The document discusses bone grafts, their indications, types, and techniques used for various orthopedic procedures. It covers the properties of bone grafts, their sources, and healing stages, while also highlighting bone graft substitutes and recent advances in grafting technologies. Additionally, it reviews the advantages and disadvantages of different graft types and the clinical applications of bone grafting in treating complex fractures and other conditions.

1. Bone Graft and Bone Substitutes
Dr Santosh Ghimire
Moderator:Asst.prof Dr Suman Dhoj Kunwar
Department Of Orthopaedics
Nobel Medical College

2. • Bone graft are bone that is transplanted from one area of
skeleton to another to aid in healing, strengthening or
improving function.
• Bone or bone like materail used in bone graft may come from
same person, from a donor or man made source.

3. BONE GRAFT INDICATIONS
 To promote union or fill defect in delayed union, non
union, malunion, fresh fractures and osteotomies
 Fill cavities or defects resulting from cyst, tumors
 Bridge joints and perform arthrodesis
 Provide bone blocks to limit joint motion (arthroereisis)
Campbell’s Operative Orthopedics. Vol 1. 14th
ed. 2021:18-26

4. BONE GRAFT INDICATIONS
 Bone grafting is used
 to improve bone fracture which are extremely complex
 pose a significant risk to a patient,
 Fracture failed to heal preoperly.
 Bone graft is also used
 to help fusion between vertebrae
 correct deformity
 provide structural support for fracture of spine
 In addition to fracture repair, bone graft is also used to repair in the bone caused by
 congenital disorder
 traumatic injury
 or surgery for bone cancer

5. Types Of Bone Graft
Based on Source:
Autograft, Isograft, Allograft, Xenograft
Based on contents:
Cortical, Cotico-canceellous, Cancellous
Based on Vascularity:
Vascular, Non- Vascular
Based on method of preservation:
fresh, frozen, freeze dried, deminieralized

6. Types Of Bone Graft
Synthetic grafts or Substitutes
Orthopic transfer:
host site is of same tissue as that from which graft was
donated.
Heterotopic transfer:
here bone is transferred to a new environment (eg- bone
placed in a a bed of soft tissue)

7. PROPERTIES OF GRAFT
Property Description
Osteoinduction Process of recruitment, proliferation & differentiation of host
mesenchymal stem cells into chondroblast & osteoblast
Osteoconduction Process by which a graft acts as a scaffold passively hosting
the necessary cells for healing
Osteogenesis Ability of a material to form new bone without the
requirement of outside cells
Rockwood and Green’s Fracture in adult. Vol 1. 9th
ed. 2020:102-139

8. STRUCTURE OF BONE GRAFT
• Cancellous
- Advantage of rapid incorporation
- Lack significant structural integrity
• Cortical
- Advantage of structural integrity
- Trade off is delayed incorporation

9. AUTOGENOUS BONE GRAFT
• Transplanting bone from site of abundance to site of need within an
individual
• Gold standard
• Osteoinductive, osteoconductive and osteogenic properties
S.
N
Advantages Disadvantages
1. No processing required Donor site morbidity
2. No risk of histocompatibility and
disease transmission
Inherently limited supply

10. AUTOGRAFT TYPES
• Cancellous
• Cortical
• Free vascular transfers
• Muscle pedicle bone graft
• Bone marrow aspirate

11. BONE MARROW ASPIRATE
• RIA( Reamer Irrigator and Aspirators)
• Technique to harvest sizable amount of bone marrow, which
is particularly rich in mesenchyamal stem cells
• Growth factors: FGF-2, IGF-2, TGF-Beta
• Absence of BMP-2

12. BONE MARROW ASPIRATE
• Advantages:
- Enriched osteogenesis
- Decrease intramedullary canal pressure
- Minimal risk of fat embolism
- Source of autologous bone, mesenchymal cells, growth factor
• Complications:
- Perforation of medullary canal
- Significant blood loss
- Fracture of donor bone

13. BONE GRAFT TECHNIQUES
Onlay cortical grafts:
• Graft is placed subperiosteally across the fragments without
mobilizing the fragments
• Usually supplemented with cancellous bone for
osteogenesis
• Applied to fresh malunited and ununited fractures and
bridging joints to produce arthrodesis
• Single and dual graft technique
• Most nonunion, malunion
• Fixation
• Arthrodesis

14. Inlay graft:
• A slot or rectangular defect is created in the cortex of the host
bone
• A graft the same size or slightly smaller is fitted into the defect
• Occasionally used in arthrodesis , particularly at the ankle
• In treatment of diaphyseal nonunions, the onlay technique is
simpler and more efficient and has almost replaced the inlay
graft

15. BONE GRAFT TECHNIQUES
 Multiple cancellous chips:
• Widely used
• Particulary useful for filling cavities and defect, osteotomies and
supplement healing
 Hemicylindrical grafts:
• Obliterating large defects
• Limited use
 Whole bone transplant:
• Usually fibula used
• Tibia and femur transplant in massive tumor recection

