Synthetic Bone Substitute

ß Tri-Calcium Phosphate is an osteoconductive material that facilitates trabecular
bone formation.
Tri-Calcium Phosphate as a Bone Graft Substitute in Trauma: Preliminary Report
Mark P. McAndrew, Paul W. Gorman and Thomas A. Lange
Department of Orthopaedic Surgery, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
Journal of Orthopaedic Trauma, Vol.2, No. 4 pp 333-339, 1989
Allogran-R
®
Synthetic
Bone
Substitute
synthetic calcium composites
for tissue regeneration
Allogran-R
®
Synthetic Bone Substitute
Biocomposites, is dedicated to tissue regeneration through
synthetic calcium-based technologies.
A focussed research programme has developed Allogran-R, a
highly consistent, polycrystalline and porous ß tri-calcium
phosphate bone substitute.
Biocomposites’ proprietary process provides a synthetic and
multiporous granular matrix with outstanding biocompatibility.
Allogran-R, ß tri-calcium phosphate is fully resorbed through
dissolution and cell mediation to be replaced by new bone.
Extensive research has shown a completely non-toxic and
favourable immunological reaction to the ß tri-calcium
phosphate.
Studies also show its conversion in-vivo to hydroxyapatite
- the mineral constituent of natural bone.
Early cases of delayed union have shown Allogran-R to
fully resorb concurrently with its replacement by new bone.
on e
The Future of Bone Grafting
The Case for Synthetic Bone Substitutes
Autograft
Autograft availability is limited and its harvesting, usually from
the iliac crest, increases surgery time, can prolong hospital stay
and very often results in donor site morbidity.
Allograft
Galea et al stated that the source from bone banks cannot
meet the demand for the increasing incidence of revision
surgery.
J Bone Joint Surgery (Br) Vol. 80-B No. 4, July 1998
Palmer et al referred to their findings of pathological lesions
present in osteoarthritic femoral heads; unknown to both
the patient and the medical staff.
J Bone Joint Surgery (Br) Vol. 81-B No. 2, March 1999
“...tissue banks vary in complexity and scope of operation
and depend on a variety of techniques in the selection of
donors and the exclusion and preparation of bone and tissue
allografts...”
“...therefore it behoves orthopaedic surgeons to find out
specifically how the allografts they are about to use were
excised and prepared...”
“...irradiation clearly alters biomechanical properties of collagen,
hence bone structure, and diminishes its osteoinductive
potential...”
Extracts taken from - Bone Loss in Revision Surgery: How to Manage the Femoral Side.
C.A. Engh, Sr., W.C. Head, A.G. Rosenberg, F.H. Sim
American Academy of Orthopaedic Surgeons 68th Annual Meeting, 2001.
t wo
Performance
Allogran-R is designed to provide an osteoconductive scaffold
for initial bone growth, acting as a short-term bone defect filler.
It is resorbed by osteoclasts and replaced by living bone cells
which grow in direct contact to the material without encapsulation.
Key features engineered for the indication
Allogran-R
Present
Essential Properties
Inter-granular macroporosity >100µm
(vascularisation)
3
Bioreplaceable
implant scaffold
Polycrystalline microporosity
<10µm for early cell attachment
3
Osteoconductive
Osteoconductive matrix promoting
osteoblast proliferation
3
Bioactive
High purity ß tri-calcium phosphate
with controlled chemistry
3
Biocompatible
Stoichiometric calcium to phosphorus
ratio 1.5
3
Total resorption
Microstructure
Electron micrograph showing
microporous structure of Allogran-R
granules - a key factor in early cell
attachment
t h re e
Performance
Allogran-R is a fully resorbed, porous granular material
with an average particle size of 2.0mm. The irregular
particles, when combined with saline or blood, assume a
cohesive regenerative matrix for the treatment of skeletal
defects.
Key advantages
Micrograph showing osteoblasts
proliferating on the microporous
surface of Allogran-R at 21 days in-vitro
Engineered porosity for complete resorption
Osteoconductive
Proven biocompatibility
No risk of disease transmission or antigenicity
Elimination of donor site morbidity
Resorption process in-vivo
Resorption of Allogran-R
Stage 1
Physicochemical dissolution of individual particles
Stage 2
Biological absorption by intercellular digestion
Delayed union right distal tibia
At 6 weeks post op
Good callus formation
fou r
Technical Profile
Specification
Characteristic
Specification
Chemical
Ca3 (PO4)2 (Conforms to ASTM-F 1088-87)
Physical
Irregular granule ~ 2000µm
Purity
>99%
Crystallinity
>95% ß tri-calcium phosphate
Matrix structure
>200µm macropores, <10µm micropores
Appearance
Irregular granules combining to form a multiporous matrix.
Indications
To fill a bone defect caused by
Allogran-R granules
Delayed union or non-union
Removal of a tumour or cyst
Trauma
Osteomylitis
Surgical Method
When exposed to saline or blood, Allogran-R becomes a
cohesive matrix.
When combined with clotted blood, it can be introduced
percutaneously using a syringe to provide a source of
appropriate osteoblast precursors and platelet drived
growth factor.
Expose the defect.
Raise a window of cortical bone or alternatively the
periosteum.
Allogran-R percutaneous insertion with
patient’s blood using syringe
The defect is packed with Allogran-R matrix.
five
Allogran-R
®
Pot Size
Supplied sterile
ready for immediate
use:
Catalogue Ref
5cc
800-005
10cc
800-010
20cc
800-020
® Allogran is a registered trademark of Biocomposites Ltd.
© 2001. All rights reserved. No unauthorised copying, reproduction, distributing or republication is allowed unless
prior written permission is granted by the owner, Biocomposites Ltd.
Keele Science Park, Keele, Staffordshire, England. ST5 5NL
Telephone: +44 (0)1782 338580 Facsimile: +44 (0)1782 338599
E-Mail: info@biocomposites.com
www.biocomposites.com