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
Implementation of digital design and solid free-form fabrication for customization of implants in trauma orthopaedics
Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.ORCID iD: 0000-0001-5954-5898
Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
2012 (English)In: Journal of medical and biological engineering, ISSN 1609-0985, Vol. 32, no 2, 91-96 p.Article in journal (Refereed) Published
Abstract [en]

Bone plates for the fixation of complex fractures in proximity to joints often have to be reshaped to follow the bone contour. Good adhesion of the screws in areas where the bone is osteoporotic is also a challenge. One possible solution to these issues is to tailor-make plates by creating a digital three-dimensional model of the fracture from a computed tomography (CT) scan, digitally reducing the fracture, designing a plate, and finally manufacturing it directly from the digital model with solid free-form fabrication (SFF) technology. This study designs a custom plate for a distal tibia fracture, and investigates and refines the procedure from the CT scan to the final implant, with the aim of making it usable in trauma orthopaedics. The bone plate is manufactured using electron beam melting (EBM) technology. The challenges of bone plate design using digitalization and SFF are discussed. The virtual models created by the engineer while digitally reducing the fracture and modeling the plate are valuable for the physician while planning the surgery. A combination of surgery planning and digital plate design improves the surgeon's preparations and ensures correspondence between the plan and the designed implant. The proposed procedure, with the approximate required time in brackets, includes the separation of bone in the DICOM file (60 min), the reduction of fracture (5-30 min), revision (30 min), modelling of the plate (30-120 min), confirmation (30 min), manufacturing with SFF (10 h), post-processing (60 min), and finally cleaning and sterilization (90 min). The whole procedure requires about three working days.

Place, publisher, year, edition, pages
2012. Vol. 32, no 2, 91-96 p.
Keyword [en]
Bone plate; Electron beam melting; Orthopaedic implant; Solid free-form fabrication; Trauma
National Category
Biomedical Laboratory Science/Technology
Identifiers
URN: urn:nbn:se:miun:diva-14393DOI: 10.5405/jmbe.883ISI: 000303147300003Scopus ID: 2-s2.0-84864007060OAI: oai:DiVA.org:miun-14393DiVA: diva2:436655
Available from: 2011-08-24 Created: 2011-08-24 Last updated: 2014-09-15Bibliographically approved
In thesis
1. The use of additive manufacturing in the custom design of orthopedic implants
Open this publication in new window or tab >>The use of additive manufacturing in the custom design of orthopedic implants
2011 (English)Licentiate thesis, comprehensive summary (Other academic)
Place, publisher, year, edition, pages
Sundsvall: Mid Sweden University, 2011. 14 p.
Series
Mid Sweden University licentiate thesis, ISSN 1652-8948 ; 63
Keyword
additive manufacturing (AM), electron beam melting (EBM), total hip replacement (THR), orthopedic imiplants, digital design, computer aided design (CAD), bone plates
Identifiers
urn:nbn:se:miun:diva-14390 (URN)978-91-86694-42-5 (ISBN)
Presentation
2011-05-27, 10:00 (Swedish)
Opponent
Supervisors
Available from: 2011-08-24 Created: 2011-08-24 Last updated: 2012-08-01Bibliographically approved
2. 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, MarieRännar, Lars-ErikBäckström, Mikael
By organisation
Department of Engineering and Sustainable Development
Biomedical Laboratory Science/Technology

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 1170 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