_United States Patent
`Androphy
`
`[19]
`
`[11] Patent Number:
`[45] Date of Patent:
`
`4,567,885
`Feb. 4, I986
`
`[54] TRIPLANAR KNEE RESECFION SYSTEM
`[75]
`1“"°m°"=
`G31‘? W- A“d1'°l-‘"3’! P-Q B03 533-
`Gumeev 111- 50031
`«ms:
`5613- 13¢ 1934
`
`an
`P2] Filfidi
`
`-
`Related U_3_ Application Data
`
`'-‘R.M.C. Total Knee System", Richards Mfg. Co. Inc.,
`Memphis, TN, 1978.
`"Total Condylar Knee Prosthesis Surg. Tech)’, How-
`rnedica Inc., Rutherford, N.J., 1978.
`
`“M ‘"m““
`
`Primary Examr‘ner—-»Gene Mancene
`Assistant Exam:'ner——C. W. Shedd
`Attorney. Agent. or F:'rm——An'_|old, White &. Durkee
`
`[62]
`
`Division of Ser. No. 317,375. Nov. 3, 1931. Pat. No.
`
`[57]
`
`ABSTRACT
`
`A11 imtproved triplanar knee resection system is pro-
`vided or preparing a knee joint for a prosthesis. The
`apparatus of the mplanar knee system includes a single
`.d
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`oondyles, the proximal tibia, and the distal femur. The
`guide rn_emlb:::'.cooiperates wrcilth §:)§i1!1p1i_.EBd s:§Sofinstl1;u-
`ments, mcu mg emur an
`ti
`ia gm e r
`, a ti ia
`adaptor, a_ tibia bar, and_a femur bar, for establishing
`equal flexion and extension gaps and tnplanar resec-
`tions. The method of the triplanar knee system provides
`a simplified procedure for use by an orthopedic surgeon
`in properly preparing a knee joint for implantation of a
`prosthesis.
`
`5 Claims, 16 Drawing Figures
`
`A6113‘ 5/04
`128/92 I-I, 128/303 R
`123/92 H, 92 R, 303 R
`
`4’437'2°3'
`[51]
`Int. Cl.‘
`[52] US. Cl. ...............
`[53] Field of Search
`
`
`
`[55]
`
`References cited
`U'S‘_PA.TENT DOCUMENTS
`-1,211,228 7/1980 Cloutier
`4,48';',203 12/1984 Andmphy
`OTHER PUBLICATIONS
`
`12.8/303 R
`128/303 R
`
`“Knee Replacement Using the Insall/Burstein Total
`Condylar Knee System", Zimmer Inc., Warsaw, IN,
`1980.
`
`
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 1
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 1
`
`

`
`US. Patent
`
`1%eb.4,19s6
`
`_Sheetl of6
`
`4,567,885
`
`Zimmer Holdings, Inc. and Zimmer, Jnc.
`
`-
`
`-
`
`Exhibit 1005 -__2
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 2
`
`

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`U. s. Patent
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`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 3
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`
`

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`
`'Sheet3of6
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`4,567,885 I
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`Zimmer Holdings, Inc. and Zimmer, Inc.
`'
`Exhibit 1005 - 4
`
`'
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 4
`
`

`
`U.S. Patent
`
`Feb. 4, 1936
`
`L
`
`Sheet4of6
`
`4,567,885
`
`AXISOFHIPJOINT
`
`AXISOF FEMUR
`
`._/
`
`¢—F
`
`10?
`
`_
`
`_
`
`Zimmer_Ho|dings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 5
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 5
`
`

`
`U.S. Patent
`
`Feb. 4, 1986
`
`% Sheet5of6
`
`4,567,885
`
` AX!5OFHIPJOINT
`
`
`
`A:-:rs'on=FEMUR
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`-
`Exhibit 1005 - 6
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 6
`
`

`
`Patent
`
`Feb. 4, 1936
`
`%
`
`'Sheet6of6
`
`4,567;8$5
`
`" '" '-iiliilliilllillliiijjjilii
`
`
`
`
`
`Zimmer Hdldings, Inc. and Zimmer, Inc.
