This PPT consist of basic knowledge of different types of Bone grafts used in orthopaedics, their uses, advantages & disadvantages

1. BONE AUTOGRAFT AND
ALLOGRAFT
DR. SUNIL MANN
PG 3RD YEAR

2. INTRODUCTION
• Bone grafts are able to stimulate osteogenesis
through the differentiation of mesenchymal
cells into osteoprogenitor cells and also they
provide linkage across defects and a scaffold
upon which new bone can form.

3. Properties of a graft

4. Types of Bone Grafts
• Autologus: source is the patient himself ,
usually from tibia , fibula or ilium.
• Allogenic : source is an individual other than
the patient but from same species
• Xenograft: derived from different species

5. Autologus Bone Graft
• Bone is transferred from one site to another in
the same individual. These are the most
commonly used grafts and are satisfactory
provided that sufficient bone of the sort
required is available and the recipient site
have a clean vascular bed.
• “Gold standard”

6. Autologus Bone Grafts
Types
• Cancellous
• Cortical

7. Autologus: Cancellous Bone
Grafts
• Harvested from the iliac crest, posterior superior iliac spine,
femur, proximal tibia, distal radius, and olecranon.
• Cancellous bone is able to fill osseous defects, but does not
provide significant mechanical support, so it is usually used
as an adjunct to some form of internal or external fixation.
• It incorporates quickly and can reach strength similar to
cortical bone graft after 6 months to 1 year.

8. Autogenous: Cancellous Bone
Grafts
• CREEPING SUBSTITUION: process by which
graft is replaced by new bone
- Large number of osteoblasts, MSCs, BMPs and
growth factors, while the cancellous matrix
provides an excellent scaffold for vascular
ingrowth and infiltration of osteoblastic cells,
conferring to it osteogenic, osteoinductive,
and osteoconductive properties.

9. • Induced membrane method-technique
utilizing autologus cancellous graft chips is
particularly useful when dealing with necrotic
or infected bone tissue.

10. Cancellous Autograft: BMA (RIA)
• Another potential source of cancellous autograft is
from the medullary canal of long bones.
• The reamer/irrigator/aspirator (RIA) technique was first
developed to prepare long bones for intramedullary
nail fixation.
• The particulate aspirate and liquid filtrate have
revealed osteogenic and osteoinductive properties

11. • Aspirate is rich in mesenchymal stem cells and
growth factors like FGF-2, IGF-2, TGF beta but
Absent bone morphogenetic protein-2
• BMA can be aspirated from the posterior ilium
at volumes of up to 150mL with low
associated rates of morbidity.

14. Cortical autografts
• Cortical autografts are primarily osteoconductive grafts
with very little osteoinductive ability.
• They can be harvested and transplanted with or without
their associated vascular supply
• Common sites of harvest are
- iliac crest and distal radius for non-vascularized autograft.
- Fibula, iliac crest, distal radius, and ribs for vascularized
grafts.

15. Cortical autografts
• Non-vascularized grafts undergo local necrosis and resorption at the
graft-host interface with concomitant revascularization during the
first six weeks.
• Vascularized grafts undergo direct bone healing, vascularized grafts
are stronger than nonvascularized grafts during this time period.
• Defects >6cm that require some structural support--cortical
autograft is ideal.
• Defects >12cm-vascularized cortical autograft is ideal due to the
higher failure rate of non-vascularized grafts in defects of this size.

16. Autologus Bone graft from Iliac crest
• All types- cortical, cancellous & combined
• Patient – Supine- Ant 1/3rd , Prone- Post 1/3rd of
ilium
• If rigidity not a concern- multiple sliver or chips
• If more rigid- ant or post 1/3rd of iliac crest is used
• To preserve the iliac crest outer cortex of ilium
can be removed along with cancellous bone
• For wedge grafts- cut at right angle to crest

19. Graft from iliac crest

20. Complications of iliac crest graft
• Full thickness iliac crest graft lead to herniation.
• The lateral femoral cutaneous and ilioinguinal
nerves are at risk during harvest of bone from
the anterior ilium
• Altering the contour of the anterior crest,
produces significant cosmetic deformity
• Arterio-venous fistula, pseudoaneurysm,
ureteral injury, anterior superior iliac spine
avulsion, and pelvic instability

21. Grafts from tibia
• The subcutaneous anteromedial aspect of
tibia is the source of structural autografts.
• The plateau of tibia supplies cancellous bone.
Disdvantages
• Normal limb is jeopardized
• Increased duration of surgery
• Protected weight bearing for atleast 6 to 12
months

23. Bone graft from fibula
• 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.
• The middle third of fibula can serve as the
peroneal artery based vascular graft
Precautions
• 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.

