Its a try to make an understand about ILIZAROV to my colleagues. reply me on dr_chachan@yahoo.com if u like my presentation..thank you all

1. Ilizarov
 Dr.Abhishek chachan
Mahatma gandhi hospital
sitapura, jaipur
Rajasthan, INDIA

2. Historical review
 Gavriil Abramovich
Ilizarov
( 15 june 1921 – 24 july
1992)
 Russian physician,
known for inventing the
Ilizarov apparatus

3. Historical review
 Ilizarov was born in the Azerbaijan
 In 1944 he was sent to a rural hospital in
Kurgan Oblast in Siberia
 In 1951, he developed a revolutionary technique
and called it a RING FIXATOR .

4. Priciples of Illizarov
 DISTRACTION OSTEOGENESIS. This refers to the
induction of new bone between bone surfaces that are pulled
apart in a gradual, controlled manner.
 The distraction initially gives rise to
NEOVASCULARISATION which is what actually stimulates
new bone formation.
 In addition, there is simultaneous histogenesis of muscles,
nerves and skin; in bone diseases (osteomyelitis , fibrous
dysplasia, pseudo-arthrosis) this new bone replaces
pathological bone with normal bone.

5. Indications of Illizarov
 In treating of bone infections
 In Poliomyelitis Sequelae (in limb lengthening and
correction of deformities)
 In treating of malunited fractures and non-unions
 To correct deformities of the limbs, both congenital
and acquired
 In treating badly comminuted fractures (multiple
fragments) in the limbs
 Lengthening of limb stumps, foot stumps and fingers
 To increase height (for dwarfs)

6. Instruments and their use
 Primary components – That join skeleton to
finished frame
 Transosseous wires
 Rings
 Wire fixaion bolts

7. Instruments and uses
 Secondary components – Used to construct
frame
 Threaded and telescopic rods
 Connecting plates
 Hinges and posts
 Nuts and bolts

8. Instruments used in ilizarov

9. Wire fixation bolt
 Cannulated
 Cannulated with
threaded head
 Slotted

10. Wire fixation buckle
 Allows mechanical
derotation or angular
corrections

11. Telescopic rod
 Provide stability when
long distance must be
spanned between
rings
 Allows lengthening

12. Hinge ( Male and female)

13. Threaded socket
 Inerconnect threaded
rods
 Stabilize two rings
together

14. Wires
 Trocar- Cancellous bone
 Bayonet – Cortical bone
 Olive wires

15. Dynamometric wire tensioner

16. Biomechanics
 Tensioned wires (1.5 and 1.8) achieve rigidity
equal to half pins.
 And retain elasticity and low axial stiffness.
 Should not exceed 50% of yield strength of wire
 Maximum limits
 90 kg for 1.5 mm wire
 130 kg for 1.8 mm wire

17. Biomechanics
 Tension in soft tissues also determine the
tension to be applied to wire
 In Lengthening its safer to tension wires to 80
-90 Kg
 Increasing wire tension from 90-130 increases
bending and axial stiffness but lowers torsional
stiffness

18. Biomechanics
 Number of wires
 More the number/ring more stable is
the fixator
 Wire spread
 90/90 ideal- Anatomical constraints
 45/135 configuration less stable in
flexion
 Off centering
 Higher axial stiffness and lower
torsional stiffness.
 Olive wires
 increase bending, axial and torsional
stiffness

19. Biomechanics
 Wires are self stiffening
 Wires derive increasing rigidity with increasing
deflection
 On releasing deflection load, wires spring back to its
original axially tensioned position
 Allows axial micromotion

20. Biomechanics
 Wire diameter
 Increase diameter increases tension
 Optimum wire
 1.5 mm for children
 1.8 mm for adults

21. Biomechanics of Ring
 Stability of assembly
 Number
 Size
 Position of rings
 Closer the middle two rings to the fracture more
stable is the configuration

22. Biomechanics
 Reduction of 2 cm of radius of rings
 77% rise in axial stiffness under 100 N load
 Only torsional stiffness increased with increasing
ring diameter
 Ilizarov recommends minimum of 2 cm
between skin and ring to accomadate edema as
blood flow increases

23. Biomechanics of Fulcrum
 In deformity correction Olive wires are used as
fulcrum to prevent slippage of wires

24. Biomechanics of hinges

25. Biomechanics of Hinges
 Central hinge
causes distraction
on concave side
and compression
on convex side.

26. Biomechanics Hinges
 Fulcrum on the convex
side
 Hinge at apex of
deformity – distraction
on convex side

27.  Hinge placed more
laterally results in
lengthening along
with angular
correction

28. Factors affecting stability of fixator
 I Apparatus related (Extrinsic) factors
 Spread between crossing wires approaching 90/90
 Increase in wire diameter and tension
 Increase in number of rings
 Decreased ring size (wire span distance of 2-3cm
around the limb)
 Close positioning of center rings to fracture or
nonunion site.
 Use of olive (stop) wires.