`Exhibit 1005
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 7
`
`

`
`1
`
`4,567,885
`
`2
`
`SUMMARY
`
`TRIPLANAR KNEE RESECTION SYSTEM
`
`This is a division of my co-pending application Ser.
`No. 3l7,875,_ filed Nov. 3, 1981, now U.S. Pat. No.
`4,487,203.
`
`BACKGROUND
`
`-
`
`The invention relates generally to knee surgical tech-
`niques and, more particularly, to apparatus and method
`for resection of the knee joint for a knee prosthesis.
`Replacement of a knee joint with a prosthesis in-
`volves a comprehensive surgical procedure, as is known
`to those skilled in the -art. The surgical procedure is
`complicated by the fact that only a relatively small area
`of the patient’s leg. namely the knee, is exposed during
`the operation. ‘The remainder of the patient’s leg, as
`well as most of his body, is covered with sterile drapes.
`The R.M.C. TM Total Knee System technique manual
`published by Richards Manufacturing Company, Inc.,
`1450 Brooks Rd., Memphis, Tenn. 38116 illustrates this
`aspect of the surgical procedure. The surgical proce-
`dure is further complicated by the presence of the mus-
`cle and skin tissue which surrounds the knee joint.
`Once the knee joint is exposed by known techniques,
`the distal femur and proximal tibia must be prepared to
`enable implantation of the prosthesis. Such preparation
`includes resection of the anterior and posterior distal
`femoral condyles, the proximal tibia, and the distal fe-
`mur. In order to achieve proper stability of the knee
`prosthesis when implanted, the aforementioned resec-
`tions must be accurately aligned relative to an imagi-
`nary axis extending through the hip joint, knee joint,
`and ankle joint.
`_
`It is necessary for the distal femoral condylar resec-
`tions to be parallel to the proximal tibial resection when
`the knee is in flexion and for the proximal tibial resec-
`' ticn when the knee is in extension. These "triplanar”
`resections should be made to provide equal flexion and
`extension gaps, i.e., the distance between the posterior
`femoral condylar resection and the proximal tibial re-
`section with the knee in llexion (the flexion gap) should
`be equal to the distance between the distal femoral re-
`section and the proximal tibial resection with the knee
`in extension (the extension gap). Furthermore, the re-
`sected proximal tibia and resected distal femur should
`be perpendicular to the above-referenced imaginary
`axis when the knee is extended.
`The necessity of accurately making the triplanar re-
`sections has led to the development of relatively com-
`plicated instrumentation to aid the orthopedic surgeon.
`Illustrative of such instrumentation are the How-
`Inedica ® Universal TM Total Knee Instrument System
`as shown in the catalogue published by Howmedica,
`Inc., Orthopaedics Division, 359 Veterans Blvd., Ruth-
`erford, NJ. 07070 _and the Insall/Burstein surgical in-
`strument system as designed by John Insall, MD. and
`Albert H. Burstein, Ph.D. and shown in the publication
`entitled “Knee Replacement Using the Iusall/Burstein
`Total Condylar Knee System."
`Although providing some guidance to the orthopedic
`surgeon,
`these prior instrument systems utilize long
`alignment rods which have proved to be less than satis-
`factory under sterile operating room conditions, as de-
`scribed previously. Furthermore, such instrument sys-
`tems include numerous components which still require
`much manual manipulation and which are cumbersome
`.touse.
`
`5
`
`In accordance with the present invention, an im-
`proved triplanar knee resection system, free of many
`disadvantages of the prior art, is provided. The triplanar
`knee system includes a single guide member for use in
`making the proper bone resections The guide member
`_includes an alignment opening for cooperating with a
`guide rod. The guide rod has a 90' angle bend and is
`adapted to beinserted into the femur for use in aligning
`the guide member. In one aspect of the present inven-
`tion, the guide rod is designed such that it remains in-
`_ serted in the femur during the surgical procedure,
`thereby establishing a common reference point for the
`bone resections.
