permedica

GKS
BUTTERFLY
Rotating Hinged
Knee
SURGICAL TECHNIQUE
0426

O RT H O PA E D I C S
GKS - Tecnica Chirurgica GKS BUTTERFLY

INDEX OF THE MAIN CHAPTERS

P Introduction page 1
P Pre-operative planning page 2
P Special Warnings page 2
P Surgical access page 3
P Surgical Technique page 3
1. Tibial resection page 3
1.1 Use of the External guide page 4
1.2 Resection of the proximal Tibia page 5
2. Femoral preparation page 6
2.1 Femoral resections page 7
3. Preparation of the femoral diaphysis page 9
3.1 Preparation of the tibial diaphysis page 10
4. Chamfering of the femoral condyles page 11
4.1 Trial evaluations page 12
5. Preparation of the proximal Tibia page 13
6. Assembling of the definitive components page 14
7. Implantation of the definitive prosthesis page 15
7.1 Femoral Component page15
7.2 Tibial Component page 16
8. Use of the MICROLOY® ANTILUXATION version page 17
9. Use of the Tibial Compensatory Plates page 18
10. Hints for revision cases page 19
11. Instructions for spare parts replacement page 19
P Special instructions for use of MICROLOY® e BIOLOY® versions page 20
P APPENDIX 1: Tibial resection with Intramedullary Guide page 21
P APPENDIX 2: Patellar replacement page 22

ATTENTION:
This Surgical Technique is to be intended as an example, or an aid for orthopaedic
Surgeons already experienced in Knee Arthroplasty, with the objective of
demonstrating the correct use of permedica's GKS BUTTERFLY Instrumentation.
The Surgeon should in any case rely on his own knowledge and expertise in
performing each single step of the intervention.

Both our Sales Representatives and Product Specialists are at Your complete
disposal for any further intormation and/or explanation regarding the contents of
this Surgical Technique.
 GKS
GKS - Surgical technique GKS BUTTERFLY

INTRODUCTION
A Total Knee Arthroplasty aims to relieve pain and restore the original
mobility and stability of the natural knee joint, in both the shortterm
and the longterm.
permedica’s Global Knee System is a complete system conceived for
the different pathological conditions that Total Knee Replacement
Butterfly
procedures necessitate. The design of the GKS prostheses guarantees PRIMARY
optimal mobility by restoring the muscle-ligamentous funcionnality
and ensures correct limb alignment and even load distribution with
better fixation and a reduction in material wear, thanks to the special
MICROLOY® finishing technology used to achieve the metal
articulating surfaces.

REVISION
GKS Butterfly is a tri-compartimental rotating hinged knee prosthesis
stabilized on all planes.
It is available in two versions:
Primary indicated for primary replacements in severe varus/valgus
corrections (> 20°) and is without trochlear shield;
Revision presents a trochlear shield to restore the femoro-patellar
gliding surface in revision procedures.
Important positive features are represented by the presence of two
rotation axis, a deep trochlear groove, asymmetrical shape of the
femoral condyles and tibial articular surface allowing the kinematic,
dynamic and tribological functions of a natural knee to be best
reproduced.
The availability of modular stems (cemented and cementless) and tibial
augmentation plates allows the surgeon to choose the most
appropriate implant for each single case.
Both the models are also available in MICROLOY®, Antiluxation and
BIOLOY® coated version.
The GKS Butterfly MICROLOY® version is characterized by the special
joint between the femoral bush and the tibial pivot providing a metal-
on-metal coupling. The femoral component of this prosthesis has a
special MICROLOY®metal bush instead of the standard made of
REVISION
polyethylene. Such a coupling avoid the problems due to the wear of BIOLOY®
the polyethylene bush, thus improving the prosthesis duration
The GKS Butterfly MICROLOY® ANTILUXATION is also provided with
MICROLOY® metal-on-metal coupling between the femoral bush and
tibial pivot. In this version the femoral bush and the tibial polyethylene
insert has been modified in order to avoid luxation of the components
once locked.
The main feature of the GKS Butterfly BIOLOY® version is that all the
components (except those made of Titanium) are coated by a layer of
Titanium Niobium Nitride (TiNbN). Such a coating ensures an improved
hardness of the articular surfaces and reduces the ions release by the
underlying metal material. They are therefore particularly indicated for
patients requiring low metal ions release.

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PRE-OPERATIVE PLANNING
Before executing a TKA, a careful evaluation of the clinical case based on
a combined clinical and radiological study is recommended, by means
of Anterior-Posterior and Medial-Lateral radiographs of the whole
lower limb in load conditions in order to determine any extra-articular
deviations concerning the femur and/or the tibia and to reveal the
presence of dislocations either in the frontal or in the sagittal plane.
Template overlays could help in identifying the optimal evel for both
distal femur and proximal tibia resections, as well as the correct
centering of femoral and tibial medullary canal during intramedullary
rod insertion.
It may be helpful to remind that the template overlay must refer to the
best preserved femoral condyle, in order to avoid a higher joint line
position and, consequently, a lower patellar placement.

SPECIAL WARNINGS
Before implantation of a GKS BUTTERFLY knee prosthesis it is important
to be awared of the following warnings:
1. Coupling of Femoral and Tibial Components of different size is not
allowed.
2. In selecting the Intramedullary Stems it would be advisable to
consider the general conditions both of the knee joint and the patient
in order to evaluate the best option to achieve a suitable fixation of
the device. Generally, in the cemented version, the Intramedullary
Stems of 105mm length are used as standard option; use of shorter
(40 or 90mm) or longer stems should be considered to face particular
situations.
3. Intramedullary Stems are exclusively intended as anchoring devices
for the prosthetic components and they must never be used for
intramedullary osteosinthesys purpose. Improper use of
Intramedullary Stems could promote abnormal stress of the involved
components, highly improving risks of coponents fracture.
4. Use of Cementless Press-Fit Stems should be considered whenever
intramedullary cemented fixation would not be desired. The Femoral
and Tibial Components however MUST ALWAYS BE CEMENTED.
5. Use of Distal Centralizers is advisable to allow a correct centering of
the Intramedullary Stems into the medullary canal and it is possible
WARNINGS: only on 105 and 160mm length cemented stems.
Before using the device, it is necessary to 6. Intrinsic stability of the Trial Components is clearly inferior than the
understand the surgical requirements of a Total definitive prosthesis, particularly under varus-valgus solicitations,
Knee Replacement and become familiar with due to the missing of the hinge in trial femoral component and the
both the instruments and the implants. lower height of the tibial pivot in order to allow for easier positioning
and removal of the trial components and to dissuade the surgeon in
Other than the implementation of a correct executing wide release of soft tissues and collateral ligaments, thus
Surgical Technique, a good clinical outcome of a preserving the prosthesis from excessive stresses that could improve
joint replacement, also depends upon several risks of early mobilzation or fatigue failure.
factors such as bone stock quality, soft tissue
balancing, wear values and correct implant
sizing.

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SURGICAL APPROACH
Any surgical approach can be used, according to the Surgeon’s habits
and experience, provided that a satisfactory exposure of the femoral
condyles and the proximal tibia can be achieved.
The knee joint should be exposed and any medial and lateral adhesion
should be cleared; both the Cruciate Ligaments (ACL and PCL) should
be removed as well as the residual Meniscus.
Collateral Ligaments can be preserved or sacrified. Although
preservation should not really be necessary, as the device is totally
constrained, it would be preferrable to evaluate this option during the
trials or even after the implantation of the defininitive components.
Whenever excessive thigthening of the Collateral Ligaments and/or
Popliteal Tendon should be detected, proceed to a total or partial
release of the involved structures.

SURGICAL TECHNIQUE
The following procedure describes the basic standard technique for the
implantation of all the GKS Buttefly prosthesis versions in both
cemented and cementless press-fit stems version.
After complete exposal of the knee joint and removal of any osteophyte
from both the femur and tibia margins, in order to restore the normal
dimension, it will be possible to proceed in preparing the bony
extremities.
It is up to the surgeon’s choice to start the procedure with the tibial or
the femoral resection. However it should be considered that the
coupling of the Femoral and Tibial components of different size is not
allowed as in standard prosthesis. Therefore it is advisable to evaluate
the dimensions of both the bony extremities, selecting the size that will
better fit.

