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`usooszszsosa
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`‘
`
`United States Patent
`
`[19]
`
`[11] Patent Number:
`
`5,282,803
`
`[45] Date of Patent: Feb. 1, 1994
`Lackey
`
`
`
`[54}
`
`[75]
`
`[731
`
`[21]
`
`[22]
`
`[631
`
`[51]
`[52]
`
`[581
`
`[55]
`
`INSTRUMENTATION FOR LONG STEM
`SURGERY
`
`Inventor:
`
`Jennifer J. Lackey, Memphis, Tenn.
`
`Assignees Smith a Nephew Richards Ilc.,
`Memphis, Tenn.
`
`Appl. No.: 859,884
`
`Filed:
`
`Mar. 30, 1992
`
`Related US. Application Data
`
`Continuation-impart of Ser. No. 765,379, Sep. 25, 1991,
`Pat. No. 5,100,408, which is a continuation of Ser. 1110.
`666,262, Mar. 7,1991, Pat. No. 5,053,037.
`
`Int. Cl.5 ......................... A613 17/00; A61F 2/32
`US. Cl. ........................................ 606/80; 606/88;
`606/96
`Field of Search ....................... 606/79,' 80, 78, ‘62,
`‘
`606/57, 96, 86, 87, 88; 623/16, 17
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`"
`
`4,467,801 8/ 1984 Whiteside ............................. 606/80
`14,474,177 10/1934 Whiteside
`606/80
`4,437,203 12/1984 Androphy
`128/303
`4,567,885 2/1986 Androphy
`128/92
`4,567,886 2/1986 Petersen ............ 128/92
`4,590,929
`5/1986 Klein ............. 606/80.
`4,646,729
`3/1987 Kenna ..
`..... 606/80
`4,703,751 11/1987 Pohl ...................... 128/92
`4,719,919
`1/1988 Marchosky et a].
`L
`128/401
`4,721,104
`1/1988 Kaufman et a1.
`..... 128/92
`4,722,330 2/1988 Russell et a1. ......’... 128/92
`4,736,737 4/1988 Fargie et al.
`.
`..... 128/92
`4,738,253 4/1988 Buechel ........
`. .606/80
`4,738,254 4/1988 Buechel et a1.
`..
`..... 128/92
`
`4,759,350 7/1988 Dunn et a1. ........... 128/92
`
`4,773,407 9/ 1988 Petersen ................ 128/92 .
`
`1/1990 Zamowski et al.
`..
`..... 606/82
`4,892,093
`
`l/l990 Dale et a1. ................. 606/87
`4,893,619
`
`4,907,578 3/ 1990 Petersen ............ 606/79
`
`4,926,847 5/ 1990 Luckman .............................. 606/88
`
`
`
`
`6/1990 Whiteside et al. .................... 606/88
`4,935,023
`8/1990 Bowman ..........
`4,952,213
`4,959,066 9/1990 Dunn et [1.
`..
`5,(X)2,545
`3/1991 Whiteside .
`.
`5,037,423
`8/1991 Kenna ......
`5,053,037 10/1991 Lackey .....
`5,1w,408
`3/1992 ' Lackey .....
`5,108,405 4/1992 Mikhail ................................. 606/80
`
`
`
`FOREIGN PATENT DOCUMENTS
`
`.
`0122669 10/1984 European Pat. on“.
`685364 12/1939 Fed. Rep. of Germany .
`
`Primary Examiner—Michael A. Brown
`Attorney, Agent, or Firm—Pravel, Hewitt, Kimball &
`Krieger
`
`[57]
`
`ABSTRACT
`
`,
`
`A method and apparatus for installing a knee prosthetic
`component on a patient’s tibia includes the selection by
`a surgeon of one of a plurality of reamers, each of the
`reamers having a different cutting size diameter such as
`for example between ten and twenty-two millimeters of
`cutting diameter. The reamer is initially selected as a
`. very‘ small reamer and the surgeon places progressively
`larger cutting diameter rcamers in the patient’s inter-
`medullary canal until resistance or until the reamer
`becomes stuck. When the surgeon finds a reamer that is
`. sized so that it will ream and cut cortical bone prefera-
`bly a full three hundred and sixty degrees (360'), the
`patient’s intramedullary canal is cut and reamed into a
`depth which corresponds to the length of the stem por-
`tion of the femoral prosthetic component. Instrumenta-
`tion is installed on the upper generally cylindrically
`shaped portion of the reamer as soon as cutting and
`reaming is completed and without removal of the
`”reamerfrom the intermedullary canal. This insures that
`cutting instrumentation will be properly oriented with
`regard to the hole that is cut and reamed to prepare the
`intermedullary canal.