`
`IO
`
`25
`
`The guide member includes three pairs of parallel
`guide slots which are utilized in making the triplanar
`bone resections. The guide member cooperates with the
`guide rod to enable resection of the knee joint with the
`knee always in flexion.
`A second identical guide rod is provided along with
`a tibia adapter and a tibia bar for use with the guide
`member in resecting the proximal tibia. A fur bar is
`provided for use with the guide member and femur
`guide rod in making the resection of the distal fur.
`In a second aspect of the present invention, the femur
`guide bar is designed to compensate for the appropriate
`valgus angle of the femur relative to an imaginary axis
`extending through the hip joint, knee joint, and ankle
`30 joint. In another-aspect of the present invention, the
`triplanar knee system achieves equal flexion and exten-
`sion gaps of the resected knee joint. In still another
`aspect, the triplanar knee system ensures proper align-
`ment of the distal femoral resection and the proximal
`tibial resection although these two resections are inde-
`pendently aligned.
`'
`In a method aspect of_the invention,-a common refer-
`ence is established for resecting the anterior and paste-
`rior distal femoral condyles and the distal femur. This
`common reference is used to provide equal llexion and
`extension gaps.
`In another aspect of the method, the "alignment of the
`guide member for resecting the distal femur is accom-
`plished without the use of any "eye
`" techniques.
`
`35
`
`45
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`50
`
`55
`
`65
`
`These and other advantages and features of the pres-
`ent invention will become apparent from the following
`detailed description considered in connection with the
`appended drawings in which like parts are given identi-
`cal reference numerals and in which:
`
`FIG. IA is an illustrative view of a triplanar guide
`member cooperating with a guide rod for making the
`distal femoral condylar resections in accordance with
`the present invention;
`FIG. 1B is an illustrative view, partially cut away for
`- detail, of the rear side of the triplanar guide member of
`FIG. 1A;
`FIG. 2A is a side view of the guide member cooperat-
`ing with a second guide rod, a tibia adaptor, and a tibia
`bar for resecting the proximal tibia in accordance with
`the present invention;
`_
`FIG. 2B is an illustrative view of the tibia adaptor of
`FIG. 2A;
`.
`FIG. 2C is an illustrative view of the tibia bar of FIG.
`2A:
`FIG. 2D is a cross section of the tibia guide rod taken
`along section line 2D—2D in FIG. 2A;
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 8
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 8
`
`

`
`3
`FIG. 2E is an illustrative view of the rear side of the
`triplanar guide member of FIG. 2A, partially cut away
`for detail;
`FIG. 3 is an illustrative view of the femoral guide rod
`being used to determine the flexion gap in accordance
`with the present invention;
`FIG. 4 is a top view of the femoral guide member
`being used to establish an extension gap equal to the
`flexion gap in accordance with the present invention;
`FIG. 5A is a top view of the guide member cooperat-
`ing with the femoral guide rod and a femur bar for
`proper positioning of the guide member with the knee
`extended in accordance with the present invention;
`FIG. 5B is an illustrative view of the femur bar of
`FIG. 5A;
`FIG. 6 is a side view of the guide member cooperat-
`ing with the femoral guide rod and femur bar with the
`knee in flexion in accordance with the present inven-
`tion;
`FIG. ‘TA is an illustrative view of a modified femur
`bar;
`FIG. 7B is an illustrative view of a pointer for use
`with the modified femur bar of FIG. 7A;
`FIG. TC is a schematic diagram of the modified femur
`bar cooperating with the pointer and the guide member
`to establish the proper valgus angle in accordance with
`the present invention; and
`FIG. 8 is an illustrative view of a modified tibia bar
`for use with the pointer of FIG. ‘TB.
`DETAILED DESCRIPTION
`
`Referring now to FIGS. 1A and 1B, shown is a knee
`joint 20 including a distal femur 22 and proximal tibia 24
`in flexion. It is to be understood that the exposure of the
`distal femur" and proximal tibia is achieved by known
`surgical techniques. Such known techniques may in-
`clude removal of the anterior and posterior cruciate
`ligaments (not shown). However, the present invention
`is applicable in making bone resections for a cruciate
`sparing prosthesis as well.
