lEEIIflV
`PS
`
`Complete Knee Solution
`
`
`
`i
`‘
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`
`
`NEXEEN®
`
`BIIMPlHE
`
`KNEE
`
`SlllllTIIIN
`
`Epicondylar
`Instrumentation
`Surgical
`Technique
`For Legacy'“
`Posterior
`
`Stabilized
`
`Knee
`
`® Zimmer
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`WMT 1028-1
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`WMT 1028-1
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`INTBIIIIIIBIIIIN
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`Successful total knee arthroplasty is directly
`
`dependent on reestablishment of normal lower
`
`extremity alignment, proper implant design
`
`and orientation, secure implant fixation, and
`
`adequate soft tissue balancing and stability. The
`
`NeXGen Epicondylar Instruments are designed
`
`to help the surgeon accomplish these goals by
`
`combining optimal alignment accuracy with a
`
`simple, straightforward technique.
`
`The center of the hip, knee, and ankle are
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`restored 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
`
`collateral ligament attachment to the epicondyles,
`
`(the transepicondylar axis). The A/P position
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`of the femoral component is ascertained by a
`
`combination of anterior and posterior referenc-
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`ing. Well-designed instruments allow accurate
`
`cuts to help ensure secure component fixation.
`
`Ample component sizes allow soft tissue
`
`balancing with appropriate soft tissue release.
`
`This surgical technique was developed in
`
`conjunction with:
`
`John N. Insall, MD.
`Director, Insall/Scott/Kelly Institute
`for Orthopaedics and Sports Medicine
`Beth Israel Medical Center-North Division
`
`New York, New York
`
`Giles R. Scuderi, MD.
`Director, Insall/Scott/Kelly Institute
`for Orthopaedics and Sports Medicine
`Attending Surgeon
`Beth Israel Medical Center-North Division
`
`New York, New York
`
`*Vaiious components 01 the Nc'XGen Complete Knee Solution and MICRO ill/LL Instrumentation System are covered by one 01 more otttlie
`following: U. S. Patent[5 4, 281 ,;420 4 3,36, 618; 4,491 ,;987 4,524,766; 4,759,351); 4,979,957, 4,997,445; 5,192,323; 5,255 ,8;38 5,290,313; 5 ,326,362;
`5,344,423; 5,3838,7;5 5,387,241, 5,395,377; 5,405,396; 5431,661i-,5,443,518, 5,4586,45; 5,474,559, 5,4844,46 5,486, 180, 5,492,67;15,540,696,
`5, 549, 686; D346, 979; D365, 396; D367, 71;)6 D369, 863; D372, 309; D373, 825 Other U S. and loteign patents pending
`
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`WMT 1028-2
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`WMT 1028-2
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`PIIHIPEIIATIVE PlANNINE
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`Use the template overlay (available through your
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`Zimmer representative) to determine the angle
`between the anatomic axis and the mechanical
`
`axis. This angle will be reproduced intraopera—
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`distal femur will be cut perpendicular to the
`
`mechanical axis and, after soft tissue balancing,
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`will be parallel to the resected surface of the
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`proximal tibia.
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`MechanicalAxis
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`tively. This surgical technique ensures that the
`MechanicalAxis
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`SlllllilflAl APPIIIIAIIH
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`The femur, tibia, and patella are prepared
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`independently, and can be cut in any sequence
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`using the principle of measured resection
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`(removing enough bone to allow replacement by
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`the prosthesis). Adjustment cuts may be needed
`
`later (pg. 15).
`
`Transverse Axis
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`‘
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`WMT 1028-3
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`WMT 1028-3
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`Read the femoral size directly from the guide
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`(Fig. 2). If the indicator is between two sizes, the
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`smaller size is typically chosen which will require
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`”in between” placement of the A/P Cutting Guide.
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`(See page IOjor more detail on “in between” place
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`ment.) The sizing can be confirmed when the
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`anterior and posterior femoral condyles are cut,
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`along with any adjustment to the A/P location.
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`
`
`
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`Fig. 2
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`SIZE TIIE fEMIIII
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`Drill a hole in the center of the patellar sulcus
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`of the distal femur (Fig. 1), making sure that the
`
`hole is parallel to the shaft of the femur in both
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`the anteroposterior and lateral projections. The
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`hole should be approximately one—half to one
`
`centimeter anterior to the origin of the posterior
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`cruciate ligament, Medial or lateral displacement
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`of the hole may be needed according to preop—
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`erative templating of the AP. radiograph.
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`Use the 8mm 1M Drill with step to enlarge the
`entrance hole on the femur to 12mm in diameter.
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`This will reduce 1M pressure during placement