29. Factors affecting stability of fixator
 II. Intrinsic factors-
 Area of tissue contact between the bone ends.
 Modulus of elasticity of tissue between bone ends
 Length of gap between bone ends.
 Tension of soft tissue surrounding bone
 Mechanical configuration and interlock between
bone ends

30. Histology of distraction
osteogenesis
 FIZ – Fibrous interzone
 PMF- Primary
mineralization front
 MCF – microcolumn
formation
 HBS – Host bone surface

35. Histology
 Latency period – similar to fracture healing
 1 week after distraction-
 Fibrous interzone fills corticotomy gap (6-7 mm)
 By 2nd week-
 Osteoblasts appear on each side of FIZ and collagen
bundles fuse with osteoid like matrix
 Later in 2nd week Osteoid mineralizes (Primary
Mineralization Front)
 New bone forms at two cut surfaces of corticotomy.

36.  3 weeks of distraction
 New bone differentiates to microcolumn formation
{MCF} with maximum diameter of 200 microns.
 FIZ persists throughout distraction
 After distraction FIZ ossifies, MCF unifies
bridging the gap
 At the conclusion of distraction, the FIZ
ossifies, creating one zone of MCF and
completely bridging the gap During this 6-week
consolidation period

37.  During the 6 weeks after frame removal, the
osteogenic area remodels into cortex and
medullary canal
 Blood flow peaks 7 times normal during first 4
weeks of distraction
 Then Decreases but remains elevated 3 times
normal for next 3 months

38. Factors affecting osteogensis
 Stability of bone fragments
 local or regional blood supply
 Latency period
 Rate and rhythm of distraction
 Function of limb
 Timing of frame removal

39. Anatomic considerations
FEMUR- When inserting wires into the femur, there
are several basic problems
First, the bulk of the soft tissues causes difficulties,
especially posteriorly, in the buttock.
Second, the neurovascular bundles,especially the
superficial femoral artery,can be damaged during
wire insertion.
Third, the sciatic nerve prevents direct AP wire
insertion.

40.  Insert the first olive wire from anteromedial to posterolateral two
fingerbreadths lateral to the femoral artery. Insert a second olive
wire from back to front, 15° medial to the first wire. The
posterior olive on this wire prevents the entire frame from
displacing anteriorly while the patient lies in bed. A third wire is
often inserted between the first two.
 To stabilize a hip during femoral lengthening.especially a hip that
might sublux or dislocate,it may be necessary to insert wires into
the supraacetabular or iliac portion of the pelvis. Leave these
wires in place (not allowing movement) until lengthening is
complete. Thereafter, the wires are removed and hip motion is
commenced.
 For the distal femur, insert wires into either the transverse
or the coronal plane. When selecting the transverse plane,
cross the wires at an angle of no less than 60°. Likewise,
insert olives from both directions for enhanced stability

41. TIBIA
The proximal ring for a tibial mounting usually incorporates
. a wire that passes through the fibular head and into the
tibia to prevent subluxation of the proximal tibia fibula
joint during lengthening or deformity correction. A
second wire through the tibia crosses the fibula wire,
paralleling the medial face of the tibia. A third transverse
drop wire is inserted across the tibia into the location
used for skeletal traction. Additional wires are inserted as
needed for greater stability. Distally, the fibula must
usually be incorporated into the configuration with a
distal fibulotibial wire.

42.  HUMERUS
 The Proximal And Distal Ends Of The Bone Can Be Secured With Three
Wires Each
 Through The Proximal Humerus, Abduct The Arm 90° and externally rotate
it 20°. Drive olive wires from both the anterior and posterior directions. The
third wire is a drop wire off the plane of the ring.
 In the distal humerus, insert olive wires crossing in the frontal plane, one
from the lateral supracondylar ridge and one from the medial supracondylar
ridge A drop wire (perpendicular to the bone's axis) completes the
configuration
 Insert the wires into both epicondyles, exiting the humerus proximally at the
medial and lateral supracondylar ridges. Take care not to transfix either the
ulnar or radial nerves. A third wire straight across from one supracondylar
ridge to the other completes the mounting.
 After all wires are in place, flex and extend the elbow: there should be no
block in either direction.