`A pair of collateral ligaments 26, which connect the
`distal femur 22 and proximal tibia 24, are left in place. It
`is to be understood that any necessary ligamentous
`release may be performed by known surgical techniques
`before making the appropriate bone resections for re-
`placement of the knee.
`In accordance with the present invention, with the
`knee in flexion, a first hole 28 is drilled into the end of
`distal femur 22, approximately centered in the medul-
`lary canal by known techniques. Likewise, a second
`hole 30 is drilled into the end of proximal tibia 24,
`slightly anterior relative to the centerline extending into
`the medullary canal of the tibia.
`A femur guide rod 32 having a longer portion 34 and
`a shorter, threaded portion 35 forming an L-shape is
`inserted into a triplanar guide member 36. Guide mem-
`ber 36 has a generally rectangular configuration with a
`front surface 38, a rear surface 40, a top surface 42, a
`bottom surface 44, a left surface 46, and a right surface
`48. Guide member 36 includes three pairs of resection
`guide slots 50, 52, 54 which are utilized to make the
`appropriate bone resections. A vertical guide slot 56 is
`centrally located in the guide member relative to sides
`£6, 48. Guide slot 56 forms a guide rod recess 58 at its
`upper end. A vertical bore 60 extends upward from
`guide rod recess 58 through guide member 36. Guide
`rod recess 58 and bore 60 are configured to matingly
`receive threaded portion 35 of guide rod 32 and to
`
`I0
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`15
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`20
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`25
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`30
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`35
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`45
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`50
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`55
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`65
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`4,567,885
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`4
`stabilize the guide rod with respect to guide member 36.
`The guide rod is secured in place with a circular nut or
`cap 62, which is threaded onto threaded portion 35 of
`the guide rod until the nut or cap abuts top surface 42 of
`guide member 36.
`Guide member 36 may be provided with a pair of
`handles 64. It is to be understood that handles 64 may be
`integrally formed with guide member 36 or may be
`threadably connected to the guide member and still
`remain within the contemplation of the present inven-
`tion. Guide member 36 is also provided with a plurality
`of pins 66 protruding outwardly from rear side -10. Pins
`66 are adapted to anchor the guide member into the
`bone to prevent the guide member from rotating during
`LISE.
`
`As shown in FIG. IA, femur guide rod 32 is inserted
`into drilled hole 28. Before pressing pins 66 into the end
`of distal femur 22, guide member 36 is manually ori-
`ented to obtain the proper alignment of the guide mem-
`ber relative to the anterior and posterior distal femoral
`condyles,
`identified as 68 and 70, respectively, as is
`known to those skilled in the art. When aligned, guide
`member pins 66 are pressed into the distal femur. Ante-
`rior distal femoral condyles 68 are resected with an
`oscillating saw (not shown) or the like by using upper
`guide slots 50. Likewise, posterior distal femoral con-
`dyles 7|] are resected with an oscillating saw with the
`aid of bottom guide slots 54. The guide member and
`guide rod are then pulled partially out to disengage pins
`66, and guide member 36 is then removed from guide
`rod 32 after removing cap 62. Preferably, femur guide
`rod member 32 is then pushed back into hole 28 and
`remains there for later resection of the distal femur. It is
`to be understood, however, that guide rod 32 may be
`removed from the femur and reinserted later for use in
`resecting the distal femur. Any remaining portion of the
`anterior or posterior distal femoral condyles, such as in
`the center region where the guide slots do not extend,
`may then be removed by using the previously resected
`bone portions as a leveling guide.
