Mathys balanSys REV User manual

Surgical technique
balanSys REV
Extension Gap First: 3in1 For healthcare professional use only. The illustrated image does not represent a connection between the use of the medical device described, nor its performance.

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balanSys REV – Extension Gap First: 3in1 – 3
Table of contents
Introduction 4
Intended use 4
Indications and contraindications 5
Optional combination possibilities with balanSys BICONDYLAR 6
Preoperative planning 7
Exposure of the revision total knee 8
Extraction of primary components 9
Surgical technique 10
Tibial preparation 10
Tibial offset determination and preparation 15
Trial tibial implant assembly 20
Femoral preparation 24
Offset and rotation 31
Final preparation 37
Trial femur implant assembly and trial reduction 38
Tibial implant assembly 46
Femur implant assembly 51
Implantation 55
Appendix 58
1 – Size compatibility of the balanSys REV Implants 59
2 – Optional combination with balanSys BICONDYLAR 60
3 – Item numbers of the balanSys REV Implants 62
4 – Packaging of screws for the balanSys REV Implants 68
5 – Item numbers of the balanSys REV 3in1 Instruments 69
6 – Item numbers of the balanSys REV measuring template 93
7 – Assembly of the Tibial Reference System 94
Symbols 95
Remark
Please make yourself familiar with the handling of the instruments, the product-
related surgical technique and the warnings, the safety notes as well as the recom-
mendations of the instruction leaflet before using an implant manufactured by
Mathys Ltd Bettlach. Make use of the Mathys user training and proceed according to
the recommended surgical technique.

4– balanSys REV – Extension Gap First: 3in1
Introduction
Intended use
The balanSys REV prosthesis is intended for treating degenerative joint diseases of
the knee joint in skeletally mature patients.
Proven articulation
balanSys REV Femur
• Identical articulation as
balanSys BICONDYLAR
• Compatible to balanSys PS Inlays
for complex primary TKA
• Compatible to all balanSys Patellas
• 5 sizes A / B / C / D / E
• Left and right
Proven geometry
balanSys REV Tibia Plateau
• Compatible to balanSys PS,
CR, UC Inlays for
complex primary TKA
• 5 sizes 64 / 70 / 75 / 80 / 85
Variability
balanSys REV Stem
• Identical stems for tibia and femur
• With morse taper connection
• Straight and 4 mm offset
• 12 diameters: 10 to 24 mm
• 3 lengths: 80, 140 and 200 mm
Bone defect management
balanSys REV Augmentation
• Femur: Distal and Dorsal
• Tibia: Half size blocks with 8°
inclination
• Thickness: 5mm and 10 mm
Stability
balanSys REV Inlays
• Up to ±4° rotational freedom
• Post to shaft connection reinforced
by metal
• Jumping height 21 mm
• Composition up to 33 mm
(incl. augment)
• 6 heights 10.5 / 13 / 15.5 / 18 / 20.5 / 23
Precision
balanSys REV Instruments
• Reproducible orientation
of stems
• All cuts guided

balanSys REV – Extension Gap First: 3in1 – 5
Indications and contraindications
Indications
• Painful and/ or disabling joint disease of the knee resulting from osteoarthritis,
avascular necrosis, inflammatory arthritis or posttraumatic arthritis
• Failure of previous surgery or medical device including knee arthroplasty
Contraindications
• Local or general infection
• Any soft tissue, ligament, nerve or vessel insufficiency which may create
an unacceptable risk of prosthesis instability, prosthesis fixation failure and / or
complications in post-operative care
• Compromised bone stock due to bone loss or bone defects and / or
insufficient bone substance, which cannot provide adequate support and /or
fixation for the prosthesis
• Hypersensitivity to materials used
• Skeletal immaturity
• Genu recurvatum
• Insufficiency of the extensor mechanism
• Progressive neoplastic disease
For further information, please refer to the instructions for use or ask your Mathys representative.

