Zimmer MIS Multi-Reference User manual

For NexGen®Cruciate Retaining &
NexGen Legacy®Posterior Stabilized Knees
Zimmer®MIS
Multi-Reference®
4-in-1 Femoral
Instrumentation
Surgical Technique

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique 1
Table of Contents
Abbreviated Surgical Technique 2
Introduction 4
Preoperative Planning 5
Surgical Approach 5
Patient Preparation 6
Incision and Exposure 6
MIS Midvastus Approach 7
MIS Subvastus Approach 8
MIS Medial Parapatellar Arthrotomy 9
Surgical Technique 10
Establish Femoral Alignment 10
Cut the Distal Femur 12
Size Femur & Establish External Rotation 13
Finish the Femur 15
Anterior Referencing Technique 15
Posterior Referencing Technique 17
MIS Notch/Chamfer Trochlear Guide 19
MIS QS Notch Guide 21
Resect Proximal Tibia 22
Check Flexion/Extension Gaps 27
Prepare the Patella 28
Resect the Patella 29
Finish the Patella 31
Patella Protectors 32
Perform a Trial Reduction 33
Tibial Position based on Anatomic Landmarks 34
Perform a Trial Reduction 35
Implant Components 37
Close Incision 41
Appendix 1 42
Surgical Technique
For MIS Multi-Reference
4-in-1 Femoral
Instrumentation

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique
2
5a
Set External Rotation
(Anterior Referencing)
1
Drill 8mm Pilot Hole
2
Insert and Secure
Mini Distal Femoral
Cutting Guide
5b
Set External Rotation
(Posterior Referencing)

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique 3
1
4
3
2
Size the Femur
3
Cut Distal Femur
4
Set External Rotation
(Posterior Referencing)
6
Place Femoral Finishing
Guide; Adjust M/L & Pin
(Anterior Referencing)
Finish the Femur
1. Anterior condyles
2. Posterior condyles
3. Posterior chamfer
4. Anterior chamfers
7

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique
4
Introduction
Successful total knee arthroplasty
depends in part on re-establishment
of normal lower extremity alignment,
proper implant design and orientation,
secure implant fixation, and adequate
soft tissue balancing and stability. The
NexGen Complete Knee Solution and
Multi-Reference 4-in-1 Instruments
are designed to help the surgeon
accomplish these goals by combining
optimal alignment accuracy with a
simple, straight-forward technique.
The instruments and technique
assist the surgeon in restoring the
center of the hip, knee, and ankle to
lie on a straight line, establishing a
neutral mechanical axis. The femoral
and tibial components are oriented
perpendicular to this axis. Femoral
rotation is determined using the
posterior condyles or epicondylar
axis as a reference. The instruments
promote accurate cuts to help ensure
secure component fixation. Ample
component sizes allow soft tissue
balancing with appropriate soft tissue
release.
The femur, tibia, and patella are
prepared independently, and can be
cut in any sequence using the principle
of measured resection (removing
enough bone to allow replacement
by the prosthesis). Adjustment cuts
may be needed later.
The Multi-Reference 4-in-1 instruments
provide a choice of either anterior or
posterior referencing techniques for
making the femoral finishing cuts.
The anterior referencing technique
uses the anterior cortex to set the A/P
position of the femoral component.
The posterior condyle cut is variable.
The posterior referencing technique
uses the posterior condyles to set
the A/P position of the femoral
component. The variable cut is made
anteriorly.
The Mini-Incision TKA technique
has been developed to combine
the alignment goals of total knee
arthroplasty with less disruption of
soft tissue. To accommodate this
technique, some of the original Multi-
Reference 4-in-1 Instruments have
been modified. However, if preferred,
a standard incision can be used with
the instruments. Prior to using a
smaller incision, the surgeon should
be familiar with implanting NexGen
components through a standard
incision.
Total knee arthroplasty using a less
invasive technique is suggested for
nonobese patients with preoperative
flexion greater than 90°. Patients with
varus deformities greater than 17° or
valgus deformities greater than 13°
are typically not candidates for an
MIS technique.
Please refer to the package inserts
for complete product information,
including contraindications, warnings,
precautions, and adverse effects.