NOTE: 2 types of pins, in different lengths, are provided with the

instrumentation set:
1) GUIDE PINS: without head; used for guide purposes for the cutting
masks allowing re-cut option.
2) FIXATION PINS: with head; used for fixation purposes for all the
cutting masks.
It is important to choose a length suitable to the dimension of the
involved bony part.

TIBIAL RESECTION 1.
With the knee in flexion, lever the tibia anteriorly using a curved
retractor ; two Hohmann retractors - one medial and one lateral to
retract the patella- are placed for a better exposure. Care must be
taken to avoid damages both at the distal femur and the posterior
structures of the tibia, as well as to prevent patellar tendon
avulsion or neurovascular damages.
To achieve a correctly aligned tibial resection, the Instruments Set
provides an external alignment device; an intramedullary
alignment guide is also available as optional (refer to procedure
described in APPENDIX 1 at page 21).

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1.1 USE OF THE EXTERNAL ALIGNMENT GUIDE

This step starts bending the knee over 90°and placing a curved retractor
Fig. 1a
(Freeman) in the posterior face of the tibia. The tibia is then levered
anteriorly by pushing onto the distal femur. Care should be taken to
avoid any damage to the resected surface and to avoid avulsion of the
Resection Guide Patellar Tendon at the tibial insertion.
To achieve the tibial resection, this technique indicates the use of the
External Alignment Guide which allows the correct alignment of the
Cutting Guide by using an extramedullary reference.
An intramedullary tibial cutting guide is also avialable on request (refer
A to page 21 for this procedure) .
The External Alignment Guide (S59170) is composed by an Ankle Fork
with fixation spring and a Telescopic Shaft supporting the Tibial Cutting
Guide. Two Tibial Cutting Guides are available for the RIGHT side
(S59198) and the LEFT side (S59199).
Assemble the correct sided Cutting Guide by engaging it into the top of
the Telescopic Shaft and screw it in by rotating the knurled knob A . It is
advisable to set the position at a middle level in order to allow both
upwards and downwards excursion. Once assembled the device, center
Telescopic Shaft the upper hole right above the tibial tuberosity and pin it with a Fixation
Pin (Fig. 1a).
Align the device to the Mechanical Axis of the tibia (see next page for
details) controlling the adjustments on the frontal plane and the sagittal
plane. The knobs must be tightened firmly once the desired alignment is
achieved.
The correct resection level is adjusted by acting on the knurled knob of
the Shaft A which raises or lowers the Cutting Guide. To check the
correct level, it is possible to use the “Halfmoon” Resection Gauge
(S59107) or the Tibial Stylus Gauge (S59105), both to be inserted into
Ankle Clamp the slot of the Cutting Guide.
The Tibial Stylus Gauge can be used in two positions:
P by inserting the stylus blade marked “2mm” a resection of 2mm
below the tip contact will be achieved. This should refer to the lowest
point of the most damaged tibial condyle (Fig. 1b).
P by inserting the stylus blade marked “10mm” a resection of 10mm
below the tip contact will be achieved. This should refer to the lowest
point of the most preserved tibial condyle.

The choice between these options is at Surgeon’s discretion and is

Fig. 1b
strictly correlated to the morphology of the tibial surface involved. Once
established the correct resection level, the Cutting Guide is secured
with 2 Fixation Pins - Medium (S53532).

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HINTS FOR A CORRECT ALIGNMENT: Fig. 2b Fig. 2a

Alignment in the frontal plane (Fig. 2a)
is correct when the Shaft of the guide
5°
runs along the Mechanical Axis of the
tibia and the distal tip is pointing the
second toe of the foot. Use the knob C C
to achieve this position.
Alignment in the sagittal plane should
aim to achieve a resection
perpendicular to the Mechanical Axis
of the Tibia.
Since the Cutting Guide provides for a
5° posteriorly sloped resection (Fig.
2b) it will be necessary to correct the
slope by loosening the knob B and
pull the shaft towards the leg to
towards the leg to decrease the
inclination

Height adjustment

Sagittal plane
B adjustment

B Sagittal plane
Frontal plane
adjustment C adjustment
2° toe

TIBIAL RESECTION 1.2

The resection of the Proximal Tibia can now be performed. Maximum
Fig. 3
care should be taken in this step, in order to achieve a perfectly levelled
surface.
It is advisable to use oscillating saw blades with length between 80 and
100mm, 1,27mm maximum cut thickness (Fig. 3).
Once completed the resection, the Cutting Guide can be removed (by
pulling out the Fixation Pins and unscrewing the knurled knob) thus
leaving the Alignment Guide in place: if a re-cut should be necessary the
Cutting Guide can be repositioned and adjusted at a lower level.

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2 FEMORAL PREPARATION
After the complete exposure of the joint and the removal of the
peripheral osteophytes from the articular surface - in order to restore
the normal anatomical dimensions of the knee - the insertion point for
the introduction of the Intramedullary Rod has to be identified when
the knee is in flexion. This point is generally located in the center of the
90° intercondylar notch, about 7-8 mm ahead of the PCL insertion (Fig. 4).
It is important, however, to exactly evaluate - using the appropriate X-
Ray templates - the correct location of the intramedullary rod into the
Fig. 4
femoral canal, in order to identify its exit point in the center of the knee.

Using the Ø 8 mm Starter Drill Bit (S40010) the femur is drilled to

accomodate the Intramedullary Rod (Fig. 5). In executing this hole it is
important to stay parallel to the femoral diaphysis both in the Anterior-
Posterior and in the Medial-Lateral plane.
Before operating the Starter Drill it may be helpful to start the femur
manually, using an awl, and to verify the medullary canal has been
Fig. 5 located by touching the cortical walls with a thin and long curette.

The Femoral Cutting Guide of the involved side is positioned onto the
Intramedullary Rod (S40009) and inserted into the femoral medullary
canal (Fig. 6).
The guide can be eventually equipped with two Stabilizing Screws A
Fig. 6 (S40018) and two Handles B (S40017) to improve the cutting guide
stability while cutting .
B B About the selection of the correct size (SMALL or MEDIUM), it is
important to remind that it is advisable to select the size that will fit
better considering both the bony extremities.

A
A

The Femoral Feeler Gauge (S40019) is screwed onto the top of the
Fig. 7 Cutting Guide: It’s tip should only skimm the anterior cortex (Fig. 7). If
the tip impinges onto the anterior cortex, use of a larger size should be
considered.
NOTE: whenever should not be possible to use a larger size (because it
wouldn’t fit properly to the tibia or the size selected is the larger one
available) it would be convenient to modify the entry hole of the
Intramedullary Rod in order to place the Femoral Cutting Guide more
anteriorly. It should be considered that this solution will produce a
bigger resection of the posterior condyles, consequently widening the
flexion gap.

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The Femoral Cutting Guide is then set with the correct rotational
alignment. Fig. 8
This can be achieved by aligning its landmarks parallel to the
transepicondylar axis.

Epicondilo Epicondilo
Mediale Laterale

Reperi epicondilari

The Femoral Cutting Guide should lean at least on the most preserved
condyle (on the other side, the Stabilizing Screw can be screwed until
reaching the bone) and it is stabilized by means of 4 Fixation Pins of
appropriate length inserted into the provided holes (Fig. 9).
Fig. 9
In presence of hard sclerotic bone, a pre-drilling with the appropriate
Drill Bit Ø 3,5 mm (S40069) is advisable.

Once the Femoral Cutting Guide is fixed, the Intramedullary Rod, the
Stabilizing Screws and the Feeler Gauge are removed.

FEMORAL RESECTIONS 2.1 Fig. 10

The femoral resections can therefore be performed using an oscillating

saw. The optimal blade should be roundabout 90mm long, 20mm wide
and 1,37mm thick.
Start with the anterior resection, using the top of the Cutting Guide to
drive the blade (Fig. 10) taking care to always keep the blade well resting
on the Cutting Guide top in order to avoid an angled resection.

WARNING: if a PRIMARY prosthesis without trochlear shield is selected

this resection is not required.

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Fig. 11

The posterior condyles are than resected by introducing the saw blade
in the posterior slots of the Cutting Guide (Fig. 11).

Fig. 12
< 45
mm Finally, the saw blade is introduced into the central slots for the
>
intercondylar resections (Fig. 12).
The saw blade should be deepened about 45mm from the external face
of the Cutting Guide in order to achieve a sufficient depth of the central
box to accept the hinge of the prosthesis.