6– balanSys REV – Extension Gap First: 3in1
Optional combination possibilities with balanSys
BICONDYLAR
For further information, please refer to the instructions for use or ask your Mathys representative.
balanSys patella can be used in combination with balanSys REV implants. For instruc-
tions to prepare and implant a balanSys patella, please refer to one of the surgical
techniques balanSys BICONDYLAR.
In case of larger bone loss in primary surgeries the REV tibia implants can be used in
combination with BICONDYLAR inlays CR, UC and PS and the appropriate BICON-
DYLAR Femur. Furthermore the REV femur implants can be used in combination with
a BICONDYLAR PS inlay. Refer to appendix 2 for a detailed description of combina-
tion possibilities.
Additional instruments are required for such combinations.
For instructions to prepare and implant a balanSys BICONDYLAR femur, inlay or tibia,
please refer to one of the surgical techniques balanSys BICONDYLAR ‹Bone Oriented›
or ‹LIS›. With a tibia or trial tibia in place, use the REV Spacer Blocks for assessment
of extension and flexion gap. The BICONDYLAR Spacer Blocks and the Ligament
Tensor are not suitable for gap assessment with a tibia or trial tibia in place. Surgical
techniques for balanSys are available on the website or from your Mathys repre-
sentative.

balanSys REV – Extension Gap First: 3in1 – 7
Preoperative planning
A complete history and physical examination of the failed knee arthroplasty is neces-
sary before revision surgery. It is necessary to understand and to determine the cause
of a failed implant preoperatively in order to maximize the probability of postopera-
tive success. Preoperative radiographies are essential for surgical planning. Radiogra-
phies of the knee in two views are recommended: A single-leg stance radiography
in the anterior-posterior (A-P) plane, and a lateral radiography of the knee joint in
90° flexion or in extension. In addition, a long-leg radiography with loading of both
legs is needed. It is useful to have a ‹skyline› or ‹sunrise› view of the patella in 40°
flexion as well.
Radiographies are needed to identify and quantify deformities and bone defects as
well as osteophytes. Using planning templates, the size of the femoral and tibial
prosthesis can be initially determined. Long-leg radiographies help to detect devia-
tions of the axis and deformities in the diaphyseal area of the femur and the tibia.
Long-leg radiographies help also to determine whether intramedullary alignment
can be performed. If bone defects exist preoperatively, the surgeon performing the
procedure must understand the implications of this bone loss as well as the tech-
niques required to manage them. In a revision situation, the balanSys REV Measuring
Template should be used to estimate the size of the femoral component by templat-
ing from a true lateral x-ray of the contralateral knee. Intraoperative restoration of
the appropriate A / P dimension of the femur will yield the most appropriate flexion
gap which can then be used to help determine the extension gap. Estimate the need
for posterior femoral augmentation by overlaying the appropriate size femoral tem-
plate on the lateral x-ray of a failed knee implant. Templating the proximal/ distal
position of the femoral component on an A/ P x-ray is often difficult. Use the inferior
pole of the patella to help determine the appropriate position of the joint line. Tem-
plating the tibial component can produce similar information. Determine the level of
bone resection and the possible need for augmentation or an offset stem by center-
ing the tibial stem within the tibial canal on the x-ray.
For the use of balanSys REV implants in a complex primary situation the alignment
and sizing of the components follows the same landmarks as balanSys BICONDY-
LAR.

8– balanSys REV – Extension Gap First: 3in1
Exposure of the revision total knee
Exposure of the revision total knee can be complicated by previous incisions, stiffness
or a fibrotic soft tissue envelope. Usually, greater exposure is required for a revision
total knee arthroplasty as compared with that of a primary TKA.
Proper tissue planes medially and laterally must be elevated and fasciocutaneous
flaps must be maintained in order to minimize wound healing complications.

