-i-
`
`Smith & Nephew Ex. 1041
`IPR Petition - USP 8,062,302
`
`

`

`
`
`
`
`
`
`
`
`TOTAL KNEE SYSTEM
`
`GENESIS Total Knee System and
`Instruments designed in conjuction with
`
`Ramon B. Gustilo, M.D.
`Professor of Orthopaedic Surgery
`University of Minnesota
`Department of Orthopaedics
`Hennepin County Medical Center
`Minneapolis, Minnesota
`
`James A. Rand, M.D.
`Professor of Orthopaedic Surgery
`Mayo Medical School
`Consultant, Department of Orthopaedics
`Mayo Clinic
`Scottsdale, Arizona
`
`Richard S. Laskin, M.D
`Professor of Orthopaedic Surgery
`Cornell University
`Attending Orthopaedic Surgeon
`Hospital For Special Surgery
`New York, New York
`
`James G. Howe, M.D.
`Professor and Chairman
`Department of Orthopaedics and
`Rehabilitation Medicine
`University of Vermont
`Burlington, Vermont
`
`Nota Bone: The technique description herein is made
`available to the healthcare professional to illustrate the
`authors’ suggested treatment for the uncomplicated
`procedure. In the final analysis, the preferred treatment is
`that which addresses the needs of the specific patient.
`
`This device is currently approved for cemented use and is under clinical investigation for oementless application.
`U.S. Patents #4,950,298, 5,053,057, and 5,100,408. Other patents pending.
`
`V
`
`-11-
`
`-ii-
`
`
`
`

`

`
`
`CONTENTS
`
`.
`Introduction .
`.
`.
`.
`Design Features .
`Short Technique .
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`. 2
`. 5
`. 4
`
`Surgical Technique
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Patient ‘Preparation .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Surgical Approach .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Femoral Preparation .
`Femoral Component Alignment .
`Anterior and Posterior Femoral
`Preparation .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Tibial Preparation .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`
`.
`.
`
`.
`.
`
`.
`.
`.
`.
`
`.
`.
`.
`.
`
`.
`.
`.
`.
`
`.
`.
`.
`.
`
`.
`.
`.
`.
`
`.
`.
`.
`.
`
`. 11
`. 12
`. 14
`. 19
`
`.
`.
`
`.
`.
`
`.
`.
`
`.
`.
`
`.
`.
`
`.
`.
`
`. 20
`. 22
`
`Tibial Extramedullary Alignment
`Method .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`
`.
`
`.
`
`.
`
`. 22
`
`Tibial lntramedullary Alignment
`Method .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Tibial Preparation (Resumed) .
`.
`.
`.
`.
`Tibial Stem Preparation .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`
`.
`.
`.
`
`.
`
`.
`
`.
`
`.
`
`.
`
`.
`
`.
`
`.
`
`.
`.
`.
`
`.
`
`.
`.
`.
`
`.
`
`. 24
`. 26
`. 30
`
`. 51
`
`
`
`
`
`Trial Insertion .
`
`.
`
`.
`
`.
`
`.
`
`.
`
`.
`
`Patellar Preparation .
`Biconvex Patella .
`
`Porous Patella .
`
`.
`
`.
`.
`
`.
`
`.
`
`.
`.
`
`.
`
`.
`
`.
`.
`
`.
`
`.
`
`.
`.
`
`.
`
`.
`
`.
`.
`
`.
`
`.
`.
`
`.
`
`.
`.
`
`.
`
`.
`.
`
`.
`
`.
`.
`
`.
`
`.
`.
`
`.
`
`.
`.
`
`.
`
`.
`.
`
`,
`
`.
`.
`
`.
`
`.
`.
`
`.
`
`.
`.
`
`.
`
`. S2
`. 32
`
`. 34
`
`.-
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Resurfacing Patella .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Alignment Verification .
`.
`Final Tibial Preparation for Nonporous
`Component .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Tibial Implantation .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`
`.
`.
`
`.
`.
`
`. 35
`. 37
`
`. 38
`. 58
`
`Final Tibial Preparation for Porous
`.
`Component .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Implantation .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Use of Optional FleX—Lok® Pegs .
`
`.
`.
`.
`
`.
`.
`.
`
`.
`.
`.
`
`. 39
`. 39
`. 40
`
`Use of Cancellous Compression
`Lag Screws .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Femoral Component Implantation .
`Porous Femoral .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Nonporous Femoral .
`.
`.
`.
`.
`.
`.
`.
`.
`Patellar Component Implantation .
`. Articular Insert Assembly .
`.
`.
`.
`.
`.
`.
`.
`Closing.....».
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Postoperative Care .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`AppendiXA .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Appendix B .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`Appendix C .
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`.
`
`. 40
`.
`.
`. 41
`.
`.
`. 41
`.
`.
`. 41
`.
`.
`. 42
`.
`.
`. 42
`.
`.
`. ..43
`.
`.
`. 43
`.
`.
`.. 45
`.
`.
`. 53
`.
`.
`. 55
`
`’
`
`
`
`