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique 5
6°
Transverse Axis
Mechanical Axis
90°
Preoperative Planning
Use the template overlay (available
through your Zimmer Representative)
to determine the angle between the
anatomic axis and the mechanical
axis. This angle will be reproduced
intraoperatively. This surgical technique
helps the surgeon ensure that the
distal femur will be cut perpendicular
to the mechanical axis and, after soft
tissue balancing, will be parallel to the
resected surface of the proximal tibia.
Surgical Approach
The femur, tibia, and patella are
prepared independently, and can be
cut in any sequence using the principle
of measured resection (removing
enough bone to allow replacement
by the prosthesis). Adjustment cuts
may be needed later.

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique
6
Patient Preparation
To prepare the limb for MIS total
knee arthroplasty, adequate muscle
relaxation is required. This may be
accomplished with a short-acting,
nondepolarizing muscle relaxant. The
anesthesiologist should adjust the
medication based on the patient’s
habitus and weight, and administer
to induce adequate muscle paralysis
for a minimum of 30-40 minutes. It is
imperative that the muscle relaxant
be injected prior to inflation of the
tourniquet. Alternatively, spinal or
epidural anesthesia should produce
adequate muscle relaxation.
If desired, apply a proximal thigh
tourniquet and inflate it with the knee
in hyperflexion to maximize that
portion of the quadriceps that is below
the level of the tourniquet.
Once the patient is draped and prepped
on the operating table, determine the
landmarks for the surgical incision with
the leg in extension.
Incision and Exposure
The incision may be made with the
leg in extension or flexion depending
on surgeon preference. The surgeon
can choose a midvastus approach, a
subvastus approach, or a parapatellar
medial arthrotomy. Also, depending on
surgeon preference, the patella can be
either everted or subluxed.
The length of the incision is dependent
on the size of the femoral component
needed. Although the goal of a MIS
technique is to complete the surgery
with an approximately 10cm-14cm
incision, it may be necessary to
extend the incision if visualization is
inadequate or if eversion of the patella
is not possible without risk of avulsion
at the tibial tubercle. If the incision
must be extended, it is advisable to
extend it gradually and only to the
degree necessary. The advantage
of a MIS technique is dependent
on maintaining the extensor
mechanism insertion.
Make a slightly oblique parapatellar
skin incision, beginning approximately
2cm proximal and medial to the
superior pole of the patella, and extend
it approximately 10cm to the level of
the superior patellar tendon insertion at
the center of the tibial tubercle (Fig.1).
Be careful to avoid disruption of the
tendon insertion. This will facilitate
access to the vastus medialis obliquis,
and allow a minimal split of the muscle.
It will also improve visualization of the
lateral aspect of the joint obliquely with
the patella everted. The length of the
incision should be about 50% above and
50% below the joint line. If the length
of the incision is not distributed evenly
relative to the joint line, it is preferable
that the greater portion be distal.
Fig. 1
Divide the subcutaneous tissue to the
level of the retinaculum.
NOTE: Using electrocautery to
complete the exposure will help
minimize bleeding after deflation
of the tourniquet, as well as late muscle
bleeding.

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique 7
MIS Midvastus Approach
Make a medial parapatellar incision
into the capsule, preserving
approximately 1cm of peritenon and
capsule medial to the patellar tendon.
This is important to facilitate complete
capsular closure.
Split the superficial enveloping
fascia of the quadriceps muscle
percutaneously in a proximal direction
over a length of approximately 6cm.
This will mobilize the quadriceps
and allow for significantly greater
lateral translation of the muscle while
minimizing tension on the patellar
tendon insertion.
Split the vastus medialis obliquis
approximately 1.5cm-2cm (Fig. 2).
Use blunt dissection to undermine the
skin incision approximately 1cm-2cm
around the patella.
Slightly flex the knee and remove the
deep third of the fat pad.
The patella can be either everted
or subluxed. If everting the patella,
release the lateral patellofemoral
ligament to facilitate full eversion
and lateral translation of the patella.
Then use hand-held three-pronged or
two-pronged hooks to begin to gently
evert the patella. Be careful to avoid
disrupting the extensor insertion.
To help evert the patella, slowly flex
the joint and externally rotate the
tibia while applying gentle pressure.
Once the patella is everted, use a
standard-size Hohmann retractor or
two small Hohmann retractors along
the lateral flare of the tibial metaphysis
to maintain the eversion of the patella
and the extensor mechanism.
NOTE: It is imperative to maintain
close observation of the patellar
tendon throughout the procedure to
ensure that tension on the tendon is
minimized, especially during eversion
of the patella and positioning of the
patient.
Remove any large patellar osteophytes.
Release the anterior cruciate ligament,
if present. Perform a subperiosteal
dissection along the proximal medial
and lateral tibia to the level of the
tibial tendon insertion. Then perform
a limited release of the lateral capsule
(less than 5mm) to help minimize
tension on the extensor mechanism.
Fig. 2