balanSys REV – Extension Gap First: 3in1 – 9
Extraction of primary components
After adequate exposure of all components has been achieved, attention is turned
to component removal. If known, the manufacturer of the components to be re-
moved should be referred for explantation. Usually, the removal of the components is
achieved through dissection of the interface between the prosthesis and the cement
or at the prosthetic/ bone interface. Most surgeons prefer to remove the femoral
component first in order to improve visualization of the posterior tibial component.
A thin, flexible osteotome or a thin oscillating or reciprocating saw should be used
to cut the prosthetic interface in order to allow removal with minimal bone loss.
Angled osteotomes can be helpful in loosening and freeing the condylar portions of
the femoral components. Providing the interfaces have been adequately freed, only
minimal force will be required to remove the femoral component. Removal of the
tibial component is then carried out in a similar fashion. As bone cement fails most
easily in tension, a controlled, well-placed blow will generally dislodge the tibial
component.
Excessive force to remove the components can lead to
femoral fracture or extensive bone loss.
In case the patella was resurfaced previously with a balanSys Patella, special atten-
tion should be given to the patella implant: if the patella implant is securely fixed,
well-positioned and does not show excessive wear then it may be left and protected
for the remainder of the case. If the patellar implant should be revised, removal is
most easily performed with an oscillating saw at the cement interface. Residual
cement and polyethylene plugs from the component may then be removed with a
small, high-speed burr. Great care must be taken during this stage of the procedure
in order to ensure that adequate patellar bone stock remains for revision component
placement so that fracture is prevented.
Once components have been removed, the remaining cement must be removed
with curettes, cement osteotomes or other appropriate instruments. The wounds
can be irrigated pulse lavage to remove loose debris and attention can then be
turned to the reconstructive portion of the procedure.
In cases you prefer retaining a stable balanSys BICONDYLAR component,
make sure to protect all articulation surfaces against damage.
Any wear, scratch or mark on an articulating implant surface must result
in removal of that component.

10 – balanSys REV – Extension Gap First: 3in1
Fig. 1
Surgical technique
Tibial preparation
If necessary, drill a pilot hole with the 8.5mm in-
tramedullary Drill Bit (71.02.3009).
Insert the intramedullary Reamer (79.02.0310 to
79.02.0325) and hand-ream the tibial canal until cor-
tical contact is achieved using progressively larger di-
ameter reamers.
The markings on the reamer shaft indicate the depth
of the reamer: 80mm, 140 mm, 200mm
• T for Tibia
• F for Femur
The markings correspond to the resection plane. In a
revision situation, the markings should be just below
the refresh cut when the reamer is in the final posi-
tion. In a primary situation, the markings should be
app. 8mm below the surface.
Remark
Be very careful when reaming. The balanSys Reamers
are sharp. Special attention must be given when con-
tact is made with cortical bone to avoid perforation.
Diameters stem /reamers
80 mm straight and offset stems:
• Diameter 10 to 24 mm: in 2 mm steps
140 mm straight and offset stems:
• Diameter 10 to 18 mm: in 1mm steps
• Diameter 20 to 24 mm: in 2 mm steps
200 mm straight and offset stems:
• Diameter 10 to 18 mm: in 1mm steps
Leave the last reamer with the best fit in the intramed-
ullary canal. It will be used to align the Tibial Reference
System.
Diameter
Length
mm 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
80
140
200

balanSys REV – Extension Gap First: 3in1 – 11
Use the Memory Board (79.02.0637) with the Plug-In
Pegs (79.02.0638) to record the diameter of the last
reamer (in this example: diameter 16 mm, length
140 mm).
For stabilization of the Reamer, slide the Guide Sleeve
(79.02.0510 to 79.02.0525) which fits best over the
shaft until it reaches the level of the tibial osteotomy
(only required for the 140 and 200 mm reamers).
Use the Positioning Fork (79.02.0029) to hold down
the Guide Sleeve.
The Tibial Reference System will be guided by the in-
tramedullary Reamer (79.02.0310 to 79.02.0325).
Remark
The assembly of the Tibial Reference System is ex-
plained in Appendix 7.
Slide the assembled Tibial Reference System over the
shaft of the last used Reamer (79.02.0310 to
79.02.0325).
Fig. 2
Fig. 3
Fig. 4

