The design and in vivo testing of a locally stiffness-matched porous scaffold
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
An increasing volume of work supports utilising the mechanobiology of bone for bone ingrowth into a porous scaffold. However, typically during in vivo testing of implants, the mechanical properties of the bone being replaced are not quantified. Consequently there remains inconsistencies in the literature regarding ‘optimum’ pore size and porosity for bone ingrowth. It is also difficult to compare ingrowth results between studies and to translate in vivo animal testing to human subjects without understanding the mechanical environment. This study presents a clinically applicable approach to determining local bone mechanical properties and design of a scaffold with similar properties. The performance of the scaffold was investigated in vivo in an ovine model.
The density, modulus and strength of trabecular bone from the medial femoral condyle from ovine bones was characterised and power-law relationships were established. A porous titanium scaffold, intended to maintain bone mechanical homeostasis, was additively manufactured and implanted into the medial femoral condyle of 6 ewes. The stiffness of the scaffold varied throughout the heterogeneous structure and matched the stiffness variation of bone at the surgical site. Bone ingrowth into the scaffold was 10.73 ± 2.97% after 6 weeks. Fine woven bone, in the interior of the scaffold, and intense formations of more developed woven bone overlaid with lamellar bone at the implant periphery were observed. The workflow presented will allow future in vivo testing to test specific bone strains on bone ingrowth in response to a scaffold and allow for better translation from in vivo testing to commercial implants.
The density, modulus and strength of trabecular bone from the medial femoral condyle from ovine bones was characterised and power-law relationships were established. A porous titanium scaffold, intended to maintain bone mechanical homeostasis, was additively manufactured and implanted into the medial femoral condyle of 6 ewes. The stiffness of the scaffold varied throughout the heterogeneous structure and matched the stiffness variation of bone at the surgical site. Bone ingrowth into the scaffold was 10.73 ± 2.97% after 6 weeks. Fine woven bone, in the interior of the scaffold, and intense formations of more developed woven bone overlaid with lamellar bone at the implant periphery were observed. The workflow presented will allow future in vivo testing to test specific bone strains on bone ingrowth in response to a scaffold and allow for better translation from in vivo testing to commercial implants.
Date Issued
2019-06-01
Date Acceptance
2019-02-22
Citation
Applied Materials Today, 2019, 15, pp.377-388
ISSN
2352-9407
Publisher
Elsevier
Start Page
377
End Page
388
Journal / Book Title
Applied Materials Today
Volume
15
Copyright Statement
© 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
License URL
Sponsor
Wellcome Trust
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (E
Engineering & Physical Science Research Council (EPSRC)
Medical Research Council (MRC)
Wellcome Trust
Wellcome Trust
Identifier
https://www.sciencedirect.com/science/article/pii/S2352940718307182?via%3Dihub
Grant Number
088844/Z/09/Z
EP/K027549/1
RC0000658 / RG.MECH.115148
EP/R042721/1
MR/R015651/1
098411/Z/12/Z
097816/Z/11/B
Subjects
Science & Technology
Technology
Materials Science, Multidisciplinary
Materials Science
Porous titanium
Scaffold
Mechanobiology
Bone ingrowth
Additive manufacturing
BONE INGROWTH
MECHANICAL-PROPERTIES
SCANNING STRATEGIES
LASER PARAMETERS
TRABECULAR BONE
TITANIUM
ALLOY
0204 Condensed Matter Physics
0912 Materials Engineering
1007 Nanotechnology
Publication Status
Published
Date Publish Online
2019-03-14