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`of subsequent 1M guides. Suction the canal to
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`remove medullary contents.
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`Insert the 1M Femoral A/P Sizing Guide into the
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`hole until it contacts the distal femur. Compress
`
`the guide until the anterior boom contacts
`
`the anterior cortex of the femur, and both feet
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`rest on the cartilage of the posterior condyles.
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`Flexion or extension of the guide can produce
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`inaccurate readings. Check to ensure that the
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`boom is not seated on a high spot, or an unusu-
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`ally low spot on the anterior cortex.
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`T
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`WMT 1028-4
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`WMT 1028-4
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`ESJABHSH fiMflBA‘l
`AllEN‘MENI
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`The Standard cut Block must be attached to a
`the IM Alignment Gulde for a standard dlstal
`femoral resection. The plate should be tight-
`
`Ih this step, the valgus angle and depth of distal
`femoral resection are set.
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`ened on the guide prior to use, but the screws
`should be loosened for sterilization. Remove the
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`First, set the [M Alignment Guide to the proper
`valgus angle as determined by preoperative
`radiographs. Check to ensure that the proper
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`Standard Cutting Block if a large flex10n contrac—
`ture ex15ts. This will allow for an additional 3mm
`Of distal femoral bone resection (Fig. 4)'
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`“Right" or “Left” indication is used and engage
`the lock mechanism
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`(Fig. 3).
`
`Fig. 4
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`
`
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`
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`femoral component, but keeps the distal cut
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`insert the guide into the IM hole on the distal
`femur.
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`Optional Technique:
`An Extramedullazy AlignmentArch and Alignment
`
`0
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`Rod can be used to confirm the alignment. If this
`
`is anticipated, idennfi/ the center of thefemoral
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`head before draping. If extramedullaiy alignment
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`will be the only mode ofalignment, use a palpable
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`radiopaque markerin combination with an A/P
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`X—ray to ensure proper location of thefemoral head
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`Use the epicondylar axis as a guide in setting the
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`orientation of the 1M Alignment Guide. Position
`
`the handles of the guide relative to the epi-
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`condyles. This does not set rotation of the
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`
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`Fig. 3 oriented to the final component rotation.
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`
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`Once the proper rotation is achieved, impact
`
`the 1M guide until it seats on the most prominent
`
`condyle. After impacting, check to ensure that
`the valgus setting has not changed. Ensure that o
`the guide is contacting at least one distal condyle.
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`This will set the proper distal femoral resection.
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`WMT 1028-5
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`WMT 1028-5
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`BIII THE fllSTAl HMIIII
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`While the 1M Alignment Guide is being inserted
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`by the surgeon, the scrub nurse should attach the
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`Distal Femoral Cutting Guide to the appropriate
`Distal Placement Guide.
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`The Distal Placement Guide sets 3° of flexion
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`into the distal femoral cut to help protect against
`
`notching of the anterior femoral cortex.
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`Ensure that the attachment screw is tightened
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`(Fig. 5). Verify that the anterior thumb screw is
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`backed out, away from the bone surface.
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`
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`Fig. 5
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`Insert the Distal Placement Guide with the
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`Cutting Guide into the 1M Alignment Guide until
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`the Cutting Guide rests on the anterior femoral
`cortex.
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`To further stabilize the guide, turn the anterior
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`screw by hand until it contacts the anterior
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`femoral cortex (Fig. 6). Do not overtighten.
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`
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`Place holding pins through two or three of the
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`pin holes in the anterior surface of the Distal
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`Femoral Cutting Guide to secure it further to
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`the femur (Fig. 7).
