Surgival Genutech cck User manual

Surgical Technique

Genutech®CCK total knee revision system

SURGICAL TECHNIQUE

1. TIBIAL TIME (I) 2

1.1 Intramedullary ﬁxation 2

1.2 Assembly and ﬁtting of the tibial cutting guide 4

1.3 Tibial resection 7

1.4 Measuring of the tibial tray 8

1.5 Measuring of the interline 9

2. FEMORAL TIME 10

2.1 Measuring of the femoral component 10

2.2 Intramedullary ﬁxation 11

2.3 Distal cut 14

2.4 Femoral cuts 15

2.5 Veriﬁcation of stability during ﬂexo-extension 20

2.6 Reaming to house the femoral post 21

2.7 Assembly of the trial femoral component 23

3. TIBIAL TIME (II) 24

4. MOBILITY / STABILITY CHECK 29

5. PATELLA TIME 30

6. FINAL IMPLANT 31

ANNEXES 32

IMPLANTS AND INSTRUMENTS 44

Table of contents

1. TIBIAL TIME (I)

1.1 Intramedullary ﬁxation

Diaphyseal intramedullary reaming

To ensure good stability on the diaphyseal axis of the reamer, which serves as a guide and support during surgery, intramedullary reaming is performed,

with a depth according to the length of the stem which is going to be used.

Diameter of the reaming: The recommended diameters for this reaming are normally around Ø9-10 or 11mm, although the suitability of the ﬁnal

diameter for the tibial diaphysis to be used is always at the discretion of the surgeon and, through gradual reaming, it may even be close to that

of the inner cortex diameter ﬁtting. This is the case when a 200 mm stem must be inserted.

Depth: Generally, the diaphyseal reamer is inserted up to the second 70-120-200 mark, because at this depth greater stability, accuracy, tighte-

ning and safety are achieved for the installation of the tibial cutting guide. If it is not possible to penetrate this deeply (short tibia, fracture callus

which closes the medullary cavity…), at a minimum it must penetrate as far as the 70 mark in order to house a stem which is 70 mm long.

The diameter and depth are marked on the axis of the diaphyseal reamer, and as the tibial time is being performed, depths must be adjusted according

to the marks close to the initial T, depending on the length of the tibial stem (70, 120 or 200 mm) which you intend to implant.

Surgical Technique

Set 0. Upper tray

Intramedullary reaming guided by cannulated reamers

During this step use the stem of the diaphyseal reamer as a guide.

Depth: In order to install the 70 mm stem, ream until the ﬁrst 70 mark is level with the tibia surface and if, on the other hand, the stem must be

102 or 200 mm, ream until the second 120-200 mark.

Diameter: Carry out gradual reaming in order to carve the cavity which will house the tibial stem.

Note:

When using a 200 m stem, the diameters of the reamers (diaphyseal and cannulated) will be the same, because in order to reach a reaming depth of

200 mm, you use part of the length of the reaming which has already been completed to secure the diaphyseal reamer.

(See other examples of intramedullary reaming according to the length of the stem being implanted in Annex I)

Cavity reamed

to house

tibial stem

Set 0. Lower tray

Insertion of the metaphyseal sleeve

Once the guided cannulated reaming has been completed at the chosen depth, insert a metaphyseal sleeve to ensure that there is the necessary sta-

bility to secure the cutting guides, thus ensuring optimal cutting accuracy and congruency in how the tibial tray is positioned in relation to the stem.

The diameter of the sleeve being used is the same as the diameter of the last cannulated reamer which was used, installing a short metaphyseal sleeve

if the reaming was performed in order to insert a 70 mm stem, or a long one if reaming has reached the second mark (120-200) to insert a 120 or 200

mm stem.

The sleeves must be inserted with the revision sleeve inserter/extractor at a minimum depth, as indicated on the axis of the inserter, according to the

readings which correspond to the surgical time we are performing (tibia or femur) and the type of surgery being carried out (Semi-Constrained Revision

“REV” or Primary Semi-Constrained “PRIM”).

