ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

NUMERICAL IDENTIFICATION OF THE PERMEABILITY OF A
BIOCERAMIC WITH CONTROLLED INTERCONNECTED SPERICAL
MACROPOROSITY
1. ABSTRACT
T.K Nguyen 1 , O. Carpentier 2 , P. Herin 3 and P. Hivart 4
Large bone deficits may arise from trauma, disease or congenital defects. For healing or
decreasing these defects skeletal reconstructions are necessary. Bone graft is so often
required to repair these defects. Several materials of a natural or synthetic
(biocompatible porous ceramics) origin have therefore been developed to create bone
substitutes. When this bioceramic is quite large because the skeletal defect to fill
reaches a critical size, it can no more be directly integrated by the natural bone tissue. In
most cases, a device called a bioreactor ensures the perfusion of large ceramic scaffolds
by the nutritive medium; it so allows the in vitro expansion of cells inside large bulk
materials under appropriate conditions. Actually, biologists generally choose the mass
flow rate in a bioreactor according to their experience and after experimentations.
Changing the geometry or the porosity of the scaffold obliges to renew all the
experimentations.
We present a study approach of the fluid flows through a macroporous bioceramic with
interconnected spherical pores. The final aim is to build a numerical modeling to be able
to predict the optimal mass flow rate to apply in a bioreactor in relation to geometrical
properties of our ceramic scaffolds. The first step of such a study is to identify the
permeability of the material. We have so done it by means of the velocity field through
a unit cell by using Darcy’s law. The prediction of permeability K was effected for three
types of arrangement of spherical pores. The results were compared with the empirical
or analytical models.
2. INTRODUCTION
For the filling of a loss of bone tissue, the graft is a current process in bone surgery, but
a significant deficiency leads to the use of artificial materials. Alternative to metallic
implants, bone substitutes bioceramics are now widely used 1 . But these ceramics, such
phosphocalcic ones, are basically osteoconductive but not osteoinductive. So, if small
volumes can be assimilated in situ through the natural osteosynthesis process, a large
volume, i.e. a few cm 3 , remains a ceramic at least in the heart of the bulk. In addition to
1 PhD student, Laboratoire de Génie Civil et géo-Environnement (LGCgE EA 4515, PRES Lille Nord de
France), Equipe Biomatériaux Artois, Université d’Artois, IUT/GMP, BP 819, 62408 Béthune Cedex,
France. trongkhoa.nguyen@gmail.com
2 Senior lecturer (assistant professor), Laboratoire de Génie Civil et géo-Environnement (LGCgE EA
4515, PRES Lille Nord de France), Equipe Biomatériaux Artois, Université d’Artois, IUT/GMP, BP 819,
62408 Béthune Cedex, France. olivier.carpentier@univ-artois.fr
3 Engineer, Laboratoire de Génie Civil et géo-Environnement (LGCgE EA 4515, PRES Lille Nord de
France), Université d’Artois. philippe.herin@univ-artois.fr
4 Professor, Laboratoire de Génie Civil et géo-Environnement (LGCgE EA 4515, PRES Lille Nord de
France), Equipe Biomatériaux Artois, Université d’Artois, IUT/GMP, BP 819, 62408 Béthune Cedex,
France. philippe.hivart@univ-artois.fr
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