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`
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`
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`Fig. 7
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`Completely loosen the attachment screw (Fig. 8)
`in the Distal Placement Guide.
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`_fl—
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`WMT 1028-6
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`WMT 1028-6
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`Use the Slaphammer Extractor to remove the IM
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`Check the flatness of the distal femoral cut with
`
`Alignment Guide and the Distal Placement Guide
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`a flat surface. (A/P Cutting Guides or the Distal
`
`
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`Femoral Recutting Plate may be used for this
`
`purpose.) If necessary, modify the distal femoral
`
`surface so that it is completely flat. This is
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`extremely important for the placement Of
`subsequent guides and for proper fit Of the
`implant.
`
`g)
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`(Fig. 9).
`
`Cut the distal femur through the distal cutting
`
`slot in the cutting guide using a .050" blade
`(Fig. 10). This slot removes the same amount
`of bone that will be replaced by the femoral
`component. (The correct thickness of bone
`
`resection is determined in the previous step by
`
`having the 1M Alignment Guide flush against
`
`the most prominent condyle.)
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`
`
`Fig. 10
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`—
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`WMT 1028-7
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`WMT 1028-7
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`(l
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`ESTABIISH [[Mflnnl
`IIII'I'M'IIIN
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`Plac: thie EpliiondylarGuije along the line drawn
`on t e ista emur(F1g. 1
`). Ensure correct
`orientation by checking the handles of the guide
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`Identify the epicondyles. To identify the lateral
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`relative to the epicondyles. The handles should
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`epicondyle it is necessary to dissect away the
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`be in line with the axis. Center the guide medio—
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`patello—femoral ligament. The lateral epicondyle
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`laterally using the line along the patellar sulcus
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`is a discrete point at the center of the lateral
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`or the intramedullary canal.
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`collateral ligament attachment. The medial
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`
`
`epicondyle can be found by removing the
`
`synovium from the medial collateral ligament
`attachment to the femur. The medial collateral
`
`ligament has a broad attachment to the medial
`
`epicondyle forming an approximate semicircle
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`(Fig.11). Choose the center of the diameter. Mark
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`these two points with methylene blue (Fig. 12).
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`Then, draw a line between the two epicondyles
`
`on the resected surface of the distal femur (Fig.
`
`13). This line represents the epicondylar axis.
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`A line can also be drawn along the deepest point
`
`of the patellar sulcus to serve as an additional
`
`reference point.
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`Fig. 11
`
`Fig. 13
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`Fig. 14
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`WMT 1028-8
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`—IT—
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`WMT 1028-8
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`Sfflllllllfllli lANllMllllllS fllfl FEMIIfllllrlllllMlllll
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`A/P Axis
`
`Q
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`
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`The A/P axis of the distalfemur as defined by the
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`deepest point ofthe patellar sulcus, is apprordmately
`
`at right angles to the epicondylar line although
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`there is considerable variation, (90 °i 7 °).’
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`Posterior Condyles
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`The epicondylar line is rotated externally 0—8", (4 ° i
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`4% relative to the posterior condylar line (Fig. 15).
`
`The Posterior Reference/Rotation Guide should
`read between 0° and 8°.
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`Both of these secondary landmarks can be used to
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`confirm femoral rotation.
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`When the proper rotation is achieved, secure the
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`Epicondylar Guide with two pins.
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`Using an oscillating blade marked to a 30mm
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`depth, cut the distal femur through the slot in
`
`the Epicondylar Guide (Fig. 16). The Epicondylar
`
`Guide provides a 30mm line in order to measure
`
`and mark the oscillating blade.
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`Fig. 15
`
`
`
`
`
`_fl_
`
`ez DE. Rotational Landmarks and Sizing of the
`1) Poilvache PL, Insall IN, Scuderi GR, Font-R0 '
`at the Knee Society Speciality Day, Atlanta, GA, Fe . 25, 1996.
`
`Writes—enter
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`—
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`WMT 1028-9