1.2 Assembly and ﬁtting of the tibial cutting guide

Assembly of the tibial cutting guide

After performing intramedullary ﬁxation of the reamer with the help of the metaphyseal sleeve, on the protruding stem assemble the telescopic guide

system with the corresponding tibial cutting guide (right or left), distally clamping it to the patient’s ankle with the help of the distal clamp for the

tibial guide.

Surgical Technique

Set 0. Lower tray

Set 0. Upper tray

Tibial cutting

guide

Telescopic

guide system

Tibial clamp

Fixation

screws

Tibial

cutting guide

Graduation for

displacement control

Transverse connector

Fitting of the tibial cutting guide

On the tibial cutting guide there is a threaded displacement measuring system, which allows you to have strict control over the steps we take. This

system must be adjusted into position 0 before it is used.

In order to ﬁnd reference “0”, insert the probe hook into the standard cutting slot (slot “0”) and the whole system travels on the axis of the reamer, until

the tip of it rests on the most prominent area of the tibia.

In this position tighten the blocking screws or ﬁxation screws of the transverse connector and of the telescopic guide, and then install the revision probe.

Transverse connector

Blocking

screws

Slot “0”

Reference “0”

Probe hook

Installation of the revision probe of 0-8 or 0-12 mm

In the most favourable cases, where you only need to make a thin cut to sanitise the tibial

surface, with the “0” end (short arm) of the probe, look for the most depressed area of the

tibial plateau to ensure that the cut being made is always below said point. To do this you

must use the threaded displacement measuring system to move it down until it rests on said

area. Once the most depressed area has been reached, ﬁx the tibial cutting guide and then

make the cut.

In extreme cases, in which the tibia is extremely damaged, a prosthesis has been replaced

with supplements or it is necessary to sanitise a bone which is signiﬁcantly (8 mm, 12 mm,

etc.). Using supplements, in the medial, lateral or even the bilateral area, proceed as follows:

The ”0” end (short arm of the tibial probe) must be directed towards the most depressed

area of the most prominent tibial plateau. To do this you must use the threaded displacement

measuring system to move it down until it is rests on said area.

Then note down the amount of millimetres which the system has gone down (see measure-

ment on the graduated marks on the telescopic guide).

With the arm of the rod in position “8” or “12” probe the most depressed area of the plateau

with the most wear, and the following situations may arise:

a) The 8 mm arm of the “0-8” probe does not ﬁt

In this case cut to +8 and install an 8 mm tibial supplement below the tibial tray

on that side.

b) The 8 mm arm is not in contact

In this situation, assemble the “0-12” probe, trying to ensure contact with its

12 mm arm, and the following situations may arise:

b1) The 12 mm arm does not ﬁt, leaving two options:

· Move it down with the sheave of the tibial cutting guide until the 8 mm arm

touches the area with the most wear, making a +8 mm recut in that area. In this

situation there will be additional displacement with the sheave to transfer it to

the thickness of the tibial insert (to maintain the interline), and an 8 mm tibial

supplement will be used in the aforementioned most depressed area.

· Keep the cutting guide in its initial position and recut +12 on the plateau with

most wear, using a 12 mm tibial supplement.

b2) The 12 mm arm is not in contact

Move down the threaded displacement measuring system to the 12 mm arm, ma-

king a +12 recut in the most depressed area to use a 12 mm tibial supplement.

You must also take into account the amount of millimetres which the cutting guide

has moved downwards with the threaded displacement system and add them to

the thickness of the tibial insert and ensure that the interline is maintained. Note:

Move the system down until the probe touches the ti-

bial plateau.

Surgical Technique

Set 1. Upper tray

PRIMARY TIBIAL SURGERY

When performing primary tibial surgery by implanting a semi-constrained prosthesis tibial component, install the “0-10” rod on the tibial cutting guide.

