ILIZAROV RING FIXATOR: Basic concepts, components, application, uses, challenges

1. ILIZAROV RING FIXATOR: BASICS
DR. D. P. SWAMI
AIIMS
DPS

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 DPS

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)DPS

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

5. PrincipleofIlizarov
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 DPS

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 DPS

7. Distractionosteogenesis
• 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.
DPS

8. Instrumentation
• Primary components-
elementsused to correct
skeletaldeformities.
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. DPS

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,
olivewires and half pins
Builds a fixator frame connecting two
or more rings.
Props up frame’s supplementary parts
DPS

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.
DPS

11. DPS

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

13. Ilizarovwires
• 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.
DPS

14. Olivewires
• Metallic bead in wire.
• Function-
 Interfragmentar
y compression
 Increasing stability of
the construct
 Gradual distraction
 Translation of fragment
DPS

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 DPS

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.
DPS

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 rodDPS

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.
DPS

19. Rods
• 6 mm thick stainless steel rod is
mainconnector.
• 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.
DPS

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.
DPS

21. Telescopicrod
• 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
lon
gdistance spanning is
requiredbetween
rings.• Now hollow tube may
containslotted window with
graduated metric
marking on one side.
DPS

22. Supportpost
• Type- male and female post.
• Male post- threaded
projection fixed with nut.
• Female
post-
fixed with bolt.
• Function-
threaded
hol
e
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
DPS

23. Hingepost
• 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
DPS

24. Threadedsocket&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.
DPS

25. Washer
• Washe
r
fixatio
n
use to raise a
bolt to the
wire
wir
e
thatdoes not sit directly on
ring.• Types
-
conic
al
• Slotte
d
simple, slotted
and
washer allow
wirefixation on one side in special
circumstances.
• Conical washer act as swivel
for connecting rings or plates
which are not parallel.
DPS

26. Tensioners
• Used to tension wire to an exact force, thus
improvising stability for entire bone frame
construct.
wir
e
• Types- dynamometric and
standard 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.
DPS

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.
DPS

28. Assemblyofcircularfixator
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
of
thes
e
straightening, bending, distraction, compression, rotation and
combination 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
DPS

29. Ringpositioning
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
compressionor 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. DPS

30. Ringinclination
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. DPS

31. Ringorientation
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.
DPS

32. Spacingbetweenskinandring
At the narrowest gap space of at
least 3cm should be
maintainedbetween 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.
DPS

33. Basicprinciplesofoperativetechnique
• 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.
DPS

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.
DPS

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

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

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.)
DPS

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.
DPS

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.
DPS

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

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.
• Tensioningstrength of 2-3 wires on ring in
young patient – 110 kg each ring.
• Tensioningstrength of 2-3 wires on ring in
adult patient – 120-130 kg each ring
• Tensioning strength of wire with olive
stopper- 100-110 kg.
DPS

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

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

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
DPS

45. StagesofIlizarovtreatmenttechnique
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.
DPS

46. Immediate (1st and 2nd day)-
Limb elevation, protection of
wireskin
interface
,
non
bandage for
incision,
circula
r
steril
e
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
Postoperativemanagement
DPS

47. Dynamizationofapparatus
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
with inheren
t
mechanic
al
pattern
support
.
DPS

48. Removalofapparatus
• 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.
DPS

49. Safezonesintibia
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 jointZone 4- Just inferior to the
midpointbetween the knee and ankle
joints Zone 5- 12 cm from the
ankle joint Zone 6- 2 cm
proximal to ankle joint
DPS

50. Zone1
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
DPS

51. Zone2
The
hal
f
perpendicula
r
pin is
inserted
to thesubcutaneous 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.
DPS

52. Zone3
Tibial
fixatio
n
medial-
oblique
is with
a wire
and
a
half pin inserted into the
medial aspect of the tibia
perpendicular to the medial
aspect.
DPS

53. Zone4
The insertion of the wire
and half pin at this level is
similar to that described for
Cut Two and Three.
DPS

54. Zone5
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.
DPS

55. Zone6
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.
DPS

56. DPS

57. DPS

58. DPS

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, DPS

60. Complication
• 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
• Early complication-
• Vascular complications
• Neurological
complications
• Comminuted fracture
of osteotomized bone
• Local skin tightness
• Psychologic
incompatibility
consolidation at
DPS

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
DPS

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 wi
DPS

63. Recentadvances
Taylor spatial
frame• 2 carbon rings connected by
6telescopic 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. DPS

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

65. Combinedcompression-distractiontechnique
DPS

66. Bone transporttechnique
DPS

67. Ilizarov toprevent
contracture
DPS

68. Correctionofanklejointfusedinequinusposition
DPS

69. Correctionofclubhand
DPS

70. Nonunion
DPS

71. DPS

72. Deformitycorrection
DPS

73. DPS

74. TreatingneglectedclubfootwithIlizarov
DPS

75. Treatmentofopenfractureandboneloss
DPS

76. Difficultfractures
DPS

77. DPS

78. DPS

79. DPS

80. Congenitalpseudoarthrosis
DPS

81. DPS

82. Limblengthening
DPS

83. DPS

84. Infectednonunion
DPS