`The proximal tibia is then subluxed to its forward
`position, as shown in FIG. 2A. A tibia guide rod
`adapter 72 is slidably disposed onto a longer portion 75
`of a second guide rod '13, which is identical to the first
`guide rod that remains inserted in the femur during this
`stage of the procedure. As shown in FIG. 2B, adapter
`72 has an opening 74 which cooperates with a recess 76
`to stabilize guide rod 73 relative to the adapter. Tibia
`adapter '72 is provided with a pair of pins 78, which are
`pressed into the end of the proximal tibia to prevent the
`guide rod from rotating about the longitudinal axis
`extending through longer portion 75. The guide rod
`carrying the tibia adapter 72 is inserted into drilled hole
`30, and a shorter portion '77 of guide rod 73 is manually
`oriented such that a plane extending through the L
`shaped guide rod is parallel to the sagittal plane extend-
`ing through the tibia. VVhen properly aligned, the guide
`rod is pushed further into hole 30, thereby implanting
`tibia adapter pins 78 and preventing rotation of guide
`rod 73.
`
`A tibia bar 80 having an extended threaded portion 82
`and a generally rectangular base 84, as shown in FIG.
`2C, is inserted into vertical guide slot 56 of guide mem-
`ber 36 such that threaded portion 32 extends through
`vertical bore 60 in the guide member. A second cap 63
`is threaded partially onto the threaded portion of tibia
`bar 80. The rectangular base of the tibia bar has a bore
`86 extending lengthwise therethrough, and a key lock
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 9
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 9
`
`

`
`5
`
`20
`
`35
`
`4-0
`
`45
`
`5
`88 protrudes from the bottom center of ‘bore 86. The
`bottom edges of base 84 are slightly chamfered, as
`shown at 89; Guide member 36 with the tibia bar in-
`serted therein is inverted, and the guide member and
`tibia bar are inserted onto threaded portion 77 of guide
`rod_73. The shorter portion of the guide rod includes a
`key‘ seat 90 (see'FlG. 2D) which cooperates with key
`lock 88 to properly align the guide member 36 for re-
`secting the proximal tibia. FIG. 2E. illustrates the coop-
`eration of guide member 36, tibia bar 80, guide rod 73,
`and tibia adaptor 72.
`In order to properly align the guide member for re-
`section of the proximal tibia, cap 63, threaded onto the
`threaded portion 32 of tibia bar 80, is either loosened or I
`tightened to lower (by gravity) or raise center guide
`slots 52 of the guide member relative to the proximal
`ti_bia. When properly positioned, the guide member and
`tibia bar are pushed further onto shorter portion 77 of
`the guide rod, thereby implanting pins 66 in the anterior
`side of the proximal tibia. Cap 62, threaded onto shorter
`portion 77, is then tightened. An oscillating saw is in-
`serted through center slots 52 of the guide member, and
`the proximal tibia is then resected. Cap 62, threaded
`onto the guide rod, is then loosened. guide member pins
`66 are disengaged, and guide rod 73 supporting the
`guide member and tibia bar 80 is then removed, along
`with tibia adapter 72. Any remaining portion of the
`proximal tibia. may then be leveled by using the previ-
`ously resected portions as a leveling guide.
`Having now completed two of the triplanar resec-
`tions, the flexion gap between the resected proximal
`tibia and the resected posterior distal femur is deter-
`mined. As shown in FIG. 3, threaded portion 35 of the
`guide rod 32, which remained inserted in the femur
`during resection of the proximal tibia, is oriented in a
`direction -perpendicular to the resected surface of the
`proximal tibia. Threaded portion 35 has a that portion 92
`along one side thereof. Flat portion 92 has two sets of
`marks 94, 96 which indicate the relative thicknesses of
`various tibial components for knee prostheses, such as
`_ those manufactured and sold under the names of How-
`medica ® Universal TM Total Knee Instrument System
`and Insall/Burstein Total Condylar Knee System. The
`marks are located at predetermined positions along the
`flat portion 92 of the guide rod to indicate the proper
`tibial component to be utilized in the knee prosthesis.
`With collateral ligaments 26 extended taughtly, the
`flexion gap is determined by verifying which mark is
`level with the resected surface of the proximal tibia. It
`is to be understood that any set of marks corresponding
`to a particular brand of tibial component may be utilized
`and still remain within the contemplation of the present
`invention.