Firstly, the “10” end of the probe must be directed towards the most depressed area of the most prominent plateau and then, with the arm of the rod

in position “0”, probe the most depressed area of the plateau with the most wear. If in order to probe on the most depressed plateau it is necessary to

move the system down, this measurement must be noted down.

Note:

For the “0-10” rod, which is only used for primary semi-constrained surgery, the “0” probe coincides with the deepest point of the rod, unlike the “0-8”

and “0-12” rods used for revision surgery.

1.3 Tibial resection

Once the tibial cutting guide is in the correct position, it is ﬁxed to the tibia using pins. Then the telescopic intramedullary system is removed (loose-

ning all of the ﬁxation screws, moving to the end of the stroke of the thread of the tibial cutting guide and pulling up the telescopic system), and the

intramedullary system is removed.

This is when the tibial cut is made.

First line of

parallel pins

Oblique pin

Second line of parallel pins

for “Recut +2”

Extramedullary system Intramedullary system

Set 1. Upper tray

Note:

· Should there be any difﬁculties when removing the intramedullary system because of an obstructing metaphyseal sleeve, this can be reamed with the

tip of the sleeve inserter/extractor and it can be released by tapping it outwards.

· It is recommended to insert the parallel pins on the ﬁrst line of pins, using at least three pins and one oblique pin to ensure effective ﬁxation.

· It is recommended that you ﬁrst put in place the pins at both ends, so that the central pins do not impede the removal of the intramedullary compo-

nents and then, once the intramedullary system components have been removed (diaphyseal reamer and metaphyseal sleeve), install the central pins.

· The parallel pins can be kept, by way of a reference point, to make it possible to make the 2 mm recut.

· If after removing the pins we want to recover this reference point, it is recommended to put back the cutting guide by inserting the probe hook through

the corresponding cutting slot, supporting it on the resected surface and making use of the drill holes which have already been made in order to reinsert

the pins and thus ﬁx the cutting guide in the right position. For greater accuracy when putting back the cutting guide it is recommended to perform the

above action by reassembling the extramedullary telescopic system on the intramedullary system.

1.4 Measuring of the tibial tray

After making the cut, when placing the trial templates on the tibial cut, select the size which best suits the bone morphometry of the tibial cut which

has been made.

Trial tibial template

Support handle

Surgical Technique

Set 1. Upper tray

In order to measure the interline, ﬁt the lower edge of the interline sizing guide’s ﬂange onto the ATT. As the average interline ranges approximately from

25 mm (Size 1: 23 mm, Size 2: 24 mm… Size 5: 28 mm) it is possible to determine the thickness of the tibial insert to be used in advance in order to

maintain the articular interline.

Note:

When it is necessary to perform an osteotomy of the TTA to make it possible to dislocate the patella, the height of this insertion will be marked on the

front side of the metaphysis so that measurements can be taken from this mark.

It is essential that the interline is located in the right place in order to ensure proper knee function.

Example:

If “a” is the height from the insertion of the patellar ten-

don with the ATT to the tibial osteotomy, and knowing that

the thickness of the tibial tray is approximately 4 mm and

the interline is approximately 25 mm from the insertion of

the patellar tendon with the ATT, we can conclude that the

thickness of tibial insert “I” to be used must be as follows

in order to maintain the interline:

Therefore, a 10 or 12 mm tibial insert would be used to

maintain the interline in its position.

Interline

Tibial Tray

Tibial Cut

1.5 Measuring of the interline

Set 2. Upper tray

Thickness of Insert:

(see image)

2. FEMORAL TIME

2.1 Measuring of the femoral component

Revision surgeries: using revision femoral sizing guides.

Let us consider two situations:

a) Implantation of a semi-constrained TKR on a knee with no previous surgery (primary surgery).

b) Implantation of a semi-constrained replacement in a prosthetic replacement (revision surgery).

