1. Yonca Yakut CHEM 442- Spring’12
Bone Graft
Yonca Yakut
CHEM 442- Spring’12

2. Overview Bone Chemistry Purpose of Bone Grafting
Bone healing, structural support etc.
Properties of Ideal Bone Graft
Bone Formation Mechanisms
Osteogenic, osteoconductive, osteoinductive
Types of Bone Grafts/Pros & Cons
Autograft, allograft, xenograft, alloplastic
Major application areas
Dentistry & Orthopedics
Complications

3. Principles of bone healing; IAIN H. KALFAS, M.D., F.A.C.S.
Bone Biochemistry
Made of organic & inorganic elements such as:
Inorganic calcium phosphate, calcium carbonate (65-70% by weight)
Organic matrix of fibrous protein & collagen (30-35% by weight)
Water (20% by weight)
Principles of bone healing; IAIN H. KALFAS, M.D., F.A.C.S.
Department of Neurosurgery, Section of Spinal Surgery, Cleveland Clinic Foundation, Cleveland, Ohi

4. Why Bone Grafting? To regenerate bone which is lost or missing,
To provide structural support,
To fill the bone cavity & promote bone healing,
To cover any inhereted defects or the defects emerge as a result of wearing out.
Bone grafting fundamentals;

5. Principles of bone healing; IAIN H. KALFAS, M.D., F.A.C.S.
Ideal Bone Graft
Biocompatible
Bioresorbable
Chemically & mechanically stable
Osteoconductive & osteoinductive
Non-toxic
Disease free
Minimal antigenic factors
Principles of bone healing; IAIN H. KALFAS, M.D., F.A.C.S.
Department of Neurosurgery, Section of Spinal Surgery, Cleveland Clinic Foundation, Cleveland, Ohi

6. Principles of bone healing; IAIN H. KALFAS, M.D., F.A.C.S.
Bone Formation
Osteogenic Graft
Bone forming «osteogenic» cells required
Living cells differentiate into new bone
Osteoconductive Grafts
Scaffold task: attach, migrate, grow, divide
Facilitation of new blood vessel incursion
Osteoinduction
Mesenchymal stem cells differentiate to bone forming osteoblasts
Growth factors initiate bone cell growth & maturation to healthy bone tissue
Principles of bone healing; IAIN H. KALFAS, M.D., F.A.C.S.
Department of Neurosurgery, Section of Spinal Surgery, Cleveland Clinic Foundation, Cleveland, Ohi

7. Types of Grafts Autografts Allografts Xenografts Alloplastic
From patient’s own body- hip, chin
Allografts
Cadaveric bone
Xenografts
From non-human species
Alloplastic
Ceramics: calcium phosphate, calcium sulphate
Polymers: PMMA
Bone graft substitutes; T. W. Bauer; Published online: 3 October 2007 # ISS 2007

8. Autografts «Gold Standard» Advantages: Disadvantages:
No risk for rejection
Twice surgery!! not applicable for patients with low bone density
Osteoinductive & osteoconductive
Increased operating time & blood loss
Biomechanically stable
- Insufficient quantity of bone graft
«Gold Standard»
Principles of bone healing; IAIN H. KALFAS, M.D., F.A.C.S.
Department of Neurosurgery, Section of Spinal Surgery, Cleveland Clinic Foundation, Cleveland, Ohi

9. Principles of bone healing; IAIN H. KALFAS, M.D., F.A.C.S.
Allografts
Advantages:
Disadvantages:
Availability in various shapes & sizes
Slow bone formation
Osteoconductive
Weakly osteoinductive
Transmission of infection
Lack of histocompatibility
Higher incidence of nonunion than autograft
DFDB crystals (Biomet)
Porous block (Zimmer)
Principles of bone healing; IAIN H. KALFAS, M.D., F.A.C.S.
Department of Neurosurgery, Section of Spinal Surgery, Cleveland Clinic Foundation, Cleveland, Ohi

10. Xenografts Usually cow is preffered
Must be ensured for sterility & biocompatibility
FDA check for HIV1, HIV2, Hepatitis C
Acts as «scaffold», therefore osteoinductive bone formation observed
Special protein Bone Morphogenic Protein (BMP) for initiation of response
Bio Oss (Geistlich)
Bone Grafting & Implant Dentistry; Jeffrey L. Turchi, DDS; Director of Educational and Clinical Affairs Senior Product Manager J. Morita USA Irvine, CA .

11. Alloplastic
Synthetic, man-made materials from calcium phosphate, HYDROXYAPATITE
All only osteoconductive
Dense or porous
Ceramics
Polymers
Resorbable
Non-Resorbable
PMMA
Degredable
- framework/ scaffold for normal bone growth
- Replacement bone
- Amorphous
- Stable
- Biocompatible
The use of hydroxyapatite and autogenous cancellous bone grafts to repair bone defects in rats; R. V. Silva1, J. A. Camilli1, C. A. Bertran2, N. H. Moreira2
1Department of Anatomy, Institute of Biology, State University of Campinas, Campinas, Sa˜o Paulo, Brazil; 2Institute of Chemistry, State
University of Campinas, Campinas, Sa˜o Paulo, Brazil
R. V. Silva, J. A. Camilli, C. A. Bertran, N. H. Moreira:The use of hydroxyapatite and autogenous cancellous bone grafts to repair bone defects in rats. Int. J. Oral ;Maxillofac. Surg. 2005; 34: 178–184. # 2004 International Association of Oral
and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

12. Larger the defect, the more autogenous bone is required!!
Small defects
Alloplast or
alloplast + allograft
Loss of 3 or more bony walls
Autograft
Larger the defect, the more autogenous bone is required!!
Bone-grafting materials in implant dentistry; Misch CE, Dietsh F
University Oral Implantology Center, Department of Prosthodontics, University of Pittsburgh, School of Dental Medicine, PA

13. Major Application Areas
Dentistry
Orthopedics
Repairs and rebuilds diseases bones in hips, knees, spines, joints
Dental Implant vs
Bone Graft
Base for dental implant
No requirement for healthy teeth
Bone grafting materials for dental applications: a practical guide; Gross JS ; Compendium of Continuing Education in Dentistry (Jamesburg, N.J. : 1995) [1997, 18(10):1013-8, , 1024, passim; quiz]
Design of injectable bone tissue engineering scaffold consists of ß-tricalcium phosphate beads and alginate; Tomonori Matsuno; Department of Oral and Maxillofacial Surgery, School of Life Dentistry at Tokyo, The Nippon Dental University; Japan

14. Problems with Bone Graft
Major Complications (8.6%):
Minor complications (20.6%)
Reoperation (3.8%)
Minor wound problems
Large hematomas (3.3%)
Temporary sensory loss
Infection (2.5%)
Pain greater than 6 months (2.5%)
Sensory loss (1.2%)
MORBIDITY AT BONE GRAFT DONOR SITES, Edward M. Younger and Michael W. Chapman; Department of Orthopaedic Surgery, University of California, Davis, Medical, Center, Sacramento, California, U.S.A.
Reprinted from JOURNAL OF ORTHOPAEDIC TRAUMA
Vol. 3, No. 3, pp
©1989 Raven Press, Ltd., New York

15. Commercial Products
Bone-Graft Substitutes: Facts, Fictions, Applications; American Academy of Orthopaedic Surgeons, 70th Annual Meeting; Feb ; New Orleans, Louisiana

16. Thank you!! 