After completed the resections the Cutting Guide is removed, by

extracting the Fixation Pins using the Pins Puller (S40026).
Normally, the vertical resections of the intercondylar box must be
completed to reach the posterior condyles resections.
The resected bony parts can now be removed (Fig. 13).
Fig. 13 In order to avoid condylar fractures, particular care should be taken in
removing the intercondylar bony block that is still attached to the femur
proximally.

A safe way to remove the intercondylar bony block is to use a large

Fig. 14 osteotome introducing it posteriorly, with the knee in hyperflexion
(when possible), and lever anteriorly to pull out the block.
Otherwise, if a suitable flexion could not be achieved, the block can be
split into two parts and then remove them with the osteotome by lever
posteriorly.
WARNING: in order to avoid condylar fractures, do not lever laterally or
anteriorly. .
Once the bony block is removed, it is necessary to verify the perfect
shape of the prepared site, eventually removing residual bony parts
that could impinge while introducing the trial component.

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PREPARATION OF THE FEMORAL DIAPHYSIS 3

The following chapter describes the procedure for use of the GKS
Butterfly prosthesis with cemented or cementless press-fit
Intramedullary Stems
Fig. 15a
USE WITH CEMENTED STEMS
The acces hole to the medullary canal is now visible at the bottom of the
intercondylar box. This hole should be enlarged using the Universal
Intramedullary Rasp (S40028) in order to allow the introduction of the
next instruments.
It is advisable to enlarge this hole particularly anteriorly, until reaching
the roof of the anterior cortex, and towards the medial condyle (Fig.
15b).
The landmarks onto the Universal Intramedullary Rasp are referred to
the length of the Intramedullary Stems: the more distal one refers to the
90mm Stem; the intermediate one refers to the 105mm Stem and the
more proximal one to the 160mm Stem.
These landmarks should be aligned with the entry of the medullary Fig. 15b
canal at the bottom of the intercondylar box.
WARNING:105mm Stems are normally considered as standard option.
Use of shorter or longer stems should be considered to face particular
situations.

The next step is to evaluate the diameter of the medullary canal in order
to select the proper size of Distal Centralizer to be assembled to the
Stem.

Fig. 16
The Trial Distal Centralizer Ø 12mm is screwed onto
the proper Introducer (S40029) and pushed into the
medullary canal until the landmark referring to the
selected stem length is aligned at the bottom of the
intercondylar box (Fig. 16).

Landmark
If the Ø 12mm Trial Centralizer should be too small, repeat the trial
with the Ø 15mm one; on the contrary, if it should be too large (the
landmark doesn’t reach the correct level) it should be considered the
opportunity to use the stem without the centralizer or select a shorter
stem.

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USE WITH PRESS-FIT CEMENTLESS STEMS

Fig. 17a Use of cementless press-fit stems allows to avoid intramedullary
cemented fixation and therefore the problems involved with cement
removal in case of revision.
The following chapter describes the procedure to be used with
cementless stems.

Once executed the bony resections and removed the intercondylar

bony wedge as described in chapter 3, proceed enlarging the hole using
the Cylindrical Modular Reamers in order to allow the further insertion
of the Trial Stems (Fig. 17a).
Start with the thinner reamer, increasing the diameter till reaching the
cortical walls. The reamer’s shaft is graduated to identify the length of
Fig. 17b the corrensponding stem (45 - 100 - 125 - 175mm). The marks should be
referred to the entry of the medullary canal, at the bottom of the
intercondylar box (Fig. 17b).
Once established the diameter and the length of the stem to be used,
proceed assembling the Femoral Chamfer together with the Trial Stem
of the selected sizes and follow the procedure described at page 11.

3.1 PREPARATION OF THE TIBIAL DIAPHYSIS

Fig. 18a
The medullary canal of the tibia is identified and opened (Fig. 18a) by
means of the Ø 8mm Starter Drill (S40010) .

USE WITH CEMENTED STEMS

This hole should be slightly enlarged with the Universal Intramedullary
Rasp to allow the positioning of the Cylindrical Extension (S40068) of the
Rotating Trial Tibia (Fig.18b).
As previously seen, this Rasp has 3 marks referring to the stems length:
90mm (the most proximal), 105mm (the intermediate mark) and
160mm (at the beginning of the cutting teeth) that should refer in this
Fig. 18c case to the resection plane of the tibia in order to evaluate the correct
length to be used.

Fig. 18b
USE OF THE PRESS-FIT CEMENTLESS STEMS
The tibial diaphysis is prepared by means of the Cylindrical Modular
Reamers supplied with the instruments set.
Start with the thinner reamer, Ø 12mm (ref. S42112) increasing the
diameter till reaching the cortical walls (Fig.18c).
Use the reference marks on the reamer’s shaft to determine the depth
and thus the length of the stem to be used.
WARNING: in case a Tibial Compensatory Plate should be used, the
thickness of this element must be considered and the reamer should be
deepened consequently .

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PREPARATION OF THE FEMORAL CONDYLES 4.

The Femoral Chamfer of the selected side and size (identified by the
marking SMALL or MEDIUM plus LEFT or RIGHT) is assembled with the
selected Trial Stem and teh eventual Trial Centralizer (cemented stems)
and is introduced into the prepared femoral (Fig. 19) site by means of
the proper Trials Handle (S40030).
Fig. 19

The Femoral Chamfer reproduce the inner profile of the definitive

femoral component and should be deepened until its external surface is
2mm deeper that the most preserved condyle surface (Fig. 20).
If the Femoral Chamfer would not sink enough, it would be necessary to
remove it and provide to deepen the site until reaching a suitable
sinking.

Fig. 20

The condyles are then chamfered following the surface of the Femoral
Chamfer with the oscillating saw blade (Fig. 21).
Fig. 21

After chamfering of the femoral condyles, the Femoral Chamfer is

removed and replaced by the corrensponding Trial Femoral Component
assembled with the selected Trial Stem and eventually Trial Centralizer Fig. 22
(Fig. 22).
It is now possible to visually check the congruence between the
prosthesis and the bone and evaluate the correct positioning of the
component. Whenever needed, provide the necessary adjustments to
the make the prosthesis fit.

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4.1 TRIAL EVALUATION

After positioning the Trial Femoral Component the
Rotating Trial Tibia of the selected side and size,
Fig. 24 assembled with the Cylindrical Extension (S40068),
is placed onto the resected tibia (Fig. 24).

Reduce the joint by engaging the pivot of the Trial Tibia into the hinge of
the Trial Femur (Fig. 25). Extend the knee and check stability and the
range of movement, that should allow full flexion and extension.
Also check the joint tensioning, that should not be too tight or loosen: In
Fig. 25
case of incomplete extension, a re-cut of the tibia might be necessary
(unless the joint is loosen in flexion, then the femoral component shall
be raised more proximally).
Whenever an abundant tibial resection has been made instead, and the
gap should result excessive both in flexion and extension, it will be
necessary to use a Tibial Augmentation Plate: remove the Trial Tibia,
add a Trial Augmentation Plate (5-10 or 15mm) and repeat the
evaluation(fig. 26).

Fig. 26

NOTE: for use of the Compensatory Plates, refer to chapter 9 of this

surgical technique (pag. 18).

After positioning of the trial components, the trial evaluation of the

joint is carried out by effecting the usual flexion, extension and axial
rotation movements to test the patellar tracking. By performing these
movement, the self centering of the tibial component will automatically
occur.
With the leg fully extended a landmark is traced onto the anterior tibial
cortex, corrensponding to the landmark on the trial tibia (Fig. 27).
This landmark will represent the correct anterior projection of the tibial
Fig. 27 prosthesis centre.

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PREPARATION OF THE PROXIMAL TIBIA 5

Fig. 28a Fig. 28b Fig. 28c

The Tibial Rasp corrensponding to the selected stem is introduced into

the medullary canal, aligning it’s central line to the landmark previously
marked on the tibia, and deepened until the superior margin of the
flange is levelled to the resection surface (Fig. 28a-b-c).
In this way the Tibial and the Femoral Component will be perfectly Fig. 29
aligned therefore avoiding any problem to the Extensor System due to
malpositioning of the prosthesis.
ATTENTION:
- when using a cementless Press-Fit stem, the 90mm Conical Tibial Rasp
can be utilized to prepare the keel.
- in case a Tibial Compensatory Plate is used, the rasp should be
deepened considering thethickness of this component.