`

` INTRODUCTION
`
`
`
`
`
`otal Knee Arthroplasty has undergone
`considerable evolution since the early
`prosthetic knee replacements. Yet despite
`
`improvements in the design of prosthetic
`replacements and surgical techniques, some
`clinical problems remain. Therefore, the challenge
`to both the surgeon and engineer is to define an
`
`implant system which can provide solutions to
`these clinical problems.
`
`Alignment is critical to the outcome of a total knee
`
`replacement. Instrumentation for total knees has
`
`evolved over time. To ensure that proper limb align-
`
`ment is restored, a combination of intramedullaiy
`
`alignment devices with extramedullary alignment
`
`check rods is necessary. These steps increase the
`
`probability for a successful clinical outcome.
`
`The management of bone defects can be a difficult
`
`problem in total knee replacement. A variety of meth-
`
`Many patients have ligamentous insufficiency,
`
`ods can be employed including: filling the defects
`
`usually the posterior cruciate ligament and/or the
`
`with cement, which can be reinforced with wire mesh
`
`collateral ligaments. Usually patients indicated for
`
`a total knee replacement have a deficient anterior
`
`or bone screws; altering the level of bone resection to
`eliminate the defect; the use of metal wedges or
`
`cruciate ligament. Historically, various methods
`
`custom components; and the use of bone grafts.
`
`have been employed to address the instability of the
`
`knee joint, including prostheses with greater
`
`constraint between the articulating surfaces of the
`
`femur and tibia and hinged prostheses. The
`
`negative aspect of these methods, however, is that
`
`the inventory burden can become excessive. A
`
`solution is provided by using a prosthesis with
`modular articular inserts for the tibial
`
`components. Modularity allows a variety of
`
`articular surface types without the inventory
`
`burden associated with non-modular, “fixed”
`
`prostheses.
`
`The need for modularity extends beyond the tibial
`
`component. Frequently, intraoperative decisions
`
`must be made regarding component dimensions,
`
`soft tissue balance, or ligamentous stability
`
`warranting changes in the choice of femoral
`
`component. Non—modular systems require a
`
`separate prosthesis, often requiring different bone
`cuts and different instruments. To address the
`
`problem more efficiently, a prosthetic knee system
`
`should feature components that can be modified
`
`through the addition of “conversion modules” to
`
`optimize surgical flexibility. The change from a
`
`Cruciate—Retaining to a Posterior—Stabilized
`
`component can be made intraoperatively by the
`addition of .a conversion module to the standard
`
`femoral component.
`
`Metal wedges can provide more surgical flexibility
`than custom implants and can avoid some of the
`
`problems associated with other options for
`
`management of bone defects such as cement
`
`shrinkage or laminations, limited donor bone, or
`
`failure of graft incorporation. Metal wedge studies
`have shown that the levels of force transmission are
`
`
`
`uniform and approach that of a custom implant.
`
`Preoperative planning provides only a limited View
`
`of the exact patient conditions for a total knee
`
`arthroplasty candidate. In some extreme
`
`conditions, the indications at arthrotomy reveal a
`
`different picture and require a different treatment.
`
`In order to best address this occurrence, a total
`
`knee system should be flexible enough to address
`
`the unexpected. The GENESIS Total Knee System is
`
`designed to do precisely that. The system
`
`incorporates features designed with clinically
`
`verified principles in mind. The modularity of
`GENESIS allows the surgeon to custorn~assemble
`
`an implant for each individual patient.
`
`The surgical technique that follows has been
`
`developed as a guide to using the GENESIS
`
`Posterior—Stabilized implants. It will also
`
`demonstrate that, for primary or revision
`
`procedures, the GENESIS design combines superior
`
`fit with remarkable flexibility.
`
`
`
`
`
`

`

`
`
`
`
`DESIGN
`
`FEATURES
`
`
`
`Femoral component is a cobalt-
`chromium alloyfor increased
`hardness and superior resistance to
`micro-fretting againstpolyethylene,
`when compared to titanium alloy.
`
`Tallerposterior condyles improve
`R. 0,114. in higher angles offlexion.
`
`Distal andposterior condyles are
`both 7.5 mm “thin”, to minimize
`resection and maintain
`
`flexion/extension gap equivalence.
`
`Optional Flex—Lole pegsfor the
`femur and tibia.
`
`9.5 mm compression screwsprovide
`superior tibialfixation.
`
`Hour-glass shaped cam maximizes
`contact area with the tibial
`eminence to minimize wear and
`
`coldflow.
`
`Conversion modules loc/2 onto
`
`threadedposts with removable
`fixation lugs that eliminate relative
`motion and allow easy
`intraoperative conversionfrom a
`cruciate-retaining to aposterior-
`stabilized component.
`
`
`
`Raised lateralflange reduces
`chance ofpatellar subluxation.
`
`Axisymmetricpatellar articular
`surface eases surgical
`implantation.
`
`Asymmetric tibial tray shape is
`more anatomically correctfior
`maximumproximal tibial
`coverage.
`
`Finned central stem evenly
`distributes stress and resists
`
`rotationalforces.
`
`Metal base is inset into the
`cortical bone.
`
`Dovetail loc/aing mechanism
`allows convenient anterior
`
`
`
`loading, while the tibial
`eminence and angled tibial
`surfacespromotefemoral
`rollback,
`
`

