Distraction osteogenesis is a method of producing unlimited quantities of living bone directly from a special osteotomy by controlled mechanical distraction. The new bone spontaneously bridges the gap and rapidly remodels to a normal macrostructure for the local bone.

1. Distractation
Histiogenesis

2. Distraction histiogenesis
Refers to the use of a distracting force to
stimulate the formation of
 Skin
 Muscle
 Nerve
 Vascular structures
 Connective tissue
 Bone (distraction osteogenesis)
Distracting histiogenesis: principles and indications J Am Acad orthop surg 1996

3.  Distraction osteogenesis is a method of
producing unlimited quantities of living
bone directly from a special osteotomy by
controlled mechanical distraction. The new
bone spontaneously bridges the gap and
rapidly remodels to a normal
macrostructure for the local bone
Ilizrov GA. The tension stress effect on the genesis and growth of tissues.
Clin orthop 1989

4. Callotasis
Limb lengthening by callus distraction. J Pediatr Orthop 1987

5. Chondrodiastasis
Limb lengthening by distraction of the epiphyseal plate. J Bone Joint Surg 1986

6. Clinical applications
 Limb length inequality
 Angular deformities
 Segmental bone loss
 Non unions
 Contractures

7. Components of distraction
histiogenesis
 External fixator
 Corticotomy or osteotomy of the bone
 Post operative period
 Latency phase
 Distraction phase
 Consolidation phase
Distracting histiogenesis:principles and indications J Am Acad orthop surg 1996

9. External Fixator
The use of an external fixator
provides stability and applies the
forces that produce lengthening,
angular correction, or
transportation of bone
Distraction histiogenesis:principles and indications J Am Acad orthop Surg 1996

10. Safe zones
Ant tibial a,v
Deep peroneal N
Post tibial A,V
Tibial N

11. Ant tibial a,v
Deep peroneal N
Post tibial A,V
Tibial N

12. Common peroneal N
Popliteal A,V
Tibial N

13. Popliteal A,V
Tibial N
Common peroneal N

14. Popliteal A,V
Sciatic N

15. Femoral A,V
Sciatic N
Ischial tuberosity

16. Various frame designs

17. Ilizarov fixator
 Correction of deformities with angulation
or rotation

18. Hybrid fixator
 For areas where it is difficult to insert
trans-osseous wires

19. Monolateral fixator
 Easier for the surgeon to apply and for the
patient to tolerate

20. Lengthening over nail
 Reduced time in external fixation
 More rapid return of knee motion

21. Mechanical Characteristics of the
fixator that affect osteogenesis
 Wire diameter (1.8mm > 1.5mm)
 Orientation of the wires ( 90 > 45 )
 Tension on each wire
 Number of wires used
Biomechanics of the ilizarov fixator for fracture fixation. Clin. Orthop. 1992

22. Mechanical characteristics (cont)
 Diameter of the rings ( smaller ring )
 Number of rings
 Spacing between the rings
 Gross instability of the frame
• Non union
• Premature consolidation
Biomechanics of the ilizarov fixator for fracture fixation. Clin. Orthop. 1992

23. Corticotomy
 Corticotomy is a low-energy osteotomy of
the cortex, preserving the local blood
supply to both periosteum and medullary
canal
Ilizrov GA. The tension stress effect on the genesis and growth of tissues.
Clin orthop 1989

29. Debastiani method

32. Larger surface area
Improved blood supply
Larger cancellous component

33. Postoperative period
Latency phase
 It refers to the period from frame application and
corticotomy to the initiation of lengthening or
angular correction
 5-7 days
 Fibrin-enclosed hematoma and inflammatory cell
infiltration fill the gap at the corticomy site
 Enhances the formation of bone

34. Postoperative period
Distraction phase
 The distraction phase involves active
lengthening, transport or angular correction
through frequent small steps.
 This results in the formation of new bone or
regenerate in longitudinal columns along the
plane of distraction.
 Rate – 1 mm/day
 Rhythm – 4 times/day

35. Postoperative period
Consolidation Phase
 The consolidation phase begins after the desired
correction has been achieved.
 This period allows for maturation of the
regenerate and corticalization before fixator
removal.
 Usually twice the distraction phase

36. Histology
Bone

38. Week 2

40. Week 3

42. Consolidation

46. The response of muscle to limb
lengthening
 Certain lengthening regimes led to an increase
in the number of sarcomeres per myofibril,
showing that new muscle tissue was created.
myofibrillogenesis with traction neogenesis of
skeletal muscle during limb lengthening does
exist and occurs mainly near the myotendinous
junction.
The response of muscle to limb lengthening J Bone Joint Surg 1995
Ultrastructural studies on myofibrillogenesis and neogenesis of skeletal
Muscles after prolonged traction in rabbits.Histol Histopathol 1996

47.  Muscle responds initially by stretching without
cell proliferation, followed by a cellular response.
 First, there is a recruitment of satellite cells.
These undergo neohistogenesis and contribute
to the growth in length of new muscle.
 Second, there is an addition of sarcomeres to
existing muscle cells.