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique
8
MIS Subvastus Approach
The subvastus medial arthrotomy
has been slightly modified to optimize
minimally invasive surgery. It provides
excellent exposure for TKA while
preserving all four attachments of
the quadriceps to the patella. This
approach does not require patellar
eversion, minimizes disruption of the
suprapatellar pouch, and facilitates
rapid and reliable closure of the
knee joint.
Dissect the subcutaneous tissue down
to but not through the fascia that
overlies the vastus medialis muscle.
Identify the inferior border of the vastus
medialis muscle, and incise the fascia
at approximately 5cm to 8cm medial
to the patellar border (Fig. 3) to allow
a finger to slide under the muscle belly
but on top of the underlying synovial
lining of the knee joint. Use the finger
to pull the vastus medialis obliquis
muscle superiorly and maintain slight
tension on the muscle.
Use electrocautery to free the vastus
medialis from its confluence with the
medial retinaculum, leaving a small
cuff of myofascial tissue attached to the
inferior border of the vastus medialis.
The tendonous portion of the vastus
medialis extends distally to insert
at the midpole of the medial border
of the patella. Be careful to preserve
that portion of the tendon to protect
the vastus medialis muscle during
subsequent steps. An incision along
the inferior border of the vastus
medialis to the superior pole of the
patella will result in a tear, split, or
maceration of the muscle by retractors.
Incise the underlying synovium in a
slightly more proximal position than
is typical with a standard subvastus
approach. This will allow a two-layer
closure of the joint. The deep layer will
be the synovium, while the superficial
layer will be the medial retinaculum
and the myofascial sleeve of tissue that
has been left attached to the inferior
border of the vastus medialis.
Carry the synovial incision to the
medial border of the patella. Then turn
directly inferiorly to follow the medial
border of the patellar tendon to the
proximal portion of the tibia. Elevate
the medial soft tissue sleeve along the
proximal tibia in a standard fashion.
Place a bent-Hohmann retractor in
the lateral gutter and lever it against
the robust edge of the tendon that
has been preserved just medial and
superior to the patella. Retract the
patella and extensor mechanism
into the lateral gutter. If necessary,
mobilize the vastus medialis either
from its underlying attachment to the
synovium and adductor canal, or at its
superior surface when there are firm
attachments of the overlying fascia to
the subcutaneous tissues and skin.
Depending on surgeon preference, the
fat pad can be excised or preserved.
Flex the knee. The patella will stay
retracted in the lateral gutter behind
the bent-Hohmann retractor, and the
quadriceps tendon and vastus medialis
will lie over the distal anterior portion
of the femur. To improve visualization
of the distal anterior portion of the
femur, place a thin knee retractor along
the anterior femur and gently lift the
extensor mechanism during critical
steps of the procedure. Alternatively,
bring the knee into varying degrees of
extension to improve visualization by
decreasing the tension on the extensor
mechanism.
Fig. 3

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique 9
MIS Medial Parapatellar
Arthrotomy
Minimally invasive total knee
arthroplasty can be performed
with a limited medial parapatellar
arthrotomy. Begin by making a 10cm-
14cm midline skin incision from the
superior aspect of the tibial tubercle
to the superior border of the patella.
Following subcutaneous dissection,
develop medial and lateral flaps,
and dissect proximally and distally
to expose the extensor mechanism.
This permits mobilization of the skin
and subcutaneous tissue as needed
during the procedure. In addition, with
the knee in flexion, the incision will
stretch 2cm-4cm due to the elasticity
of the skin, allowing broader exposure.
The goal of minimally invasive surgery
is to limit the surgical dissection
without compromising the procedure.
The medial parapatellar arthrotomy
is used to expose the joint, but the
proximal division of the quadriceps
tendon should be limited to a length
that permits only lateral subluxation
of the patella without eversion (Fig.
4). Incise the quadriceps tendon for
a length of 2cm-4cm initially. If there
is difficulty displacing the patella
laterally or if the patellar tendon is at
risk of tearing, extend the arthrotomy
proximally along the quadriceps
tendon until adequate exposure
is achieved. Fig. 4

