The Ilizarov apparatus is a type of external fixation used in orthopedic surgery to lengthen or reshape limb bones; as a limb-sparing technique to treat complex and/or open bone fractures; and in cases of infected nonunions of bones that are not amenable with other techniques. It is named after the orthopedic surgeon Gavriil Abramovich Ilizarov from the Soviet Union, who pioneered the technique.

1. IlIzarov fIxator
DR.SAYF ALDEEN HUSSAMDR.SAYF ALDEEN HUSSAM
ORTHOPEDIC DEPARTMENTORTHOPEDIC DEPARTMENT

2. Ilizarov apparatusIlizarov apparatus
 It is an external fixatorIt is an external fixator
Consisting of parts which canConsisting of parts which can
be assembled in unlimitedbe assembled in unlimited
configurationsconfigurations
 Can overcome deformities byCan overcome deformities by
providing :providing :
●●CompressionCompression
●● DistractionDistraction
●● AngulationsAngulations
●● RotationRotation
 At the same time limb is madeAt the same time limb is made
stable enough to permit weightstable enough to permit weight
bearingbearing

3. Principles of IlizarovPrinciples of Ilizarov
 Law of tension stressLaw of tension stress
 Distraction osteogenesisDistraction osteogenesis
 Mechanical induction of new bone formationMechanical induction of new bone formation
 NeovascularizationNeovascularization
 Stimulation of biosynthetic activityStimulation of biosynthetic activity
 Activation and recruitment of osteoprogenitor cellsActivation and recruitment of osteoprogenitor cells
 Intramembranous ossificationIntramembranous ossification

4. Law of tension-stressLaw of tension-stress
 Ilizarov developed the law of tension-stress, whichIlizarov developed the law of tension-stress, which
describes the process of new bone and soft tissuedescribes the process of new bone and soft tissue
regeneration under the effect of tension-stress caused byregeneration under the effect of tension-stress caused by
slow and gradual distractionslow and gradual distraction

5. Distraction osteogenesisDistraction osteogenesis
 is a surgical process used to reconstruct skeletalis a surgical process used to reconstruct skeletal
deformities and lengthen the long bones of the body. Adeformities and lengthen the long bones of the body. A
corticotomy is used to fracture the bone into twocorticotomy is used to fracture the bone into two
segments , and the two bone ends of the bone aresegments , and the two bone ends of the bone are
gradually moved apart during the distraction phase,gradually moved apart during the distraction phase,
allowing new bone to form in the gapallowing new bone to form in the gap

6. Indications of IllizarovIndications of Illizarov
 Indications In traumatologyIndications In traumatology::
1-Comminuted fractures1-Comminuted fractures
2-Intra-articular fractures2-Intra-articular fractures
3-Open fractures3-Open fractures
4-Non-union4-Non-union
5- Infection (osteomyelitis)5- Infection (osteomyelitis)

7. Indications of IllizarovIndications of Illizarov
Indications In orthopedics:Indications In orthopedics:
 Elongations ( therapeutic and cosmetic)Elongations ( therapeutic and cosmetic)
 Deformity correction (congenital or acquired)Deformity correction (congenital or acquired)
 ArthrodesisArthrodesis
 arthrodiastasisarthrodiastasis

8. ComponentsComponents
 Primary componentsPrimary components – That join skeleton to– That join skeleton to
finished frame:finished frame:
 Transosseous wiresTransosseous wires
 RingsRings
 Wire fixaion boltsWire fixaion bolts

9. ComponentsComponents
 Secondary componentsSecondary components – Used to connect the– Used to connect the
primary components to construct frame :primary components to construct frame :
 Threaded and telescopic rodsThreaded and telescopic rods
 Connecting platesConnecting plates
 Hinges and postsHinges and posts
 Nuts and boltsNuts and bolts

10. Instruments used in ilizarovInstruments used in ilizarov

11. Wire fixation boltWire fixation bolt
 CannulatedCannulated
 Cannulated withCannulated with
threaded headthreaded head
 SlottedSlotted

12. Wire fixation buckleWire fixation buckle
 Allows mechanicalAllows mechanical
derotation or angularderotation or angular
correctionscorrections

13. Telescopic rodTelescopic rod
 Provide stability whenProvide stability when
long distance must belong distance must be
spanned betweenspanned between
ringsrings
 Allows lengtheningAllows lengthening

14. Hinge ( Male and female)Hinge ( Male and female)

15. Threaded socketThreaded socket
 Interconnect threadedInterconnect threaded
rodsrods
 Stabilize two ringsStabilize two rings
togethertogether

