Do you know what is a cerclage cable? During hip replacement and treatment of associated peri-prosthetic fractures, it is often necessary to hold the bone or fragments of bone together to create a stable environment for healing to occur. This is typically done with metal wires or cables using a technique called Cerclage. A cerclage wire or cable is wound around a bone or bony fragments to hold them together to allow them to heal.

1. Biomedeeks

2. CERCLAGE SYSTEM
Surgical Fracture Treatment
To restore early and complete
function of bone, limb and
patient
Cerclage
 Circular application of various diameters of
malleable wire to stabilize fractures not
amenable to other forms of internal
fixation.
A. Used on their
own
B. Combined
with struts of
various materials
A B

3. CERCLAGE SYSTEM|FUNCTIONS
Temporarily
• As a reduction tool
Long-Term
• As permanent fixation implant
 Cerclage is used rarely as an exclusive
implant.
 Its most popular indication:
The treatment of middiaphyseal spiral
fractures of the tibia.

4. CERCLAGE TECHNIQUE|CONVENTIONAL
METHOD
Conventional method
of passing the wire
Cannulated
semicircular instrument
It dislodges a major
part of the soft tissues
1. Passing the
Cable
2. Sleeve
Positioning
3. Cable
Tensioning
4. Crimping
the Sleeve
5. Cutting the
Cable

5. CERCLAGE TECHNIQUE|PERCUTANEOUS
METHOD
Percutaneous cerclage passer
Two semicircles that can be applied
sequentially and assembled
Minimal soft-tissue stripping
1. Insertion of the cerclage passer
2. Connection and closure of the cerclage passer
3. Insertion of cerclage wire
4. Removal of the forceps
5. Reduction of the fracture
The percutaneous cerclage passer 6. Percutaneous cutting of the wire

6. INSTRUMENTS AND MATERIALS
System Components:
 Cerclage loop (cable/wire):
- Titanium;
- Stainless Steels;
- Chromium-Cobalt.
 Standard Diameters: 1,0-2,0 mm.
 Cables: 7x7 constructs;
 Locking Mechanism of Cables – Crimping.
 When combined with struts of various materials:
Cable Plate.

7. INSTRUMENTS AND MATERIALS
 System Instruments:
Cable Passer
•It feeds the
cable through a
hole until the
cable
completely
surrounds the
bone
Tensioner
•It applies equal
tension to the
cables
Crimper
•After reaching
the desired
cable tension,
the Crimper is
used to crimp
the sleeve
Cable Cutter
•The cable is
easily cut by
passing each
cable end
through the hole
in the Cable
Cutter and
squeezing
together the
handles

8. APPLICATIONS OF CERCLAGE
 Orthopaedic trauma surgery: periprosthetic fractures, to
prevent or stabilize femoral fractures, patella fractures,
humerus and ankle fractures.
For temporary fixation
during open
reductions
During revisions in total
hip arthroplasty (THA)
To secure allografts
To manage fractures
with plates or other
fixation devices
Especially
recommended for
intraoperative femoral
cracks and fractures

9. LIMITATIONS
High local surface
stress
Biological damage
at insertion of the
cerclage loop
“Pressure necrosis”
or bone resorption
Formation of
grooves beneath
the cerclage
“Strangulation” of
periosteal blood
vessels
(controversy)
The vascular damage beneath the cerclage wire (left)
and cable (right)
Formation of bone grooves produced by
dynamic strain of periosteal soft tissues

10. CASE STUDY|CERCLAGE
FIXATION
 Twisting is clinically the most frequently applied method for tightening
and maintaining cerclage fixation.
 However, certain factors affect the mechanical behavior of the
cerclage during twisting.
Objective: Investigate the influence of different parameters of the
twisting procedure on the fixation strength of the cerclage.

