This document discusses the anatomy and types of bone grafts. It begins by describing the two types of bone tissue: cortical/compact bone, which forms the dense outer layer, and cancellous/spongy bone, which fills the interior. Bone grafting is then introduced as a surgical procedure to repair broken or defective bone using donor bone material. The document proceeds to explain the three key processes in bone graft incorporation: osteoinduction, osteoconduction and osteogenesis. It provides details on the types of bone grafts, including those based on donor origin (autograft, allograft, xenograft) and composition (cortical, cancellous). Risks, techniques and applications of different bone graft procedures are

2.  Bone is not a uniformly solid material, but
rather has some spaces between its hard
elements.
 CORTICAL /COMPACT BONE - The hard outer
layer of bones is composed of compact bone
tissue, so-called due to its minimal gaps and
spaces. Its porosity is 5–30%.
- 80% of total bone mass of a skeleton
- consists of haversian canal and osteons

3.  CANCELLOUS/SPONGY/TRABECULAR BONE
- Filling the interior of the bone is the
trabecular bone tissue
- composed of a network of rod- and plate-
like elements that allow room for blood
vessels and marrow.
- accounts for the remaining 20% of total
bone mass.
- Its porosity is 30–90%

5.  Bone grafting is a surgical procedure that
places new bone or a replacement material
into spaces between or around broken bone
(fractures)
or in holes in bone (defects) to aid in healing.

6.  Used to repair bone fractures that are
extremely complex, pose a significant risk to
the patient or fail to heal properly.
 Used to help fusion b/w vertebrae, correct
deformities or provide structural support for
fractures of the spine.
 To repair defects in bone caused by
congenital disorders, traumatic injury, or
surgery for bone cancer.
 Also used for facial or cranial reconstruction

7.  OSTEOGENESIS
 OSTEOINDUCTION
 OSTEOCONDUCTION

8.  Hemorrhage
 Inflammatory response
 OSTEOGENESIS - formation of new bone by the
cells contained within the graft.
 OSTEOINDUCTION
involves the stimulation of osteoprogenitor cells
to diffr. into osteoblasts that begin new bone
formation.
Most widely studied type of osteoinductive cell
mediators in grafts are bone morphogenetic
proteins (BMPs).

9.  OSTEOCONDUCTION
 bone graft material serves as a scaffold for
new bone.
 Osteoblasts from the margin of the defect
utilize the bone graft material as a
framework upon which cells spread and
generate new bone

10.  To promote union as in
- Fresh fractures
- Delayed union
- Malunion
- Osteotomies

11.  To bridge joints and thereby provide
arthrodesis.
 To bridge major defects or establish the
continuity of a long bone.

12.  To fill cavities/defects
secondary to
- Trauma
- Tumor
- Infections and other
conditions

13. 1)based on the donor origin
- autograft
- allograft
- xenograft
2)based on composition
-cortical
-cancellous
-osteochondral

14. 3) Blood supply:
 Non-vascularised
 Vascularised
4) Preservation
- fresh
- frozen
- freeze dried
- demineralized

15. 5) based on anatomical features
- epiphyseal
-metaphyseal
-diaphyseal

16.  Bone harvested from the patient’s own body.
 Gold standard - sufficient bone of the sort
required is available & at the recipient site,
there is a clean vascular bed.
 Iliac crest – commonest site.

17. SOURCES
1) Cortical bone graft – for filling bone gaps
Tibia mainly, iliac crest & fibula also.
2) Cancellous bone graft – for osteogenic
purpose (eg: non-union).
 Thicker portions of the ilium, greater
trochanter, proximal metaphysis of the tibia,
lower radius, olecranon or from an excised
femoral head.
3) Whole bone graft – fibula.

18.  Cancellous grafts become incorporated
more quickly & more completely than
cortical grafts
 The graft stimulates an inflammatory
response with the formation of a
fibrovascular stroma; through this, blood
vessels & osteoprogenitor cells can pass from
the recipient bone into the graft.

19.  donor site morbidity
 Ambulation is delayed until the defect is
partially healed
 pain and infection at the site from which the
graft is taken
 Vascularized grafts - sophisticated
microsurgical techniques are necessary & in
major sites of loading , osseous hypertrophy
may occur

21.  Muscle-pedicle bone grafting
bone graft is taken along with pedicle of
muscle (with intact blood supply which will
supply blood to graft).
- eg: non-union fracture neck of femur.

22.  Free vascularised grafting – bone (fibula) is
taken along with the vessels supplying it.
- eg:- the iliac crest (complete with one of
the circumflex arteries), the fibula (with the
peroneal artery).
- Middle 1/3rd of fibula– used as a
vascularised free autograft based on the
peroneal artery and vein pedicle using
microvascular technique - for treatment of
large defects in cong pseudarthrosis of tibia.

24.  Graft obtained from a person other than the
patient (live or dead).
 Indicated in
1) small children, where the usual donor sites
don’t provide cortical grafts large enough
to fill a large cavity and when there is
possibility of physeal injury.
2) aged persons
3) patients with poor operative risks
 Usually taken from cadavers; it is typically
sourced from a bone bank.

25.  There are three types of bone allograft
available:
1. Fresh or fresh-frozen bone
2. Freeze-dried bone allograft (FDBA)
3. Demineralized freeze-dried bone
allograft (DFDBA)

26.  Using allograft tissue from another person
eliminates the need for a second operation
to remove autograft bone or tendon.
 It also reduces the risk of infection, and
safeguards against temporary pain and loss of
function at or near the secondary site.