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique
10
Step One
Establish Femoral
Alignment
Use the 8mm IM Drill w/Step to drill a
hole in the center of the patellar sulcus
of the distal femur (Fig. 1a), making
sure that the drill is parallel to the
shaft of the femur in both the
anteroposterior and lateral projections.
The hole should be approximately
one-half to one centimeter anterior
to the origin of the posterior
cruciate ligament. Medial or lateral
displacement of the hole may be
needed according to preoperative
templating of the A/P radiograph.
The step on the drill will enlarge the
entrance hole on the femur to 12mm.
This will reduce intramedullary pressure
during placement of subsequent IM
guides. Suction the canal to remove
medullary contents.
The Mini Adjustable IM Alignment
Guide is available with two
intramedullary rod lengths. The rod
on the standard instrument is 229mm
(9 inches) long and the rod on the
short instrument is 165mm (6.5
inches). Choose the length best suited
to the length of the patient’s leg,
which will provide the most accurate
reproduction of the anatomic axis. If
the femoral anatomy has been altered,
as in a femur with a long-stemmed hip
prosthesis or with a femoral fracture
malunion, use the Adjustable IM
Alignment Guide, Short and use the
optional extramedullary alignment
technique.
NOTE: The Mini Adjustable IM
Alignment Guide, Short (Fig. 1b)
is a shortened version of the Mini
Adjustable IM Alignment Guide, Long.
When the Mini Standard Cut Plate is
attached to the Mini Adjustable IM
Alignment Guide, Short, the same
amount of bone is removed as when it
is attached to the Mini Adjustable IM
Alignment Guide, Long. This is different
than the original Multi-Reference 4-in-
1, Micro IM Alignment Guide 165mm
(6.5 inch) which was intended for
use with Micro implants. When the
Standard Cut Plate was attached, the
Micro IM Alignment Guide removed
one millimeter less distal bone than
the standard Adjustable IM Alignment
Guide with the Standard Cut Plate
attached. The new Mini IM Alignment
Guides accommodate the resection for
the Micro implants with the Mini Micro
Cut Plate.
NOTE: It is preferable to use the longest
intramedullary rod to help ensure
the most accurate replication of the
anatomic axis.
Set the Mini Adjustable IM Alignment
Guide to the proper valgus angle
as determined by preoperative
radiographs. Check to ensure that the
proper “Right” or “Left” indication
(Fig. 1c) is used and engage the lock
mechanism (Fig. 1d).
Fig. 1a
Fig. 1b
Fig. 1c
Fig. 1d

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique 11
The Standard Cut Plate must be
attached to the Adjustable IM
Alignment Guide for a standard distal
femoral resection. Use a hex-head
screwdriver to tighten the plate on
the guide prior to use (Figs. 1e & 1f),
but the screws should be loosened
for sterilization. If preferred, remove
the Standard Cut Plate if a significant
flexion contracture exists. This will
allow for an additional 3mm of distal
femoral bone resection.
Fig. 1e
Fig. 1f
Insert the IM guide into the hole in
the distal femur. If the epicondyles
are visible, the epicondylar axis
may be used as a guide in setting
the orientation of the Adjustable IM
Alignment Guide. If desired, add the
Threaded Handles to the guide and
position the handles relative to the
epicondyles. This does not set rotation
of the femoral component, but keeps
the distal cut oriented to the final
component rotation.
Once the proper orientation is
achieved, impact the IM guide until it
seats on the most prominent condyle.
After impacting, check to ensure that
the valgus setting has not changed.
Ensure that the guide is contacting at
least one distal condyle. This will set
the proper distal femoral resection.
Optional Technique: An Extramedullary
Alignment Arch and Alignment Rod can
be used to confirm the alignment. If
this is anticipated, identify the center
of the femoral head before draping. If
extramedullary alignment will be the
only mode of alignment, use a palpable
radiopaque marker in combination with
an A/P x-ray film to help ensure proper
location of the femoral head.
NOTE: The Mini Micro Cut Plate can be
used when templating has indicated
that a Micro implant is likely. When
the Mini Micro Cut Plate is attached
to the MIS Adjustable IM Alignment
Guide, Short, one millimeter (1mm)
less bone is removed. However, if a
significant flexion contracture exists
and no plate is attached, an additional
4mm will be removed compared to the
distal femoral cut when the Mini Micro
Cut Plate is attached. For less bone
resection, adjustments can be made
using the +2mm/-2mm holes on the
Mini Distal Cut Guide.