`
`‘
`
`15 Claims, 8 Drawing Sheets
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`Feb. 1, 1994
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`5,282,803
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`INSTRUMENTATION FOR LONG STEM
`SURGERY
`
`CROSS REFERENCEVTO RELATED
`APPLICATIONS
`
`5 .
`
`15
`
`2
`_ guide rod, the guide rod being used as an alignment
`means for the guide member. This patent is a divisional
`of US. Pat. No.‘4,487,203, issued Dec. 11, 1984.
`US. Pat. No. 4,722,330, entitled “Femoral Surface
`Shaping Guide For Knee Implants”, discloses a distal
`femoral surface shaping guide for mounting on an intra-
`medullary alignment guide. The main body of the shap-
`This is a continuation-in-part of copending US. in-
`ing guide preferably contains at least one shaping guide
`tent application ser. No 07/765,379, filed Sep. 25, 1991,
`_' now U.S. Pat. ,No. 5,1(Xl,408, which1s a continuation of
`10' surface. It may have an attachment for other shaping
`oguides, however, preferably the main body of the shap-
`-U.S. patent application ser. No. 053,037, both of whrch
`are hereby incorporated herein by reference.‘
`ing’guide has'integrally formed shaping guide surfaces.
`U.S. Pat. No. 4,791,919, entitled “Surgical Instru-
`BACKGROUND OF THE INVENTION
`men ”, discloses a set of femoral instruments which
`includes a femoral intramedullary alignment rod which
`may be introduced intothe medulla by an alignment rod
`introducer. An angle adaptor which slides over the
`alignment rod forms a basis for the preparation of the
`femur using saw guides to receive the femoral compo-
`nent of the knee prosthesis.
`US. Pat. No. 4,703,751, entitled “Method And Appa-
`ratus For, Resecting A Distal Femoral Surface”. The
`'751 patent discloses a method and apparatus for resect-
`ing a distal’femoral surface. The apparatus includes an
`intramedullary rod,»a jig which attaches to the rod, a
`cutting plate and a reference bar. The method and appa-
`ratus disclosed are for forming the initial resection
`along the transverse axis.
`U.S. Pat. No. 4,738,254, entitled “Positioner For Sur-
`gical Instruments”, discloses a positioner for surgical
`instruments'used to invade a bone. The positioner com—
`prises a body means, an alignment plate, and an align-
`ment rod. The body has at least one guide surface for
`positioning a rescctioning surgical
`instrument. The
`alignment 'rod which extends into the femoral shaft is
`used to locate the main body of the femoral resection
`guide in the correct position.
`' In US. Pat. No. 4,759,350, there is disclosed an appa-
`ratus and system for preparing distal femur and proxi-
`mal tibia ends to receive a knee prosthesis. An intramed-
`ullary alignment guide is used to reference a femoral
`alignment guide for attachment across the distal femur
`after the distal femur out has been made. The femoral
`alignment guide is in turn a reference for several cutting
`guides.
`US. Pat. No. 4,907,578, discloses a distal femoral
`resector for resecting the distal femur. The resector
`comprises a T-shaped base with a rotating rod mounted
`' through the base and an intramedullary alignment rod.
`50'
`The resectOr has a guide slot for guiding a cutting tool.
`U.S. Pat. No. 4,935,023, there is disclosed a distal
`_, femoral surface shaping guide which is mounted on an
`intramedullary alignment
`rod. The apparatus and
`method disclosed are particularly suitable for shaping
`one cbndyle for attachment of a unicondylar prosthesis.
`SUMMARY OF THE INVENTION
`
`_
`1. Field of the Invention
`The prgent invention relates to improved tibial and
`femoral instrumentation method and apparatus for use
`in knee surgery and utilizing a plurality of reamers, each
`having a different cutting diameter to prepare a bore for.