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`Ellflllllllli HIE IIEEE'BIIII'N, [WEI IISINE HIE
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`I'IISIEIIIIIII BESEIITIIIN lillllllf
`
`Attach the Posterior Resection Gauge to the
`
`A/P Cutting Guide. Rotate the arm of the gauge
`
`to check the posterior resection level (Fig. 19).
`
`The points where the tip of the arm contact the
`
`posterior condyles indicates the position of the
`
`posterior condyles of the femoral component, not
`
`the resection level. (Note: Typically, more bone is
`
`removed from the medial posterior condyle.)
`
`
`
`Fig. 19
`
`If the posterior condyle location is not satisfac—
`
`tory, reevaluate the sizing step, or continue with
`the Posterior Reference/Rotation Guide check
`
`which is detailed next.
`
`
`
`cur THE AllTElIlllll
`
`Ann'pnsrinlnn
`
`fEMlIBAl lillllIIVlES
`
`Select the correct size A/P Cutting Guide using
`the measurement from the 1M Femoral A/P
`
`Sizing Guide. Insert the fin of the A/P Cutting
`
`Guide into the slot cut in the distal femur (Fig. 17).
`This determines the rotation of the instrument.
`
`
`
`To set the A/P location, tap the guide on the
`
`anterior edge until the boom contacts the anterior
`
`femoral cortex (Fig. 18). The boom indicates the
`
`depth at which the anterior cut will exit the femur.
`
`The resection level can be checked using either
`
`the Posterior Resection Gauge or the Posterior
`Reference/Rotation Guide.
`
`Fig. 18
`
`
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`WMT 1028-10
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`_n_
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`WMT 1028-10
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`lirllffl‘lllllli lflf .H'ESEIHIIIN [WEI llSil‘llli HIE
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`I'll-Slflllflll BEFEHENEE/fllflflllflfl lllllllf
`
`The Posterior Reference/Rotation Guide may be
`
`used in place of the Posterior Resection Gauge
`
`to verify femoral sizing and/or check rotation.
`
`Lock the femoral position indicator on the
`Posterior Reference/Rotation Guide to the zero
`
`(0) position (Fig. 20). This zero setting ensures
`
`that, when the feet are flush with the posterior
`
`condyles, the amount of posterior bone resection
`
`will average 9mm.
`
`
`
`Attach the Posterior Reference/Rotation Guide
`
`to the A/P Cutting Guide. If the posterior condyles
`
`prevent this guide from seating, unlock the
`
`femoral position indicator. The resulting femoral
`
`position indicator reading represents the variation
`
`from the standard posterior resection required to
`
`balance flexion and extension gaps.
`
`With this information, the A/P Cutting Guide may
`
`be adjusted in order to minimize any potential
`
`imbalance in the flexion and extension gaps. The
`
`3° distal flexion cut will facilitate this adjustment
`
`and help to protect against notching of the
`anterior femoral cortex.
`
`“Ill IIHWEHI” Sl‘llllli
`
`Typically, it is better to choose the smaller size
`
`when selecting afemoral component. This means,
`
`however, that additional bone must be removed
`
`either anteriorly 0r posteriorly. Ifadditional anterior
`
`bone is removed, there is a risk ofnotching the
`
`femur. Additional posterior resection enlarges the
`
`flexion gap. ”In-between” placement minimizes
`
`both these reflects. By moving the anterior boom
`
`of the A/P Cutting Guide medially, the guide can
`
`be positioned more posteriorly and an additional
`
`2—3mm ofan terior bone can be resected. The 3°
`
`distalfemoral cutfacilitates this shift and protects
`
`against potential anterior notching. The Posterior
`
`Reference/Rotation Guide helps determine ”in
`
`between” placement. The zero (0) mark on the
`
`Posterior Reference/Rotation Guide measures an
`
`average 9mm posterior resection and provides a
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`scale which indicates any variancefrom that 9mm
`
`average. If the posterior resection, as determined
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`—___4___.___‘__al__'__—__—._-4
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`For example, the 2mm line below the "0" setting
`
`by the guide, is not within the 2mm markings, the
`
`would indicate that 2mm of additional posterior
`
`femoral size should be re—evaluated.
`
`condyle bone would be resected. Stated another
`
`way, the flexion gap would be 2mm larger than
`
`the extension gap.
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`K).
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`WMT 1028-1 1
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`WMT 1028-11
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`«A
`'1»,
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`Insert two pins to secure the MP Cutting Guide
`(Fig. 21). Use the appropriate thickness (.050"/
`
`Remove the A/P Cutting Guide and excise the
`anterior and posterior cruciate ligaments and
`
`1.27mm) blade and an oscillating saw to cut the
`
`the menisci or their remnants.
`
`
`
`anterior and posterior femoral condyles (Fig. 22).
`
`To yield the optimum cut and implant fit, be sure to use a blade of proper thickness.
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`WMT 1028-12
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`IIIIT THE PBIIXIMM "BIA
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`travel so it can be adjusted up or down.
`
`To improve the exposure of the tibial surface,
`
`Place the foot of the Extramedullary Tibial
`
`lever the tibia anteriorly using the Tibial Retractor.
`
`Carefully position the retractor so it hugs the
`
`posterior cortex of the tibia subperiosteally to
`
`prevent neurovascular injury. Another Tibial
`
`Retractor can be used to retract the patella
`
`
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`laterally.
`
`The Extramedullary Tibial Cutting Guide allows
`
`for variability in the thickness of tibial resection
`
`after the alignment of the guide has been
`
`secured. This facilitates the handling of bone
`
`defects in the proximal tibia. Initially set the
`
`cutting platform in the middle of its range of
`
`Fig. 23
`
`Cutting Guide over the distal tibia pointing to
`
`the center of the ankle (Fig. 23). The center of
`
`the talus (the true center of the ankle) is about
`
`5—10mm medial to the midpoint between the
`
`subcutaneous palpable medial and lateral
`malleoli. Another accurate landmark is the
`
`subcutaneous tibial crest about 3 inches above
`
`the ankle joint. This usually corresponds with
