculoskeletal analysis, Orthopedic implants, Clavicle, Finite element analysis, Computer aided design, Osteosynthesis plate, Hip stem implants
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:miun:diva-22902 (URN)978-91-87557-63-7 (ISBN)
Supervisors
Available from: 2014-09-15 Created: 2014-09-11 Last updated: 2015-03-13Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Cronskär, MarieBäckström, Mikael
By organisation
Department of Quality Technology and Management, Mechanical Engineering and Mathematics
Biomedical Laboratory Science/Technology

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 2217 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf