This document discusses bone grafting and bone graft substitutes. It begins by defining a bone graft as viable bone tissue implanted from a donor site to a recipient site to repair, restore, and regenerate tissue. It then covers the history of bone grafting, types of grafts including autogenous, allogenic, and xenografts. Specific bone graft techniques and various bone graft substitutes are also summarized, including calcium sulfate, hydroxyapatite, tricalcium phosphate, demineralized bone matrix, and bone morphogenetic proteins.

1. SRI SIDDHARTHA MEDICAL COLLEGE
TUMKUR
BONE GRAFT
BONE BANK
BONE GRAFT SUBSTITUES
SUBJECT SEMINAR
CHAIRPERSON: PROF. & HOD DR. KIRAN KALAIAH
MODERATOR: PROF. & HOD DR. KIRAN KALAIAH
SPEAKER: Dr. G. ARUN SIVA RAM

2. BONE GRAFT
• A viable bone tissue that after removal from a donor site is implanted with in a
reciepient tissue is then restored repaired and regenerated.
what is grafting ?
• Grafting is a procedure used to replace/ restore missing bone tissue.

3. • bone grafts are the materials used for replacement or augmentation of bone.

4. HISTORY
The principles, indication and techniques of bone grafting were established before
the metalurgic age of orthopedic surgery
•  The first recorded bone implant was performed in 1668
•  Lane and sandhu introduced internal fixation
•  Albee,henderson,campbell intoduce the principle of osteogenesis in bone
grafting

6. BIOLOGICAL CONCEPT

7. INDICATIONS
• Fill cavities or defects resulting from cysts or tumors
• Bridge joint and provide arthrodesis
• Bridge major defects or establish continuity of long bone

8. • provide bone block to limit joint motion(arthroereisis)
• Establish union in a pseudarthrosis
• Promote union or fill defects in delayed union , malunion , fresh fracture or
osteotomies

9. TYPES
• Origin: −Autogenous
−Allogenous
• Blood supply: −Nonvascularised
−Vascularised
• Type of bone : −Cortical
Cancellous
−Corticocancellous

10. MESENCHYMAL STEM CELLS
• In the elderly the pool of these cells diminishes
• Progenitor cells that provide a source of cells to differentiate into chondroblasts
and osteoblasts during endochondral and intramembranous bone formation
• Bone marrow is the source of adult MSCs

11. TYPES OF BONE GRAFTS:ON THE BASIS OF SOURCE
• Allogenic : source is an individual other than the patient
• Autogenous: source is the patient , usually from tibia , fibula or ilium.
• Xenograft: derived from different species

12. AUTOGRAFT
• Gold standard
• Bone is transferred from one site to other in the same individual
•
• Ideal as bone graft posses all characteristic necessary for new bone growth i.e
osteoconductivity, osteoinductivity osteogenicity

13. ADVANTAGE
• no immune reaction
• all three properties present

14. DISADVANTAGE
additional surgery
donor site morbidity
-fractures,inflamation ,infection, chronic pain and cosmetic
limited quantities of bone graft

15. AUTOGENOUS
• Cancellous
Cortical
Free vascular transfers
• Muscle pedicle bone graft
• Bone marrow aspirate

16. • Three dimensional scaffold (osteoconductive)
• Osteocytes and stem cells (osteogenic)
• A small quantity of growth factors (osteoinductive)ss
• CREEPING SUBSTITUION: process by which graft is replaced by new
bone (I year)
• Used in boneloss: depressed tibial plateau fractures, revision hip
and knee arthroplasty

17. CREEPING SUBSTITUTION
• Creeping substitution, the process of bone remodeling by
osteoclastic resorption and creation of new vascular channels with
osteoblastic bone formation resulting in new haversian systems, is
the method by which strong cortical bone is formed from grafted
material.

18. SOURCES:
• Ribs
• Fibula
Crest of the ilium (also called as tricortical graft)
It can be of two types:
• Conventinal nov vascular
• Vascularised bone graft

20. CORTICAL AUTOGRAFT
• Obtained from tibia
• fibula iliac crest
• Used primarily for structural support

21. CANCELLOUS AUTOGRAFT
Obtained from
• thicker portion of ilium
• greater trochanter
• proximal metaphysis of the tibia
• lower radius
• olecranon
• from an excised
• femoral head
• More rapidly incoporated into host bone than cortical autografts

22. USES OF CANCELLOUS BONE GRAFT
• excellent choice for non unions with <5 to 6 cm of bone loss and that do not
required structural integrity
• - used to fill bone cyst or bone voids after reduction of depressed articular
surface such as in tibial plateu fracture
• Stable internal or external fixation is required for graft consolidation and fracture
healing

23. VASCULARISED BONE GRAFT
• Bone is transferred with its blood supply which is anastomosed to vessel at recipient site
• Available donor sites iliac crest(with
one circumflex artery)
• fibula(with the peroneal artery)
• radial shaft

24. • Vascularised grafts remain completely viable and incoporated like that of fracture healing

25. ALLOGENIC BONE GRAFT
• Graft is obtained from an individual other than the patient .
• used in small children where sufficient graft is not available from donor site .
• in adults where large defects have to be filled like-
periprosthetic long bone fracture revision total joint surgery reconstruction after
tumor excision .

26. • The morbidity and limited amount of autogenic bone graft calls for a need of
allogenic bone Graft.
They are indicated in
1.Children
2. Elderly
3.Poor surgical risk
4.Enough graft cannot be harvested

27. • Cortical
• Frozen
• Freeze dried
• Cancellous
• Frozen
• Freeze dried

28. ADVANTAGE
no donor site
morbidity
large amount can be used
DISADVANTAGE
immune reaction
risk of infection
disease transmission
reduced osteoinductivity and osteogenicity

29. •  Graft must be harvested under sterile condition and donor must be cleared for
malignancy , syphilis, cmv and hiv .
• Antigenicity can be reduced by freezing (at 70 deg c) , freeze drying or by ionizing
radiation .
•  Demineralization also reduces antigenicity and enhances osteoconductive
property .

30. BONE ALLOGRAFTS
• Plentiful supply
• Cancellous or cortical
• Limited infection risk (varies based on processing method)
• Provide osteoconductive scaffold
• May provide structural support

31. FREEZE-DRIED
•
– Even less antigenic
– Time to test for diseases
– Strictly regulated by FDA
– Can be stored at room temperature up to 5 years – Mechanical
properties degrade

33. BONE BANK
• It is a facilitiy to provide safe and efficient allograft material.

36. DONOR SELECTION GENERAL EXCLUSION
CRITERIA

38. SPECIFIC EXCLUSION CRITERIA

41. TECHNIQUE
• Bone is collected in clean and unsterile environment.
• It is nibbled to remove the articular cartilage.
• It can be sterilized by irradiation, ethylene oxide or strong acid(
0.55 % HCl)
• It is subject to deep freeze upto -70 to -80 degrees celcius(frozen)
• Freeze drying involves removal of water and vacuum packaging of
the tissue

42. STORAGE AND PROCESSING

43. • In case of cadaveric donors, bone allograft must be procured as
early as possible and definitely within 12 hours of death of donors.
• National Health and medical research council recommended that a
neuro histopathological analysis of cerebral tissue from donors
should be performed to look for signs of CREUTZFELDT JACOB
DISEASE

45. FREEZE DRIED BONE GRAFT
• Decreases expression of MHC 1 complex in osteoblasts
• Decreased osteoinductive properties
Reduced mechanical integrity
Decreased number of viable cells
Slow revascularisation and delaye remodelling
• Histologically mono nuclear cells surround the newly developed blood
vessels

47. DEMINERALIZED BONE MATRIX
• Prepared from cadaveric human bone
• Acid extraction of bone leaving
• Collagen(type 1)
• Noncollagenous proteins
• Bone growth factors
• BMP quantity extremely low and variable
• Sterilized which may decrease the availability of BMP

48. • Available from multiple vendors in multiple preparations
Gel
– Putty
– Strip
– Combination products with cancellous bone and other bone graft substitute
products

49. • Growth factor activity varies between tissue banks and between batches
• While they may offer some osteoinductive potential because of available growth
factors, they mainly act as an osteoconductive agents

50. SECONDARY STERILISATION

51. • Ethylene oxide sterilisation but risk of subsequent elution of the agent from the
allograft segment rendered this unpopular
• Once sterilised, allograft segments are stored at -70*c to -80*c and trasported in
specially sealed STYROFOAM container packed with dry ice.

52. DOCUMENTATION

53. • Size of the allograft.
• Allocation date, expiry date
• Recipient records- equally important.

54. BONE GRAFT SUBSTITUTES

55. • Bone substitutes are natural, synthetic or composite materials used to fill bone
defects and promote bone healing .

56. • Need for bone graft alternatives has lead to development of numerous bone graft
substitutes .
• Avoid morbidity of autogenous bone graft harvest Mechanical properties vary
Most offer osteoconductive properties.
Some provide osteoinductive properties .

57. POTENTIAL ROLE
• Extender for autogenous bone graft
• Large defects
• Multiple level spinal fusion Enhancer
• Enhancer :
To improve success of autogenous bone graft
• Substitute:
To replace autogenous bone graft

58. IDEAL BONE GRAFT SUBSTITUTE
Scaffolding for osteoconduction
 Growth factors for osteoinduction
Progenitor cells for osteogenesis
Biocompatible and biodegradable and mechanical properties
similar to the surrounding bone
Each substitute available nowadays fulfill only some of the criteria

59. CLASSIFICATION
• Laurencin et al, proposed a classification system of material based groups
Includes:
• Allograft based
• Factor based
• Cell based
• Ceramic based
• Polymer based

60. ALLOGRAFT BASED
• Includes allograft bone used alone or in combination with other material
• Available as Demineralized bone matrix, and other forms as an autograft, Eg-
corticocancellous grafts etc.

61. DEMINERALISED BONE MATRIX
• Has osteoconductive and osteoinductive properties
• Does not provide structural support
• Very good for filling bone defects and cavities
• Biological activity - proteins and growth factors present in the
extracellular matrix
• Prepared by a standard process- Urist et al, modified by Reddi and
huggins

62. Pulverized allogenic bone (74-420 micrometer)
Demineralization in 0.5N HCL for 3 hours
Extra acid rinsed- sterile water, ethanol and ethyl ether

63. USES
• Excellent for contained stable defects Eg- cysts and cavities
• Have been used for non unions and acute bone defects
• Also been used to enhance arthrodesis Eg- spine etc.

64. • DBM is available in various forms as
• Freeze dried powder Crushed granules, chips Paste
Gels
• mixture of DBM with autologous bone marrow has also been used as injection*

65. DISADVANTAGES
• Infection
Disease transmission
Variable potency- multiple donors, manufacture processes
• No RCT has been done comparing its efficacy

66. FACTOR BASED
• Involves natural or recombinant factors
• Factors responsible for differentiation of progenitor cells and regulation of activity
• Mechanism of action based mostly on activation of protein kinases
• Combined and simultaneous activity of various factors- controlled resorption and
formation of bone

67. Factor + Receptor on cell surface
Activation of protein kinases
Transcription of mRNA proteins
Regulation of cell activity

68. • include TGF-beta, insulinlike growth factors I and II, PDGF, FGF, and BMPs
• Mostly in research phase

69. BONE MORPHOGENIC PROTEINS

70. BMP 7
• It plays a key role in osteoblastic differentiation
• It induces the prodution of SMAD 1
• It plays a key role in renal development and repair
BMP 2
• Acts as a disulfide linked homodimer and helps in bone and cartilage formation
• It is a candidate as retinoid mediator and helps osteoblastic differentiation

71. • Produced by recombinant technology
• Two most extensively studied and commercially available
• – BMP-2
• – BMP-7
• – BMP-2 and BMP-7 are water soluble and require a carrier to remain in the
operative area to be effective

72. CELL BASED
• Based on in vitro differentiation of mesenchymal stem cells to osteoblastic
lineage
•
• They have been used along with ceramics
• Proposed to be used in bone repair prosthetic setting

73. CERAMIC BASED
• About 60% BGS involves ceramics- alone or in combination
• Eg : calcium sulfate, calcium phosphate, bioactive glass
• Primary inorganic componet is calcium hyroxyapatite
• Property of osteointegration, newly formed mineralised tissue forms intimate bond with
implant materials

74. CALCIUM PHOSPHATE CERAMICS
• Enable osteoconduction but use is limited due to poor tensile strength and
brittleness
• Injectable pastes of calcium and phospate

76. CALCIUM SULFATE(PLASTER OF PARIS)
• Osteoconductive void filler
• Low compressive strength – no structural support
• Rapidly and complete resorption
May be used as a autogenous graft extender

78. HYDROXYAPATITE(HA)
• It is a slowly resorbing compound of calcium phosphate
• Source :synthetic and animal
• Hydrothermal process converts it from its native coral form to more stable HA form with
pore diameters between 200 to 400 micron
• Interconnected porous structure closely resembles the porosity of human cancellous
bone

79. HYDROXYAPATITE:INDICATIONS
• Valgus instability following lateral tibial plateau fracture
• Varus instability following medial condyle fracture of tibia
• Articular incongruence of 10 mm or more
• Translation of major condylar fragment of more than 5mm

80. TRICALCIUM PHOSPHATE(TCP)
• TCP composition is similar to calcium and phosphate phase of human bone and
has porous nature
• TCP undergoes partial resorption and some of it may be converted to HA once
implanted in the human body
• Complete resorption at 6 months
• Wet compressive strength slightly less than cancellous bone
• Available as blocks, wedges, and granules

81. CALCIUM PHOSPHATE CEMENTS(CPC)
• CPC is used as void filler in defects
• It consists of inorganic calcium and phosphate combined to form an injectable
paste

82. POLYMER BASED
• Can be divided: natural/synthetic
• Further divided into: biodegradable/non biodegradable
• Collagen Based Matrices :
• Highly purified Type 1 bovine dermal fibrillar collagen
• Bone marrow is added to provide bone forming cells

83. COMPOSITE GRAFT
• In this two or more type of bone graft substitutes combined together
• So that osteoconductive and osteoinductive properties of different BGS, is
combined

84. CALCIUM PHOSPHATE-COLLAGEN COMPOSITE
• Collagen provides binding sites for matrix proteins
• Type I and III is added to HA,TCP and autologous bone marrow to form a graft
material
• Although no structural support but augments fratcure healing

85. INCORPORATION OF GRAFT

86. PRIMARY PHASE
• - haemorrhage
- inflamation
- accumulation of haematopoietis cells
• including neutrophills, macrophages, and
• osteoclasts
- removal of necrotic tissue

87. • osteoconductive factors released from graft during resorption and cytokines
released during inflamation
• - recruitment and stimulation of mesenchymal stem cells to osteogenic cells
• - active bone formation

88. SECONDARY PHASE
• Osteoblasts lines dead trabecule lay down osteoid
• - haemopoitic marrow cells forms new bone in transplanted bone
• - remodeling i.e woven bone slowly being transformed into lameler bone by cordinated
activities of osteoblasts and osteoclasts
• - incorporation of graft

90. VARIOUS BONE GRAFT TECHNIQUES

91. ONLAY CORTICAL GRAFT
•  graft is placed subperiosteally across the fragments without mobilizing the
fragments .
•  Cortical graft was suplemented with cancellous bone for osteogenesis.
• Advantages-
- simple to do
• - blood suply of the fragments and the normal impacting forces of fracture is
not disturbed

92. • Uses-
- malunited , nonunited fracture of shaft of
• long bone
- bridging joints to produce arthrodesis
• Fixation is achived by internal or external metalic device

93. DUAL ONLAY GRAFT
• Two cortical onlay grafts are placed opposite each other on the host bone
across the nonunion and are fixed with the same set of screws
• They grip the fragments like a vise
 Uses-
• to fix nonunited short osteoporotic fracture near a joint

95. ADVANTAGE
•
• Mechanichal fixation is better than fixation by a single onlay bone graft
• two grafts add strength and stability
• Grafts form a trough into which cancellous bone may be packed
• during healing the dual graft prevent contracting fibrous tissue from
compromising transplanted cancellous bone

96. DISADVANTAGE
• same as single cortical grafts
• not as strong as metalic fixator devices
• Extremity usualy must serve as a donor site if autogenous graft are used
• Not as osteogenic as autogenous iliac grafts
• The surgery necessary to obtain them has more risk

97. INLAY GRAFTS
• A slot or rectangular defect is created in the cortex of host bone then a graft of
the same size or slighty smaller is fitted in to the defect .
• Ocaisonaly used in arthrodesis, particularly at the ankle .

98. MULTIPLE CANCELLOUS CHIP GRAFTS
• Usefull for-
filling defects or cavities resulting from cysts, tumor
for establishing bone blocks and for wedging in osteotomies
• Cancellous grafts are usefull for arthrodesis of spine because osteogenesis is
prime concern

99. • Harvested from
- anterior iliac crest using an acetabula reamer,
- femoral canal using a reamer-irrigator- aspirator(large volume cancellous bone
graft can be harvested)

100. HEMICYLINDRICAL GRAFTS/ MASSIVE SLIDING
GRAFT
• A massive hemicylindrical cortical graft from the affected bone is placed across
the defect and supplemented by cancellous iliac bone
•  Suitable for obliterating large defects of the tibia and femur
•  Applicable for resection of bone tumor when amputation is to be avoided

101. WHOLE BONE TRANSPLANT
• Fibula graft is most commonly used.
•  Usefull for filling large defects in the diaphsial portion of bones of upper extremity
•  In children ,the fibula can be used to span a long gap in the tibia

102. ILIAC BONE GRAFT
• iliac crest is an ideal source of bone graft because –
• it is relatively subcutaneous
• has ample cancellous bone
• has cortical bone of varying thickness Removal of the bone carries minimal risk
• usually there is no significant residual disability

103. • Large cancellous and corticocancellous grafts may be obtained from the
anterosuperior iliac crest and the posterior iliac crest.
•  In children the physis of the iliac crest is preserved together with the attached
muscle

104. • Generaly only one cortex and the cancellous bone are removed for grafts
• the fractured crest along with the apophysis is replaced in contact with the
remnanat of the ilium by nonabsorbable suture.