`

`SHORT ‘TECHNIQUE
`
`FEMORAL 8: TIBIAL PREPARATION
`
`
`
`FEMORAL PILOT HOLE
`
`INTRAMEDULLARY
`ALIGNMENT \-
`
`
`
`TIBIAL DRILL GUIDE
`
`ASSESSING
`
`ROTATIONAL
`ALIGNMENT
`
`Mark
`Correct
`Tibial
`Rotation
`
`
`
`
`
`

`

`
`
`
`
`SEEGRY YEEHEEEQEEE
`
`FOR THE POSTERIOR—STABILIZED KNEE, TURN TO PAGE 8
`
`FEMORAL COMPONENT
`SIZING
`
`Nonporous
`
`

`

`
`
` SELECT THE APPROPRIATE
`REAMING DEPTH 3% g
`P»
`
`

`

`RESURFACING PATELLAR PREPARATION J
`
`MEASURE PATELLAR THICKNESS
`
`RESECT PATELLA
`
`DRILL FOR FIXATION PEGS
`
`
`
`
`
`

`

`fiilfllil” lE£Hl.l§flliE
`
`ADDITIONAL STEPS FOR THE POSTERIOR—STAB1LIZED FEMORAL CUTIINO 5:
`DISTAL FEMORAL RESECTION
`X
`
`
` SQUARE—UP NOTCH
`WITII OSTEOTOME
`
`
`
`
`
`
`
`
`
`
`
`Place Notch
`Guide on
`Distal Femur
`
`Ream Through
`Femoral Notch
`Guide
`
`‘
`gegsufie
`"_ °
`'
`
`:.
`
`’
`
`Use 4 mm
`
`Spacer Plate
`with Spacer
`Blockin
`Extension
`
`I
`
`
`
`
`
`
`
`POSTERIOR-STABILIZED
`
`HOUSING RESECTION
`
`

`

`
`
`
`
`
`
`
`
`
`
`
`SIZING OF NOTCH
`
`Housing Sizer
`11—4815
`
`
`
`FEMORAL COMPONENT
`
`ANTERIOR—POSTERIOR
`
`‘r
`
`
`
`ET
`
`{'3
`1!II
`
`I5
`1I
`
`i I
`
`‘1 E
`
`RESECTION
`
`Do not make charnfer
`cuts until after housing
`has been prepared.
`
`CUT CHAMFERS WITH THE POSTERIOR—
`STABILIZED CHAMFER CUTTING BLOCK
`
`,1I
`
`
`

`

`
`

`

`
`
`SURGlCAL TECHNIQUE
`
`THE GENESIS TOTAL KNEE SYSTEM
`
`Primary Surgical Technique
`
`As Described byjczmes A. Roma’, M.D.
`
`PATIENT PREPARATION
`
`Place a radiographic marker over the
`
`* femoral head of the patient and confirm
`
`its position by an X—ray immediately
`preoperatively (Figure I). The marker
`will allow intraoperative determination of
`the mechanical axis of the limb. Perform
`
`a standard surgical scrub and iodoform
`
`forepainting of the extremity, with
`placement of a tourniquet high on the
`thigh. Utilize sterile draping of the
`extremity. Place a nonbulky drape around
`the foot and ankle so that the bony
`
`anatomy can be palpated when using the
`
`tibial guide.
`
`
`
`Figure I
`
`

`

`Shllfiltilli
`
`l’E£tlliEQl3E
`
`SURGICAL APPROACH
`
`Exsanguinate the limb and inflate the
`
`tourniquet to the appropriate level. Make
`
`a straight longitudinal incision just
`medial to the midline of the knee,
`
`beginning four inches proximal to the
`superior border of the patella, and ending
`at the level of the tibial tuberosity (Figure
`
`2). Carry the dissection through the
`
`subcutaneous tissues to the prepatellar
`
`bursa. Divide the prepatellar bursa and
`
`elevate its flaps medially and laterally.
`Make a medial parapatellar capsular
`
`incision %" from the medial edge of the
`
`patella, extending proximally between the
`
`interval of the lateral edge of the vastus
`
`medialis and the rectus tendon (Figure
`
`3). Splitting of the tendonous fibers
`
`rather than cutting through muscle will
`
`allow a better repair of the extensor
`mechanism.
`
`
`
`Figure
`
`

