general discussion about Ilizarov external fixator with its history, principles, indication, application, advantage and disadvantage

1. ILIZAROV FIXATOR
DR PRATIK AGARWAL

2. Outline
 History
 Principles
 Application of circular fixator
 Basic principles of operative techniques
 Stages of Ilizarov treatment technique
 Post operative management
 Dynamization and removal
 Safe zones in tibia
 Indication
 Complication
 Advantage
 Disadvantage
 Recent advances in Ilizarov
 Different applications of Ilizarov

3. History
• Born in Soviet Union.
• In 1950, sent to Kurgan, Siberia to
look after injured Russian soldier.
• Inspiration- by shaft of bow harness
on horse carriage.
• Using spokes of bicycle from local
bicycle shop, he devised ring external
fixator.
• Accidently he found new bone
formation radiologically in a patient
who turned compressing rods
between rings in distraction rather
than compression.
• He revolutionized the treatment of
difficult musculoskeletal problems.
Professor Gavril Abramovich Ilizarov (1921-1992)
“THE MAGICIAN OF KURGAN’’

4. RUSSIAN ILIZAROV SCIENTIFIC CENTRE OF RESTORATIVE TRAUMATOLOGY AND ORTHOPEDIC ,KURGAN ,RUSSIA

5. Principle of Ilizarov
Based on the principle ‘’that growing bone changes its form and volume according
to external stimuli’’ (Wolff’s law), Ilizarov subjected bone to continual external
tension in any direction, which can lengthen the bone or correct deformities.
Distraction osteohistiogenesis
 Mechanical induction of new bone formation
 Neovascularisation
 Stimuli of biosynthetic activity
 Activation and recruitment of osteoprogenitor
cells
 Intramembranous ossification

6. Cont…
His biological principles can be
summarized as follow-
 Minimal disturbance of bone and
soft tissues
 Delay before distraction
 Rate and rhythm of distraction
 Site of lengthening
 Stable fixator of external fixator
 Functional use of limb and
intense physiotherapy

7. Distraction osteogenesis
• Defined as biologic process of new bone
formation between surfaces of 2 segments
of bone that are gradually separated by
incremental traction.
• Bone formation follows vector of
distraction.
• Bone is separated by corticotomy.
• Distraction is done @ 1mm/day in four
interval i.e. 0.25mm four times per day.
• When desired length is achieved
consolidation phase follows.

8. Instrumentation
• Primary components- elements
used to correct skeletal
deformities.
Eg- ring, wire, wire fixation bolt
and buckles, pin and pin clamps.
• Secondary component-
element necessary for
assembly of frame.
Eg- rods, plates, support, post,
hinge, washer , sockets, bushing,
bolts and nuts.

9. Rings
• Principle component
• All rings are placed perpendicular to
long axis of bone.
• Made up of stainless steel or carbon
fiber to bear high stress (up to 150 kg)
• Internal diameter measures from 80-
240 mm.
• Function-
Support transfixation of ilizarov, olive
wires and half pins
Builds a fixator frame connecting two or
more rings.
Props up frame’s supplementary parts

10. Rings
• Holes in the ring used for introduction
of threaded rod, a hinge or connector
plate.
• Two half ring can be connected to form
full ring or oval ring.
• Five-eight ring facilitate joint motion
and is commonly deployed near knee
and elbow joint.
• It also facilitate introduction of cross
wires, distinct advantage near these
joint.
• Omega rings is modified five-eight ring
fits deltoid area of shoulder.
• Five-eight ring and omega ring are weak
so needed 3 point fixation to a full ring.

12. Arches
• Larger diameter than
half rings.
• Extra holes for use at the
level of proximal femur
or humerus.
• Does not limit joint
motion.

13. Ilizarov wires
• Stainless steel of critical hardness and
elasticity.
• Types- beaded and non- beaded.
• With trocar point- better directional
hold when drilling cancellous bone
such as metaphysis and epiphysis.
• With bayonet point- better directional
hold when drilling cortical bone such
as diaphysis.