Whenever a cemented stem is used, it is advisable to size the diameter

of the medullary canal in order to determine the properly fitting size of
the Distal Centralizer to be assembled onto the Stem (Fig. 29).
The Trial Distal Centralizer Ø 12mm is screwed onto the proper
Introducer (S40029) and pushed into the medullary canal until the
landmark referring to the selected stem length is aligned at the level of
the tibial resection.
If the Ø 12mm Trial Centralizer should be too small, repeat the trial with
the Ø 15mm one; on the contrary, if it should be too large (the landmark
doesn’t reach the correct level) it should be considered the opportunity
to use the stem without the centralizer or select a shorter stem.
It is now possible to proceed with implantation of the definitive
prosthesis.

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6 ASSEMBLING OF THE COMPONENTS

All the selected components are pulled out
from their packages by following the usual
aseptic procedure and disposed onto the
sterile trolley.
Fig. 30a
The selected Intramedullary Stems, Fig. 30b
cemented or cementless, are screwed into
the proper sites onto the Femoral and Tibial
Components (Fig. 30a), and tightened (Fig.
30b) using the Tightening Wrench (S42019)
and the Open Wrench (S42021) as
counterholder.

Fig. 31
Eventual UHMWPE Distal Centralizers are
inserted at the tip of each Cemented Stem
(Fig. 31).

Fig. 32a

Any eventual Tibial Augmentation Plate is

assembled to the inferior face of the Tibial
Component (Fig. 32a) and secured by means
of the proper Screws (Fig. 32b) tightened
with the Screwdriver on the Tightening
Wrench (S42019).

NOTE: for the correct assembly of the Fig. 32b

Augmentation Plates, refer to chapter 9 of
this surgical technique (pag. 18).

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IMPLANTATION OF THE PROSTHESIS 7

It is advisable to proceed first with the implantation of the Femoral
Component and than, after anterior dislocation of the tibia, the Tibial Fig. 33a
Component. On the contrary, the pivot of the Tibial Component could be
an obstacle in introducing the Femoral Prosthesis.
The medullary canal, both of the femur and the tibia, should be
accurately washed and suctioned to remove possible bony fragments or
residual blood. Plugging of the medullary canal (by means of UHMWPE,
resorbable or bony plugs) and use of a syringe for «retro-filling»
cementing technique is advisable in order to achieve a proper filling.
For improved cementing technique it would be advisable to provide a
surface as dry as possible, by sucking eventual blood into the medullary
canal and tamponing the femoral condyles with a compress

IMPLANTATION OF THE FEMORAL COMPONENT 7.1

NOTE: whenever a cementless (Press-fit) stem is used, ignore any
reference to intramedullary cementing technique.
Fig. 33b

The bone cement is injected by means of the syringe until the medullary
canal is completely filled and the cement overflows in the intercondylar
box (Fig. 33a-b).

Further bone cement can be applied to

the posterior part of the prosthesis to
fill eventual gaps of the condyles.

The Femoral Component, previously assembled with the selected Fig. 34

Intramedullary Stem and the eventual Distal Centralizer, is manually
introduced into the prepared site and impacted by means of the
Femoral Impactor (S40036) until its final seating (Fig. 34).
Pressure should be applied, avoiding any stress to the component, until
the final hardening of bone cement.

The exceeding bone cement is removed using a curette. Particular care

should be taken to remove completely the bone cement in the posterior
part of the hinge. Fig. 35

The plastic strip protecting the hinge of the prosthesis should be

removed only once the cement is in a doughing phase (no more sticky)
by pulling its posterior edge (Fig. 35).
After removal of the protective film, the mobility of the hinge should be
checked.

15
 GKS - Surgical technique GKS BUTTERFLY

7.2 IMPLANTATION OF THE TIBIAL COMPONENT

The proximal tibia is dislocated anteriorly by positioning of a Homann
retractor to allow insertion of the Tibial prosthesis, taking care in
Fig. 36b
protecting the femoral component previously implanted to avoid any
Fig. 36a damage. For a better cemented fixation it would be advisable to
accurately wash and suction the medullary canal.

The bone cement is injected by means of a syringe until the medullary

canal is completely filled and the cement overflows onto the resection
surface (Fig. 36a-b).
Further bone cement can be applied to the posterior part of the
prosthesis.
Whenever cementless stem is used, bone cement is applied to the
posterior part of the prosthesis.

The definitive Tibial Component, previously assembled with the

selected Intramedullary Stem and eventual Distal Centralizer, is
manually introduced into the prepared site and impacted by means of
the Tibial Impactor (S40060) until its final seating.
Pressure should be applied, avoiding any stress to the component, until
Fig. 37 the final hardening of bone cement. The overflowing bone cement is
removed using a curette (Fig. 37).

After complete polimerization of the bone cement, it is possible to

perform the final reduction of the prosthesis:
the thigh should be pulled upward to allow the tibial pivot engagement
into the femoral hinge, while the tibia should be pulled downward and
pushed posteriorly (Fig. 38). Once engaged, extend the Tibia for final
reduction (Fig. 39).
In case that reduction should result difficult to be achieved, due to
excessive tensioning of the Collateral Ligaments (whenever preserved)
or the Popliteal Tendon, a total or partial «release» of the involved
structures should be provided.

Fig. 39
Fig. 38

16
GKS - Surgical technique GKS BUTTERFLY

USE OF THE ANTILUXATION VERSION 8 MICROLOY®

The MICROLOY® ANTILUXATION version is
characterized by the presence of a metal
sleeve in the femoral bush (instead of
Fig. 8.1 Polyethylene) with a wide lip that, once the
Femoral and Tibial components are reduced,
is locked by the UHMWPE Insert onto the
Tibial Plate, thus avoiding the excursion and
possible dislocation .
The implantation technique is the same as
the standard prosthesis, the only difference
Fig. 8.2 is that the Tibial Component is implanted
without the UHMWPE Insert. This will be
assembled afterward.
Therefore in implanting the Tibial
Component it will be advisable to follow
some hints:

- the insert Safety Screw should be screwed

into its threaded seat to avoid this to be
filled by bone cement (Fig. 8.1) and
removed once cement has hardened.
- Once the prosthesis is reduced, the
Butterfly ANTILUXATION Insert, included
into the same packaging of the prosthesis,
is inserted onto the tibial baseplate sloping
posteriorly, in order to engage the niche on
the baseplate (Fig. 8.2) and impacted with
the proper Impactor (S42022).
- After the Insert has been lodged, lock it
with the Safety Screw supplied with the
Insert (Fig. 8.3) using the Screwdriver on
the Tightening Wrench (S42019).
Fig. 8.3

17
 GKS - Surgical technique GKS BUTTERFLY

9. USE OF THE TIBIAL AUGMENTATION PLATES

Augmentation Plates are used to to fill TOTAL AUGMENTATION PLATES
eventual gaps; they are intended to be fixed
distally to the definitive Tibial Component by
Fig. 9.1 Fig. 9.2
means of the proper 8mm long Locking
Screws (Ref. 45008).
When gaps more than 15mm are to be filled, 1
A= 6mm TIBIAL COMPONENT
2 Augmentation Plates can be overplaced 23mm B= 15mm AUGMENTATION 15mm 2
15mm
one over the other (Fig. 9.1) using 23mm C= 2mm AUGMENTATION 5/10/15mm
3
long Locking Screws (Ref. 45023). In this way 5-10-15mm
it is possible to fill gaps up to 30mm (15+15).
The example shows a 20mm compensation 4x
by assembling 1x15mm and 1x5mm 23mm
Augmentation Plates.
23mm is the length of the screw’s stem and thread (without
considering the head). This length allows fixation of Augmentation
Wa r n i n g ! W h e n o v e r p l a c i n g t w o Plates as showed above (Fig. 9.2).
Augmentation Plates (Total or Hemi) a 15mm
must always be placed immediately under Components #1 and #2 remains the same, only #3 is variable (5, 10 or
the tibial component and the second one 15mm for full wide Augmentation Plates, 10 or 15mm for hemi).
added distally (the reverse wouldn’t allow As the value c) is the same in all the plates, the 23mm screw fits in any
the assembly because the 23mm screw case.
would be too long). If component #2 should be less than 15mm, the value b) would change
and the screw would result too long, pushing up the polyethylene liner.