`

`
`
`
`
`
`
`
`
`
`
`Attempt eversion and lateral dislocation of
`
`the patella. Further proximal dissection
`
`may be necessary if the soft tissues are
`
`tight. Evert the patella and flex the knee
`
`to 90° (Figure 4). Routine tissue cultures
`
`and biopsies for histological evaluation
`
`are performed at the discretion of the
`
`surgeon.
`
`Sharply separate the deep portion of the
`
`medial capsule from the tibia to the
`
`midline posteriorly. Preserve the
`
`superficial medial collateral ligament and
`
`pes anserinus ligament attachments.
`
`Release the lateral epicondylopatellar
`
`ligament to mobilize the patella and
`
`expose the lateral compartment of the
`
`knee. Excise or preserve the fat pad as
`
`necessary to visualize the anterior aspect
`
`of the tibia adequately. Remove all
`
`osteophytes from the tibial plateau, femur,
`
`and intercondylar notch to allow
`
`visu alization of the true anatomy. If
`
`osteophytes are not removed, it may result
`
`in errors in jig placement. Excise the
`remnants of the menisci and divide the
`
`anterior cruciate. Preserve the posterior
`
`cruciate ligament. If synovitis is present,
`
`perform a synovectomy.
`
`Figure 4
`
`13
`
`

`

`t
`A
`
`e
`
`3
`
`
`
`'
`
`V
`
`SUREECAL lE£tllllQUE
`
`FEMORAL PREPARATION
`Place retractors under the medial and
`lateral collateral ligaments adjacent to
`the femoral epicondyles, so that the distal
`articular surface of the femur is fully
`exposed. The intercondylar notch should
`be easily defined after removal of the
`osteophytes, and you should be able to see
`the posterior cruciate ligament’s femoral
`attachment. Make a 9.5 mm drill hole
`just above the posterior cruciate’s femoral
`attachment (Figure 5). Deepen the hole
`with the 3/s" drill bit so that the intra-
`
`medullaiy canal of the femur can be
`easily identified and the intramedullary
`rod can be seated. The drill bit should be
`
`angled slightly laterally in the direction
`of the femoral shaft to avoid medial
`
`cortical penetration.
`
` Femoral Drill—9.5 mm
`
`11-4947
`
`

`

`
`
`§i_lRGEt:Al..
`
`lE€l
`
`E
`
`Insert either the fluted or hollow
`
`intramedullary rod into the femoral
`
`canal. Applying negative suction pressure
`to the hollow intramedullary rod (Figure
`
`6) allows aspiration of marrow contents
`through the rod which will minimize the
`
`possibility of fat embolization. An
`alternative instrument is the fluted
`
`intramedullary rod. Its diameter is
`smaller than that of the 3/s" drilled
`
`hole, and the groove along the rod’s
`
`length will also decrease the
`possibility of fat embolization. Set
`the distal femoral
`
`intramedullary alignment
`
`
`
`
`
`
`
`5iv.,_
`lg
`
`
`
`guide to the selected valgus
`
`angle, as calculated from
`measurements of the full—
`
`length preoperative X—ray
`
`(Figure 7). The angle of
`cut must be set for the
`
`appropriate left or right knee so that the
`transverse cut on the femur is in the
`
`correct degree of valgus in relation to the
`intramedullary canal of the femur.
`
`Tighten the set screw.
`
`Example ofselected 7"
`valgus czlz'gnmem‘fo7'
`left leg.
`
`
`
`Hollow
`Intramedullary Rod
`11-4987
`
`
`
`Fluted Femoral
`Intramedullary Rod
`1 14859
`
`
`
`Distal emoral
`hitramedullary Guide
`114862
`
`

`

`Figure 8
`
`\\\
`
`
`
`
`
`
`
`
`
`
`
`Insert the intramedullary rod through the
`
`distal femoral intramedullary alignment
`
`guide and into the distal femur. Attach the
`
`distal femoral cutting block to the distal
`
`femoral intramedullary alignment guide.
`
`If a captured out is preferred, attach the
`slotted distal femoral cutting block to the
`distal femoral intramedullary alignment
`.
`guide. Back both cannulated screws all
`the way out. Insert the distal femoral
`
`cutting guide assembly onto the distal
`
`femur and advance it until the paddles on
`
`the cutting guide contact the most
`
`prominent portion of the distal femoral
`condyle. The paddles on the alignment
`guide ensure that 7.5 mm of bone, the
`thickness of the prosthesis distally, is
`removed from the distal femur
`(Figure 8).
`
`In cases of asymmetric femoral bone loss,
`rotate the appropriate cannulated screw
`on the paddle until the end of the screw
`contacts the bone surface to further secure
`
`the assembly. Rotate the block into
`neutral rotation based on the intact
`
`posterior femoral condyles (Figure 9). If
`
`the posterior femoral condyles are
`
`deficient, then rotation will have to be
`assessed on the basis of the femoral
`
`epicondyles, the lateral of which is
`
`slightly posterior to the medial
`epicondyle. Insert a 1/8" pin or bone spike
`through the cannulated screw in the
`lateral’ paddle. It is only necessary to lock
`one paddle to secure the rotational
`
`
`‘M Distal Femor
`Cutting Block
`114865
`
`
`S1°“Efit:i:aé£:‘E°rfl
`11-4669
`
`
`
`
`
`
`
`orientation of the component.
`
`v
`
`
`
`Fz‘gme 9
`
`