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique
12
Step Two
Cut the Distal Femur
While the Adjustable IM Alignment
Guide is being inserted by the surgeon,
the scrub nurse should attach the Mini
Distal Femoral Cutting Guide to the 0°
Distal Placement Guide (Fig. 2a).
Ensure that the attachment screw
is tight. Insert the Distal Placement
Guide with the cutting guide into the
Adjustable IM Alignment Guide until
the cutting guide rests on the anterior
femoral cortex (Fig. 2b). The Mini Distal
Femoral Cutting Guide is designed to
help avoid soft tissue impingement.
Optional Technique: The 3° Distal
Placement Guide can be used to place
the Mini Distal Femoral Cutting Guide
in 3° of flexion to protect the anterior
cortex from notching.
Using the 3.2mm drill bit, drill holes
through the two standard pin holes
marked “0” in the anterior surface of
the Mini Distal Femoral Cutting Guide,
and place Headless Holding Pins
through the holes (Fig. 2c).
Additional 2mm adjustments may be
made by using the sets of holes marked
-4, -2, +2, and +4. The markings on the
cutting guide indicate, in millimeters,
the amount of bone resection each
will yield relative to the standard distal
resection set by the Adjustable IM
Alignment Guide and Standard
Cut Plate.
If more fixation is needed, use two
3.2mm Headed Screws or predrill and
insert two Hex-head Holding Pins in the
small oblique holes on the Mini Distal
Femoral Cutting Guide, or Silver Spring
Pins may be used in the large oblique
holes (Fig. 2d).
The IM guide can be left in place during
resection of the distal condyle, taking
care to avoid hitting the IM rod when
using the oscillating saw.
Fig. 2a
Fig. 2c
Fig. 2b
Fig. 2d
Completely loosen the attachment
screw (Fig. 2e) in the Distal Placement
Guide. Then use the Slaphammer
Extractor to remove the IM guide and
the Distal Placement Guide (Fig. 2f).
Cut the distal femur through the
cutting slot in the cutting guide using
a 1.27mm (0.050-in.) oscillating saw
blade (Fig. 2g). Then remove the
cutting guide.
Check the flatness of the distal femoral
cut with a flat surface. If necessary,
modify the distal femoral surface
so that it is completely flat. This is
extremely important for the placement
of subsequent guides and for proper
fit of the implant.
If you prefer to complete tibial cuts
prior to completing the femur, refer
to page 22.
Fig. 2e
Fig. 2f
Fig. 2g

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique 13
Step Three
Size Femur and Establish
External Rotation
Flex the knee to 90°. Attach the MIS
Threaded Handle to the Mini A/P Sizing
Guide, and place the guide flat onto
the smoothly cut distal femur (Fig. 3a).
Apply the guide so that the flat surface
of the Mini A/P Sizing Guide is flush
against the resected surface of the
distal femur and the feet of the Mini
A/P Sizing Guide are flush against the
posterior condyles.
Slide the body of the Mini A/P Sizing
Guide along the shaft to the level of
the medullary canal. Position the guide
mediolaterally, and check the position
by looking through both windows of
the guide to ensure that the medullary
canal is not visible through either.
NOTE: Remove any osteophytes that
interfere with instrument positioning.
While holding the Mini A/P Sizing
Guide in place, secure the guide to
the resected distal femur using short
3.2mm (1/8 inch) Headed Screws or
predrill and insert short head Holding
Pins into one or both of the holes in
the lower portion of the guide. Do not
overtighten or the anterior portion will
not slide on the distal femur.
MIS Screws are available in 3 lengths
(27mm, 33mm, 48mm). The length
needed will vary depending on the
patient’s bone dimensions.
NOTE: Remove the Threaded
Handle before using the Screw
Inserter/Extractor.
Slightly extend the knee and retract
soft tissues to expose the anterior
femoral cortex. Clear any soft tissue
from the anterior cortex. Ensure that
the leg is in less than 90° of flexion
(70°-80°). This will decrease the
tension of the patellar tendon to
facilitate placement of the guide.
Attach the MIS Locking Boom to the
Mini A/P Sizing Guide. Ensure that the
skin does not put pressure on the top
of the boom and potentially change
its position. The position of the boom
dictates the exit point of the anterior
bone cut and the ultimate position
of the femoral component. When the
boom is appropriately positioned, lock
it by turning the knurled knob (Fig. 3b).
See Appendix 1 for alternative MIS
Telescoping Locking Boom technique.
Fig. 3a
Fig. 3b
Fig. 3c
Read the femoral size directly from
the guide between the engraved lines
on the sizing tower (Fig. 3c). There are
eight sizes labeled “A” through “H”. If
the indicator is between two sizes, the
closest size is typically chosen. If using
a posterior referencing technique, and
the indicator is between two sizes,
the larger size is typically chosen to
help prevent notching of the anterior
femoral cortex.