27.  Bone variability because it is harvested from
a variety of donors.
 Longer time to incorporate with the host
bone and may be less effective than an
autograft.
 Possibility of transferring diseases to the
patient(viral transmissions).
 Potential immune response complications.

28.  Graft obtained from another species.
 Xenograft bone substitute has its origin from
a species other than human, such as bovine.
 Xenografts are usually only distributed as a
calcified matrix.
 S/E- foreign body reaction.

29.  Material derived from corals
 Artificial bone can be created from
ceramic such as calcium phosphates
– porous str. (e.g.hydroxyapatite
and tricalcium phosphate), Bioglass
and calcium sulphate; all of which
are biologically active to different
degrees depending on solubility in
the physiological environment.
 Hydroxyapatite is crystalline calcium
phosphate. Slow resorption

31.  made from hydroxylapatite, a naturally
occurring mineral that is also the main
mineral component of bone. They may be
made from bioactive glass.
 calcium carbonate - unpopular ;completely
resorbable in short time which make the
bone easy to break again

32.  These materials can be doped with growth
factors, ions such as strontium or mixed with
bone marrow aspirate to increase biological
activity.
 The presence of elements such as strontium
can result in higher bone mineral density and
enhanced osteoblast proliferation in vivo.

34.  The surgeon does a clinical examination, and
conducts tests to determine the necessity of a
bone graft,to determine the precise location of
damage,exact amount of damage.
 These tests include x-rays, MRI, CT scan
 Arrange for blood in case a transfusion is needed
 Proper nutrition to achieve good nutritional
status before and after surgery.

35.  Single onlay cortical graft: was mainly used for
ununited diaphyseal fractures , used for a
limited group of fresh, malunited and ununited
fractures.
- bridging joints to produce arthrodesis, for both
fixation and osteogenesis.
 Dual onlay grafts: used in treating difficult and
unusual nonunions or for bridging of massive
defects.
- eg: for nonunion near a joint
- not as strong as metallic fixatives
- not very osteogenic

37.  Inlay Grafts:
- A slot or rectangular defect is created in
the cortex of the host bone.
- occasionally used in arthrodesis particularly
at ankle.
- complex and less efficient

38.  Peg Grafts- for fixation alone
- weaker
- use limited to non-union of medial
malleolus and small bones of hand ,wrist or
foot.
 Medullary Graft - poor healing, interferes
with endosteal circulation; rarely used
except in metatarsals, metacarpals and
distal radius.

39.  Osteoperiosteal Grafts- less osteogenic than
multiple cancellous grafts ,and are rarely
used.
 Multiple cancellous chip grafts
-widely used, best osteogenic material.
-useful for filling cavities & cysts ,for
establishing bone blocks, and for wedging in
osteotomies.
-Soft and friable.

40.  Hemicylindrical grafts- for obliterating large
defects in tibia and femur.
- massive hemicylindrical cortical graft from
affected bone is placed across the defect and
is supplemented by cancellous bone.

41.  Tourniquet to be applied.
 Make a slightly curved longitudinal incision
over AM aspect of tibia
 Incise and reflect the periosteum
 Drill a hole at each corner of the anticipated
area.
 Remove the graft by cutting through the
cortex at an oblique angle.
 Remove cancellous bone from the proximal
end of tibia with a curet.

42.  Disadvantages
- normal limb is jeopardised
- Convalescence is prolonged
- Tibia more prone for fractures for 6-12
months.

44. 3 points to be considered:-
-peroneal nerve must not be damaged.
-distal 1/4th of the bone must be left to
maintain a stable ankle.
-do not cut peroneal muscles.
 Resect the middle 1/3rd
Dissect along the anterior surface of septum
b/w peroneus longus and soleus.

45.  Reflect peroneal muscles anteriorly.
 Start stripping till fibula exposed.
 Drill holes through fibula at the anticipated
area of graft.
 Graft harvested

47.  acquired bowel herniation (this becomes a
risk for larger donor sites (>4 cm)).
 meralgia paresthetica (injury to the lateral
femoral cutaneous nerve also called
Bernhardt-Roth's syndrome)
 pelvic instability
 fracture (extremely rare and usually with
other factors)

48.  injury to the ilioinguinal nerve
 infection
 minor hematoma (a common occurrence)
 deep hematoma requiring surgical
intervention
 seroma
 ureteral injury
 pseudoaneurysm of iliac artery (rare)

50.  To efficiently provide safe and useful
allograft material.
 Uses thorough donor screening,rapid
procurement, and safe sterile processing.
 Donor screening for bacterial,viral and
fungal infection.
 C/I- malignancy( except BCC), collagen
vascular diseases,metabolic bone dissease
and presence of toxins.

51.  Bone can be harvested in a clean nonsterile
environment, sterilised by irradiation,strong
acid or ethylene oxide , and then freeze
dried for storage.
 Bone under sterile conditions , can be deep
frozen (70-80 deg) for storage.
 Fresh frozen bone is stronger than freeze-
dried bone.
 Cancellous bone can be obtained in a
demineralised form.

52.  New BMP products are expected to be strong
inducers of bone growth (osteoinductive).
 These new products will be relatively
expensive, but will grow bone better than
the patient's own bone, eliminating the need
for bone graft harvesting.
 The INFUSE Bone Graft (rhBMP-2, BMP 7) has
received approval.

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