25. Special bone graft tech.- Phemister
• 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
preexisting callus
• Bone graft is taken by elevating the
osteoperiosteal flaps.
ONLAY grafting TECH

26. 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

27. Advantages of Autograft
• Readily available
• Quick and reliable incorporation
• No immunogenicity
• No clearance hassles for authority
• No risk of transmitting infections
• Different forms- cortical, cancellous, combined
available

28. Disadvantages of Autograft
• Increased operating time
• Limited amount can be procured, will not suffice
in large reconstruction and defects
• Pain at operative sites, morbidity and increase
length of stay
• Increase cost of surgery
• Second surgery and potential risk of infection
• Chronic pain may persist
• Possibility of hernia and secondary complications

29. Allograft
• In this graft is obtained from an individual other than
patient
• Indications:
• Reconstruction of bone defects as a result of primary joint
arthroplasty osteolysis
• Reconstruction of skeletal defects following tumour
resection
• Reconstruction of congenital or developmental bone and
joint defects(protrusio acetabuli, dysplastic hip) and
deformities

30. • Repair of fresh comminuted fractures with
bone loss
• Treatment of non unions and complicated
osteoporotic fractures
• Arthrodesis of large joints
• Treatment of scoliosis and spinal fusion
• Repair of massive segmental bone defects
• Repair of periodontal osseous defects

31. Allograft types
• Cortical
- Fresh Frozen
- Freeze dried
• Cancellous
- Fresh Frozen
- Freeze dried

32. • Fresh frozen
It is less immunogenic but needs additional procedure for
sterilization
Advantage – preserves BMP
• Freeze dried (lyophilized)
- Bone must be extracted from donor within 8-12 hours of death
- i/c and e/c enzymes cause enzymatic autodigestion and leads to
loss of inductive factors and BMP
- The type that retains inductive factor is k/as Antigen extracted
allogenic (AAA) bone

33. Preparation of Allograft
• Chloroform-methanol is used to extract lipids
and cell membrane lipoproteins
• HCL extracts acid soluble proteins and
requires 24hrs to demineralize the surface
• Neutral phosphate buffer is used to remove
endogeous intracellular and extracellular
tranplantation antigen
• The bone is then frozen and freeze dried and
stored at -60 degree C

34. Demineralized Bone Matrix
• Demineralized bone matrix (DBM) is produced via acid
extraction of allograft bone and contains proteins, collagen,
and growth factors.
• It is a digested source of BMP
• It enables the natural bone formation process, due to its
increased surface area for osteoconductive and
osteoinductive cellular attachments.
• The osteoinductive properties of each individual vary.

35. DBM
• It is used as bone graft expander
• Available in 2 forms- dry and injectable
• DMB has to be mixed with a carrier, inert
carriers such as hyaluronic acid, glycerol,
collage, gelatin, actual derivatives of DBM
itself
• Second generation DBM putties where the
carrier is loaded with BMP have higher
concentration of BMP and are possibly better

36. • Osteochondral allografts
• It is a bony chunk along-with cartilage cover
• Used for large articular defects in
osteochondoses of knee
• Shell Allografts
• Devascularized osteoarticular graft with a
small bony component is used for biologic
resurfacing of articular defects

37. • Large composite Allografts
• Usually required for excision of large tumors
or reconstruction of defects in revision
arthroplasty after freeze thawing

38. Advantages of Allograft
• Quick and easy to use
• Available in various shapes and sizes
• Large amount for massive recon available
• Shortens operative time

39. Disadvantages of Allograft
• Requires setup and maintenance
• Not readily available in INDIA
• Various regulatory clearances needed
• Risk of infection esp. clostridial and viral
• Weak osteogenic potential though provides
good structural support
• Procurement,processing and preservation
need expertise

40. Complication of BG (auto and
allograft)
• Development of incisional hernia
• Vascular injury
• Neurological injury- posterior iliac grafting-
cluneal nerves, anterior iliac grafting- LFCN
• Fractures of donor bone
• Hematoma and seroma formation
• Cosmetic concern and chronic pain
• Transmission of infection (allogarft)
• Very rarely tumor cell transplantation

41. •Thank You