14. Olive wires
• Metallic bead in wire.
• Function-
 Interfragmentary
compression
 Increasing stability of the
construct
 Gradual distraction
 Translation of fragment

15. Bolts
Hexagonal head of 10mm
Threaded shaft of 6mm diameter
Pitch of thread is 1 mm
Length of 10, 16, and 30 mm used.
Have longitudinal holes or slot just
below head to fix wires to the ring or
other components of the frame.
It is use to connect the threaded
socket and bushing through the rings,
for connecting plate, for fastening rods
and half pins through socket aperture.

16. Bolts
To achieve stability wire must be
tensioned, by turning 2 wrenches
simultaneously tension is applied on wire
as it wrap around the bolt.
To obtain optimal stability each wire
should be place on top and bottom of
each ring.
Coupled effect avoids torque of each bone
segment fixed to the ring.
Fixing the wire on the both surface also
prevent wrapping of the ring.

17. Nuts
Diameter- 6 mm
Height- 6, 5 and 3 mm
Pitch of thread- 1mm
So 1/4th turn four times per day is
recommended distraction compression rate.
Turn of nut is used as driving force in Ilizarov
system.
Function-
• Tighten the connecting bolt
• Stabilizes connecting rods
• Driving vector for distraction- compression
movement
• Lock socket and bushing onto threaded rod
• Secure hinge clearance and gap on threaded rod
• Affix pulling wire of distraction device.

18. Buckle
Combine a plate with 2 fixed
threaded rod with two hole
plate held together with 2
nuts.
A longitudinal groove hold a
wire to ring like a slotted bolt.
Allow mechanical derotation
or angular correction.

19. Rods
• 6 mm thick stainless steel rod is main
connector.
• 4 rods at equidistant are used to connect 2
neighboring rings.
• By turning nuts we can fix rods to the frame.
• We can produce desired compression or
distraction needed.
• Rods are machined so that thread causes
1mm translational along its longitudinal axis
with each complete 360* revolution of nut.
• Slotted cannulated rod with 2*2 mm slot and
length of 20 thread, act as pulling device.

20. Plates
• Use to reinforce ring fixator.
• Short plates used as extension of
rings.
• Long plates used to reinforce
large frames during bone
fragment transport.
• Plates with threaded rod use to
support a hinge as well as a
frame.
• Twisted plates used to connect
two components positioned at
right angle to one another.
• Curved plates used to increase
circumference of half ring and
connect two half ring.

21. Telescopic rod
• Hollow rods used as support and
connecting elements of the rings.
• Base is machined to accept 10
mm open end wrench.
• Head have 2 holes-
1st for threaded rod.
2nd for bolt to lock rods.
• Provide stability when long
distance spanning is required
between rings.
• Now hollow tube may contain
slotted window with graduated
metric marking on one side.

22. Support post
• Type- male and female post.
• Male post- threaded projection
fixed with nut.
• Female post- threaded hole
fixed with bolt.
• Function-
Third wire can be connected to
post.
Can also work as hinge.
Can be connected to other part of
apparatus to provide additional
stability.
Wire can be tensioned

23. Hinge post
• Have supporting base with two flat
surface matching the standard 10
mm wrench
• Important function is correction of
angulation.
• Type – male and female hinge post

24. Threaded socket & bushing
• Threaded rod interconnect threaded
rods.
• It stabilize two rings together.
• Hole on side, can be used for
threaded rod in horizontal direction.
• Bushing is 12 mm long spacer with
smooth longitudinal hole that
provide free motion of threaded rod
length wise.

25. Washer
• Washer use to raise a wire
fixation bolt to the wire that
does not sit directly on ring.
• Types- simple, slotted and
conical
• Slotted washer allow wire
fixation on one side in special
circumstances.
• Conical washer act as swivel for
connecting rings or plates which
are not parallel.