`the true center of the ankle.
`
`Adjust the slide at the foot of the guide so that
`
`the cutting head is parallel to the proximal tibial
`
`plateau (Fig. 24).
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`WMT 1028-13
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`WMT 1028-13
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`Position the guide at the proximal tibia so it
`
`is proximal to the tibial tubercle beneath the
`
`infrapatellar ligament. Center the guide over the
`
`proximal tibia in the mediolateral direction so
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`it parallels the mechanical axis of the tibia. The
`
`longitudinal axis of the guide will usually lie just
`
`medial to the midpoint of the tibial tubercle and
`
`be centered over the intercondylar eminence.
`
`Hold the guide in position and pin it to the
`
`proximal tibia with one pin on the lateral side.
`
`Fine tune all the distal guide positions. Then,
`
`insert a second pin in the proximal portion to
`
`secure the guide.
`
`Adjust the cutting platform to the desired level
`
`of tibial resection (Fig. 25).
`
`A Tibial Depth Resection Gauge is available
`
`to help determine the position of the cutting
`
`platform. Place the 10mm tab into the cutting
`
`slot, and adjust the platform until the arm of the
`
`gauge rests on the cartilage of the good condyle
`
`(Fig. 26). This will allow the removal of the same
`
`amount of bone that the thinnest tibial compo-
`
`nent would replace.
`
`
`
`Fig. 26
`
`Before pinning the cutting platform to the bone,
`
`check the location of the cut on the posterior
`
`tibia by placing the Tibial Resection Guide
`
`through the cutting slot (Fig. 27).
`
`
`
`Secure the cutting platform by inserting two
`
`1/8" fixation pins or two Silver Spring Pins. The
`
`cutting platform is designed so the tibial cut can
`
`be made either on top of the guide or through
`
`the slot in the guide. If the Tibial Depth Resection
`
`Gauge was used to determine the amount of
`
`resection, the slot should be used to make the
`cut.
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`WMT 1028-14
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`T
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`WMT 1028-14
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`cut the upper surface of the tibia flat (Fig. 28).
`
`Remove the Extramedullary Tibial Cutting Guide
`
`when the tibial preparation is complete.
`
`
`
`If the first cut of the proximal tibia is not deep
`
`enough, lower the cutting platform to the desired
`
`level. Secure the telescoping portion of the guide
`
`using different pin holes on the cutting platform
`
`and recut the tibia. Calibrations on the telescop-
`
`ing portion of the guide are 2mm apart.
`
`Optional Techniques:
`When there is a need to resect additional tibia]
`
`bone, use the 2mm Recutter. If varus/valgus
`
`correction is required, use the 2° Varus/Valgus
`
`Recutter. Both recutters reference the existing cut
`
`and are secured to the bone with 1/ ” pins.
`
`Insert tension Spreaders and clean out the
`
`intercondylar notch. The cuts should appear
`
`parallel.
`
`Perform the final ligament balance.
`
`
`
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` Use a 1.27mm (.050") oscillating sawblade to
`
`
`MEASIIIIE TIIE HEXIIIN
`
`Mill HHENSIIIN BAP-S
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`With the knee flexed, insert the thinnest Spacer/
`
`Alignment Guide between the resected surfaces
`
`of the femur and tibia. Insert progressively
`
`thicker Spacer/Alignment Guides until the proper
`
`soft tissue tension is obtained (this is defined
`
`as very limited A/P motion when pushing and
`
`pulling on the tibia). Center the arm of the guide
`
`over the tibial tubercle and insert the Alignment
`
`Rod with Coupler through the hole in the arm.
`
`The rod should be parallel to the anatomic axis
`
`of the tibia (Fig. 29), and the distal end of the rod
`
`should be near the center of the ankle, but slightly
`closer to the medial malleolus.
`
`Remove the Spacer/Alignment Guide and extend
`
`the knee. Reinsert the Spacer/Alignment Guide
`
`and the Alignment Rod with Coupler. With the
`
`knee fully extended and the foot dorsiflexed, the
`
`distal end of the rod should be slightly closer to
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`
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`WMT 1028-15
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`WMT 1028-15
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`modate this size of spacer, the distal femur should
`
`-
`
`»w
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`the medial malleolus. Attach the Alignment Rod
`
`IIISl‘lll HMlllilll BEBIIIIINE
`
`extension to the Coupler. The proximal end of
`
`The Spacer/Alignment Guide that was selected
`
`the rod should be over the center of the hip joint
`
`for the tlexion space should fit comfortably in
`
`(Fig. 30).
`
`If the knee is too tight in flexion and extension
`
`with the thinnest spacer, the proximal tibia
`
`should be recut. If the knee is tight only in
`
`extension, the distal femur should be recut.
`
`If the knee is tight only in flexion, the femoral
`
`extension. If the extension space will not accom-
`
`be recut using the Distal Femoral Recutter.
`
`Note.- When the extension space is too light, it is
`
`incorrect to solve this problem by using a thinner
`
`spacer block in jlexion (i.e., a thinner tibial compo—
`
`nent when this option is available). A thinner tibial
`
`
`
`
`
`
`
`
`
`
`
`component should be downsized.
`
`
`component will give a looserflexion fit that could
`result in flexion instabilig/ or dislocation.
`
`
`
`The amount of additional distal femoral resection
`
`
`is determined by using thinner spacer blocks in
`extension. (Use Minus Spacer Blocks if necessary.)
`
`
`
`The Distal Femoral Recutting Guide provides
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Fig. 30
`
`quick, reproducible results to recut 3 or 5mm
`
`of bone. Lay the guide on the anterior cut surface
`
`of the femur with the engraving facing up. Place
`
`pins through the appropriate holes for the amount
`
`of additional resection desired (3 or 5mm) and
`
`slide the guide proximally until the pins contact
`
`the existing distal cut surface. Pin the recutting
`
`guide in place with standard or silver spring pins
`
`and recut through the slot (Fig. 31).
`
`7
`
`
`
`
`WMT 1028-16
`
`