`

`W
`
`._
`
`5
`
`I
`
`‘
`
`‘ ll
`‘gs’
`
`E
`
`g
`
`Use the extramedullary alignment tower
`and extramedullary alignment guide rod
`as a check of the intramedullary position.
`The extramedullary alignment guide rod
`should point to the radiographic marker
`on the center of the femoral head (Figure
`Z0). Remove the extramedullary
`alignment tower and extramedullary
`alignment guide rod. Using a 76 mm drill
`bit, drill through the level of holes on the
`
`anterior face of the distal femoral cutting
`
`block marked “primary,” and insert ‘/s" _
`
`pins into the drill holes to fix the block to
`the anterior femur. Remove the intra
`medullaiv rod and the laterally placed
`pin.
`
`
`
` NOTE: Femoral cutting for the
`Posterior—Stabilized Knee requires
`a different technique. If this is a
`Posterior-Stabilized Knee, turn
`to Appendix A on page 45
`for specific femoral
`
`‘wt
`
`'3
`
`cutting instructions.
`
`After completing the
`Posterior—Stabilized Femoral Preparation
`Appendix, return to-page 22 of this
`surgical technique and resume with the
`
`Tibial Preparation section.
`
`Assess the level of the distal femoral
`
`cutting block.
`
`\ 1‘ if s:
`
`\ \
`
`‘vs
`
`
`
`7,2tr?
`
`
`
`'l"E€tlNlf.éll;l'E
`
`
`
`l
`
`'
`Efttrarnedullaiy
`Ah‘5’;’i‘_e4“6‘6T;’We”
`
`,:..
`
`M
`
`it
`
`‘If
`
`v‘
`
`,l
`
`~f
`
`l
`
`1:
`
`p
`
`‘
`
`Emmeduuaw
`A“8“m1"f_‘4‘§‘ade R°d
`
`A
`
`76 mmmm
`
`11.4959
`
`

`

`
`
`Using a GENESIS sawblade, resect the
`
`distal portion of the femur by cutting
`across the distal aspect of the femoral
`cutting block (Figme 1]) or through the
`slotted distal femoral cutting block
`
`(Figure 12) with an oscillating saw. Take
`care to keep the GENESIS sawblade
`
`flat against the distal femoral
`
`cutting block.
`
`The cuts should be
`
`checked for flatness
`by means of the
`
`4
`
`viewing plate or
`
`
`
`parallel bars. Any
`uneven spots should be leveled with a saw
`
`
`
`or a file (Figure 13).
`
`For the ligament balancing surgical
`technique, please see Appendices B a11d C.
`
`
`
`Figure 12
`
`
`
`
`
`Figure 13 X
`
`
`
`Sawblades:
`Stryker 11«4551
`SM 11-4553
`New Attachment
`Amsco~Hall 11-4542
`New Attachment
`Stryker 11-4549
`
`
`
`Femoral File
`1 1-4894
`
`
`
`18
`
`