`the stern of a knee prosthesis and wherein the instru-
`mentation registers upon aselected of the reamers that 3°
`is of sufficient diameter particularly, the present inven-
`tion relates to a systemof knee surgery instrumentation
`that allows a surgeon to custOm fit a knee prosthesis
`having a stem to a particular patient wherein the sur-
`geon initiates a reaming of the intramedullary canal
`using a smallest cutting diamger reamer selected from a
`set of rearriers, and progresses up in selected cutting
`diameters of the reamers until one of the reamers gets
`fixed or stuck in the patient’s intramedullary canal,
`meeting resistance frém cortical bone cutting or resect-
`‘ ing inStrumentation then registers upon the selected
`reamer after it cuts the cortical bone to prepare a bore
`" ' for the prosthesis stem. All rescctioning of the knee
`jbint can be referenced to the reamer that15 left111 posi-
`tion when reaming is cornplete. The stem component of
`a knee prosthesis will closely fit the bore formed; by the
`reamer. Instrumentation includes a cutting block ori-
`ented on the reamer, and all cuts made by the surgeon
`' will be oriented relative to the stem or spike component.
`of the prosthesis.
`2. General Background
`' Often a knee prosthesis must be replaced, referred‘ to ‘
`. as a revision case. In revision surgery, the existing com-
`"ponent is removed from the tibia or femur. If cement
`_ was the means of attachment, it is cleaned and removed.
`The tibia or femur must then be recut.
`Various devices have been patented which relate to
`the rescctioning and preparation of the tibia or femur
`' for prosthetic devices. In US; Pat. No. 4,474,177, enti:
`tied “Method and Apparatus For Shaping A Distal
`Femoral Surface”, thereIS disclosed a method and ap-
`paratus for rescctioning of the distal femur. An intra-
`' medullary reamer is usedto internally locate the central:
`,
`longitudinal axis of the femur. The reamer is then re-
`moved ~and an intramedullary alignment guide is in-
`serted in its place. The alignment guide has a handle
`attached to a rod portion at a preselected angle. Femo-
`. ral surface modifying instruments can then be fixed to
`the guide handle and thus assume proper alignment
`with respect to the central longitudinal axis of the fe-
`mur.
`
`25
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`35
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`45
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`55
`
`In U.S. Pat. No. 4,567,885, entitled “Triplanar Knee
`Resection System”, there is provided a system for pre-
`paring a knee joint for a prosthesis. The triplanar system
`includes a guide member which has three pairs of paral-
`lel slots. The system further includes an intramedullary
`guide rod which is inserted into the femur. The guide
`rod has a 90° bend. The guide member is affixed to the
`
`65
`
`The present invention provides an instrumentation
`' system for long stern surgery. The present invention
`provides a number of reamers in a set, and cutting in-
`strumentation mounts to a selected of the reamers after
`the selected size cuts a prepared bore for the knee pros—
`thesis in cortical tissue. The instrumentation will be
`used in knee surgery where a knee prosthesis compo-
`nent has a stem that registers in a patient’s tibia or fe-
`mur.
`
`Instruments are always correctly oriented as is the
`knee prosthesis, by making all cuts relative to a selected
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`If the case is a revision surgery, the existing compo-
`nent is removed from the tibia or femur. If cement was _
`the means of attachment, it is cleaned and removed.
`The present invention thus provides an imprdved
`method and apparatus for implanting a knee prosthesis
`component having a stem that registers with a patient’s
`leg bone intermedullary canal.
`The method and apparatus of the present invention
`first uses a reamer selected from a group or set of ream
`ers. Each of the reamers is of an increasingly larger
`external diameter. For example, the first reamer can be
`relatively small such as for example, having a cutting .
`15
`diameter of ten milliliteters. Additional reamers can be
`in sizes up to for example tWenty-t'wo millimeters, and
`in one millimeter increments. The surgeon then15 'al-
`lowed to start with a small reamer such as the ten milli-
`meter sizeand progresswith increasingly latger exter-
`‘nal cutting diameter reamers to preliminarily ream the
`intermedullary canal of the patient’s leg bone. By using
`progressively larger reamers to ream the patient’5 leg
`bone, a surgeon can insure thatthe smallest possible size
`reamer will be selected yet still cut into cortical bone
`sufficiently to define a prepared bore that will closely
`conformto and abut the stem of the selected knee pros-
`thesis component during use Thus for example, the
`.surgeoncan select a reamer that initially does not cut'
`certical bone three hundred and sixty degrees (360').