`

`
` H‘MIIIIM IEIIMPIIIIH" IIIIWNBIIIHIE
`
`When the flexion space is smaller than the
`extension space, consideration should be given
`
`the anterior boom or the Posterior Resection
`Gauge to verify A/P POStttOh-
`
`A/P Cutting Guide within the femoral slot, using
`
`to downsizing the femoral component. To down—
`size, reinsert the smaller size A/P Cutting Guide
`into the MP slot on the femur. The additional
`bone resection can be divided between anterior
`and posterior femur or be completely posterior,
`according to the surgeon’s judgment. The exact
`position t5 determined by moving the fin 0f the
`
`Downsizing can also be accomplished by using
`the Epi Notch/Chamfer Guide of the next smaller
`femoral size in the next step. The posterior aspect
`of the guide can be used as a cutting block to
`recut the posterior condyles for that femoral size
`(Fig. 32). This results in 4mm of additional bone
`resection posteriorly and none anteriorly.
`
`
`
`Fig. 32
`
`WMT 1028-17
`
`
`
`WMT 1028-17
`
`

`

`
`
`HNISII THE fEMll'll
`
`Select the Epi Notch/Chamfer Guide that is the
`
`same size as the A/P Cutting Guide used in the
`
`previous step. Place the Epi Notch/Chamfer
`Guide flush with the anterior and distal surfaces
`
`of the femur (Fig. 33).
`
`
`
`Position the guide mediolaterally, using the
`
`anterior portion of the guide to replicate the
`
`location for the anterior lateral flange of the
`
`femoral component. This is important because
`
`it dictates the mediolateral positioning of the
`
`femoral component. Also, the width of the guide
`
`equals the distal width of the Legacy LPS femoral
`
`component. Ensuring that the guide does not
`
`move, insert two to three pins to secure the
`
`guide to the femur (Fig. 34). (Pin the anterior
`
`flange first to stabilize the M/L position.)
`
`
`
`Fig. 34
`
`f4")
`
`
`
`insert the corresponding Notch Slot Attachment
`
`into the Epi Notch/Chamfer Guide. Using the
`
`same oscillating blade marked to a 30mm depth,
`
`cut the sides of the intercondylar notch for the
`
`cam of the femoral component (Fig. 35). It is
`
`important to cut to the 30mm mark to ensure
`
`proper depth of the box cut. Finish the box cut
`
`by cutting the base of the intercondylar notch
`
`with a reciprocating or narrow oscillating
`
`sawblade (Fig. 36).
`
`Remove the Notch Slot Attachment.
`
`
`
`
`
`Fig. 35
`
`Fig. 36
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`T
`
`T 1028-18
`
`
`WMT 1028-18
`
`

`

`
`
`
`
`Make the anterior and posterior chamfer cuts
`
`trochlear recess through the slot with a recipro-
`
`through the slots in the guide (Fig. 37).
`
`cating sawblade (Fig. 39).
`
`Use a reciprocating sawblade or narrow oscillat-
`
`Drill the holes for the two femoral pegs (Fig. 40).
`
`ing blade to first cut the base of the trochlear
`
`recess (Fig. 38). Do not angle or fan the blade
`
`medially or laterally. Then, cut the sides of the
`
`Remove the Notch/Chamfer Guide.
`
`Fig. 39
`
`
`Fig. 38
`
`
`
`WMT 1028-19
`
`
`
`WMT 1028-19
`
`

