Historical Background Preoperative Planning Fracture Reduction Techniques and Devices for Internal Fixation

1. PRINCIPLES OF INTERNAL FIXATION
» DR MANU MATHEW
» MODERATOR DR GAURAV SHARMA

2. • Historical Background
• Preoperative Planning
• Fracture Reduction
• Techniques and Devices for Internal Fixation

3. Historical Background
• First reports on modern techniques
of internal fixation are only about 100 years old.
• Elie and Albin Lambotte “osteosynthesis” of
fractures with plates and screws, wire loops and
external fixators

4. Robert Danis (1880
to 1962) introduced the term of
“soudure autogéne

5. Maurice Müller was impressed by
DANIS &founded the
Arbeitsgemeinschaft
für Osteosynthesefragen (AO)

6. Gerhard Küntscher
(1900 to 1972) in Germany had
developed the technique of IM
nailing,

7. • GOAL OF OPERATIVE FRACTURE
FIXATION
• full restoration of function
• faster return to his preinjury status
•
• minimizethe risk and incidence of
complications.
• Predictable alignment of fracture fragments

8. The purpose of implants
to provide a temporary support
to maintain alignment during the
fracture healing
to allow for a functional rehabilitation

9. Biology and Biomechanics on
Fracture Healing
fractured bone needs
- a certain degree of immobilization
-optimally preserved blood supply
-biologic or hormonal stimuli in order
to unite.

10. Soft Tissue Injury and Fracture Healing
“every fracture is a soft tissue injury,
where the bone happens to be
broken,”
The more extensive the zone of injury and the
tissue destruction, the higher is the risk for a delay
of the healing process or for other complications

11. mechanical stability,
Absolute stability
rigid fixation that does
not allow any micro motion
elastic fixation
provided by internal or
external splinting
of the bone

12. High Rate of HealingHigh Rate of Healing
Spectrum of Healing
Absolute Stability =
10
Bone Healing
Relative Stability =
20
Bone Healing
Biology of Bone Healing
THE SIMPLE VERSION...
Fibrous Matrix >
Cartilage > Calcified
Cartilage > Woven
Bone > Lamellar Bone
Haversian
Remodeling
Minimal
Callus
Callus

13. Absolute
(Rigid)
– eg Lag screw/ plate
– Compression plate
Relative
– (Flexible)
– eg
– IM nailing
– - Bridge plating
No callus
Fixation Stability
Callus
Reality

14. Functions of Fixation
• Interfragmentary
Compression
– Lag Screw
• Plate Functions
– Neutralization
– Buttress
– Bridge
– Tension Band
– Compression
– Locking
• Intramedullary Nails
– Internal splint
• Bridge plate fixation
– Internal splint
• External fixation
– External splint
• Cast
– External splint
*Not internal fixation

15. Indications for Internal Fixation
• Displaced intra-articular fracture
• Axial, angular, or rotational instability that
cannot be controlled by closed methods
• Open fracture
• Polytrauma
• Associated neurovascular injury

16. The components of a preoperative plan
• Timing of surgery
• Surgical approach
• Reduction maneuvers
• Fixation construct
• Intraoperative imaging
• Wound closure/coverage
• Postoperative care
• Rehabilitation

17. Prophylactic Antibiotics
• In general a second generation cephalosporin
with a broad spectrum is recommended,
applied as single dose
• 30 minutes before the start of surgery or for a
period of a maximum
• 24 to 48 hours postoperatively

18. Fracture Reduction
• The goal of reduction is to restore the
anatomical relationship

19. Direct Reduction
• Direct reduction
– fragments are manipulated
directly by the application of different
instruments or hands, via open exposure of
the fracture
•

20. joysticks

21. Collinear reduction clamp

22. Reduction Forceps
provide an excellent purchase on
the fragments without stripping or
squeezing the periosteum
EG WEBERS FORCEPS

25. ADVANTAGES
precise restoration
of anatomy;
DISADVANTAGES
1 more interference with
bone and soft tissue biology.
2 higher risk of infection and
3 possibly a delay in bony union

26. Open Reduction
• Open reduction implies that the fracture site
is exposed, allowing to watch and inspect the
adequacy of reduction with our eyes.