Primary surgeries: using the primary femoral sizing guide which will indicate the correct size, supporting the posterior condyles and tapping with the

rod on the anterior cortex. In this case the sizing guide is inserted with the diaphyseal reamer through the centring sleeve. So for primary surgeries,

ream with the diaphyseal reamer and then measure the size of the femoral component.

Note:

· At this moment, check and assess the size which was

previously selected for the tibia (see 1.4.)

· When the sizing gauge is positioned between two sizes,

the smaller size must be selected.

Surgical Technique

Set 2. Upper tray

2.2 Intramedullary ﬁxation

Diaphyseal intramedullary reaming

In order to ensure good stability for the axis of the diaphyseal reamer, which serves as a guide and support during surgery, gradual intramedullary

reaming is performed with a depth according to the length of the stem which is going to be used.

Diameter of the reaming: The recommended diameters for this reaming are normally around Ø9-10 or 11 mm, although the suitability of the ﬁnal

diameter for the femoral diaphysis to be used is always at the discretion of the surgeon and, through gradual reaming, it may even be close to that

of the inner cortex diameter ﬁtting. This is the case when a 200 mm stem must be inserted.

Depth: Generally, the diaphyseal reamer is inserted up to the second 70-120-200 mark, because at this depth greater stability, accuracy, tighte-

ning and safety are achieved for the installation of the femoral cutting guide. If it is not possible to penetrate this deeply (short femur, fracture

callus which closes the medullary cavity…), at a minimum it must penetrate as far as the 70 mark in order to house a stem which is 70 mm long.

As the femoral time is being performed, the depths must be adjusted to the marks close to the initial F, as indicated in the image below.

Reaming guides with cannulated reamers

Deciding the length of the stem which is going to be used prior to the operation, ream with a cannulated reamer to the depth which was chosen, reaming

with an incremental diameter.

Depth: To install a 70 mm stem, penetrate as far as the ﬁrst 70 mark. If, on the other hand, the stem must be 102 or 200 mm, ream until the second

120-200 mark. As this is the femoral time, pay attention to the depth marks closest to the initial F.

Set 0. Upper tray

Set 0. Lower tray

F-70 F-70

Diameter: Carry out gradual reaming in order to carve the cavity which will house the femoral stem.

Cavity to house

stem

Note:

When using a 200 m stem, the diameters of the reamers (diaphyseal and cannulated) will be

the same, because in order to reach a reaming depth of 200 mm, you use part of the length of

the reaming which has already been completed to secure the diaphyseal reamer.

(See other examples of intramedullary reaming according to the length of the stem being

implanted in Annex I)

Set 0. Lower tray

Surgical Technique

Insertion of the metaphyseal sleeve

Much like for the tibial time, in order to give the system greater possible stability for subsequent assemblies and surgeries, a metaphyseal sleeve is

installed, occupying the position which has been machined with the cannulated reamer and which is subsequently occupied by the femoral stem.

The diameter of the sleeve being used is the same as the diameter of the last cannulated reamer which was used, inserting a short metaphyseal sleeve

if the reaming was performed up to the 70 mark, or a long one if reaming has reached the 120-200 mark.

The sleeves must be inserted with the revision sleeve inserter/extractor, with its threaded cap which protects the extracting thread, at a minimum

depth, as indicated on the axis of the inserter, according to the readings which correspond to the surgical time we are performing (femur) and the type

of surgery being carried out: Semi-Constrained Revision or Primary Semi-Constrained.

Note:

It is recommended to insert the sleeve with its threaded cap (to protect the extracting thread).

When inserting a sleeve of Ø10 mm the inserter must be used without the cap because if this protective cap is used it will exceed the 10 mm

diameter of the sleeve.

Set 0. Lower tray

2.3 Distal cut

On the axis of the diaphyseal reamer insert the distal cutting mask, which has been installed on the 5° angular guide which crosses the axis.