`

`
`
`l
`
`2""
`
`\‘V‘w
`
`Hmsn tilt mm
`
`The tibia can be finished prior to trial reduction
`
`if the implant position will be chosen based on
`
`anatomic landmarks. Alternatively, the provi—
`
`sionals, in combination with the sizing plate,
`
`can be used to perform a trial range of motion
`to aid in tibial location.
`
`Position Based on Anatomic Landmarks
`
`Select the Stemmed Tibial Sizing Plate Provi—
`
`sional* that provides the desired tibial coverage
`
`(Fig. 41).
`
`
`
`Fluted Stem Tibial Sizing Plate
`
`Fig. 41
`
`Compare the selected color code designation
`
`on the tibial sizing plate provisional to the color
`
`code designations on the anterior flange of the
`
`selected femoral provisional. At least one of
`the colors listed on the femoral trial must
`
`match at least one color on the sizing plate
`
`to ensure that the components in combination
`
`with the articular surface will be kinematically
`
`matched. The colors must match exactly. For
`
`example, Yellow = Yellow. The striped colors are
`
`not the same as the standard colors (Yellow :6
`
`Striped Yellow) and should not be viewed as a
`match. If there is no match between the femoral
`
`provisional and sizing plate, adjust the size of
`
`the sizing plate being used to yield a match.
`
`
`
`
`
`Attach the modular handle to the selected sizing
`
`plate by depressing the button on the handle
`
`and engaging the dovetail on the handle with
`
`the dovetail on the sizing plate. Secure by
`
`tightening the thumb screw (Fig. 42).
`
`Align the handle with the anterior aspect of the
`
`tibia. Rotate the sizing plate so the handle points
`
`at, or slightly medial to, the midpoint of the
`
`tibial tubercle (Fig. 43). The alignment rod can
`
`be used to aid in confirming proper varus/
`
`valgus alignment.
`
`Pin the plate in place with two Short Head
`
`Holding Pins.
`
`Fig. 43
`
`
`
`
`* Do not use the Pegged Tibial Tray with the NexGen LPS System.
`
`T
`
`T 1028-20
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`WMT 1028-20
`
`

`

`If using the provisionals and performing a range
`
`and sizing plate. Ensure that soft tissue balance
`
`of motion to determine tibial component place-
`
`is appropriate.
`
`color match chosen for the femoral provisional
`
`
` Position Based on Trial Range of Motion
`
`ment, complete the patella preparat1on first.
`Then, select the proper srze of t1b1a15121ng plate
`prov1510nal. Ensure that the plate chosen
`prov1des the desrred Ublal coverage. Agaln, a
`color match With the femoral provrsional must
`occur for a proper kinematic match.
`
`Flex and extend the knee with the provisionals
`in place. With proper soft tissue balancing
`complete, the tibial component tends to seat
`itself in the position where it best articulates
`with the femur (Fig. 44).
`
`
`
`Insert the proper femoral provrsional, patella,
`Slzmg plate and art1cu1ar surface. Select the
`color of articular surface that is the same as the
`
`After this self-centering process has occurred,
`mark the position of the component with
`methylene blue or electro—cautery (Fig. 45).
`
`
`Fis- 45
`
`Fig. 44
`
`—
`
`WMT 1028-21
`
`l,j
`
`WMT 1028-21
`
`

`

`C lllilll'l. PIIAIE PIIEPA‘BMIIIN
`Once the sizing plate is pinned in position, place
`the Cemented Stem Tibial Drill Guide on the
`
`sizing plate and drill for the stem with the
`
`Cemented Stem Tibial Drill (Fig. 46). Drill until
`
`the first engraved line on the drill is in line with
`
`the top of the guide (Fig. 47).
`
`Fig. 46
`
`
`
`
`
`
`
`
`
`
`
`Fig. 47
`
`Assemble the proper size Tibial Broach to the
`
`Broach Impactor (Fig. 48). The broach can only
`be assembled from the front.
`
`Fig. 48
`
`
`
`T
`WMT 1028-22
`
`
`WMT 1028-22
`
`

`

`
`
`
` J
`
`50). Impact the provisional (Fig. 51).
`
`Be sure that the provisional is fully seated against
`
`the resected proximal tibia.
`
`WMT 1028-23
`
`Seat the impactor on the sizing plate and impact
`
`the broach to the proper depth indicated by the
`
`etched groove on the shaft aligning with the
`
`impactor handle. The broach has a built—in stop
`
`so it cannot be over—impacted (Fig. 49).
`
`Remove the Broach Impactor assembly using
`
`the built—in slaphammer, then remove the sizing
`
`plate.
`
`
`
`_____k__.__._4__‘_..a
`
`
`
` Use the correct size Stemmed Tibial Provisional
`
`to ensure proper fit before implanting the final
`
`components. Assemble the impactor onto the
`
`tibial provisional until completely seated (Fig.
`
`WMT 1028-23
`
`