16. WiresWires
 Trocar- Cancellous boneTrocar- Cancellous bone
 Bayonet – Cortical boneBayonet – Cortical bone
 Olive wiresOlive wires

17. Dynamometric wire tensionerDynamometric wire tensioner

18. Biomechanics of wiresBiomechanics of wires
 Tensioned wires (1.5 and 1.8) achieve rigidityTensioned wires (1.5 and 1.8) achieve rigidity
equal to half pins.equal to half pins.
 Should not exceed 50% of yield strength of wireShould not exceed 50% of yield strength of wire
 Maximum limitsMaximum limits
 90 kg for 1.5 mm wire90 kg for 1.5 mm wire
 130 kg for 1.8 mm wire130 kg for 1.8 mm wire

19. Biomechanics of wiresBiomechanics of wires
cont.cont.
 Number of wiresNumber of wires
 More the number/ring more stable isMore the number/ring more stable is
the fixatorthe fixator
 Wire spreadWire spread
 90/90 ideal- Anatomical constraints90/90 ideal- Anatomical constraints
 45/135 configuration less stable in45/135 configuration less stable in
flexionflexion
 Off centeringOff centering
 Higher axial stiffness and lowerHigher axial stiffness and lower
torsional stiffness.torsional stiffness.

20. Biomechanics of ringsBiomechanics of rings
 Stability of assembly depend on:Stability of assembly depend on:
 NumberNumber
 SizeSize
 Position of ringsPosition of rings
 Closer the middle two rings to the fracture moreCloser the middle two rings to the fracture more
stable is the configurationstable is the configuration

21. Biomechanics of ringsBiomechanics of rings
cont.cont.
 Only torsional stiffness increased with increasingOnly torsional stiffness increased with increasing
ring diameterring diameter
 Ilizarov recommends minimum of 3 cmIlizarov recommends minimum of 3 cm
or 2 finger breadth between skin and inner ringor 2 finger breadth between skin and inner ring
to accommodate edema as blood flow increasesto accommodate edema as blood flow increases

22. Factors aFFectingFactors aFFecting
stability oF Fixatorstability oF Fixator
 I Apparatus related (Extrinsic) factorsI Apparatus related (Extrinsic) factors
 Spread between crossing wires approaching 90/90Spread between crossing wires approaching 90/90
 Increase in wire diameter and tensionIncrease in wire diameter and tension
 Increase in number of ringsIncrease in number of rings
 Decreased ring size (wire span distance of 2-3cmDecreased ring size (wire span distance of 2-3cm
around the limb)around the limb)
 Close positioning of center rings to fracture orClose positioning of center rings to fracture or
nonunion site.nonunion site.
 Use of olive wires.Use of olive wires.

23. Factors aFFectingFactors aFFecting
stability oF Fixatorstability oF Fixator
 II. Intrinsic factors-II. Intrinsic factors-
 Area of tissue contact between the bone ends.Area of tissue contact between the bone ends.
 Length of gap between bone ends.Length of gap between bone ends.
 Tension of soft tissue surrounding boneTension of soft tissue surrounding bone
 Mechanical configuration and interlock betweenMechanical configuration and interlock between
bone endsbone ends

24. removal oF apparatusremoval oF apparatus
 A month too late is better than a day too early.A month too late is better than a day too early.
 The x-rays must show at least three cortices; i.e. out of fourThe x-rays must show at least three cortices; i.e. out of four
cortices (anterior, posterior, medial and lateral) in AP &cortices (anterior, posterior, medial and lateral) in AP &
lateral projections, at least three should be fully ossified,lateral projections, at least three should be fully ossified,
with a sharp outline of the cortical bone.with a sharp outline of the cortical bone.
 Finally before actually removing the frame the patient mayFinally before actually removing the frame the patient may
be administered a stress test‘ and asked to use the limb in abe administered a stress test‘ and asked to use the limb in a
functional manner ( weight bearing for the lower limb andfunctional manner ( weight bearing for the lower limb and
functional activities for the upper limb).functional activities for the upper limb).
If the patient is able to do this the frame can then beIf the patient is able to do this the frame can then be
removed with confidence.removed with confidence.

25. complicationscomplications
1-muscle contractures1-muscle contractures
2-joint stiffness or subluxation2-joint stiffness or subluxation
3-axial deviation3-axial deviation
4-NV injury4-NV injury
5-premature consolidation5-premature consolidation
6-delayed consolidation6-delayed consolidation
7-wire site problems7-wire site problems
8-refracture 8-refracture