1. PRINCIPLES OF EXTERNAL FIXATION
Dr. Rami Eid
27/06/2006

2. Frame components
Pins.
Clamps and Rings.
Connecting rods.

3. Pins

4. Clamps and Rings

5. Frame Design
One plane.
Two planes.
Ilizarov.
Hybrid.

6. One plane frame
Resisting sagittal bending.
Decrease compression.

7. Biplanar frame Increase frontal bending stiffness.
Increase resistance to torsion.

8. Multiplanar frame Obstructs soft tissue access.
More stability and early weight bearing.
Bone defect reconstruction.

9. Hybrid frame
Rigid fixation of periarticular fractures with less complexity than a ring fixator.

10. Factors affecting the stability of external fixation

11. To Be Safe and Effective :
Avoid injuries to the vital limb anatomy.
Provide access for wound debridement and other procedures.
Meet the mechanical demands of the patient and the injury.

12. Complications Loosening and chronic pain. Pin site infection.
Deformity, delayed union, nonunion.
Nerves and vessels injuries, joint pyarthrosis.
Soft tissues contracture.

13. Professor De Bastiani started it all in the 1970’s
…. in Verona, Italy

14. He did not like Plates and Screws for treating fractures
More soft tissue damage
Disturbed fracture site
Damaged periosteum
Significant deep infection
Second operation to remove
Risk of refracture

15. And he didn’t like available External Fixation Frames
Difficult to assemble
Multilateral types heavy and cumbersome
Too rigid for good callus
Second operation to remove

16. What fractures need to heal ?
Initial stability (but not complete rigidity)
- to reduce pain
- to keep the pieces in the right place
- to help bridging callus to start growing
Additional movement later on
- to help callus to mature and become hard

17. Orthofix Rapidly applied Monolateral Lightweight Stable
Minimally invasive
Half-pins
Reduction facility
Converted from RIGID to DYNAMIC
This is the original series of fixators. They are sometimes referred to as DAFs (Dynamic Axial Fixators). You need to know about them because:
a. You will still meet many surgeons who have them and continue to use them
b. The unique features of this fixator (and many more) have been incorporated into our current ‘state of the art’ ProCallus fixator (See ProCallus Training Manual for full details).

18. Orthofix

19. The Orthofix (10.000) The special features of this fixator:
The conical screws and their design
The ball-jointed clamps
The telescopic body

20. Screw Characteristics
Non-transfixing (half-pins)
Conical thread
Self-tapping
Capable of minimal flexion on weightbearing
The conical shape means they can be removed easily in the out-patient department at the end of treatment.
But they must not be inserted too far to begin with, because if the surgeon tries to back them out, they will become loose!
A low insertion temperature means less chance of thermal damage of bone..

21. Screw Characteristics

22. Callus starts to form even before Dynamization begins
This is Cyclic Micromovement because the force is released when weight is taken off the limb, and the screw returns to its former shape.

23. CYCLIC MICROMOVEMENT
The fracture gap opens and closes sequentially.

24. The Ball-Jointed Clamps
Either straight clamps or T-clamps
360° of rotation and 36° of angulation in any plane to assist fracture reduction
In today’s version the ball-joints have been strengthened and the design of the clamps improved, but the range of movement and the general principles are exactly the same.

25. The Ball-Jointed Clamps

26. The Telescopic Body
Central body locking nut can be loosened to convert fixator to the DYNAMIC mode

27. The Telescopic Body
Note that the major part of the load passes through the screws and fixator body before the central body locking is loosened (left hand picture).
Once the central body locking nut has been loosened the load is transferred directly to the fracture site (right hand picture).

28. DYNAMIZATION Stable fractures: 2 – 4 weeks
Unstable fractures: 5 – 8 weeks
If the surgeon dynamizes an unstable fracture too early with a , there is a danger that the fracture could collapse.
Collapse can be prevented, however, by using a Dyna-Ring cushion, which allows unstable fractures to be dynamized as early as stable ones.

29. DYNAMIZATION

30. If Dynamization starts too late
Prolonged healing times
Non-union
Screw loosening

31. Patient Benefits Short operation and anaesthetic time
Lightweight device
Early mobilization
Early weightbearing
Early hospital discharge (unless polytrauma)
Joint function preserved
Out-patient removal (no second operation)

33. MoKazem.com
هذه المحاضرة هي من سلسلة محاضرات تم إعدادها و تقديمها من قبل الأطباء المقيمين في شعبة الجراحة العظمية في مشفى دمشق, تحت إشراف د. بشار ميرعلي.
الموقع غير مسؤول عن الأخطاء الواردة في هذه المحاضرة.
This lecture is one of a series of lectures were prepared and presented by residents in the department of orthopedics in Damascus hospital, under the supervision of Dr. Bashar Mirali.
This site is not responsible of any mistake may exist in this lecture.
Dr. Muayad Kadhim
د. مؤيد كاظم