`

`l:
`
`PREPARE IIIE 9mm
`
`Sharply dissect through the pre-patellar bursa to
`
`expose the anterior surface of the patella. This
`
`will provide exposure for affixing the anterior
`
`surface into the patella clamp and assures
`accurate bone resection.
`
`Remove all osteophytes and synovial insertions
`
`from around the patella. Be careful not to dam-
`
`age tendon insertions onto the bone. Use the
`
`caliper to measure the thickness of the patella
`
`(Fig. 52). Subtract the implant thickness from
`
`the patella thickness to determine the amount
`
`of bone that should remain after resection.
`
`
`
`PMEllA IHIBKNESS- IMPlANlTHIBIlNESS : BIINE 'IIEMAININ‘E
`
`ALL-POLY IMPLANT THICKNESSES*
`
`Standard
`
`7.5mm
`
`8.0mm
`
`9.5mm
`
`8.5mm
`
`9.0mm
`
`* Do not use metal-backed patellar components with the NexGen Legacy LPS System.
`
`“‘Do not use 26mm, 29mm and 32mm patellas with NexGen Legacy LPS size G and H Femoral
`Components.
`
`Note: At least 11mm of total bone will remain to allow for implant pegs if the Patella Reamer is used.
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`WMT 1028-24
`
`E
`
`WMT 1028-24
`
`

`

`
` Pfllfllfl IIHIMHI lflllllllfl'llf
`
`Use the Patella Reamer Surfacing Guides as
`
`templates to determine the appropriate size
`
`guide and reamer. Choose the guide which fits
`
`TOTAL SURFACING PROCEDURE
`
`
`
`
`snugly around the patella, using the smallest
`
`guide possible (Fig. 53). If the patella is only
`
`slightly larger than the Total Surfacing Guide in
`
`the mediolateral dimension, use a rongeur to
`
`remove the medial or lateral edge until the bone
`
`fits the guide.
`
`Insert the appropriate size Patella Reamer
`
`Surfacing Guide into the Patella Reamer Clamp
`
`(Fig. 54). Turn the locking screw until tight.
`
`(J
`
`WMT 1028-25
`
`WMT 1028-25
`
`

`

`
`
`
`
` l l
`
`I
`
`
`
`Apply the Patella Reamer Clamp at a 90° angle
`
`to the longitudinal axis with the Patella Reamer
`
`Surfacing Guide encompassing the articulating
`
`surface of the patella. Squeeze the clamp until
`
`the anterior surface of the patella is fully seated
`
`against the fixation plate (Fig. 55). Turn the
`
`clamp screw to hold the instrument in place.
`
`The anterior surface must fully seat upon the
`
`pins and contact the fixation plate.
`
`Turn the clamp wing to the proper indication
`for the correct amount of bone that is to remain
`
`after reaming (Fig. 56).
`
`
`
`Attach the appropriate size Patella Reamer Blade
`
`to the appropriate size Patella Reamer Shaft
`
`(Fig. 57). Use only moderate hand pressure to
`
`tighten the blade. Do not overtighten the blade.
`Insert the Patella Reamer Shaft into a Drill/
`
`Reamer. Insert the reamer assembly into the
`
`Patella Reamer Surfacing Guide. Raise the
`
`reamer slightly off the bone and bring it up to
`
`full speed. Advance it slowly until the prominent
`
`high points are reamed off. Continue reaming
`
`with moderate pressure until the step on the
`
`reamer shaft bottoms out on the clamp wing.
`
`Remove the reamer clamp assembly.
`
`
`
`
`
`
`
`7 7
`
`T
`WMT 1028-26
`
`WMT 1028-26
`
`

`

`
`
`
` l...)
`
`
`
`Insert the appropriate size Patella Reamer
`
`Insetting Guide into the Patella Reamer Clamp.
`
`Turn the locking screw until tight.
`
`Apply the Patella Reamer Clamp at a 90° angle
`
`to the longitudinal axis with the Patella Reamer
`
`Insetting Guide on the articulating surface.
`
`Squeeze the clamp until the anterior surface
`
`of the patella is fully seated against the fixation
`
`plate. Turn the clamp screw to hold the instru-
`
`ment in place. The anterior surface must fully
`
`seat upon the pins and contact the fixation plate.
`
`Turn the clamp wing to the “inset” position.
`
`
`
` INSETTING PROCEDURE
`Attach the appropriate size Patella Reamer Blade
`Use the Patella Reamer Insetting Guides as
`to the appropriate size Patella Reamer Shaft.
`
`templates to determine the appropriate size
`
`Use only moderate hand pressure to tighten the
`
`guide and reamer. Choose the guide which will
`
`blade. Do not overtighten the blade (Fig. 59).
`
`allow approximately 2mm between the superior
`
`edge of the patella and the outer diameter of the
`
`guide (Fig. 58).
`
`Use the Patella Reamer Depth St