16. GRAFT FROM ILIAC CREST
• Large cancellous and corticocancellous grafts obtained from
anterior superior iliac crest and posterior iliac crest
• In prone position posterior third used and in supine anterior third
used
• Complications:
- Hernias (landslide)
- Neurovascular injury
- Cosmetic deformity
- Arterivenous fistula

17. GRAFT FROM ILIAC CREST
Campbell’s Operative Orthopedics. Vol 1. 14th
ed. 2021:18-26

18. GRAFT FROM TIBIA
• Subcutaneous anteromedial is excellent for cortical graft
• Tibial plateau supplies cancellous graft
• Now rarely used due to
- Normal limb is jeopardized
- Duration and magnitude of procedure increase
- Ambulation of patient delayed
- Extra care for tibia

19. GRAFT FROM TIBIA
Campbell’s Operative Orthopedics. Vol 1. 14th
ed. 2021:18-26

20. GRAFT FROM FIBULA
• Proximal two third of fibula can be used for bone graft
• Middle third can be used as vascularized free autograft based on
peroneal artery and vein
• Patient may complain muscle pain
Campbell’s Operative Orthopedics. Vol 1. 14th
ed. 2021:18-26

21. PHEMISTER BONE GRAFT
• Subcortical cancellous bone grafting
• A bone graft of cortical bone with cancellous bone chips to enhance
callus formation
• Requisites are
- Mobility at fracture site should be minimal
- Fracture should have acceptable alignment

22. URIST AAA BONE GRAFT
• Composed of bone morphogenic protein, antigen extracted and autogenic
bone
• Adjuvent treatment of nonunions

23. ALLOGRAFT
• One that is obtained from an individual other then the patient
• Limited amount of autogenic graft calls for a need of allogenic graft
• Indicated in elderly, children and surgical risk patients
S.N Advantages Disadvantages
1. Unlimited supply Lack of osteoinductive and
osteogenic properties
2. Lack of donor site morbidity Risk of disease transmission
3. Reduced mechanical
properties from processing

24. ALLOGRAFT TYPES
Anatomy
Cortical
Cancellous
Osteochondral
Graft processing
Fresh
Frozen
Freeze dried
Demineralized

25. BONE BANK
• To provide safe and useful allograft materials efficiently
• Donor must be screened for bacterial, viral, fungal infections
• Malignancy, collagen vascular disease,metabolic bone
diseaseand the presence of toxins are contraindication to
donation
• Bone and ligament and bone and tendon are banked now
• Articular cartilage and menisci can be cryopreserved

26. BONE BANK
• Bone can be sterilize in several forms
- Sterilised by irradiation
- Strong acid
- Ethylene oxide
• Bone storage
- Frozen (-70˚c to -80˚c)
- Fresh frozen is stronger then freeze dried

27. STAGES OF GRAFT HEALING
Stages Activity
Inflammation Chemotaxis stimulated by necrotic
debris
Osteoblast differentiation From precursors
Osteoinduction Osteoblast and osteoclast function
Osteoconduction New bone forming over scaffold
Remodeling Process continues for years
Miller’s review of orthopaedics. 8th
ed. 2020: 16-18

28. BONE GRAFT SUBSTITUTES
Property Description Classes
osteoconductive Provides passive porous scaffold to support or
direct bone formation
Calcium sulfate
ceramics
Calcium phosphate cement
Collagen
Bioactive glass
Synthetic polymers
Osteoinductive Induces differentiation of stem cells into
osteogenic cells
Demineralized bone matrix
Bone morphogenic proteins
Growth factors
Gene therapy
Osteogenesis Provides stem cells with osteogenic potential,
which directly lays down new bone
Bone marrow aspirate
Combined Provides more then one properties Composites
Campbell’s Operative Orthopedics. Vol 1. 14th
ed. 2021:18-26

29. BONE GRAFT SUBSTITUTES
• Laurencin et al divided 5 major categories
1. Allograft based
2. Factor based
3. Cell based
4. Ceramic based
5. Polymer based

30. ALLOGRAFT BASED BONE GRAFT
• Preparations:
- Freeze dried
- Irradiated
- Decalcified
• Freeze dried and irradiated obtained from cortical bone and used for
structural support

31. ALLOGRAFT BASED BONE GRAFT
• Demineralized bone matrix (DBM)
- Decalcifed form of allograft that contains osteoinductive proteins for bone
formation
- Supplied as putty, injectable gel, paste, powder, strips and mixed
- Carriers are glycerol, calcium sulfate powder, sodium hyluronate and gelatin
- Sterilization is by gamma irradiation and ethylene oxide
- Contraindicated in sever vascular and neurological diseases, fever,
uncontrolled diabetes