48.  Overall soft tissue (primarily muscle) tolerance of
gradual lengthening seems to be limited to 15%
to 20% of the original length of the lower limb
segment, and lengthenings greater than this
amount are associated with a substantially
higher incidence of complications.
Attempted limb lengthenings beyond 20% of the initial bone length.
Results and complications. J Pediatr Orthop 2000

49. Histology muscle

51. Nerves
 Ilizarov described histologic evidence of
development and growth of nerves,
including axon elongation and Schwann
cell lengthening and envelopment around
the lengthened axon.
 Other studies, however indicate a more
deleterious effect.

52. nerves

54.  It seems logical that the likelihood of nerve injury
would be related to the amount or percentage of
lengthening.
 However studies have not demonstrated an
association between the number of centimeters
of lengthening and occurrence of nerve injury.
Nerve lesions associated with limb lengthening. J Bone Joint Surg 2003
Attempted limb lengthenings beyond 20% of the initial bone length.
Results and complications. J Pediatr Orthop 2000

55. Blood Vessels
 Blood vessels can adapt to continuous tension
during callus distraction without suffering
structural damage.
 Fewer degenerative changes are found in blood
vessels than in nerves, muscles, and tendons.
Behavior of Blood Vessels During Lower-Leg Lengthening Using the Ilizarov
Method J Pediatr Orthop 1999

56. Mechanisms
 Due to the sliding of the vessels within their
surrounding tissue, the traction should at first
lead only to a straightening of the curved blood
vessels during distraction.
 The high viscoelastic properties of blood vessels
enable them to be lengthened considerably
without suffering structural damage.
 The small distraction steps leading to
histoneogenesis in the vascular wall.
Behavior of Blood Vessels During Lower-Leg Lengthening Using the Ilizarov
Method. J Pediatr Orthop 1999

57.  Thus vascular tissue is the least limiting
factor concerning distraction speed,
distraction rhythm, and distraction length
during callus distraction
Behavior of Blood Vessels During Lower-Leg Lengthening Using the Ilizarov
Method J Pediatr Orthop 1999

58. Effect of limb lengthening on
articular cartilage
 Stanitski noted gross cartilage fibrillation
and loss of proteoglycan staining in the
knees of dogs that underwent 30%
femoral lengthening.
 The reactive forces in the hip and the knee
measured during an gradual femoral
lengthening were shown to increase
linearly with continued distraction.
Joint reaction forces during femoral lengthening. Clin. Orthop. 1994
The effect of limb lengthening on articular cartilage. Clin orthop. 1994

59.  Extending the apparatus across the knee
had a protective effect on cartilage by
preventing joint compression during
lengthening.
The effect of femoral lengthening on knee articular cartilage:
role of apparatus extension across the joint. J Pediatr orthop 1996

61. Blood flow
 llizarov hypothesized that distraction
osteogenesis increases blood flow to the
lengthened bone. He hypothesized that
these increases in flow could potentiate
healing of osteomyelitis or of distant
hypovascular nonunions.
Ilizarov,GA :Personal communication, 1988

62.  (1) Does distraction osteogenesis increase
blood flow (amplitude) beyond the normal
increase seen with fracture healing?
 (2) Can the hyperemic response be prolonged
(temporally) by the distraction itself?
 (3) Does the hyperemia affect distant sites
(spatially) in the same bone?

63. Blood flow
Temporal and spatial increases in blood flow during distraction osteogenesis.
Clin. Orthop 1994

64.  The spatial increases in blood flow extend to the
distal half of the tibia, distant from the distraction
zone.
 In conclusion, using quantitative Tc scintigraphy
to measure relative regional blood flow, the
distraction osteogenesis model demonstrated
massive increases in local and distant blood
flow to the lengthened tibia that persisted for four
months.
Temporal and spatial increases in blood flow during distraction osteogenesis.
Clin. Orthop 1994

65. Imaging
 Plain radiography
• Immediate postoperative AP and lateral
radiographs to check the corticotomy for
completeness.
• Central radioleucent zone
• >8mm disraction is too fast
• <2mm distraction is too slow
• Increased radiation dose
• Upto 3 weeks

67. Imaging (cont)
 Ultrasound
• Early detection and assessment of newly
formed bone
• Detection of cysts or ossification defects
with possible therapeutic aspiration
• Cannot quantify bone regenerate
Imaging in bone lengthening. A review Clin Orthop 1994

69. Dual energy bone
densitometery
Quantify bone
Identify
cortication

70. Methods of assessing new bone formation during limb lengthening
J bone joint surg 1993

71. Thank
you