`\
`Once the flexion gap is determined by selecting the
`appropriate tibial component mark, theknee is tempo-
`rarily placed in extension, as shown in FIG. 4. The
`guide rod is then positioned with shorter portion 35
`extending upward and perpendicular to resected ante-
`rior distal femur 6B such that the outer edge of the
`shorter portion rests upon the resected proximal tibia
`when collateral ligaments 26 are extended taughtly.
`Referring now to FIGS. 5A and 5B, with the knee in
`extension, a femur bar 98 having a smooth extended
`portion 100 and a generally rectangular base 102 is
`inserted into guide member 36 such that smooth exten-
`sion 100 extends through vertical bore 60. Base 102 of
`femur bar 98 has its bottom edges slightly chamfered as
`shown at 103, like the chamfered edges described in
`
`"4,36i,ss5
`
`6
`connection with base 84 of tibia bar 80. Femur bar base
`
`102 has a bore 10-! extending lengthwise therethrough.
`A key lock 106 protrudes from opening 104 at a position
`offset 7' from the bottom center of the opening. Key
`lock 106 is offset to compensate for the valgus angle of
`the femur. As is known to. those skilled-in the art, the
`valgus angle typically has a magnitude of 5°-8’. How-
`ever, the valgus angle may be less than 5“ or greater
`than 8'. It is to be understood that key lock 106 may be
`offset from the bottom center of bore 104 by any
`amount and still remain within the contemplation of the
`present invention. Alternatively, a plurality of femur
`bars having a key lock offset at a variety of different
`angular displacements may be provided.
`The positioning of the femur bar in guide member 36
`is critical in that key lock 106 must be oriented to one
`side or the other depending upon whether the left knee
`.or right knee is being resected. When resecting the right
`knee, the femur bar is inserted into the guide member
`such that key lock 106 is to the left of center (when
`viewing the guide member from the front). When re-
`sectingthe left knee, the femur bar is inserted into the
`guide member such that key lock 106 is to the right of
`center. Thus. the apparatus of the present invention -is
`universally applicable regardless of which knee joint is
`being resected.
`With the femur bar properly inserted into guide mem-
`ber 36 and the knee still in extension with shorter por-
`tion 35 positioned in an upward direction, the femur bar
`and guide member inserted thereon are placed onto the
`guide rod such that bore 104 of femur bar 98 slides onto
`shorter portion 35 of the guide rod. Key lock 106 in
`bore 104 engages key seat 90 in shorter portion‘ 35 of the
`guide rod to prevent the guide member from rotating
`relative to the longitudinal axis extending through the
`shorter portion of the guide rod.
`_
`As shown in FIG. 5A, the guide member is then
`slidably positioned along smooth extension lllll of femur
`bar 98 until the top edge, identified as 107, of base 102
`.is aligned with the appropriate mark 94, 96, which was
`determined by verifying the flexion gap. When top edge
`10‘? is properly aligned, guide member pins 66 are
`pressed into the anterior distal femur to prevent the
`guide member from moving. Cap 62 is then threaded
`tightly onto threaded portion 35 of guide rod 32.
`Referring now to FIG. 6, the knee is once again
`placed in flexion, and the guide member is already prop-
`erly positioned for resecting the distal femur without
`the need for any manual alignment. An oscillating saw
`is inserted into center slots 52 of the guide tuber, and
`the distal femur is resected. Cap 62 is then loosened,
`guide member pins 66 are disengaged, and the femur
`guide rod supporting the guide member and femur bar
`are then removed. Any remaining portion of the distal
`femur may then be removed by using the previously
`resented portions as a leveling guide.
`An important feature of the present invention resides
`in the fact that all of the resections are made with the
`knee in flexion. ‘This reduces the danger of cutting the
`popliteal artery. Another important feature of the pres-
`ent invention is that the extension gap is in effect mea-
`sured from the resected proximal tibia (see discussion in
`connection with FIG. 4). However, the alignment of
`the distal femur resection is made, without any "eye-
`ball” techniques, by using the reference point estab-
`lished by the femur guide rod instead of using the re-
`sected proximal tibia as a reference point.
