Zimmer MIS Multi-Reference Surgical Technique page 22

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Zimmer MIS Multi-Reference 4-in-1 Femoral Instrumentation Surgical Technique
Apply the matching size MIS Trochlear
Guide to the MIS Notch/Chamfer Guide
with the holes in the Trochlear Guide
aligned with the threaded holes in the
Notch/Chamfer Guide (Fig. 4y). Thread
the MIS Threaded Handle through
one of the threaded holes to secure
the Trochlear Guide to the MIS Notch/
Chamfer Guide (Fig. 4z).
Fig. 4y Apply the matching size MIS Trochlear
Guide with the holes aligned
Fig. 4z MIS Trochlear Guide secured to
MIS Notch/Chamfer Guide
Protect the tibia. Use a reciprocating
saw through the slots in the Trochlear
Guide to cut the sides and base of the
trochlear groove (Fig. 4aa). Remove
the Trochlear Guide, and insert an
osteotome over the resected tibial
surface below the trochlear groove.
Then use the reciprocating saw to finish
the trochlear cuts.
Remove the MIS Notch/Chamfer Guide.
Fig. 4aa Cut the sides and base of the
trochlear groove
Using the MIS Notch/Chamfer
Guide to downsize the femur
If there is a need to downsize the
femur, the MIS Notch/Chamfer and
Trochlear Guide can be used for
sizes C-G Standard implants and the
Notch/Chamfer Guide can be used for
all flex sizes.
NOTE: Size A, B and H MIS Trochlear
Guides cannot be used for downsizing.
Select the preferred size Notch/
Chamfer Guide and pin to the distal
femur with two Short Spring Screws
or 3.2mm (1/8-inch) headed screws
(48mm length). Alternatively, insert two
Hex Headed pins. Ensure that the guide
is seated on the anterior and distal
femur. Use a reciprocating saw to recut
the sides of the intercondylar box. Use
an oscillating saw to recut the anterior
and posterior chamfers.
If downsizing for a CR-Flex or LPS-Flex
implant, use the posterior surface of
the MIS Notch/Chamfer Guide for the
posterior cut. If downsizing for a CR
or LPS implant, use the MIS Threaded
Handle to attach the matching size MIS
Trochlear Guide to the Notch/Chamfer
Guide, and use the posterior surface
of the MIS Trochlear Guide for the
posterior cut.
Remove the MIS Trochlear and Notch/
Chamfer Guides.
Surgeon Notes & Tips
• Although a sequence of femoral
cuts has been provided, the cuts
may be made in any sequence. It
is recommended for the surgeon to
complete the cuts in a consistent
sequence to help ensure that all
cuts are performed. However, the
peg holes should be drilled prior to
assembling the MIS Trochlear Guide.
• If the MIS Femoral Finishing Guide is
used, the flexion gap should equal
the extension gap.
• If the MIS Flex Femoral Finishing
Guide is used, then the flexion gap
will be approximately 2mm greater.
For a Flex implant, use an MIS
Spacer Block with the MIS Spacer
Block Flex Adapter to check
flexion gap.
• An oscillating saw with a narrow
blade may also be used, or a
reciprocating blade may be used
to cut the sides and a chisel or
osteotome used to cut the base of
the notch.
• Remember that the incision can be
moved both medial-to-lateral and
superior-to-inferior as needed to
gain optimal exposure.
• To facilitate the use of the mobile
window, when resecting on the
medial side, use retraction on
the medial side while relaxing
the lateral side. Likewise, when
resecting on the lateral side, use
retraction on the lateral side while
relaxing the medial side.