`That particular reamer may be for example,
`twelve
`millimeters"in diameter. However, if the surgeon con-
`tinues to increase in size, it is possible that the fourteen
`millimeter cutting diameter reamer for example, might
`' ‘meetjre'sist‘ance and become initially stuck1n the inter-
`medullary'canal so that the surgeon knows that three
`hundred and sixty degrees (360’) of cortical bdne tissue
`is out once reaming is completed
`After the surgeon prepares a bore by cutting three
`hundred and sixty degrees (360') of cortical bone,a
`knee prosthesis'15 selected having a stem With the same
`external diameter as the cutting diameter of the selected
`reamer. Further, the surgeon can then correlate a cut-
`ting of the legbone knee joint area to conform to the
`angle between the stem and the table of the knee pros-
`thesis. Thus, cutting instrumentation is mounted upon
`the selected reamer as the reamer occupies the inter-
`medullary canal and as the distal end portion or cutting
`end portion of the reamer fits against the prepared bore.
`In short, the surgeon simply leaves the reamer in posi-
`tion as soon as the prepared boreis cut. Thus, the
`reamer defines a reference axis for the cutting instru-
`mentation installed thereon.
`~
`Once the cutting instrumentation is installed, the
`surgeon cuts the leg bone at the knee joint area using the
`cutting. instrumentation supported by the selected
`reamer and externally of the intermedullary canal.
`The upper portion of the reamer is preferably cylin-
`Vdrically shaped, defining a non-cutting end portion of
`the reamer that supports the instrumentation during
`cutting.
`The plurality of reamers are of different cutting diam-
`eters, each having preferably a ‘cylindrically shaped
`cutting end portion that conforms to the shape of the
`stem of the knee prosthesis.
`The surgeon begins with a smaller reamer having a
`smaller diameter and inserts progressively larger ream-
`ers into the patient’s intermedullary canal until a reamer
`is selected that is capable of reaming three hundred and
`
`35
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`40
`
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`50
`
`After the tibia or femur cut is completed a correct
`size femoral drill guide15 chosen by determining which
`guide fits bestin the anterior/posterior and medial/lat-
`eral dimensions to ensure equal flexion and extension
`spaces. The femoral drill guide is positioned on the
`distal femur by placing the anterior ledge on the existing
`anterior femoral cortex.
`Once correct medial/lateral and rotational orienta-
`tion is achieved, the femoral drill guide1s affixed to the
`' femur anteriorly and/or medial/laterally by means of at
`45' least one pin or drill bit through the anterior ledge or
`through the. attachable handle. The appropriate size
`femoral collet is attached to the femoral drill guide and
`positioned for a left or right knee.
`The matching sized femoral reamer is then inserted
`through the femoral collet and is advanced into the
`intramedullary canal. The femoral reamer can be cali-
`brated to determine how deep into the canal the reamer
`has advanced. Femoral
`lug holes can be drilled, if
`needed, through the femoral drill guide. When reaming
`and drilling is complete, the femoral drill guide is re-
`moved from the femur' and the femoral reamer is left in
`place in the intramedullary canal.
`The same size revision femoral anterior/posterior
`(A/P) cutting block is then attached to the intramedul-
`lary reamer. Ifthe femoral lug holes have been drilled
`to accept the revision femoral A/P cutting block studs,
`the studs can then be placed into the holes for correct
`rotation orientation. If there is little or no femoral bone
`to affix the femoral anterior/posterior cutting block
`studs in, then the adaptable anterior femoral ledge can
`be attached to the cutting block. The correct rotation
`can be determined and the femoral anterior/posterior
`cutting block can be affixed to the anterior and/or me-
`
`,7
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`reamer after it has cut a prepared bore into the cortical
`bone tissue.
`
`4
`sixty degrees (360') of cortical bone tissue at the distal
`end of the reamer.