26. Tensioners
• Used to tension wire to an exact force, thus
improvising stability for entire bone frame
construct.
• Types- dynamometric and standard wire
tensioner.
• Wire should be tensioned from 50-130 kg.
• Amount of tensioning depends upon-
 Weight of patient
 Local bone quality
 Treatment plan
 Local frame construct
• Standard wire tensioner not calibrated and
cumbersome to use.

27. Dynamometer
Parts of dynamometer-
 Handle for applying pressure
 Dynamometer scale
 Fixed jaw
 Mobile jaw
Using of dynamometer-
 Rotate handle anti clockwise until wire get
inside
 Engage the fix jaw to the ring
 Rotate handle clockwise until desired
tension is achived.
 Tighten the nut at desired tension.
 Rotate handle anti clockwise to loosen the
wire.

28. Assembly of circular fixator
Major considerations-
• Stability of fixation of the frame to the bone.
• The prevention of gross bone fragment motion.
• Ability to manipulate bone and to perform necessary fragment movement such as
straightening, bending, distraction, compression, rotation and combination of these
movement.
Construction of frame can be done in advance or during surgery.
Important aspect of frame assembly-
• Ring positioning
• Ring inclination
• Ring orientation
• Ring level
• Spacing between skin and ring

29. Ring positioning
Rings are main component
Types-
 Main proximal frame supporting ring- it bears weight of
entire construction. Located 3-5 cm away from joint.
 Stabilizing frame supporting ring- may be stationary or
moveable. Located 3-5 cm away from joint.
 Pushing pulling ring- moveable ring used for compression
or distraction. Located 3-5 cm distal to fracture-
osteotomy-nonunion site.
 Reference ring- used as reference for supporting rings or
distraction-compression rings. It corresponds to apex of
bone angulation.
 Connecting rings- used for application of special forces in
transverse or oblique direction for correcting deformities.

30. Ring inclination
Ring is positioned around the
anatomic bony center of fixation.
Inclination of ring is perpendicular to
bone segment fragment.
Minor inclination could produce large
derangement at the distal end.

31. Ring orientation
Rings at different level and in
different inclination are oriented so
that the connections of half rings
must aligned on same straight line.
After correction rings arrive in
parallel position to each other and
bone fragments in good alignment,
however half rings connections are
rotated location.

32. Spacing between skin and ring
At the narrowest gap space of at
least 3cm should be maintained
between inner curve of ring and skin.
Achieved in 3 ways-
• Limb measured in 2 plane and
largest diameter is considered.
Add 6cm to this diameter which
provide you size of ring.
• Attach most anticipated size and
seek a space of 3cm.
• Use plastic template.

33. Basic principles of operative technique
• Exit and entrance sites must be pre
determined. It must be located 1.5- 2 cm
from neurovascular bundle. Wire must be
introduced slowly and on the side
containing critical structure. Skin must be
supported by finger pressure to secure exact
point of wire penetration. In planned
distraction skin should be pushed towards
site of corticotomy.

34. • Loosely attached slotted fixation bolt at
entrance site guide K-wire and prevent
deflection during introduction and drilling.
• One wire one hole to prevent incorrect
positioning.
• Push wire manually to bone before
drilling.

35. Prior to passing wire each muscle
should be stretched maximally to its
functional length to prevent
contracture.

36. Wire is drilled through both
the cortex, passing through
bony canal and bone marrow
transmedullary.

37. For stability 2 wire criss crossing at an
angle as close to 90* are required. (if
angle ⩽ 30*- chance of side to side
ring displacement; If angle 30-45*-
chance of ring sheering movement.)

38. • Ring should be well stabilized to bone
for that wire should not be brought
down to the ring, ring should be
brought upto the wire using washer,
support, post or hinges.
• When greater load is required, 3 wire
can be transfixed to one ring.

39. When wire is close to ring
connector, it bear small axial load
and when it is away from ring
connector it bears greater axial load,
developing larger diameter hole in
bone.