`

`
`
` a
`
`Modular Femoral
`Drill Guide
`
`
`
`
`Insert
`11-4873
`11-4825
`
`
`
`3° External Rotation
`Insert
`11-4875
`11-4827
`
`
`3° External Rotation
`Insert w/2 mm
`Anterior Shift
`11-4881
`11-4829
`
`
`
`Femoral Drill
`Guide Stylus
`11-4868
`11-4858
`
`
`
`Anterior
`Reference Guide
`1 1-4885
`
`Femoral Drill
`11-4869
`11-4879
`
`19
`
`
`
`1
`
`
`
`FEMORAL COMPONENT ALIGNMENT
`
`Rotational, medial-lateral, and anterior-
`
`posterior orientation of the femoral
`prosthesis is determined by the modular
`femoral drill guide. This jig has two
`runners which are positioned between the
`posterior femoral condyles and the tibial
`plateaus. Through the use of modular
`inserts, this instrument provides the
`option of neutral rotation relative to the
`coronal plane of the distal femur, 5° of
`external rotation, a 2.5 mm anterior shift,
`or a combination of 3° of external
`rotation and 2.0 mm anterior shift.
`
`Verify that there are equal amounts of
`articular cartilage on the posterior aspects
`of the femoral condyles. If there are
`unequal amounts, you may inadvertently
`rotate the femoral component internally
`or externally. Center the jig in the medial-
`lateral position on the flat out distal
`femoral surface. Be sure that the jig is flat
`and contacting the entire distal cut
`surface; Lock the femoral‘ drill guide in
`place with two bone spikes or 1/8" pins.
`
`Attach the femoral drill guide stylus to the
`superior aspect of the drill guide. Center
`the movable stylus over the highest point
`on the anterior femoral cortex in the
`
`medial-lateral direction. Lower the stylus
`until it approximates the anterior femoral
`cortex. Read the correct size of the
`
`implant from the drill guide. When the
`correct size is selected, the proximal tip
`of the stylus should be on or slightly
`above the highest point of the anterior
`femoral cortex. Be sure that the
`
`‘
`
`runners are flush with the posterior
`condyles. This will ensure that the
`
`nterior femoral cortex is not notched
`
`when the anterior femoral cut is made.
`
`The grooves on the side of the femoral
`drill guide can be used as a “double
`check” for implant size. Place the
`anterior reference guide in the
`appropriate groove. The top of the guide
`should lie over or on the anterior cortex of
`
`the selected implant size. When correct
`positioning of the guide has been assured,
`drill two 9/32" holes for the femoral
`
`prosthesis fixation pegs using the femoral
`drill (Figure 14). Drill to the depth
`provided by the stop on the drill.
`
`If the femoral drill guide falls between
`two sizes, the larger of the two is normally
`selected. However, if the surgeon wishes to
`go to a smaller sized component, he must
`flip over the insert marked “regular” to
`the side that is marked “2.5 mm shift.”
`This will shift the orientation of the
`
`prosthesis in an anterior direction by
`2.5 mm, and therefore guard against
`notching of the anterior cortex.
`
`If desired, the orientation of the femoral
`prosthesis may be externally rotated by 3°.
`To perform this, utilize the 3° insert; one
`side of the insert is for the right knee, and
`the other is for the left knee. When oper-
`ating on the right knee, “right” will be
`facing up. When operating on the left
`knee, “left” will be facing up. If in between
`two sizes and you wish to go to the smaller
`size and externally rotate the femoral
`component 3°, utilize the insert that reads
`“2.0 mm shift 3°.” Utilize only one
`insert when drilling for orientation of
`the femoral prosthesis.
`
`_,
`
`.
`
`
`
`

`

`
`
`)
`
`vL’
`
`‘. ~=v""‘
`
`POSTERIOR
`
`FEMORAL PREPARATION
`
`
`s
`
`° ANTEREJRe
`
`
`
`
`
`Figure I6
`
`Following the removal of the femoral drill
`guide, insert the two posts of the correctly
`sized anterior-posterior cutting block (as
`determined by the drill guide) into the
`distal femoral fixation holes (Figure 15).
`Make sure the A—P cutting block is flush
`with the flat cut distal femur. The anterior
`plane of the cutting jig should intersect
`the anterior cortex of the femur at the
`
`proximal margin of the patellar facets.
`The point of intersection of the anterior
`cut with the femur should be carefully
`
`assessed prior to cutting to ensure that
`femoral notching does not occur. Before
`cutting, use the anterior reference guide
`placed on the superior surface of the
`block or through the slot to assess the
`level of cut. This should make certain that
`
`the anterior femoral cortex is not notched.
`
`If it is preferred to cut through a slot, use
`the slotted anterior—posterior cutting block
`(Figure 16). The sawblade should
`remain flush against the cutting guide
`
`during this procedure.
`
`Complete the anterior and posterior
`femoral cuts.
`
`
`A-P Cutting Block
`3:23;?
`11-4874
`
`
`
`11-4878
`
`
`
`

`

`Chamfer Cutting
`Block
`11-4880
`11-4882
`1 1-4884
`11-4888
`11-4889
`
`
`
`Remove the A—P cutting block. Center the
`
`chamfer cutting block on the two
`previously made distal femoral drill holes
`(Figure I 7J. The anterior and posterior
`femoral chamfer cuts are then performed.
`
`If it is preferable to perform the chamfer
`cuts through slots, this can be done using
`the A—P cutting block. Take care that all
`
`cutsare accurate. Since the sawblade
`
`meets the bone at an oblique angle, there
`
`is a tendency for the blade to skive
`
`away from sclerotic or hard bone,
`resulting in removal of too
`little bone. All cuts should
`
`be carefully assessed with a
`
`straight edge.
`
`Frequently, excessive bone remains in
`the intercondylar notch area on both the
`distal and chamfer cuts (Figure 18).
`
`Some residual articular cartilage in this
`
`area can best be removed with a scalpel.
`
`Use a rasp to smooth any prominent
`areas. A flat, even surface is essential.
`
`After the principle femoral cuts have been
`made, the joint should be fully debrided,
`removing all residual osteophytes and the
`
`posterior horn remnants of the meniscus.
`The posterior cruciate ligament should be
`identified and carefully preserved.
`
`
`
`
`
`
`
`Figure I 7
`
`
`
`sclerotic Bone
`
`It is essential to remove posterior
`
`osteophytes as well as osteophytes
`
`adjacent to the posterior cruciate
`
`ligament.
`
` V Figure 18
`
`