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique
14
If using a posterior referencing
technique, remove the Mini A/P Sizing
Guide and go to page 19, “Step Four –
Finish the Femur, Posterior Referencing
Technique.”
There are four External Rotation Plates:
0°/3° Left, 0°/3° Right, 5°/7° Left,
and 5°/7° Right. Choose the External
Rotation Plate that provides the desired
external rotation for the appropriate
knee. The 0° option can be used when
positioning will be determined by the
A/P axis or the epicondylar axis. Use
the 3° option for varus knees. Use
the 5° option for knees with a valgus
deformity from 10° to 13°. The 7°
option requires a standard exposure,
and is for knees with patellofemoral
disease accompanied by bone loss and
valgus deformity greater than 20°. In
this case, use the A/P axis to double
check rotation.
Attach the selected plate to the Mini
A/P Sizing Guide (Fig. 3d). Place two
Headless Holding Pins in the plate
through the two holes that correspond
to the desired external rotation, and
impact them (Fig. 3e). Leave the pins
proud of the guide.
NOTE: Do not impact the Headless
Holding Pins flush with the External
Rotation Plate.
Fig. 3d
Fig. 3e
Careful attention should be taken when
placing the headless pins into the
appropriate External Rotation Plate as
these pins also set the A/P placement
for the MIS Femoral Finishing Guide
in the next step of the procedure. It is
important to monitor the location of the
anterior boom on the anterior cortex of
the femur to help ensure the anterior
cut will not notch the femur. Positioning
the anterior boom on the “high” part
of the femur by lateralizing the location
of the boom can often lessen the
likelihood of notching the femur.
Unlock and rotate the boom of the
guide medially until it clears the medial
condyle. Then remove the guide, but
leave the two headless pins. These
pins will establish the A/P position and
rotational alignment of the Femoral
Finishing Guide.

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique 15
Step Four
Finish the Femur
Anterior Referencing Technique
Select the correct size MIS Femoral
Finishing Guide (silver colored) or
MIS Flex Femoral Finishing Guide
(gold colored) as determined by
the measurement from the A/P
Sizing Guide. An additional 2mm
(approximately) of bone is removed
from the posterior condyles when
using the Flex Finishing Guide.
Place the finishing guide onto the
distal femur, over the headless pins
(Fig. 4a). This determines the A/P
position and rotation of the guide.
Remove any lateral osteophytes
that may interfere with guide
placement. Position the finishing
guide mediolaterally by sliding it on
the headless pins. The width of the
finishing guide replicates the width
of the NexGen CR Femoral Component.
The width of the flex finishing guide
replicates the width of the NexGen
LPS, LPS-Flex, and CR-Flex
Femoral Components.
When the M/L position of the Femoral
Finishing Guide is set, use the Screw
Inserter/Extractor to insert a 3.2mm
Headed Screw or predrill and insert
a Hex-head Holding Pin through the
superior pinhole on the beveled medial
side of the guide (Fig. 4b). Then secure
the lateral side in the same manner. If
needed, predrill and insert two Short-
head Holding Pins through the inferior
holes on one or both sides of the guide.
For additional stability, use 6.5mm
screws in the peg holes.
Remove the headless pins from the
Femoral Finishing Guide (Fig. 4c) with
the Headless Pin Puller.
Use the Resection Guide through the
anterior cutting slot of the finishing
guide, and check the medial and lateral
sides to be sure the cut will not notch
the anterior femoral cortex (Fig. 4d).
Fig. 4a
Fig. 4b
Fig. 4c
Fig. 4d