40. Stabilize ring through wire with
stoppers and offsite wire, which is
fasten to ring by support

41. Adequate tension is paramount importance.
Inadequate tensioning adversely effect
development.
• Range of wire tensioning- 50- 130kg.
• Tensioning strength of wire on half ring- 50-70
kg.
• Tensioning strength of offsite wire- 50-80 kg.
• Tensioning strength of single wire on ring-
100kg.
• Tensioning strength of 2-3 wires on ring in
young patient – 110 kg each ring.
• Tensioning strength of 2-3 wires on ring in
adult patient – 120-130 kg each ring
• Tensioning strength of wire with olive stopper-
100-110 kg.

42. Position of wire in relation to
hole and type of fixation part
appropriate to each situation.

43. Technique of wire bending- bending wire around outer wall of
ring prevent scratch or puncture of physician or patient skin.

44. Corticotomy
• It is low energy osteotomy of
cortex preserving local blood
supply to both periosteum and
medullary canal.
• Types- monofocal & bifocal
• Ideal corticotomy-
 Long oblique
 Metaphyseal in situation
 No comminution
 No disruption of endosteal &
periosteal blood supply
 Fixed in anatomical position with
gap <2mm

45. Stages of Ilizarov treatment technique
1. Fixator application and following latency period of 4-7 days.
2. Period of distraction/compression(1-4 months depending on case).
3. Period of immobility and fixation of bone position (usually twice
period of distraction /compression).
4. Discontinuation of distraction-compression and frame dynamization
15 to 20 days prior to fixator removal.
5. Period of immobilization with a cast or brace.

46. Immediate (1st and 2nd day)-
Limb elevation, protection of wire
skin interface, non circular
bandage for incision, sterile
dressing.
1st week (after 2 days)-
Sterile dressing, active and passive
immobilization, partial weight
bearing, physiotherapy.
After 1 week till removal-
Check for wire tension, look for
wire site infection, nuts and clamp
tightness, dynamization
Post operative management

47. Dynamization of apparatus
When dynamization is done?
Satisfactory appearance of regenerate
calcification, complete recanalization
and formation of cortex is seen.
What to do for dynamization?
Loosen the nuts at sides of connecting
rod.
Purpose of dynamization?
Allow static fixator to distribute weight
across fracture site, as a result elasticity
of callous decreases, bone stiffens and
strength increases. Thus axial
dynamization helps to restore cortical
contact and produce stable fracture
pattern with inherent mechanical
support.

48. Removal of apparatus
• A month too late is better than a day too early.
• X-ray must show at least 3 cortices ossified out of four.
• Before removing frame, patient may be asked to use limb in a
functional manner.
• Before cutting wires, tension of wires must be removed.

49. Safe zones in tibia
The diagram demonstrates the wide
medial and lateral access to the tibia that
is available for pin insertion.
Zone 1- 13-15 mm distal to the articular
surface
Zone 2- 7-8 cm distal to the knee joint
Zone 3- 12 cm distal to the knee joint
Zone 4- Just inferior to the midpoint
between the knee and ankle joints
Zone 5- 12 cm from the ankle joint
Zone 6- 2 cm proximal to ankle joint

50. Zone 1
1. First reference wire inserted for fine wire
fixation i.e. in the transcondylar
transverse plane anterior to the fibula
(13-15 mm distal to the articular surface).
2. Optimum fixation is then obtained using
two half pins placed anteriorly. The
medial one can be used to also fix the
fibula head.
3. Alternatively a 2-3mm smooth pin can be
used to transfix the proximal tibio-fibular
joint, for example in tibial lengthening.
This is inserted by palpating and
protecting the common peroneal nerve
with the thumb and holding the soft
tissues posteriorly, while the knee is
flexed and the pin is driven through the
fibular head. The pin is directed
anteriorly, medially and slightly distally
toward the closest available ring.