11. CASE STUDY|MATERIALS AND
METHODS
 A fragment of 25 mm was cut from the mid–diaphysis of fresh-frozen
human femoral diaphyseal bone and mounted on two metallic half
cylinders with a radius of 10 mm forming a full circle;
 1.0 mm, 1.25 mm and 1.5 mm stainless steel wire cerclages as well as a 1.0
mm cable cerclage were applied to the bone.
 Cable cerclage (left) and single-stranded wire
 Test setup
cerclage (right)

12. CASE STUDY|PROCEDURE
 The influence of the following
parameters on the cerclage
performance was investigated:
Investigated parameters and study groups
 The application of the cerclage was
followed by cyclic loading which starts
with a peak of 150 N;
 With each cycle the cerclage tension
increases by 10 N;
 Data was acquired from the test system’s
transducers at 64 Hz.
1. Cerclage diameter;
2. Traction during cerclage twisting;
3. Degree of deformation;
4. Cutting after twisting;
5. Bending direction.

13. CASE STUDY|CERCLAGE DIAMETER
 The larger the wire, the higher
was the initial compression
force.
 After locking (cutting and
bending down the twist) the
cerclage tension decreased
with increasing wire diameter.
* Pre-tension: Tension on the tightened knot or
crimp before loading to failure.
 Increasing the cerclage tension lead to
gradually decrement of cerclage pretension.
 The cable cerclage provided the longest
lasting pretension*.

14. CASE STUDY|TRACTION DURING CERCLAGE
TWISTING
Different test options
Mean cerclage tension for cerclages closed with and
without traction
 Twisting the cerclage without applied
traction produced less cerclage
tension compared to twisting under
traction;
 Twisting the wire cerclage under
permanent traction facilitates the
installation of pretension.

15. CASE STUDY|DEGREE OF
DEFORMATION
 After locking the twist, cerclages with elastic and
plastic deformation showed 47% remaining
pretension (almost half of the initial tension).
 Still, the cerclage tension at fragment separation
(failure) was significantly higher for the plastically
deformed twist.
Ensure a plastic deformation
in the twisted part of the wire
Tighten, and stable
cerclage

16. CASE STUDY|CUTTING AFTER
TWISTING
Cutting within
the twist
56 % of
tension left
Cutting only the
wire ends
88% of
tension left
Cutting within
the twist and
then bending
21 % of
tension left
Cutting only the
wire ends and
then bending
37 % of
tension left
 Note: The perpendicular bending caused an additional loss of pretension.

17. CASE STUDY|BENDING DIRECTION
B – Forward bending
•55% of pretension left.
•Mean cerclage tension at failure was 334 N.
C- Backward bending
•10% of remaining pretension.
•Mean cerclage tension at failure was 178 N.
D- Perpendicular bending
•47% of remaining pretension.
•Mean cerclage tension at failure was 332 N.
* A – Counter clockwise twisting
Influence of the bending direction of the twist on the
cerclage’s pretension.
Mean cerclage tension at fragment separation for
different bending directions of the twist.

18. CASE STUDY|MAIN CONCLUSIONS
•Although larger wire diameter led to substantial
increase of the initial tension, it also caused huge loss
of pretension;
•Cable cerclage, on the contrary, was advantageous
in maintaining pretension.
Cerclage diameter
•Traction facilitates the installation of pretension;
•Twisting the wires without traction should be avoided.
Traction
•A plastic deformation must be ensured to produce a
sufficiently tightened and stable cerclage.
Degree of deformation
•Cutting only the wire ends of the twist showed a less
loss of pretension.
Cutting after twisting
•Bending caused an additional loss of pretension;
•Perpendicular and forward bending showed better
results in maintaining pretension.
Bending direction of the twist

19. IMPROVEMENTS/NEEDS
 A systematic investigation on wire closing is still missing. Many
unsatisfactory results are due to shortcomings of the application
procedure.
 High tension of the wire may imply the risk of local mechanical overload.
An optimal balance between stabilization and bone strength needs to
be investigated.
 Factors associated with implants and instrumentation design need to be
addressed and better understood to optimize the performance of
cerclage cables.
 The use of crimps, set-screws, etc is also responsible for initial cable
tension loss. Loosening of cerclage cables is problematic and needs to
be addressed.