32. GROWTH FACTOR BASED
• Bone morphogenic proteins (BMP)
- In 1965 urist discovered BMP
- BMP activites regulated by Smads and Noggin
- BMPs are required for skeletal development and healing
- Currently BMP-2 and BMP-7 are clinically approved
• Transforming growth factor β (TGF β)
- Structurally related to BMP and uses similar set of signal
transduction molecules
- Stimulate proliferation of differentiated cells present in
young

33. The synergistic effect of autograft and BMP-7 in the
treatment of atrophic nonunions
• Giannoudis PV, Kanakaris NK, Dimitriou R,
Gill I, Kolimarala V, Montgomery RJ. The
synergistic effect of autograft and BMP-7 in
the treatment of atrophic nonunions. Clinical
Orthopaedics and Related Research®. 2009
Dec;467:3239-48.
• Conclusion:
- Synergism exist between rnBMP and

34. GROWTH FACTOR BASED
• Wnt
- Level of Wnt signaling regulate bone mass in the skeleton and bone
healing
• Fibroblast growth factor (FGF)
- FGF contribute fracture healing by affecting angiogenesis and
proliferation of MSCs
- Clinically rhFGF-2 applied radiological union was better
• Vascular endothelial growth factor (VEGF)
• Platelet derived growth factor (PDGF)
• Arachidonic acid metabolites

35. CELL BASED
• Mesenchymal stem cells
- Multipotent adult progenitor cells that give rise to bone,
cartilage, muscle and other mesenchymal tissues
- Distributed throughout body
- 872 clinical trial are being performed with MSCs out of
which only 17 studies testing efficacy related fracture healing
- Continued research is needed to realize full potential in
fracture healing

36. CELL BASED
• Platelet concentrates
- Autologous blood preparations containing supra
physiological concentration of activated platelets
- Effective platelet concentrate for bone regeneration is 2 –
6 fold increase (ideally 5 lower have no effect and higher
concentrate negatively impact bone healing)
• Bone marrow aspirates

37. CERAMIC BASED
• Calcium phosphate ceramic
- Three general forms: Hydroxyapatite, tricalcium phosphate, calcium phosphate
- Differ in there rate of reabsorption and mechanical strength
- Hydroxyapatite reabsorbed slowest, calcium phosphate takes between 6 months
to 10 years and tricalcium phosphate over 6 to 18 months
- Calcium phosphate cement have highest strength
Advantage Disadvantage Indication
Structural strength Slow/ incomplete remodeling Augmentation of acute
fracture fixation

38. • Calcium phosphate cements
– Used as bone – void fillers in treatment of bony defects associated with acute fractures
– Inorganic calcium and phosphate combined to form paste and delivered to fracture site
– CPC hardens within minutes , achieving maximum compressive strength after
approximately 4 hrs
– Strength comparable to intact cancellous bone
– Strength significantly diminished in torsion or shear so should be used as an adjunct rather
than primary method of fixation

39. CERAMIC BASED
• Calcium sulfate ceramic
- Calcium sulfate is resorbed much more rapidly then calcium phosphate
ceramic
- Much less biomechanical stability
Advantage Disadvantage Indication
Structural
strength
Rapid remodeling and loss
of biomechanical strength
Augmentation of acute fracture
fixation and antibiotic delivery
device

40. Affecting factors

41. POLYMER BASED
• Natural and synthetic
• Biodegradable and non biodegradable
• Resorption of these products limits there use in load bearing

42. Plate fixation of ununited humeral shaft fractures: Effect
of type of bone graft on Healing
• Hierholzer C, Sama D, Toro JB, Peterson M,
Helfet DL. Plate fixation of ununited humeral
shaft fractures: effect of type of bone graft on
healing. JBJS. 2006 Jul 1;88(7):1442-7.
• Conclusion:
- 100% union in autogenous bone graft use and
97% union in demineralize bone graft use
- No significant difference in outcome of two

43. RECENT ADVANCES
• 3D printing
- Custom made implants unique to patient bone defect
- Implant can be printed layer by layer using modified hydroxyapatite
powder as feed material together with a polymer based binder
- Product is dried, cleaned at 1250˚C for two hours
- Clinically available in next 10 to 20 years
Archunan MW, Petronis S. Bone Grafts in Trauma and Orthopaedics. Cureus. 2021 Sep 4;13(9).

44. RECENT ADVANCES
• Gene therapy
- Promising method to promote new bone growth
- Transfer of genetic encoding information to the target site and induce
bone healing by production of specific protein
- Use of virus vector for the expression of BMP has been successfully
demonstrated in animal models
- There are limitations like infection, tumor development
Archunan MW, Petronis S. Bone Grafts in Trauma and Orthopaedics. Cureus. 2021 Sep 4;13(9).

45. References
• Campbell Operative Orthopaedics , 14th
edition
• Rockwodd and Green’s Fractures in Adult , 8th
edition