27. Indications for open reduction
1 Displaced articular # with impaction of the joint
surface
2 #which require exact axial alignment (e.g.,
forearm #, simple metaphyseal #)
3 failed closed reduction due to soft tissue
interposition
4 Delayed surgery where granulation tissue or
early callus has to be removed
5 high risk for neurovascular structures
6 no or limited access to perioperative imaging to
check reduction

28. Indirect reduction
• Indirect reduction means that the reduction
and alignment of the # by applying reduction
forces indirectly
• via the soft tissue envelope—to the main
fragments by manual Or skeletal traction, a
distractor, or some other means.

29. • classical example of indirect reduction is the
“closed” insertion
• of an intramedullary nail on a fracture table

30. The distractor

31. Indirect reduction
ADVANTAGES
virtually NO exposure of
the fracture site ;
LESS damage to the
vascularity of the tissue
DISADVANAGES
1demanding
technique and that
2the correct overall
alignment of the fracture
is more difficult to assess,
especially in rotation

32. Closed Reduction
• Closed reduction relies entirely on indirect
fragment alignment by ligamentotaxis or the
pull of the soft tissue envelope

33. • Traction is the most common means to
reduce a fracture
– D/A applied across a joint and that there are
limited possibilities to move the limb.
Eg The fracture table

34. The distractor
offers many possibilities and more freedom of
movement
•D/Aquite demanding to manipulate and
requires considerable practice

35. advantages of closed reduction
• minimal damage to soft tissues
• safer
• more rapid fracture repair
• lesser infection.

36. Indications for closed reduction
• Most diaphyseal fractures
• • Minimally displaced articular fractures.
• Geriatric femoral neck fractures,
trochanteric fractures,
subcapital humerus fractures,
and certain distal radius fractures

37. Techniques and Instruments
for Fracture Reduction

38. Screws
• The two basic principles of a conventional
screw are
• to compress a fracture plane (lag screw) and
• to fix a plate to the bone (plate screw)

39. • Cortical screws:
–Greater number of threads
–smaller pitch
–Outer thread diameter to core
diameter ratio is less
–Better hold in cortical bone
–Usually fully threaded
–Size1-4.5mm diameter
–Self tapping ,cannulated etc
Figure from: Rockwood and Green’s, 5th
ed.

40. •Cancellous screws:
– Larger thread to core diameter
ratio
–pitch is greater
-Lag effect with partially-threaded
screws
-
– Theoretically allows better
fixation in cancellous bone
- indicated for meta-epiphyseal ,
cancellous bone
Tapping is recommend

41. LHS
•The LHS have a head with a
thread
•that engages with the reciprocal
thread of the plate hole.
•a screw-plate device with angular
stability
variable angular stability, which
allows angulating locking
screws within the plate hole to
address specific fracture
configurations

42. LAG SCREW

43. Positioning Screw
a fully threaded screw that joins two anatomical
parts at a defined distance
without compression.
The thread is therefore tapped
in both cortices.
example is a screw placed between fibula
and tibia in a malleolar fracture

46. Plates
• Conventional non locked screws used to fix a plate
to the bone plate is pressed against the bone
which produces preload and friction between the
two surfaces.
• #forearm bones ,
• simple metaphyseal fractures of long bones,
malunion and nonunions,
D/A local cortical necrosis

47. HISTORY OF PLATES
• Early modern plates - round holes the conical--firm fit
the dynamic compression
• plate (DCP) by Perren
. spherical screw head and an inclined oval screw hole

48. •Angle blade plates tubular plates,
•reconstruction plates, the sliding hip screw
and dynamic condylar
•LC-DCP (limited contact-
•DCP)

49. THE FIVE FUNCTIONS OF PLATING
• Neutralization or protection
• Compression
• Buttressing
• Tension band function
• Bridging

50. Neutralization Plates
• Neutralizes/protects
lag screws from
shear, bending, and
torsional forces
across fx
• “Protection Plate"

51. Buttress / Antiglide Plates
• “Hold” the bone up
• Resist shear forces during axial
loading
– Used in metaphyseal areas to
support intra-articular
fragments
• Plate must match contour of bone
to truly provide buttress effect
• Buttress Plate
– When applied to an intra-
articular fractures
• Antiglide Plate
– When applied to diaphyseal
fractures

52. • Order of fixation:
• Articular surface compressed with
bone forceps and provisionally fixed
with k-wires
1. Bottom 3 cortical screws placed
• Provide buttress effect
2. Top 2 partially-threaded cancellous
screws placed
• Lag articular surface together
3. Third screw placed either in lag or
normal fashion since articular
surface already compressed
Buttress Concepts
Figure from: Schatzker J, Tile M: The Rationale of
Operative Fracture Care. Springer-Verlag, 1987.