51. Zone 2
The half pin is inserted
perpendicular to the
subcutaneous border of the tibia
on the medial aspect. The fine
wire is inserted slightly obliquely
to the transverse plane of the tibia
to engage it in its widest portion.

52. Zone 3
Tibial fixation is with a
medial-oblique wire and a
half pin inserted into the
medial aspect of the tibia
perpendicular to the medial
aspect.

53. Zone 4
The insertion of the wire and
half pin at this level is similar
to that described for Cut Two
and Three.

54. Zone 5
The wire at this level is placed
almost parallel to the frontal
plane of the tibia. The half pin
is inserted again on the
medial aspect, slightly
obliquely to the wire as
shown in the diagram.

55. Zone 6
A distal tibial reference wire is the initial fixation
used, with a direct medial to lateral wire.
The fibular stabilization takes place through a
lateral oblique wire directed from posterolateral
to anteromedial.
Additional stabilisation can be achieved with a
wire directed form anterolateral to
posteromedial, anterior to the neurovascular
bundle.
Alternatively a stabilizing half pin can be inserted
anteriorly, lateral to the tibialis anterior tendon.
This should be done with care using a limited
open technique through a small incision, which is
dilated with an artery forceps. The forceps is used
to displace the soft tissues and therefore protect
the anterior neurovascular bundle, allowing safe
pre-drilling and insertion of a 5 or 6mm half pin.

59. Indication
• Fracture nonunion
• Limb lengthening procedures
• Long bone deformity correction
• Open fractures
• Malunion
• Correction of joint contractures
• Correction of congenital
deformity (hemimelia, club foot,
club hand, congenital
pseudoarthrosis)
• Reconstruction of bone defect
• Vascular insufficiency (TOA,
Berger’s disease)

60. Complication
• Early complication-
• Vascular complications
• Neurological complications
• Comminuted fracture of
osteotomized bone
• Local skin tightness
• Psychologic incompatibility
• Late complication-
• Pin site infection
• Pain at corticotomy site and during lengthening
• Soft tissue contractures and joint stiffness
• Osteoporosis
• Reflex sympathetic dystrophy
• Progression of angular deformity or creation of
new one after fixator removal.
• Limb swelling
• Nonunion or premature consolidation at
lengthening site
• Compartment syndrome
• Joint subluxation

61. Advantage
• Minimally invasive
• Relatively easy application
• Allows deformity to be corrected in 3 dimensions (axial, angular &
translational)
• Patient is mobile through out course of treatment
• Early physiotherapy prevents joint stiffness and contractures.
• Bone grafting in unnecessary
• Simple hard ware removal

62. Disadvantage
• Mechanical
• Distraction of fracture site
• Pin bone interface failure
• Bulky frame
• Refracture
• Longer duration of surgery
• Instability of apparatus
• Breaking or loosening of wires
• Long learning curve
• Biological
• Pin tract infection
• Neurovascular injury
• Tethering of muscle
• Soft tissue contracture
• Pain
• Oedema
• Joint stiffness
• Osteolysis around wires

63. Recent advances
Taylor spatial frame
• 2 carbon rings connected by 6
telescopic linkage rods called strut.
• Strut have virtual hinge joint at
both the ends.
• Can be applied with ilizarov and
other fixator system.
• It provide universal and 3
dimensional bone movement, so
that path of reduction or
correction can easily be modified.

64. Recent advances
Hybrid fixator-
• Proximal ring connected to 2 or 3
pins distally with connecting rods.
• Mostly for proximal tibia fracture

65. Combined compression-distraction technique

66. Bone transport technique

67. Ilizarov to prevent
contracture

68. Correction of ankle joint fused in equinus position

69. Correction of club hand

70. Non union

72. Deformity correction

74. Treating neglected club foot with Ilizarov

75. Treatment of open fracture and bone loss

76. Difficult fractures

80. Congenital pseudoarthrosis

82. Limb lengthening

84. Infected nonunion

85. Berger’s disease

86. Thank you
You can be taller even after 18 yrs with Ilizarov