12 – balanSys REV – Extension Gap First: 3in1
Fig. 5
Fig. 6
Fig. 7
Set the varus-valgus orientation to a neutral position
(the groove of the bracket must be aligned with the
open slot of the adjusting screw).
In a revision case or situation with huge bone loss, set
the superior surface of the Tibial Cutting Guide
(79.02.0290) at the level of the proximal tibia. Check
with the Reference Plate (77.02.0031).
In a primary case, use the Reference Plate (77.02.0031)
to determine the original joint line.
Affix the Tibial Reference System proximally with at
least two Pins (71.02.3054) in the specified holes
(oblique and straight). The holes should be pre-drilled
with the Drill Bit (315.310).
Remark
Tibia shaft axis is orientated 90° to tibia plateau (0°
posterior slope). Hence rotational alignment does not
influence the slope orientation.
Revision case = Refresh cut: Lower the Tibial Cutting
Guide (79.02.0290) to the required level and perform
the cut.
Primary case = Tibia cut: Lower the Tibial Cutting
Block 6 –8 mm to set the resection height.
Description of the Tibial Cutting Block:
• Superior surface of the Tibial Cutting Block for the
refresh cut
• 1st Slot: 5 mm below superior surface of Tibial
Cutting Block (for a 5mm augmentation)
• 2nd Slot: 10 mm below superior surface of Tibial
Cutting Block (for a 10mm augmentation)
After performing the refresh-cut, remove the Tibial
Cutting Guide (79.02.0290) to have better access to
the cut surface.

balanSys REV – Extension Gap First: 3in1 – 13
Fig. 8
Fig. 9
Fig. 10
Determine the tibial prosthesis size with the Tibial
Template (79.02.0291 to 79.02.0295), taking the rota-
tional alignment into account.
Remark
It must be ensured that the chosen template provides
the desired tibial coverage. Check if the chosen tibial
size is compatible with the probable femur size (Ap-
pendix 1 – Size Compatibility of the balanSys REV Im-
plants).
Use the Memory Board (79.02.0637) to record the
tibial size (in this example: REV Tibial Plateau 75).
After the refresh-cut, an augmentation might be nec-
essary.
Insert the Tibial Cutting Guide (79.02.0290) again into
the Aiming Device Proximal.
Depending on the thickness (5 or 10 mm), the correct
slot needs to be chosen:
• 1st Slot: 5 mm below superior surface of cutting
block (for a 5mm augmentation)
• 2nd Slot: 10 mm below superior surface of cutting
block (for a 10 mm augmentation)
For different augmentation heights medial and lateral,
a Pin (71.02.3054) should be inserted into the central
hole of the cutting guide. It will guide the saw blade
and act as a barrier.
Remark
The tibial augments are 8° chamfered.
Remark
Place bone retractors to protect the ligaments during
tibial resection.
Remark
To reduce heat and the risk of osteonecrosis, it is rec-
ommended to cool the saw blades during sawing.

14 – balanSys REV – Extension Gap First: 3in1
Fig. 11
Fig. 12
Use the Memory Board (79.02.0637) to record the
necessary augmentation (in this example: REV Tibial
Augmentation LL / RM 5 mm).
If the medial and lateral augments have different
heights, use a saw or chisel in order to perform the
central cut and to remove the bone block.

balanSys REV – Extension Gap First: 3in1 – 15
Fig. 13
Fig. 14
Fig. 15
Assemble the Tibial Template (79.02.0291 to
79.02.0295) with the necessary Trial Tibia Augmen-
tation (79.02.0160 to 79.02.0187). This is achieved
with a click-on mechanism.
In this example (left knee), a 5 mm tibial augmenta-
tion for the lateral compartment has been chosen.
Click on the Offset Graduated Collar (79.02.0258)
onto the Tibial Template (79.02.0291 to 79.02.0295).
Remark
Scale can be read by the operator, 12 o’clock = poste-
rior.
Insert the last used Reamer and check the depths. The
marking must be at least equal with the lower side if
the Tibial Template. If the Reamer is not inserted deep
enough, it is necessary to re-ream.
Put the entire configuration (Tibial Template with the
Offset Graduated Collar and Tibial Augmentation)
with the aid of the Holder Tibial Template (71.34.0196)
over the reamer shaft onto the tibial osteotomy.
Surgical technique
Tibial offset determination and preparation