AUGMENTATION HEMI-PLATES
Fig. 9.3 Augmentation Hemi-plates are available in 10 and 15mm thickness
and can be used in case only one tibial hemiplate should be ecxessively
compromised.
Resection should be carried out in 2 steps: a first resection (Fig. 9.3) of
the less involved part in order to achieve the minimum space for the
prosthesis (10mm);
10mm afterwards a second cut to provide the space for the Augmentation
10-15mm Hemi-plate, using a trial as sample (Fig. 9.4)

Fig. 9.5

15mm
10-15mm

2x
2x 8mm
23mm

Fig. 9.4 Augmentation Hemi-plates are fixed to the tibial plate in the same way,
but using only two 8mm Locking Screws (Ref. 45008).
The Hemi-plates can even be assembled one over the other, using the
23mm long Locking Screws (Ref. 45023).
It is also possible to combine a Hemi-plate with a full wide type: in this
case two 23mm screws and two 8mm are needed (Fig. 9.5)..

18
GKS - Surgical technique GKS BUTTERFLY

HINTS FOR USE IN REVISION CASES 10

PREPARING THE FEMUR: as the femoral condyles has been already The difference in procedure for revision
resected, the only intercondylar box has to be prepared to receive the cases is due to the fact that the involved bony
prosthesis hinge. Use of the Femoral Cutting Guide is therefore extremities were previously resected and is
superfluous. quiet normal to face bone defects, even of
After identification of the medullary canal, the Universal Intramedullary severe entity, due to the mobilization or
Rasp (S40028) is used to enlarge the entry hole. Than proceed whit the removal of the previous prosthesis.
sizing of the canal in order to identify the proper diameter of the Distal After removal of the previous components,
Centralizer to be used (see page 9). In case of cementless stems, use the eventual bone cement residual should be
proper Modular Reamers (see page 10). removed.
The Femoral Chamfer of the Whenever necessary the tibial resection
selected side and size (identified should be levelled to achieve an even
by the marking SMALL or surface. In sizing the implant it should be
MEDIUM plus LEFT or RIGHT) is considered that the coupling of the Femoral
assembled with the selected and Tibial components of different size is
Trial Stem and Trial Centralizer Fig. 10.1 not allowed as in standard prosthesis.
a n d i nt ro d u c e d i nto t h e Therefore it is advisable to evaluate the
enlarged hole by means of the dimensions of both the bony extremities,
proper Trials Handle (S40030); selecting the size that will better fit.
after determining the correct
rotational alignment, the device
is impacted until its posterior
part reaches the condyle. The
resection of the intercondylar
box is than effected by means of
the oscillating saw, using the
Femoral Chamfer as a guide (Fig. 10.1).
After removal of the Femoral Chamfer, follow the standard procedure
as described from page 11.
PREPARING THE TIBIA: proceed as described in the standard technique
(pag. 10) only avoiding to drill the tibia because the canal should be
already open.

INSTRUCTION FOR SPARE PARTS REPLACEMENT 11

Femoral nuts and polyethylene tibial inserts are available as spare
parts for those cases when a replacement should be needed in case of
wear and/or breakage, thus avoiding the removal of the whole
prosthesis. In particular, the following parts are available
P Standard UHMWPE Insert + Safety Screw
P ANTILUXATION UHMWPE Insert + Safety Screw
P UHMWPE Femoral Bush Sleeve (SMALL, MEDIUM, LARGE)
®
P MICROLOY Femoral Bush Sleeve
®
P MICROLOY ANTILUXATION Femoral Bush Sleeve .

Procedure for replacement of the Tibial Polyethylene Insert :

P The tibia is dislocated anteriorly by positioning a retractor and
levering on the femur, taking care to protect the femoral prosthesis
to avoid any damage to the articular surface.
P Unlock the Safety Screw of the Articular Insert by means of the
appropriate screwdriver (Torx or Hexagonal) and remove the
damaged insert by levering anteriorly using an osteotome.
P Replace the Articular Insert and lock it with the provided Safety
Screw;
P Engage the tibial pivot into the femoral hinge and proceed with the
joint reduction.
WARNING: replacement od these components requires use of
proper instruments supplied on request.
Use of improper instruments should be avoided.

19
 GKS - Surgical technique GKS BUTTERFLY

Procedure for replacement of the Polyethylene Sleeve of the hinge:

Fig. 11.1
The polyethylene femoral sleeve can be replaced only on the GKS
Butterfly prosthesis intended for this type of nut, and therefore GKS
Butterfly e GKS Butterfly BIOLOY standard type.
P The joint is exposed and, with the knee in flexion, the tibial pivot is
disengaged from the femoral hinge.
P Unlock and remove the small screw placed frontally onto the hinge
(Fig. 11.1) by means of the appropriate Screwdriver (S60007).
P Remove the damaged Polyethylene Sleeve and replace it with the
new one, by means of the appropriate Clamp.
Fig. 11.2 P Place the new Polyethylene Sleeve and screw it completely into the
hinge (Fig. 11.2).
P Re-position the frontal locking screw and lock it with the appropriate
Screwdriver (S60007).
P Engage the tibial pivot into the femoral hinge and proceed with the
joint reduction.

Procedure for teh replacement of the MICROLOY® sleeve:

The MICROLOY® metal sleeve can be replaced only on the GKS Butterfly
prosthesis intended for metal-on-metal coupling, and therefore only
the GKS Butterfly MICROLOY®. To replace the nut proceed as follows:
P expose the joint and, with the knee in maximum flexion, disengage
the tibial pivot from the femoral hinge;
P remove the MICROLOY® metal sleeve to be replaced (Fig. 11.3-4)
using the proper Wrench for Me/Me sleeve (S42016).
P place the new MICROLOY® metal sleeve and screw it in completely
and tighten;
Fig. 11.3 P Engage the tibial pivot into the femoral hinge and reduce the joint.
NOTE: the MICROLOY® metal sleeve is available in a STANDARD size,
fitting all sizes of prosthesis.

Procedure for teh replacement of the MICROLOY® ANTILUXATION

Sleeve:
The MICROLOY® ANTILUXATION metal sleeve can be replaced only on
the GKS Butterfly prosthesis intended for metal-on-metal coupling and
ANTILUXATION insert, and therefore only the GKS Butterfly
MICROLOY® ANTILUXATION. To replace the sleeve proceed as follows:
P expose the joint and, with the knee in maximum flexion, disengage
the tibial pivot from the femoral hinge;
P unlock the safety screw of the polyethylene Tibial Insert using the
Screwdriver tip of the Tightening Wrench (S42019)
Fig. 11.4 P remove the polyethylene insert by levering anteriorly with an
osteotome;
P with the knee in maximum flexion, disengage the tibial pivot from
the femoral hinge;
P remove the MICROLOY® ANTILUXATION metal sleeve to be replaced
(Fig. 11.3-4) using the proper Wrench for Me/Me sleeve (S42016).
P place the new MICROLOY® ANTILUXATION metal sleeve and screw it
in completely and tighten;
P Engage the tibial pivot into the femoral hinge and reduce the joint,
then proceed as described in chapter 8 of this technique (pag. 17).
NOTE: the MICROLOY® ANTILUXATION metal sleeve is available in a
UNIVERSAL size, fitting all sizes of prosthesis.
ATTENTION: MICROLOY® ANTILUXATION femoral sleeve and the
correnspondant ANTILUXATION polyethylene insert (of the correct
size and side) can be used onto the standard Butterfly MICROLOY®
version to provide ANTILUXATION properties.

20
GKS - Surgical technique GKS BUTTERFLY

SPECIAL WARNINGS FOR USE OF BUTTERFLY MICROLOY®

Use of the prosthesis providing MICROLOY® metal sleeve femoral hinge BIOLOY®
is mainly indicated in particularly young and active patients for whom
the tribological performances of the metal-on-metal coupling can
guarantee improved duration of the device, or in those cases when - in
surgeon’s opinion - the patient clinical situation could lead to an early
wear of the polyethylene femoral nut.

Use of a prosthesis with MICROLOY® metal-on-metal coupling between

the femoral hinge and the tibial pivot is not suitable in patients with
hypersensitivity to metal ions. In those patients use of GKS Butterfly
BIOLOY should be preferred.

Use of a BIOLOY® type prosthesis is particularly indicated for those

patients for which a low metal ions release is requested.

NOTE: at the long term reliability of such barrier effect is not known and
cannot be guaranteed, it is at surgeon’s responsability the choice of use
TiNbN coated components in those patients reporting hypersensibility
to metals (i.e. Nichel) and the definition of a post-operative monitoring
to check the absence of inflammatory phenomema.