`

`__,_._zK J
`
`
`
`
`
`Figure I9
`
`Lil "lifiiilliilllii
`
`TIBIAL PREPARATION
`
`Acutely flex the knee and subluxate the tibia
`foiward. Use a wide blade Hohmann or similar
`
`blunt retractor, carefully placed in the
`
`intercondylar notch, to subluxate the tibia
`anteriorly. Be careful not to damage the distal
`
`femur, especially in osteoporotic patients.
`Retraction should be gentle, with careful
`
`attention to the patellar ligament attachment on
`the tibia to prevent patellar tendon avulsion.
`
`At this point, the surgeon has the choice between
`extramedullary and intramedullaiy alignment. If
`intramedullary is chosen, turn to page 24.
`
`Tibial Extramedullary Alignment Method
`
`The surgeon has the choice between a '
`proximally spiked fixation rod and a nonspiked
`proximal rod. If the proximally spiked rod is
`selected, slide the rod through the slotted or
`
`nonslotted tibial cutting block. If the nonspiked
`
`proximal rod is utilized, slide the chosen tibial
`cutting block over the top until it hits the stop.
`Both the slotted and nonslotted cutting blocks
`
`are available with 0° or 3° posterior-sloped cut.
`The Cruciate Retaining insert slopes 4° anterior
`
`to posterior. Using the 3° posterior sloped cutting
`block, a total slope of 7° is achieved. The rod is
`then inserted in the alignment sleeve which is
`
`
`
`Spiked
`Fixation Rod
`11-4661
`
`Tibial Cutting Blocks
`0“ — 11-4665
`5° — 11-4665
`
`
`
`Tibial Cutting Blocks,
`Slotted
`0° — 11-4664
`3° ~ 11-4666
`
`attached to the ankle clamp. After locking the
`
`ankle clamp in the open position, place the
`assembly over the anterior crest of the tibia
`(Figure 19). The distal portion of the tibial
`assembly should lie over the center of the tibia
`which is medial to the center of the ankle. To
`
`‘
`
`Alignment Sleeve
`11-4660
`
`p
`
`
`secure the ankle clamp, depress the button on
`
`either side of the ankle clamp.
`
`

`

`
`
`
`
`1-».
`
`Extramedullaiy
`Alignment Rod
`1 1-4861
`
`
`
`-
`
`ls
`
`Extramedullary
`Alignment Tower
`11-4667
`
`if
`It
`
`2;;5»Y9»
`
`Figure 20
`
`The ankle clamp allows the surgeon to
`offset the distal end of the alignment guide
`
`up to 8 mm toward the medial side to allow
`alignment over the center of the talus. An
`offset of 8 mm minimizes the chance for a
`
`varus cut. Extendthe proximal portion of
`the tibial assembly up over the proximal
`
`tibia. Impact the long spike into the
`
`proximal tibia at a point just anterior to
`the tibial spine. Adjust the position of the
`distal portion of the rod assembly until the
`rod is parallel to the mid—coronal plane of
`the tibia to ensure that the tibial cut is
`
`perpendicular to the tibial axis in‘ all
`planes. The extramedullary alignment
`tower and rod can be used as a method of
`
`checking this alignment. (If the cutting
`plane is in Varus or Valgus, the distal 8 mm
`offset can be fine—tuned at this time to
`
`ensure correct alignment of the tibial out.)
`
`If a posterior~sloped cut is desired, adjust
`the position of the distal portion of the
`assembly to the desired angle (no more
`than 5°), or use the 3° posterior sloped A
`
`cutting block. Impact the shorter spike on
`the proximal portion of the assembly into
`the tibia (Figure 20).
`
`Assess the compartments of the tibia to
`determine the lowest point of the tibia. In
`
`cases of large bone loss on the medial or
`
`lateral compartment, it may be necessary
`to adjust the cutting level proximal to or
`above the level of maximum bone loss and
`
`to subsequently bone graft the defect or use
`an augmentation wedge. Raise the tibial
`cutting block to its most proximal position
`on the extramedullary alignment rod.
`
`Please turn to page 26 to bypass the Tibial
`
`Intramedullary Alignment Method and
`
`continue with the suggested surgical
`
`approach.
`
`

`

`
`
`
`
`u!
`
`" 3
`
`
`
`.13»
`
`B‘‘‘‘““
`
`it“Wrl
`
`.."—"\.:
`
`°““ii““
`
`“_Z“:..”
`
`..........
`
`ff)
`
`5::
`
`fir“:
`
`Tibial Intramedullary Alignment
`
`Method
`
`Begin by making a conservative rough cut
`on the proximal tibia by removing only
`the prominent peaks thereby leaving a
`flatter surface. Place the correctly sized
`tibial drill guide onto the proximal tibia
`and make a mark through the drill guide
`with methylene blue.
`
`
`
`TibialImmeduumy
`Alignment Assembly
`11-4599
`
`
`
`
`
`.
`
`M
`
`l
`
`“
`
`’
`
`_
`
`4 2]
`F.
`zgme
`
`,
`
`,
`
`Hollow
`m[rmI11:‘_1g1§;yR°d
`
`Fluted mgfiirledunaw
`11-4359
`
`Make a pilot hole with a gouge on this
`methylene blue dot on the surface of the
`tibial plateau. The hole should lie in the
`midline mediolaterally, and approxi-
`mately 7 to 10 mm anterior to the
`midline of the surface anteroposteriorly.
`
`CAUTION: Do not make the pilot hole
`
`directly in the anteroposterior midline.
`The posterior aspect of the tibia slopes
`forward and an intrarnedullary rod
`inserted through this point will abut
`against the inner posterior cortex. Enlarge
`the pilot hole using the 9.5 mm femoral
`drill (Figure 2]).
`
`Place the intrarnedullaiy rod through the
`tibial intramedullary alignment assembly
`and tighten the locking screw. Advance
`the intrarnedullary rod down into the
`tibia (Figure 22). Testing has shown that
`the rod will meet firm resistance at the
`level of the previous epiphyseal scar of the
`distal tibia. The rod must be seated at
`
`least to this level to gain adequate
`
`purchase and stability.
`
`
`
`Femoral Drill~9.5 mm
`11-4947
`
`