Then insert the mask until it comes into contact with the distal part of the femur, supporting the mask’s upper visor on its front and secure with threa-

ded pins of Ø 4.4 mm.

Two options can be seen on the cutting mask, which are marked on the cutting slots. Through these you will take into account the readings on the left

to perform “Primary Semi-Constrained” surgery and those on the right for “Semi-Constrained Revision” surgery.

In the case of “Primary” surgery, cut the support area to 8 mm, and for “Revision” surgery cut to 1 mm. We will also ﬁnd slots marked for additional

recuts of 4, 8 and 12 mm, to enable sanitising or on condylar cuts. In these cases we will use distal supplements with the same thickness as the distal

cut which has been made.

Note:

Before ﬁtting the mask and making the cuts it is advisable to take into account its degree of rotation, perpendicularly aligning the mask with

the tibial axis. This is performed by inserting the “Alignment Bar” through the hole of the “5° Angular Guide”, aligning it with the “tibial crest”.

Alternatively, the mask can also be guided using the femoral epicondyles.

Set 2. Upper tray

Surgical Technique

2.4 Femoral cuts

Positional adjustment of femoral cutting mask

Remove the distal cutting mask and the angular guide and set up the reamer with its sleeve. Place the cutting guide of the previously selected size on

the handle of the reamer (see 2.1) with the insert positioner and the concentric positioner.

A “Revision” or “Primary” rod has been ﬁtted onto the cutting guide, depending on the type of surgery. Then check whether or not the rod is resting on

the anterior cortex.

REVISION

rod

PRIMARY

rod

If it is being supported offsetting is not necessary. If it is not being supported remove the concentric positioner and put the eccentric positioner in its

place, rotating it to the left or right until the rod is resting on the frontal area of the femur.

Once the rod is touching it, externally rotate the cutting mask by 3°.

Note I:

The medial-lateral displacement resulting from this off-

setting must be carried out as deemed appropriate by

the physician, seeking to centre the femoral component,

although it must be noted that rotating towards the ex-

ternal part has the advantage of reducing the tension on

the patella and is conducive to it being centred on the

femoral component.

Note II:

The cutting mask has housings for 4, 8 and 12 mm dis-

tal supplements, which must be installed to provide pro-

per distal support to the cutting mask, mainly in those

cases where recuts have been necessary on the distal

condyles.

3° of external rotation

With the knee at 90° ﬂexion, and the posterior condyles resting on the surface of the tibia which has previously been cut, insert the 3° external rotation

system into the posterior cutting slots of the cutting guide.

Fit the alignment bar into the hole 3° to the left or right. When this bar is aligned with the axis of the tibia, externally rotate the cutting guide by 3°.

This support also has a hole at 0° which may be used at the discretion of the surgeon.

Surgical Technique

Set 3.

Reading of the offset

In this position the offset reading is taken, if an offset has been necessary, because the stem must be ﬁxed to both the trial and ﬁnal femoral

components.

To take this reading it is important to pay attention to the number of the insert positioner which coincides with the mark of the eccentric positioner.

Alignment

bar

Tibial axis

Alignment of bar with

tibial crest

Fixation of the cutting mask with threaded pins

Subsequently, secure the cutting mask to the femur with threaded pins of Ø 4.4 mm and then remove the rod, the concentric or eccentric positioner, the

insert positioner, the metaphyseal sleeve and the diaphyseal reamer.

Note:

It is recommended to insert the thread as far as possible, only leaving one or two threads outside the cortex to ensure that the system has optimal

ﬁxation and stability. The pins have a reference slot which indicates the maximum depth to which the pins should be inserted to avoid problems

when extracting the diaphyseal reamer and the sleeve from inside the intramedullary axis.

If we are making a 12 mm distal recut, the ﬁxation of this condyle will be unstable if we only insert the pin as far as the slot, because only the tip