GKS Butterfly BIOLOY® is intended to be used with special Titanium

stems. Do not use GKS Butterfly BIOLOY® with Cobalt Chrome or
Stainless Steel stems.

21
 GKS - Surgical technique GKS BUTTERFLY

APPENDIX 1 INTRAMEDULLARY TIBIAL RESECTION GUIDE

Fig. 1 Fig. 2
Using the Starter Drill Ø 8mm (S40010)
supplied with the GKS instrumentation the
upper tibia is drilled (Fig. 1), paying attention
to keep an axial direction in both planes.
T h e I nt ra m e d u l l a r y A l i g n m e nt Ro d
(S59103/104) fitted on the I/M Rod Handle
(S59100) is carefully inserted into the
medullary canal (Fig. 2).
The I/M Rod Handle is removed and the I/M
Connection Slide, previously assembled with
the I/M Rotating Guide, is inserted in the I/M
Rod protruding from the tibia (Fig. 3).
By adjusting the traslation knobs 1 and 2 the
Tibial Cutting Guide may be positioned in
order to place it on the anterior margin of the
tibia (Fig. 4).
It is now possible to check the correct axial
1
placement of the Tibial Cutting Guide, by
Fig. 3
introducing the External Alignment Rod Fig. 4
(S40040) into the anterior bush of the guide 2
and verifying its correspondence to the center
of the Talus (Fig. 5).
If a wrong positioning of the device is detected
- with angular deviations of the resection
plane - the alignment may be adjusted simply
by loosening the lower knob 3 of the Rotating
Guide and by rotating the External Alignment
Rod until it is on the same line as the center of
the talus, thus automatically correcting the
Tibial Resection Guide orientation.
The only caution to be taken in using this
alignment option is to verify carefully the
Fig. 5
ortogonal placement of the Tibial Resection
Guide, prior to correct its orientation: it
should not be intra nor extra-rotated (Fig.6). Fig. 6

22
GKS - Surgical technique GKS BUTTERFLY

The correct level of the tibial resection is

determined by positioning the Tibial
Resection Stylus (S59106) into the slot of the
Cutting Guide and adjusting the level until it’s
tip will touch the articular surface (Fig. 7).
Fig. 7
The Stylus can be used in two positions:
- by inserting the stylus blade marked “2mm” a
resection of 2mm below the tip contact will be
achieved. This should refer to the lowest point
of the most damaged tibial condyle.
- by inserting the stylus blade marked “10mm”
a resection of 10mm below the tip contact will
be achieved. This should refer to the lowest
point of the most preserved tibial condyle.
The optimal resection level is achieved by
loosening the locking knob 2 and
consequently adjusting the level of the device.
Once the optimal resection level is
2
determined, two Guide Pins-Long (S40074)
Fig. 8 are introduced into the parallel holes
indicated by arrow landmarks (Fig. 8). This will
allow the repositioning of the Tibial Cutting
Guide whenever a re-cut should be necessary
(see step 6).
A Fixation Pin of appropriate length is
introduced into one of the lower converging
holes to secure the device to the tibia.
Remove the Alignment Guide leaving the only
Cutting Guide in place, and proceed with the
tibial resection (Fig. 9) using an oscillating saw
blades with length between 80 and 100mm,
1,27mm maximum cut thickness.
After the resection has been carried out it is
possible to take off the Cutting Guide by
Fig. 9
pulling off the Fixation Pins (Fig. 10) using the
Pins Extractor (S40026) leaving the Guide Pins
in place.
A 2,5mm re-cut may be executed by lowering
the Tibial Cutting Guide:
remove it by sliding it on the parallel Guide
Pins A and reposition it into the more
Fig. 10
proximal holes B .

23
 GKS - Surgical technique GKS BUTTERFLY

APPENDIX 2 PATELLA PREPARATION

ATTENTION:
The Patella Instruments are not provided with the standard Instruments
Set but supplied as optional.
To check out the analitical composition of the GKS BUTTERFLY
Instruments Set please reter to the following documents:
SSPE016 Instruments Technical Sheet GKS BUTTERFLY

The GKS PRIME FLEX dome shaped patellar Fig. A Fig. B

prosthesis is available in 6 sizes (28, 30, 32, 34,
36 and 38mm).

The articulating surface of the patella is

resected by means of the oscillating saw (Fig.
A), removing about 8/9mm of bone to be
replaced by the prosthesis.
The Patella Clamp (S40055) is posistioned
onto the resection, slightly medialized and
with the handle laying externally and
ortogonal to the main axis of the limb (Fig. B).
The Clamp is then equipped with the Patella
Drill Guide (S40091). Its correct positioning is
guided by a pin; the Patella Drill Bit (S40066) is
used to drill the holes for the pegs of the Fig. C Fig. D
prosthesis (Fig. B).
The Patella Clamp is removed and the Trial
Patella of the selected size is positioned in
order to evaluate the effectiveness (Fig. C).
The definitive UHMWPE Patella can now be
cemented: the Patella Clamp is used upside-
down to press the prosthesis while bone
cement is hardening (Fig. D).

24
Reference Table
GKS BUTTERFLY Femoral-Tibial components
STANDARD BIOLOY® MICROLOY®
Primary ANTILUXATION

PRIMARY REVISION PRIMARY REVISION PRIMARY REVISION

Size Side reference reference reference reference reference reference

RIGHT 40601 40101 40701 40201 40901 40401
Small LEFT 40602 40102 40702 40202 40902 40402
RIGHT 40603 40103 40703 40203 40903 40403
Revision
Medium LEFT 40604 40104 40704 40204 40904 40404
RIGHT 40605 40105 40705 40205 40905 40405
Large LEFT 40606 40106 40706 40206 40906 40406
BIOLOY®

GKS BUTTERFLY - Cemented Stems GKS BUTTERFLY - Press-fit stems

CrCo BIOLOY® Centralizers Ø 14mm Ø 15mm Ø 16mm Ø 17mm Ø 18mm

Length reference reference Ø reference Length reference reference reference reference reference

40 mm 41004 41520 12mm 42012 45 mm 42401 42501 42601 42701 42801

90 mm 41509 41521 15mm 42015 100 mm 42402 42502 42602 42702 42802
105 mm 41530 41524 125 mm 42403 42503 42603 42703 42803
160 mm 41536 41525 175 mm 42404 42504 42604 42704 42804

GKS BUTTERFLY - Tibiali Augmentations AUGMENTS SCREWS

Length reference
PM734 BIOLOY®
8mm 45008
SMALL MEDIUM LARGE SMALL MEDIUM LARGE 23mm 45023
Thickness reference reference reference reference reference reference
5mm 43301 43302 43303 43601 43602 43603 GKS PRIME FLEX
10mm 43401
15mm 43501
43402
43502
43403
43503
43701
43801
43702
43802
43703
43803
Patella

GKS BUTTERFLY - Tibial Hemi-augmentations

PM734 BIOLOY®
MEDIAL RIGHT - LATERAL LEFT LATERAL RIGHT - MEDIAL LEFT size Ø reference
28mm 53028
SMALL MEDIUM LARGE SMALL MEDIUM LARGE 30mm 53030
Thickness reference reference reference reference reference reference 32mm 53032
34mm 53034
10mm 44201 44203 44205 44202 44204 44206
36mm 53036
15mm 44301 44303 44305 44302 44304 44306
38mm 53038

SPARE PARTS
FEMORAL HINGE SLEEVES UHMWPE TIBIAL INSERT + Locking Screw
UHMWPE SMALL MEDIUM LARGE
Size reference STANDARD
SMALL 46908 Side reference reference reference
MEDIUM 46909 RIGHT 46901 46903 46905
LEFT 46902 46904 46906