`
`-
`
`.Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 10
`
`65
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 10
`
`

`
`4,567,885
`
`'7
`Still another important feature of the present inven-
`tion is that overall alignment of the triplanar resections
`is assured even though they are aligned independently
`of each other. Furthermore, the simplified instrumenta-
`tion of the present invention is designed such that the
`proximal tibial resection and the distal femoral resection
`are perpendicular to an imaginary axis extending
`through the hip joint, knee joint, and ankle joint and
`such that
`the distal femoral condylar resections are
`parallel to said imaginary axis. Yet, these resections are
`made without any direct reference to this imaginary
`axis.
`
`8
`120 is aligned with the axis extending through the hip
`joint, as shown schematically in FIG. 7C. Thus, the
`modified femur bar in cooperation with the pointer
`enables the guide member to be aligned at the proper
`valgus angle, regardless of whether the valgus angle is
`5“, 8”, 12°, or any other angular measurement.
`In another embodiment, a modified tibia bar 132 may
`be provided. as shown in FlG. 8. Modified tibia bar 132
`with its threaded extension 133 is identical to tibia bar
`80, except that the modified tibia bar has a shorter
`smooth extension portion 134 extending from the top of
`its base 136. Shorter extension 134 has a pair of key seats
`138 disposed 180° apart for cooperating with key locks
`130 of pointer 12!]. Also, a bore 140 in base 136 is pro-
`vided without a key lock. With the modified tibia bar
`inserted into inverted guide member 36 and placed out
`threaded portion 7‘? of guide rod 73 inserted into the
`tibia, pointer 120 may be placed onto shorter extension
`134 to properly align the guide member, such that the
`pointer is parallel to the axis extending through the
`ankle joint. Thus, the modified tibia bar in cooperation
`with the pointer enables the proper alignment of the
`guide member regardless of the shape of the tibia.
`As the bone resections are triplanar, as described
`above, overall alignment of the resected knee joint is
`ensured even though pointer 120 is aligned with only
`one of the extreme leg joints (the ankle joint when mak-
`ing the proximal tibial resection and the hip joint when
`making the distal femoral resection).
`The apparatus and method of the present invention
`provide a simplified and improved system for making
`the triplanar bone resections of the knee joint. The
`guide member eliminates the necessity for a different
`type of guide component for each triplanar resection,
`thereby ensuring proper alignment of a knee prosthesis
`with the axis extending through the hip joint, the knee
`joint, and the ankle joint. Furthermore, the triplanar
`knee resection system of the present invention ensures
`equal flexion and extension gaps while providing for
`proper valgus alignment.
`It is to be understood that the apparatus of the present
`invention will admit of other embodiments. The de-
`tailed description is given only to facilitate understand-
`ing of the invention by those skilled in the art and
`should not be construed as limiting the invention.
`What is claimed is:
`1. In a system for making triplanar bone resections for
`total knee replacement, the system including a set of
`instruments for resecting the anterior and posterior
`femoral condyles, the proximal tibia, and the distal fe-
`mur, the resections being made to provide equal flexion
`and extension gaps, the improvement comprising a sim-
`plified set of instruments, including:
`an L-shaped guide rod having a first elongated por-
`tion adapted to be inserted into the medullary canal
`of the femur and a second portion disposed at a
`right angle to the first portion; an
`guide member having a planar slot therein, said
`member being adapted to be mounted on the sec-
`ond portion of said guide rod with said slot being
`parallel to the second portion and disposed relative
`to the first portion at a minor angle equal to 90°
`minus the valgus angle.
`2. The system of claim 1, further including:
`a femur bar having a key lock and being adapted to be
`inserted into the guide member and being adapted
`to be mounted on the second portion of said guide
`rod. and wherein the second portion of said guide
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 11
`
`The method of the present invention also establishes
`the flexion gap first. An extension gap equal to the
`flexion gap is then established by means of the present
`invention. This method eliminates the possibility that
`the flexion gap will be too small, thereby requiring the
`distal femoral condylar resections to be made too deep.
