What is fixation? Fixation in orthopedics is the process by which an injury is rendered immobile. This may be accomplished by internal fixation, or by external fixation. What is internal fixation? Internal fixation is an operation in orthopedics that involves the surgical implementation of implants for the purpose of repairing a bone Rigid internal fixation refers to the direct method of fracture fixation where the hardware or implant used for fixation provides sufficient rigidity for the jawbone to withstand masticatory stresses. Avoids immobilization by MMF Does not allow micromotion of fracture segments Goals of AO/ASIF technique for rigid fixation Anatomic reduction of bone fragments Functionally stable fixation of the fragments Preserving the blood supply to the fragments by atraumatic surgical procedures Early, active and pain free mobilisation Compression osteosynthesis Based on AO/ASIF principles These plates included pear-shaped holes at the extreme ends Dynamic compression plate Produce compression between bone fragments on activation 300kPa/cm2 Indication Nonoblique fracture with good bony apposition after reduction Contraindications Severely oblique fracture Comminuted fracture Fracture with bone loss Properties of plate Plate has inclined plane in the hole proximal to the fracture The highest portion of the inclined plane lies on the outer aspect 2 types of screws- compression screw and static screw Min two screws on each side Unfavourable fracture requires longer plates with more screws Order of fixation Plate bending Bicortical screws are used Fixation protocol Disadvantages Require precise adaptation If used on oblique fractures, the fragments slide over one another Maladapted plate in anterior mandiblecreates widening of mandible Technique sensitive Ideally should be placed on tension zone, but due to anatomic reasons the plate is placed on the inferior border In fracture with good reduction and no bone loss, causes stripping of screws and bone splintering adjacent to fracture Eccentric dynamic compression plate Used in situations where tension band application is not possible Presence of impacted 8 with angle fracture Edentulous mandibular fracture Avulsion of bone from fracture site Plate design Advantage Even distribution of forces along length of fracture Disadvantage Technique sensitive Results not superior to other fixation methods Lag screw Oblique fracture in long bones Principle- a screw that glides through the cortex of one fragment and engages the cortex of the opposite fragment with its thread, draws the fragments together and compresses them when tightened. Gliding holes and thread holes must be coaxial - (Pics) Fixation osteosynthesis This includes Reconstruction plate THORP Locking plate Indications Oblique fracture Comminuted fracture Loss of bone fragments in fracture Questionable post op compliance Non atrophic edentulous fracture Reconstr

1. RIGID INTERNAL
FIXATION
MADE BY
ROSHALMARIA THOMAS
IV YEAR

2. What is fixation?
Fixation in orthopedics is the process by which an injury is
rendered immobile. This may be accomplished by internal
fixation, or by external fixation.
What is internal fixation?
Internal fixation is an operation in orthopedics that involves
the surgical implementation of implants for the purpose of
repairing a bone
 Rigid internal fixation refers to the direct method of fracture
fixation where the hardware or implant used for fixation provides
sufficient rigidity for the jawbone to withstand masticatory
stresses.
 Avoids immobilization by MMF
 Does not allow micromotion of fracture segments

3. Internal fixation
Semirigid
Transosseous
wiring
Noncompression
miniplate
Rigid
Compression
Fixation
DCP
EDCP
Lag screw
Fixation
osteosynthesis
Locking plate
Reconstruction
plate
THORP

5.  Goals of AO/ASIF technique for rigid fixation
1. Anatomic reduction of bone fragments
2. Functionally stable fixation of the
fragments
3. Preserving the blood supply to the
fragments by atraumatic surgical
procedures
4. Early, active and pain free mobilisation

6. Compression osteosynthesis
Based on AO/ASIF principles
These plates included pear-shaped holes at the
extreme ends

7.  Dynamic compression plate
 Produce compression between bone fragments on
activation
 300kPa/cm2
 Indication
 Nonoblique fracture with good bony apposition after reduction
 Contraindications
 Severely oblique fracture
 Comminuted fracture
 Fracture with bone loss

8.  Properties of plate
1. Plate has inclined plane in the hole proximal to the
fracture
2. The highest portion of the inclined plane lies on the
outer aspect
3. 2 types of screws- compression screw and static
screw
4. Min two screws on each side
5. Unfavourable fracture requires longer plates with
more screws
6. Order of fixation
7. Plate bending
8. Bicortical screws are used
9. Fixation protocol

9.  Disadvantages
 Require precise adaptation
 If used on oblique fractures, the fragments slide over one
another
 Maladapted plate in anterior mandiblecreates widening of
mandible
 Technique sensitive
 Ideally should be placed on tension zone, but due to anatomic
reasons the plate is placed on the inferior border
 In fracture with good reduction and no bone loss, causes
stripping of screws and bone splintering adjacent to fracture

10.  Eccentric dynamic compression plate
 Used in situations where tension band application is not
possible
 Presence of impacted 8 with angle fracture
 Edentulous mandibular fracture
 Avulsion of bone from fracture site
 Plate design

11. Advantage
Even distribution of forces along length of fracture
Disadvantage
Technique sensitive
Results not superior to other fixation methods

12.  Lag screw
 Oblique fracture in long bones
 Principle- a screw that glides through the
cortex of one fragment and engages the
cortex of the opposite fragment with its
thread, draws the fragments together and
compresses them when tightened. Gliding
holes and thread holes must be coaxial

13. - (Pics)

14.  Fixation osteosynthesis
 This includes
 Reconstruction plate
 THORP
 Locking plate
 Indications
 Oblique fracture
 Comminuted fracture
 Loss of bone fragments in fracture
 Questionable post op compliance
 Non atrophic edentulous fracture

15.  Reconstruction plate
 Thick rigid plates primarily used in
reconstruction of mandible following resection
 Mandibular fracture involving multiple
segments

16.  THORP( titanium hollow osseointegrated
reconstruction plate)
Plate thickness 3 mm
4mm screw diameter
Special locking screws are inserted into each
screw head to perform locking principle
between bone anchored screw and
corresponding plate hole

17. Aim-
Stability to fractured bone segments without
applying pressure
Prevents focal ischemia, bone necrosis, screw
loosening and plate mobility
Components- reconstruction plate and anchor
screws
Disadvantage- screw and plate osseointegrate
with the bone making removal difficult

18.  Locking plate
 Locking plates 2.5 mm thickness
 Diameter of screws=2.4-3.0 mm
 Reduces plate mobility
 Reduces chances of infection and nonunion
 Disadvantages of THORP has been replaced by
locking plate