MICROLOY® Unique size reference ANTILUXATION SMALL MEDIUM LARGE

Standard 46910 Side reference reference reference
Antiluxation 46923 RIGHT 46917 46919 46921
LEFT 46918 46920 46922
 Information
INTENDED PURPOSE:
GKS BUTTERFLY is a tri-compartimental gliding knee prosthesis stabilized on all planes to be used in Total Knee Replacement surgeries. Use of the device is
indicated in cases of revision due to failure of previous arthroplasties, correction of severe axial deviation in varus/valgus and/or severe joint instability.
Fixation of the device onto the bone is achieved by means of bone cement; this can be total (using cemented intramedullary stems) as well as partial (using
press-fit stems) whenever intramedullary cement filling is not desired.
MATERIALS:
FEMUR/TIBIA components: Cobalt Chromium alloy - ISO5832/4;
CEMENTED STEMS: Cobalt Chromium forged alloy - ISO5832/12;
TIBIAL AUGMENTS: PM734 highly Nitrogenized Stainless Steel forged alloy - ISO5832/9
The device contains percentages of ferromagnetic materials that could be affected by the magnetic fields generated by diagnostic radiology equipments
such as Magnetic Resonance Imaging (MRI).
PRESS-FIT/BIOLOY STEMS - BIOLOY TIBIAL AUGMENTS: Titanium Aluminium Vanadium alloy - ISO5832/3; The devices DOES NOT CONTAIN any
INSERTS / PATELLA: UHMWPE without calcium stearate - ISO5834/1/2; ferromagnetic materials.
SURFACE FINISHING:
Articular surfaces: achieved through MICROLOY® process; roughness in compliance with ISO 7207-2 .
Bone/Prosthesis contact surface: pelleted with glass beads, with depressions for even acrylic bone cement spreading;
STERILIZATION:
Method: accelerated electron beam irradiation (b rays - nominal dose 25 kGy) in vacuum.
Validità: 5 years
CLASSIFICATION:
Class III or Class Iib as reported in Directive 2005/50/CE (and related D.lgs 26 april 2007 n.65) concerning re-classification of Hip, Knee and Shoulder joint
prostheses which modifies classification criteria of Annex IX of Directive 93/42/CEE and next integrations and amendements.