`

`
`
`
`
`Place the slotted or nonslotted cutting
`
`block on the outrigger of the tibial intra-
`
`medullary alignment assembly. Raise the
`
`tibial cutting block to its most proximal
`
`position and tighten the locking screw
`
`(Figure 23).
`
`I
`it
`
`‘Ly
`
`

`

` Figure 24
`
`
`
`
`
`Figure 25
`
`
`
`
`
`Block
`Tim
`00-11.4653
`3°" 114665
`
`Tibial Cutting
`§£°ffif;‘_,f§g§
`5° — 11-4666
`
`
`
`Note: While the illustrations show
`
`extramedullary alignment guides, the
`
`technique here is the same for either
`
`intramedullaiy or extramedullary.
`
`TIBIAL PREPARATION (RESUMED)
`Attach the desired proximal tibial stylus
`
`and tighten the stylus down by its knurled
`
`knob. Five different stylus levels are avail-
`able: 0, 2, 4, 6, and 8 mm. Using a 6 mm
`
`stylus off of the unaffected side of the
`
`tibial plateau is recommended so as to
`
`allow the use of polyethylene that is over
`6 mm in thickness.
`
`There are two holes in the tibial block on
`
`either side of the extramedullary align~
`ment rod. Insert a 1/8" pin into one hole on
`each side of the tibial rod assembly to afix
`the tibial cutting block to the anterior
`
`surface of the tibia (Figure 24). Take care
`
`to retract the patellar ligament laterally, so _
`that it is not impaled by a drill.
`
`Once the tibial cutting block is securely
`affixed to the tibia, the tibial stylus and
`alignment assembly can be removed
`
`leaving only the tibial cutting block
`
`(Figure 25). Optional angled holes on
`
`either side of the tibial cutting block may
`
`be used for additional stability. Using the
`
`anterior reference guide, carefully
`compare the level of the tibial cutting
`surface to the bone deficiency on the tibia.
`
`If it appears that too little bone is going to
`
`be removed, the block can be adjusted to
`
`remove 2 mm more bone (Figure 26). If
`
`it appears that too much bone will be
`
`removed, the block can be adjusted to
`remove 2 mm less bone. Once the correct
`
`height of the tibial cutting block has been
`selected, check the orientation of the tibial
`
`cutting block in the varus—valgus plane.
`This can be done by attaching the
`
`extramedullary alignment tower to the
`
`
`
`

`

`
`
`Wide PCL Retractor
`7121-0020
`
`‘
`.
`
`
`
`Tibia11"1i3V9i121%P1fl‘e
`11.4922
`
`11-4927
`
`.
`
`3
`
`l
`
`i
`
`T
`3
`
`3
`0‘
`
`
`
`i
`
`l
`T
`
`¥
`
`‘.2’~;§:~‘a.
`
`
`
`7
`
`Fi<5’“"e 27
`
`'
`
`V
`
`tibial cutting block and placing a long
`extramedullary alignment rod through
`the tower. The rod should center on the
`center of the talus in both the coronal and
`sagittal planes. If the orientation of the
`tibial cutting block is correct, the tibia is
`
`ready to be cut.
`
`Place a wide PCL retractor vertically into
`the tibia just anterior to the posterior
`cruciate ligament. The retractor will
`protect the posterior cruciate ligament
`during osteotomy of the tibia.
`Using a GENESIS sawblade and an
`oscillating saw, resect the proximal
`tibia by cutting across the
`proximal portion of the tibial
`cutting block (Figure 27) or
`through the slot. Keep the
`sawblade flush with the tibial
`V
`cutting block to ensure a flat cut. It may
`be necessary to remove the tibial cutting
`block and pins to complete the posterior
`portion of the cut. Using a reciprocating
`saw, out a small notch posteriorly on each
`side of the retractor to remove the cut
`
`._
`I
`
`‘
`
`portion of the tibial bone. The remaining
`bone can be removed with a rongeur to
`
`allow seating of the tibial component.
`This will prevent in