105. INCISION
• along the subcutaneous border of the iliac crest at the point of contact of the
periosteum with the origins of the gluteal and trunk muscles .
• When the crest of the ilium is not required as part of the graft, split off the lateral
side or both sides of the crest in continuity with the periosteum .

107. COMPLICATION
• Hernia devlops if full thickness massive grafts were taken.
• The superior cluneal nerves are at risk if dissection is carried farther than 8 cm lateral to
the posterior superior iliac spine
• superior gluteal vessels can be damaged by retraction against the roof of the sciatic
notch
Removal of large full-thickness grafts from the anterior ilium can result in significant
cosmetic deformity
Arteriovenous fistula,
pseudoaneurysm,
ureteral injury, paralytica ileus.
anterior superior iliac spine avulsion,
pelvic instability

108. GRAFTS FROM TIBIA
•
• The subcutaneous anteromedial aspect of tibia is the source of structural
autografts.
• The plateau of tibia supplies cancellous bone.
• tourniquet aplied to avoid excessive blood loss
• Make a slightly curved longitudinal incision over the anteromedial surface of the
tibia

109. TIBIAL GRAFT HARVEST
Because of the shape of the tibia, the
graft is usually wider at the proximal
end than at the distal end.
periosteum over the tibia is relatively
thick in children and is sutured as a
separate layer
In adults periosteum is thin and is
sutured along with the subcutaneous
tissue

110. DISADVANTAGES
• Normal limb is jeopardized Increased duration of surgery
• Protected weight bearing for atleast 6 to 12 months .

111. FIBULAR BONE GRAFT
• Entire proximal two third of the fibula can be used for bone graft
• The proximal rounded configuration of the fibula is covered with
hyaline cartilage.
• May replace distal radius or even distal third of fibula
• The middle third of fibula can serve as the peroneal artery based
vascular graft

112. POINTS TO REMEMBER FOR FIBULAR BONE GRAFT
• The peroneal nerve must not be damaged;
• The distal fourth of the bone must be left to maintain a stable ankle
• The peroneal muscles should not be cut.

113. PHEMISTER BONE GRAFT
• It is subcortical cancellous bone grafting
• A bone graft of cortical bone with cancellous bone chips to enhance callus
formation.
• Bone-grafting without disturbing the pre- existing callus
• Bone graft is taken by elevating the osteoperiosteal flaps.

114. REQUISITES FOR PHEMISTER GRAFT
• Petalling should carried out at the fracture site
• The mobility at the fracture site should be minimal
• The fracture should have an acceptable alignment
• The knee joint should have a good range of motion

115. URIST AAA BONE GRAFT
• Composed of bone morphogenic protein and autolysed , antigen-extracted and
autogenic bone.
• h-BMP/AAA composite implants represent adjunctive treatment of difficult
nonunions
• Composite implants may be implanted in either partial or complete segmental
defects of long bones

116. BONE MARROW ASPIRATE
• RIA(REAMER IRRIGATOR AND ASPIRATOR)
• It is a technique to harvest sizable amount of bone marrow,which is particularly
rich in mesenchymal stem cells .
• Growth factors supplied:
Fibroblasts growth factor(FGF)-2 Insulin like growth factor(IGF)-2 Transforming
growth factor(TGF) beta
• Absence of bone morphogenetic protein-2

117. ADVANTAGES OF RIA
• Provides enriched osteogenesis Decrease intramedullary canal pressure Minimal
risk of fat embolism
• Potential source of autologous bone, mesenchymal cells and bone growth
factors.

120. COMPLICATIONS
• Perforation of the meduallary canal which may require prophylactic
intramedullary fixation.
• Significant blood loss

121. STEPS TO MINIMIZE RISK
• Preoperatively donor radiograph should be used to measure isthmus
• Blood should be arranged for replacement.
• Switch off the aspirator when there is no reaming
• Post op ambulation should be protective
• Check haematocrit
• Avoid in metabolic bone diseases

122. Thank you