NOTES
 WARNINGS, INDICATIONS AND CONTRAINDICATIONS IFU 103240 rev. 7.0 - 30.06.2014
Warning Ø temporary or permanent nerve lesions that can cause pain and numbness throughout the limb;
Before using a product introduced onto the market by permedica spa, the surgeon is encouraged to Ø inter-operative Arterial Hypotension during the cementation;
carefully study the following recommendations, warnings and instructions as well as the specific product Ø varus or valgus deformity;
information (surgical techniques and technical product description). Negligence or lack of observance Ø cardiovascular disturbance including vein thromboses, pulmonary embolism and myocardial heart
of this aspect exonerates the manufacturer from all responsibility. attack;
Definition Ø haematoma;
Articular Prosthesis: implantable medical device, including implantable components and materials that is Ø late wound healing;
in contact with the surrounding muscle and bones, and carries out functions similar to those of a natural Ø infection.
articular joint. Pre-operative Planning
General information Failure to carry out proper preoperative planning can lead to errors (i.e. in regards to candidate selection,
A joint prosthesis should only be considered if all other therapeutic possibilities have been carefully type of prosthesis, and correct implant size). The operation should be precisely planned on the basis of
weighed and found unsuitable or inappropriate. the x-ray findings. Testing for eventual allergies to implant component materials should be established.
A joint prosthesis, even if successfully implanted will be inferior to a natural, healthy joint. Conversely for X-rays templates provide important information on the suitable type of implant, its size and possible
the patient, a joint prosthesis can be a beneficial replacement for a severely altered, pathological joint, combinations. All types of implants and implant parts in the combination recommended by the
eliminating pain and restoring good mobility and bearing capacity. manufacturer that may possibly be needed for the operation, as well as the instruments needed for their
Every artificial joint is subject to unavoidable wear and ageing. Over the course of time, an artificial joint implantation, must be available in case another size or another implant is required. Most prosthesis
initially implanted in a stable manner can loosen therefore limiting or impairing perfect functionality. components are supplied with test or trial parts for the measuring of the size to be implanted.
Wear, ageing and loosening of an implant can lead to reoperation. Patient Information
Indications for Use The doctor must explain the risks involved in the implantation of an endoprosthesis, possible side effects,
The following are the general guidelines for the use of prosthetic devices produced by permedica. and intrinsic limitations of the implant as well as the measures to undertake in order to reduce the
For more detailed information refer to the Product Technical Sheet and Surgical Technique of the possible side effects. In particular, the patient should be informed about the impact that the implant will
specific device: have on his/her lifestyle, and that the prosthesis longevity could depend also on factors such as body
l Advanced wear of the joint due to dysplasia, degenerative, post-traumatic, or rheumatic dieases.
weight and level of physical activity. Other factors regarding metal implant devices that should be
l Fractures or avascular necrosis.
communicated are:
Ø can affect the result of computer tomography (CT);
l Negative outcome of previous surgeries such as joint reconstruction, osteotomies, arthrodesis, hemi-
Ø can be detected by metal detectors;
arthroplasty or total hip prosthesis, total knee prosthesis.
Ø in the case of cremation, removal could be required depending on local regulations.
Use of this prosthetic device for reasons other than those prescribed is not permitted.
Il The patient should be informed that, whenever the implanted device contains ferromagnetic materials
Controindications (such as stainless steel or Cobalt Chrome alloys), it is not advised to undergo radiodiagnostic
Infections or other septic conditions in the area surrounding the joint, as well as allergies to the implanted investigations based on magnetic fields (MR scan).
material, (cobalt, chrome, nickel, etc) represent absolute contraindications.
Relative factors that could compromise the success of the intervention are: Sterility
l Acute or chronic local or systemic infections, even far from the implant site, (risk of haematogenous
General considerations
diffusion of the infection towards the site); Implantable devices supplied by permedica spa in a sterile state must remain closed in the original
l Insufficient bone structure at the proximal or distal level of the joint that does not guarantee good
protective packaging until the moment of implantation. Before utilizing the implant, certain controls
anchorage of the implant. should be carried out:
l Severe muscular, neural or vascular diseases that endanger the extremities involved.
o verify sterility expiration date (month/year) on the label of the product;
l Overweight or obesity.
o visually verify that the internal packaging and the label are intact;
l Osteoporosis.
o visually verify that the sterile primary packaging is integral and does not present breakage, tearing,
l Hypertrophy of the muscular tissue surrounding the joint.
holes or other types of damage.
l Metabolic disorders or lack of sufficient renal functions;
If the sterile primary package is damaged or the implant or the implant supplied by permedica spa is in a
The patient must also be: non sterile state, refer to the paragraph “Resterilization.
l Capable of understanding and following the doctor’s instructions;
Ceramic or metal implantable devices
l Avoid excessive physical activity such as heavy work or competitive sports that involve intense
Ceramic or metal implantable devices are supplied sterilized by irradiation of 25 kGy.
vibration, jerking motions or heavy loading; Plastic implantable devices
l Avoid excessive weight gain;
Plastic implantable devices are supplied sterilized by irradiation of 25 kGy or by ethylene oxide. The label
l Avoid drug abuse, including nicotine and alcohol.
of each implantable device specifies the method utilized for sterilization.
General Information and precautions for the safe use of the implant Resterilization
If a medical implant device supplied by permedica spa is sterilized or resterilized by the user, this is to be
Products of permedica Spa may be implanted only by surgeons who are familiar with the general noted in the corresponding patient documentation (i.e. operation report), and must be conserved with the
problems of ioint replacement, with implant devices, the surgical instruments and who have mastered respective accompanying documents. Components can be resterilized provided that they have not
the product-specific surgical techniques. come into contact with body fluid, bone and have not previously been implanted.
Prostheses and prosthesis parts are always components of a system, and therefore must be combined
with original parts belonging to the same system. Note must be taken of the system compatibility Validation of the cleaning and sterilization procedures, as well as the proper setting for the corresponding
according to the ‘Product Technical sheet’ and/or ‘Surgical Techniques.’ Prostheses and prosthesis parts equipment must be checked regularly.
from permedica Spa - in particular BIOLOX ceramic components - must never be combined with parts Ceramic or metal implantable devices
from other manufacturers. permedica excludes all liability for the negligent use of its implants with those Metal implantable devices can be sterilized by the user, via gas (ethylene oxide) or utilyzing superheat
of other manufacturers. Specific instruments are available for the implant devices of the various articular steam or vapour. In the case of resterilization with gas, sufficient time must be allowed for degassing.
prostheses. Improper use of these instruments can cause poor positioning of the implant components. BIOLOX ceramic components may be re-sterilized only in exceptional cases and exclusively by
permedica Spa excludes all liability for the negligent use of its instrumentation or the use of that of third permedica spa.
parties. “NON STERILE” metal or ceramic implants must not be sterilized in their original protective packages.
It is forbidden to re-utilize a prosthesis or a prosthesis part that was previously implanted in the body of a Hydroxyapatite coated or pure Titanium metal implantable devices cannot be sterilized with gas
patient or another person, or to re-utilize an implant that has come into contact with the body fluid or (Ethylene Oxide), instead can be sterilized by superheat steam or vapour..
tissue of another person, or where the mechanical integrity (superficial, geometrical, or biological) cannot Plastic implantable devices
be guaranteed. They are single-use devices. Implants made wholly or partly of polyethylene (UHMWPE) or Polymethylmethacrylate (PMMA) must not
Implants must be stored in their original packaging. Before implantation they must checked for defects be resterilized utilyzing superheat steam vapour, nor via irradiation nor via gas (ethylene oxide).
such as micro scratches or marks (can cause excessive wear or complications) on the articular surface. Instruments
And therefore must be handled with extreme attention. All pertinent details regarding the cleaning and sterilization of instruments are supplied in the
Coated prosthetic components, in particular those coated with Hydroxyapatite, should be handled with ‘Instructions for the cleaning and sterilization of surgical instruments’. Instruments must be sterilized in
extreme care avoiding damage to the surface coating. Contact of prosthetic components coated with the correct packaging via gas or vapour. Vapour sterilization should be carried out at a temperature of
Hydroxyapatite with anything other than the original package, clean surgical gloves and patient tissue 121°C for 20 minutes. The sterilization of instruments made wholly or partly of plastic must not be heated
should be avoided. Hydroxyapatite coated implants should never be cemented, instead should be above 121°C. In the case of resterilization with gas, sufficient time must be allowed for degassing.
implanted via ‘press fit’ method. Hydroxyapatite cannot be substituted with cement nor can it rectify Implant Materials
insufficient primary stability. The label of each medical implant device carries the data relative to the type of material and surface
TiNbN coating acts as an isolation barrier for the release of ions by the surrounding metallic materials. coating utilized.
Since the long term duration of this barrier is not known, it cannot be guaranteed and therefore, it is up to Endoprostheses by permedica spa are manufactured with the following materials:
the surgeon to determine if the use of TiNbN coated prosthetic components is indicated for patients with q Stainless steel 316LVM (normative ISO5832/1)
noted allergenic sensibility towards metal (nickel) and should carry out the requisite postoperative q Pure Titanium (normative ISO 5832/2)
monitoring for inflammation or allergenic development. q Titanium alloy Ti6AI4V (normative ISO 5832/3)
Literature reports possible adverse reactions caused by elevated blood levels of metal ions in patients q CrCoMo casting alloy (normative ISO 5832/4)
with metal-on-metal prosthetic joint surfaces. Long-term systemic effects due to the accumulation of
q Highly nitrogenized Stainless steel forged alloy – “PM 734” (normative ISO 5832/9)
these ions are not known and therefore long term clinical consequences can not be guaranteed. It is
therefore not recommended the of use this joint coupling in female patients of childbearing age and/or q Titanium alloy Ti6Al7Nb (normative ISO 5832/11)
people with compromised kidney function. q CrCoMo forged alloy (normative ISO 5832/12)
Literature reports possible adverse reactions caused by elevated blood levels of metal ions in patients q UHMWPE Polyethylene (normative ISO 5834/1 e 2)
with metal-on-metal prosthetic joint surfaces. Long-term systemic effects due to the accumulation of q UHMWPE Polyethylene (normative ISO 5834/1) added of Vitamin E (VITAL-E)
these ions are not known and therefore long term clinical consequences can not be guaranteed. It is q UHMWPE Polyethylene (normative ISO 5834/1) added of Vitamin E and cross-linked (VITAL-XE)
therefore not recommended the of use this joint coupling in female patients of childbearing age and/or q Polymethylmethacrylate (PMMA)
people with compromised kidney function. Before reduction or assembly, articulating or combined q Alumina based BIOLOX FORTE sintered ceramic (normative ISO6474-1) and BIOLOX DELTA
prostheses and prosthesis parts must be thoroughly cleaned; contamination, I.e. foreign particles, bone (normative ISO6474-2).
chips or residues of bone cement, can lead to third-body abrasion, incorrect functioning or fracture of the The combination of stainless steel and chrome-cobalt or Titanium implant components can cause
prosthesis or prosthesis parts. corrosion.
Joint prosthesis must not be mechanically worked or changed in any way, unless this is expressly The label of the implant carries this warning.
envisaged in the design and surgical technique. In case of doubt, recommendation must be obtained in Materials utilised for the surface coating of permedica spa implants are the following:
writing from the manufacturer. The surface of the prosthesis must not bear any writing nor be allowed to q Pure Titanium (normative ISO 5832/2)
come into contact with metallic or other hard objects (especially in the case of ceramic implants), unless q Hydroxyapatite (norma ISO 13779/2)
this is expressly envisaged by the of the ‘Surgical Technique’ description. Prostheses or prosthesis parts q TiNbN
that are contaminated, nonsterile, damaged, scratched or have been improperly handled or alterated Custom Made Implant Devices
without authorization must not be implanted under any circumstances. Reliable seating of femoral cone-
ball head combinations is only possible with the completely intact surface of the ball head cone and intact A custom made implant is foreseen for patients that cannot be fitted with a regular or series implants.
surface of the femoral stem cone. It is absolutely essential that the outer cone of the femoral stem fits This implant is produced as a ‘one of a kind’ product following the indications of the surgeon and utilyzing
perfectly with the inner cone of the ball head. The cone size is indicated on the product label and on the a regular implant design. The use of a custom made implant must be evaluated on a case by case basis.
implant itself. The surgeon must be aware of the limitations inherent in a custom made implant and must take into
Protective caps or other protective devices must be removed immediately before use. The instruments account the construction and the materials chosen. The surgeon must also have the experience and
are inevitably subject to a certain degree of wear and ageing, rarely there could be interoperative capabilities necessary for the correct specifications and optimal application of the custom made product.
breakage, especially if over utilized or misused. permedica recommends verification for breakage, Custom made implants do not have corresponding instrumentation.
deformation, corrosion and correct functioning, before use. In the case of damage, the instruments must Custom made implants are produced utilizing the technical expertise of permedica Spa acquired through
not be utilized but returned to the manufacturer for substitution. series implant design. Because these implants are custom made, there is no clinical nor test data. Risks
Observation of any additional information to that reported on the information label applied to the primary are higher with custom made products than with series implants. A custom made product must be
packaging and/or the secondary packaging relative to the indications for use is encouragement. utilized exclusively for the patient for whom it was designed.
Complications or other factors that may occur for reasons such as incorrect indication or surgical
technique, unsuitable choice of material or treatment, inappropriate use or handling of the instruments,
and/or sepsis fall under the responsibility of the operating surgeon and cannot be blamed on the
manufacturer.
Possible side effects
The following are among the most frequent possible side effects of implantable devices:
l pain;
l bone fractures due to overloading on one side or weakened bone substance;
l allergy to the implanted material, mainly to metal. This signifies the necessity of ulterior study. Implants
made of extraneous material can provoke the formation of histocitosy and consequently osteolysis;
l allergic reactions;
l metalysis and consequent osteolysis in particular for implants with metal/metal surfaces;
l prosthesis or prosthesis parts can fracture or loosen as a result of overloading, non-physiological
stresses, and superficial damage;
l prosthesis or prosthesis parts can fracture or loosen as a result of incorrect manipulation or improper
implantation ( wrong choice of implant component or size, improper alignment, incorrect fixation);
l excess wear or loosening of the implant due to breakdown of the osseous bed;
l loosening of the prosthesis due to changed conditions of load transfer (cement disintegration or
breakage and/or tissue reactions) or to early or late infections;
l dislocation, subluxation, insufficient range of movement, undesirable shortening or lengthening of the
extremity involved due to less than optimal positioning of the implant;
l Inter operative or post operative complications:
Ø perforation or fracture of the bone segments;
Ø vascular lesions;
 M I CROLOY
MICROLOY
®
®

HaX-Pore® O RT H O PA E D I C S

BI OLOY
BIOLOY
®
®
VITAL-XE ®

CHALLENGING EXCELLENCE
IN TECHNOLOGY

www.permedica.com Cod. TCE002 rel. 2.1 - 11/2016

permedica s.p.a.- Cap. Soc. 1.300.000 €- via Como, 38 - 23807 Merate (LC) - ITALY
tel.: +39 039 95.14.811 - fax +39 039 99.03.078
www.permedica.com - info@permedica.com