Internal fixation is an important step in not only treatment of trauma but also various aspects of oral and maxillofacial surgery. This ppt summarizes the principles and evolution of plating system

1. PRINCIPLES OF INTERNAL
FIXATION
Moderated By: Dr Aviral Verma
Presented By: Gauri Bargoti

2. INTRODUCTION
• LIFE IS MOVEMENT, MOVEMENT IS LIFE: This should be the guiding principle of
fracture care.
• Full, active, pain-free mobilization results in a rapid return of normal blood supply to
both the bone and the soft tissues.
• A satisfactory internal fixation is achieved only when external immobilization is
superfluous and when full, active, pain-free mobilization of muscles and joints is
possible. This is the AO's main objective and is best achieved by stable internal
fixation during the bone healing process.

3. HISTORY OF FRACTURE TREATMENT
Icart: Ligature wire on humeral
Hansmann in 1886: Metal plate with
transcutaneous screws
Albert Lambotte: Coined term internal fixation
and screw, plate along with armamentarium
Sherman: Improved Lambotte armamentarium
Luhr: Modified principles of compression

4. PRINCIPLES OF FIXATION : AO
Anatomical
Reduction
Stable
Internal
fixation
Preservation
Of blood
supply to
bone and
tissue
Early active
pain free
stabilization

5. INDICATION OF INTERNAL FIXATION

6. TECHNICAL CONSIDERATION IN
INTERNAL FIXATION
STABILITY
FORCE, STRAIN,STRESS
TYPE OF LOAD: STATIC, DYANAMIC

8. BONE HEALING DUE TO LOADS
CONTACT HEALING: OVERLOADED CONTACT AREA
CONTACT HEALING: INTACT CONTACT AREA
FRACTURE SURFACE RESORPTION: INDIRECT HEALING
DELAYED HEALING

12. BIOMECHANICS OF MANDIBLE
Trajectory of mandible Line of zero force
Implication of biomechanic in
internal fixation

13. INDICATIONS FOR INTERNAL
FIXATION
Multiple, comminuted #
Panfacial #
Defect #
Wide open #
Dislocated midface #
Atrophic mandible #
Infected # ; un-cooperative pt

14. # FIXATION: TYPES

16. ONE VS TWO POINT FIXATION

17. Principles of surgical stabilization
COMPRESSION
SPLINTING
DIFFER ON THE DEGREE OF STABILITY PROVIDED

18. SPLINTING
CONNECTS MORE OR LESS STIFF DEVICE TO FRACTURED BONE
REDUCES THE FRACTURED SEGMENTS MOBILITY BUT DON’T RESTRICT IT
COMPLETELY
Internal Splints: Surgical intervention required
External Splints: No surgical intervention required

20. EXTERNAL SPLINTS

27. COMPRESSION: THE PRIMARY AIM OF INTER-FRAGMENTAL
COMPRESSION IS THE PRODUCTION OF LARGE FRICTIONAL FORCE
Mechanism
Produce pre-load
in # segment
Increase intra-
fragment friction
Types
of
compression
Static
Dynamic

28. PERREN EXPERIMENT:S (1969A) WERE ABLE TO SHOW
CONCLUSIVELY THAT BONE WILL TOLERATE A STATIC PRESSURE OF MORE
THAN 300 KG/ CM2 WITHOUT BECOMING NECROTIC
The plate is fitted with strain gauges
accurate to with in 1.5 kg in the range
of 300 kg
The plate is prestressed using a tension
device. The tension in the plate is
directly proportional to the com pressi
on at the fracture s

29. The STATIC COMPRESSiON plate is
attached to the tibia of a sheep,
and the leads from the strain
gauges are brought out
subcutaneously to the trochanteric
area
The standard curve plotted from dozens
of measurements indicates a gradual
decIine of compression over a 4-month
period

30. STATIC COMPRESSION WITH A PRE-
STRESSED PLATE (DCP)
Designed by ASIF:
Perren, 1969
Works on spherical
gliding principle
A spherical head screw is
driven into plate that is
hollow cylinder

35. ECCENTRIC DYNAMIC COMPRESSION PLATE (EDCP) FOR
CREATING UNIFORM PRESSURE ON THE ORAL SIDE

37. OVER-BENDING THE PLATE

38. COMPRESSION: LAG SCREW

42. DYNAMIC COMPRESSION: PAUWELS EXPERIMENT

46. TENSION BAND AND MANDIBLE

48. EXPERIMENT ON TENSION BAND
SPLINT

51. PLATE AND TENSION BAND SYSTEM

52. INTRA-FRAGMENTAL COMPRESSION
WITHOUT A TENSION BAND
Angle #
Edentulous
Patient
Isolated
Transverse #

53. APPLICATION OF EDCP

58. RECONSTRUCTION PLATE
Twice thick as EDCP or DCP
6 to 24 hole length
2 way DC screws enabling longitudinal compression

61. MINIPLATES
• Miniplates have several applications in mandible fracture fixation; the most
important is the Champy method of mandibular angle fracture fixation and its use
as a tension band.
• The Champy method of mandibular angle fixation involves exposing and reducing a
fracture, as described earlier, and using the biomechanical advantage to place a
miniplate at the zone of tension—that is, the superior border.
• Depending on the exact location of the fracture, the plate is adapted to the external
oblique ridge and ascending ramus with at least two screw holes on each side

63. CHAMPY’S LINE

64. IMPLANT MATERIALS
STAINLESS STEEL Titanium
Biodegradable
Polymeric

65. IMPLANT PROPERTIES

73. MANDIBULAR FRACTURE

74. #: SYMPHYSIS AND PARASYMPHYSIS
REGION
4 types of fixation are possible

76. Transverse Fracture with dislocation

77. Fracture line with basal
triangle

79. FRACTURE OF HORIZONTAL RAMUS

80. TRANSVERSE #

81. COMMINUTED #: HORIZONTAL
RAMUS

82. TRANSVERSE ANGLE FRACTURE
WITHOUT DISLOCATION

84. ANGLE FRACTURE WITH BASAL TRIANGLE

85. COMMINUTED # OF ASCENDING
RAMUS

87. CRANIOFACIAL FRACTURE

88. COMPLICATIONS OF INTERNAL
FIXATION

89. Dental Injury
Nerve Injury
Malocclusion

90. REFERENCES
• Manual of internal fixation: 3rd edition, MULLER
• Internal fixation of mandible: Spiessel
• Manual of internal fixation: AO/ASIF
• Maxillofacial injuries in children. Rowe NL, Williams JL (eds), Maxillofacial Injuries.
Edinburgh: Churchill Livingstone.