53. Bridge Plates
• “Bridge”/bypass
comminution
• Proximal & distal fixation
• Goal:
– Maintain length, rotation, &
axial alignment
• Avoids soft tissue
disruption at # = maintain
# blood supply

54. Tension Band Plates
• Plate counteracts natural
bending moment seen wih
physiologic loading of bone
– Applied to tension side to
prevent “gapping”
– Plate converts bending force
to compression
– Examples: Proximal Femur &
Olecranon

55. Plate Pre-Bending Compression
• Prebent plate
– A small angle is bent into the
plate centered at the #
– The plate is applied
– As the prebent plate compresses
to the bone, the plate wants to
straighten and forces opposite
cortex into compression
– Near cortex is compressed via
standard methods
• External devices as shown
• Plate hole design

56. Screw Driven Compression Device
• Requires a separate drill/screw
hole beyond the plate
• Currently, more commonly used
with indirect fracture reduction
techniques

57. Dynamic Compression Plates
•

58. Dynamic Compression Plating
• Compression applied
via oval holes and
eccentric drilling
– Plate forces bone to
move as screw
tightened =
compression

59. Lag screw placement
through the plate
• Compression +
rigidity obtained a
with one
construct
• Compression
plate first
• Then lag screw
placed through
plate
Figure from: Rockwood and Green’s, 5th
ed.

60. Locking Plates
• Screw head has threads that
lock into threaded hole in
the plate
• Creates a “fixed angle” at
each hole
• Theoretically eliminates
individual screw failure
• Plate-bone contact not
critical Courtesy AO Archives

61. Locking Plates
• Increased axial
stability
• It is much less likely
that an individual
screw will fail
• But, plates can still
breakIndications:
– Osteopenic bone
– Metaphyseal
fractures with short
articular block
– Bridge plating

62. Intramedullary Nails
• Relative stability
• Intramedullary splint
• Less likely to break with
repetitive loading than
plate
• More likely to be load
sharing .
• Secondary bone healing
• Diaphyseal and some
metaphyseal fractures

63. Intramedullary Fixation
• Generally utilizes closed/indirect or minimally
open reduction techniques
• Greater preservation of soft tissues as
compared to ORIF
• IM reaming has been shown to stimulate
fracture healing
• Expanded indications i.e. Reamed IM nail is
acceptable in many open fractures

64. Intramedullary Fixation
• Rotational and axial
stability provided by
interlocking bolts
• Reduction can be
technically difficult in
segmental and
comminuted fractures
• Difficult to Maintain
reduction of fractures
in close proximity to
metaphyseal flare

65. • Open segmental
tibia fracture treated
with a reamed,
locked IM Nail.
• Note the use of
multiple proximal
interlocks where
angular control is
more difficult to
maintain due to the
metaphyseal
flare.

66. • Intertrochanteric/
Subtrochanteric fracture
treated with closed IM
Nail
• The goal:
• Restore length,
alignment, and
rotation
• NOT anatomic
reduction
• Without extensive
exposure this fracture
formed abundant callus
by 6 weeks
Valgus is restored...

67. Percutaneous Plating
• Plating through
modified incisions
– Indirect reduction
techniques
– Limited incision for:
• Passing and positioning
the plate
• Individual screw
placement
– Soft tissue “friendly”

68. •Classic example of
inadequate fixation &
stability
•Narrow, weak plate that is
too short
•Insufficient cortices engaged
with screws through plate
•Gaps left at the fx site
Unavoidable result =
Nonunion
Failure to Apply Concepts

69. Summary
• Respect soft tissues
• Choose appropriate fixation method
• Achieve length, alignment, and rotational
control to permit motion as soon as
possible
• Understand the requirements and
limitations of each method of internal
fixation

70. Thankyou