16 – balanSys REV – Extension Gap First: 3in1
Fig. 16
Fig. 17
Fig. 18
The balanSys REV System features straight stems and
stems with 4mm offset.
Insert the Offset Tibial Guide (Without offset:
79.02.0541 or with 4 mm offset: 79.02.0543) over the
reamer into the Offset Graduated Collar (79.02.0258).
Find the best coverage with the Tibial Template by ro-
tating the Offset Tibial Guide (in case of no offset, this
step is obsolete).
In this example, the 4 mm Offset Tibial Guide
(79.02.0543) is used.
Use the Memory Board (79.02.0637) to record the
required offset (in this example: a 4 mm offset is re-
quired).
Special attention must be given to the rotation of the
tibia.
Read the information from the Offset Graduated
Collar (79.02.0258): the small arrow on the Offset
Tibial Guide (4 mm offset: 79.02.0543) points to the
appropriate position. This number represents the ori-
entation of the offset (in this example: 9 o’clock).
The number references the position of the tibial pla-
teau trial and / or final implant when connected to the
trial stem and/ or final implant.

balanSys REV – Extension Gap First: 3in1 – 17
Fig. 19
Fig. 20
Fig. 21
Use the Memory Board (79.02.0637) to record the
required rotation (in this example: 9 o’clock).
Fix the Tibial Template with 4 Pins (71.02.3054).
Remove all of the following instruments:
1. Offset Tibial Guide (79.02.0541 or 79.02.0543)
2. Offset Graduated Collar (79.02.0258)
3. Reamer (79.02.0310 to 79.02.0325) and
Guide Sleeve (79.02.0510 to 79.02.0525)
4. Holder Tibial Template (71.34.0196)

18 – balanSys REV – Extension Gap First: 3in1
Fig. 22
Fig. 23
Fig. 24
The PS Reamer (79.02.0281) must be connected to
the Machine Coupling (79.02.0021) and connected to
a power drill.
Position the Reamer Guide (79.02.0286) onto the Tibial
Template and drill out of the tibial medullary space.
The depth must correspond to the appropriate length
of the anchorage stem of the predetermined balanSys
REV Tibial Plateau. Size markings are etched onto the
Reamer (marking must be flush with the end of the
Reamer Guide).
After completing the preparation for the anchorage
stem, the PS Reamer and the Reamer Guide must be
removed.
The Fin Chisel (71.34.0198) must be connected to the
Handle (71.34.0700).
The Chisel Centring Guide (79.02.0257) must be posi-
tioned onto the Tibial Template.
The Fin Chisel assembly should be impacted with care
to prevent fracture of the tibia to prepare the fins for
the balanSys REV Tibial Plateau.
Remark
In case of sclerotic bone, it might be advisable to pre-
cut the fins with a saw.

balanSys REV – Extension Gap First: 3in1 – 19
Fig. 25
Fig. 26
During introduction of the Fin Chisel care has to be
taken to protect the lateral collateral ligament and the
popliteal tendon.
Impact until the instrument bottoms out on the Tibial
Template. The depths of the fins are defined by the
size of the Tibial Template.
Remove all remaining instruments, except the Pins.
This steps are required if no or only one augmentation
is selected:
• Guide the Tibia Reamer 10 (79.02.0279) over the
Pins and mill the required number of cavities.
• These recesses will accommodate the screw-sock-
ets on the lower surface of the balanSys REV
Tibial Plateau (in this example: required on the
medial side, since a 5mm augmentation on
the lateral side is chosen).
After completion, remove all remaining pins.

20 – balanSys REV – Extension Gap First: 3in1
Fig. 27
Fig. 28
Fig. 29
Insert the Reference Plate (77.02.0031) in the slot of
the black Assembly Device (79.02.0271). Insert the
Test Stem Core straight (79.02.0668) or with offset
(79.02.0669) into the hole.
Remark
The orientation of the Test Stem Core is correct when
it can no longer be rotated. The laser marking is orien-
tated towards the Reference Plate.
Position the Trial Tibial Plateau (79.02.0060 to
79.02.0064) onto the Test Stem Core.
Put the Offset Alignment Disk (79.02.0287) onto the
Trial Tibial Plateau (put the open rectangle window
over the anterior nose of the Trial Tibial Plateau).
Surgical technique
Trial tibial implant assembly