`It is to be understood that “tlexion gap” as used herein
`means the perpendicular distance between the resected
`surface of the proximal tibia and the resected surface of
`the posterior distal femoral condyles when the knee is in -
`flexion. Likewise, “extension gap" as used herein means
`the perpendicular distance between the resected surface
`of the proximal tibia and the resected surface of the
`distal femur when the knee is in extension.
`The present invention results in a resected knee joint
`whereby the proximal tibial resection is parallel to the
`distal femoral condylar resections when the knee is in
`flexion and the proximal tibial resection is parallel to the
`distal femoral resection when the knee is in extension.
`As discussed above, the proximal tibial and distal femo-
`ral resections are perpendicular to said imaginary axis.
`The parallel and perpendicular relationships of the
`resections are what applicant refers to as “tripla:nar."
`These triplanar resections are important for stable func-
`tioning of a knee prosthesis.
`In an alternate embodiment of the present invention,
`a modified femur bar 1118, as shown in FIG. 7A, may be
`provided. The modified femur bar has a smooth ex-
`tended portion 110 and a generally rectangular base
`112, which are similar to those of femur bar 98. A sec-
`ond shorter extended portion 114 extends from the top
`of the base 112 and has two key seats 116 disposed 180"
`apart. A bore 118 in base 112 does not have a key lock.
`Thus, the modified femur bar with the guide member
`inserted thereon may rotate freely about shorter portion
`35 of guide rod 32. In such case, key seat 90 of guide rod
`32 may be eliminated.
`In order to properly align the guide member to com-
`pensate for the valgus angle, a pointer 12!] is provided as
`shown in FIG. 7B. The pointer includes an elongated
`portion 122 which is affixed to a shorter portion 124
`extending perpendicular to the elongated portion 122.
`The shorter portion is affixed to a generally rectangular
`base 126. Base 126 has a bore 128 extending lengthwise
`therethrough and parallel
`to elongated portion 122.
`Bore 128 has a pair of key locks 130 which are disposed
`180" apart. Key locks 13!] are adapted to cooperate with
`Key seats 116 disposed on shorter extension 114 of
`modified femur bar 103.
`When the guide member and the modified femur bar
`inserted therein are placed onto guide rod 32 with the
`knee in extension, pointer 120 may be slidably disposed
`onto shorter extension 114 of modified femur bar 108.
`Before implanting guide member pins 66.
`the guide
`member and modified femur bar may be rotated relative
`to shorter portion 35 of guide rod 32, such that pointer
`
`I0
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`55
`
`60
`
`65
`
`Zimmer Holdings, Inc. and Zimmer, Inc.
`Exhibit 1005 - 11
`
`

`
`9
`
`4,567,885
`
`rod has a key seat, the key seat being adapted to
`cooperate with the key lock of the femur bar to
`compensate for the valgus angle, such that said
`planar slot in the guide member is disposed relative
`to the first portion of said guide rod at said minor
`angle.
`3. The system of claims 1 or 2, wherein the guide
`member is adapted to be mounted on the second portion
`of the guide rod and is adapted to cooperate with said
`guide rod such that said planar slot is perpendicular to
`said second portion and perpendicular to the sagittal
`plane extending through the femoral medullary canal.
`-I". The system of claims 1 or 2, wherein the first por-
`tion of said guide rod is adapted to be inserted into the
`medullary canal of the tibia, and further including:
`
`25
`
`30
`
`45
`
`55
`
`10
`s tibia adapter adapted to be mounted on the first
`portion and adapted to stabilize said guide rod such
`that the second portion thereof is coplanar with the
`sagilntal plane extending through the tibial medul-
`lary canal; and
`a tibia bar adapted to be inserted into the guide mem-
`her and adapted to be mounted on the second por-
`tion of said guide rod such that the planar slot of
`the guide member is disposed perpendicular to the
`first portion of said guide rod.
`5. The system of claim 4, wherein the tibia bar has a
`key lock adapted to cooperate with the key seat of the
`second portion of said guide rod to position the tibia