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique
16
Optional Technique
To check the location of the anterior
cut and determine if notching will
occur, securely tighten the Locking
Boom Attachment to the face of the
finishing guide. Make certain that the
attachment sits flush with the Femoral
Finishing Guide (Fig. 4e). Connect the
MIS Locking Boom to the attachment
(Fig. 4f). The boom indicates the depth
at which the anterior femoral cut will
exit the femur.
Fig. 4e
Fig. 4f
1
4
3
2
Fig. 4g
Fig. 4h
Fig. 4i
Fig. 4j
Use the 1.27mm (0.050-in.) narrow,
reciprocating saw blade to cut the
base of the trochlear recess (Fig. 4i)
and score the edges (Fig. 4j). Remove
the finishing guide to complete the
trochlear recess cuts.
Use a 1.27mm (0.050-in.) narrow,
oscillating saw blade to cut the femoral
profile in the following sequence for
optimal stability of the finishing guide
(Fig. 4g):
1Anterior condyles
2Posterior condyles
3Posterior chamfer
4Anterior chamfers
Use the Patellar/Femoral Drill Bit to drill
the post holes (Fig. 4h).

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique 17
Fig. 4m
Posterior Referencing Technique
Select the correct size MIS Femoral
Finishing Guide (silver colored) or
MIS Flex Femoral Finishing Guide
(gold colored) as determined by
the measurement from the A/P
Sizing Guide. An additional 2mm
(approximately) of bone is removed
from the posterior condyles when
using the flex finishing guide.
Attach the Posterior Reference/
Rotation Guide to the selected
femoral finishing guide (Fig. 4k). Lock
the femoral position locator on the
rotation guide to the zero position (Fig.
4l). This zero setting helps to ensure
that, when the feet are flush with the
posterior condyles, the amount of
posterior bone resection will average
9mm when using the standard
MIS Femoral Finishing Guides, and
approximately 11mm when using the
MIS Flex Femoral Finishing Guides.
Fig. 4k
Fig. 4l
If desired, attach the MIS Locking
Boom to the face of the finishing guide
to check the location of the anterior
cut and determine if notching will
occur (Fig. 4n). The boom tip indicates
where the anterior femoral cut will exit
the bone.
Remove any lateral osteophytes
that may interfere with guide
placement. Position the finishing
guide mediolaterally. The width of the
finishing guide replicates the width of
the NexGen CR Femoral Component.
The width of the flex finishing guide
replicates the width of the NexGen
LPS, LPS-Flex, and CR-Flex Femoral
Components.
Place the finishing guide on the distal
femur, bringing the feet of the rotation
guide flush against the posterior
condyles of the femur (Fig. 4m).
Set the rotation of the finishing
guide parallel to the epicondylar
axis. Check the rotation of the guide
by reading the angle indicated by
the Posterior Reference/Rotation
Guide. The epicondylar line is rotated
externally 0° to 8°, (4±4°), relative to
the posterior condyles. The external
rotation angle can also be set relative
to the posterior condyles, lining up the
degrees desired.
Fig. 4n

Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique
18
23
4
1
When the proper rotation and the
mediolateral and anteroposterior
position are achieved, secure the
finishing guide to the distal femur. Use
the Screw Inserter/Extractor to insert
a 3.2mm Headed Screw or predrill and
insert a Hex-head Holding Pin through
the superior pinhole on the beveled
medial side of the Femoral Finishing
Guide (Fig. 4o). Then secure the
lateral side in the same manner. For
additional stability, predrill and insert
two Short-head Holding Pins through
the inferior holes on one or both sides
of the guide.
Fig. 4o
Use a 1.27mm (0.050-in.) narrow,
oscillating saw blade to cut the femoral
profile in the following sequence for
optimal stability of the finishing guide
(Fig. 4p):
1Anterior condyles
2Posterior condyles
3Posterior chamfer
4Anterior chamfers
Use the Patellar/Femoral Drill Bit to drill
the post holes (Fig. 4q).
Use the 1.27mm (0.050-in.) narrow,
reciprocating saw blade to cut the
base of the trochlear recess (Fig. 4r)
and score the edges (Fig. 4s). Remove
the finishing guide to complete the
trochlear recess cuts.
Fig. 4p
Fig. 4q
Fig. 4r
Fig. 4s