43. FOOT
 Before Inserting Wires Into The Calcaneus,
Consider The Diameter Of The Wires,Number ,
The Angles Between, The Direction Of
Insertion, The Plane Of The Wires.
 diameter of the wires is determined by the age
 the amount of osteoporosis and degree of
deformity influence the number of wires
selected-more then 2 wire

44.  Next, consider the direction from which the wires are
to be inserted. When correcting an equinus, insert both
olive wires from the posterior part of the heel toward
the forefoot. When correcting a cavus or calcaneus
deformity, insert the olive wires from the forepart of
the foot toward the heel. When correcting a forefoot
adduction deformity, keep both olive wires on the
medial side of the heel. When a valgus of the heel is
being corrected, place the olive on the lateral side of the
foot. In combined deformities such as talipes
equinovarus, the position of the olives is determined by
the nature of the pathology

45. Precautions
 Corticotomy complete – Confirm
fluoroscopically
 Distraction no more than 2-4 mm
 Angulation no more than 20-30 degrees

46. Radiographic classification of
regenerate
 Normotrophic
 Hypertrophic and
 Hypotrophic

47. Normotrophic
 Early radiodense bone formation b/w 21 to 28 days
 At this point bone ends have distracted approx 14 mm
apart
 Definite columns of longitudinally oriented new bone
extends from each corticotomy surface towards central
transverse radiolucent area measuring approximately 4
mm
 As distraction proceeds columns of new bone elongate
maintaining central radiolucent band
 Following distraction new bone bridges centrally &
proceeds to homogenous appearance

48. Radiologic evaluation of callus

49. Hypertrophic
 Regenerate appears
radiologically before 20
days
 Cross sectional diameter
of regenerate exceeds that
of corticotomy surface
 Rate of distraction must be
increased

50. Hypertrophic
 Factors
 Young patient
 More active patients
 Good local blood supply ( Humerus)

51. Hypotrophic
 Radioloigcal new bone appears after 30 days
 Or if bone column has multiple breaks
 Or regenerate has hourglass appearance
 Factors
 Vascular deficits
 Local scarring or swelling which constricts new
tissue formation
 Lack of function or weight bearing by the patient

52. Hypotrophic
 Type A
 Spotty radiodensities
after day 50
indicating poor
vascularity

53. Hypotrophic
 Type B
 Hourglass
configuration –
distraction rate too fast

54. Hypotrophic
 Type C
 Irregular bone columns
indicate instability or
vascular disruption

55. Hypotrophic
 Type D
 Focal failure of bone
formation indicate local
vascular injury or
periosteal damage if
peripheral

56. Timing of Frame Removal
 Depends on the condition of the limb and pathology invovled
 X Ray: Ideally the regenrate bone should be remodelled with
cortex and medullary canal of equal cross section diameter to the
host bone
 Q.C.T: Quantitave C.T. scanning of central osteogenic area
density must be 60% of opposite normal bone is satisfactory for
removal of frame
 Clinical test for frame dynamization: prior to removal the wire
tension is gradually reduced to minimum and patient allowed for
full wt bearing,if new bone supoorts full load without pain or
deformity,then device can be safely removed

57. Clinical applications
 Non unions and deformity correction
 Bone transport
 Fractures
 Limb lengthening

58. Non union
 Hypertrophic non-unions have a vital blood
supply from each bone end and a dense
collagenous interface.
 Bone formation can be stimulated by primary
distraction
 Atrophic non-unions, with thin, non-reactive
bone ends, are treated initially with compression
and then with distraction

59. Bone transport
 Intercalary defects resulting from
 trauma,
 infection,
 tumor, or
 prosthetic replacement can be treated with transport
of a segment of bone within the limb

60. Limb lengthening
 The Ilizarov method allows the surgeon to perform
complex and extended lengthening of both congenital
and acquired short limbs
 Rate and quality of bone formation can be influenced
by certain factors
 Amount of lengthening that is attempted,
 the site of the lengthening,
 the selection of the bone to be lengthened,
 and the number of sites of lengthening within the bone

61.  The rate of healing is directly proportional to the length
of the distraction gap —
 the greater the lengthening, the longer the time needed
for treatment
 Metaphyseal sites generally heal faster than diaphyseal
sites.
 The femur has been shown to heal faster than the tibia
 And tibiae lengthened at two sites heal faster than those
lengthened at only one site
 Older patients tend to heal more slowly, with greater
delays occurring after the age of twenty years

62. Complications
 Complications can involve the
 pin tracks
 bones
 Joints
 neurovascular structures
 Mental status

63.  Inflammation surrounding pin tracks is common
as a result of
 mechanical or thermal damage
 Cellulitis
 abscess or
 local osteomyelitis.

64.  Osseous complications may involve
 premature or delayed consolidation
 non-union
 axial deviation
 late bending
 fracture

65.  During the lengthening, motion of the joint may
be temporarily or permanently lost as a result of
 muscle contracture
 arthrofibrosis, or
 damage to the cartilage.

66.  Nerves and vessels may be damaged
 directly by pins or osteotomes or
 Indirectly by the actual stretching.
 Regional edema is common;
 Painful neurapraxia is less common; and
 Reflex sympathetic dystrophy, and
compartment syndrome are rare

67. Advantages of Ilizarov over
Cantilever type Ex fix
 Elastic allow axial micromotion, and controls
shear stress
 Multilevel multiplanar fixator, distribute stresses
more evenly across fracture - 3 dimensional
correction is possible intraop and post op.
 Stable- allow immediate weight bearing
 Better in osteoporotic bone
 Pins are thin and does not cause much damage
to tissues