`
`5,282,803
`
`It is preferred that the reamers span a range of milli-
`meters in size such as for example 10—22 millimeters in
`diameter, with the different reamers being spaced apart
`by one millimeter in diameter. Thus, the reamers will be
`supplied in cutting diameters of ten, eleven, twelve,
`thirteen, fourteen, fifteen, sixteen, seventeen, eighteen,
`nineteen, twenty, twenty-one, and twenty-two.
`The cutting instrumentation can include a cutting
`block providing one or more flat cutting reference sur-
`faces so that the cuts can be made by abutting a selected
`cutting‘reference surface with a cutting blade.
`The present invention also provides a cutting instru-
`mentation apparatus for use in preparing a knee joint
`area for a knee prosthesis. The apparatus includes a
`plurality of elongated rotary reamers, each having an
`upper proximal end portion and a lower distal end por-
`tion with a rotary cutting element thereon. In the set of
`reamers, each reanier is of a progressively larger cutting
`diameter.
`
`An instrumentation assembly has a means for sup-
`porting the assembly during use upon a selected reamer
`at its upper end portion and externally of the patient’s
`intermedullary canal.
`The instrumentation assembly includes at least a cut-
`ting block with a cutting'guide surface thereon for ref-
`erencing a cutting blade so that selected bone tissue cuts
`can be made adjacent the knee joint area of the patient
`by aligning the cutting blade with the cutting guide
`surface.
`
`The instrumentation system of the present invention
`also includes a drill guide for use with a selected of the
`reamers.
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`5
`dial/lateral femur byinserting at least one pin or drill bit
`through the adaptable anterior femoral ledge ‘ or the
`attachable handle. The anterior/posterior, and the an—
`terior/posterior chamt'er cuts can then be made through
`. or over the femoralanterior/posterior cutting block
`If needed, the femoral drill guide can be reattached to
`. the distal femur1n the 'saine manner as stated above and"
`larger sized femoral collets can be positionedto ram for .
`larger femoral stems.
`IQ
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`_
`
`’
`
`6
`FIG. 14 is a schematic view of the distal femur after
`cutting and prior to the affixation of a long stemmed
`femoral component thereto;
`FIG. 151s a schematic view illustrating the method of
`. the present invention wherein the intermedullary canal
`is reamedwith a reamer of selected cutting diameter;
`FIG. 16 is a schematic illustration of the method of
`the present invention illustrating an interior view of the
`instrumentation as installed upon the reamer;
`FIG. 17 is a schematic anterior view illustrating
`placement‘of a cutting block portion of the instrumenta-
`tion as referenced to the reamer;
`FIG. 18 illustrates use of the cutting block for cutting
`the bone tissue adjacent the knee joints; and
`'15- FIG. 19 is a perspective view illustrating placement
`_. of the knee'prosthesis component after reaming of the
`:intermedullary canal to accept the prosthesis stem, and
`after resectioning of the bone tissue adjacent the knee
`joint.
`
`20
`
`For a further understanding of the nature and objects
`. of the present invention, reference should be had to the
`following detailed description; taken in conjunction
`with the accompanying drawings,in which like parts
`are given like reference numerals, and wherein:
`,
`‘
`FIG. 1 is a partial perspective view of the preferred
`embodiment of the apparatus of the present invention
`illustrating the femoral drill guide portion thereof with
`collet attached;
`FIG. 2 is a partial end view of the preferred embodi-
`ment of the apparatus of the present invention illustrat-
`ing the femoral drill guide portion thereof with the
`collet attached;
`FIG 3 is a partial schematic anterior view ofthe
`preferred embodiment of the apparatus of the present
`inVention illustrating the femoral drill guide portion
`with the reamer/drillm an operative position;
`FIG 41s a partial side or lateral/medial view of the
`preferred embodiment of the apparatus of the present
`inventiOn illustrating the drill guide portion with the
`reamer/drillm an operative position;
`FIG 5 is 'a partial side, schematic view- of the pre- ‘
`.35
`ferred embodiment of the apparatus of the present in-
`vention illustrating the reamer/drill1n an installed oper-
`ative position within the intramedullary canal;
`. FIG. 61s a top view of an alignment assembly/cutting '
`block that can be used with the method of the present
`invention;
`FIG 7 is a side view or lateral/medial view of an»?
`. alignment assembly/cutting block as aligned upon the
`drill/reamer as part of the method of the present inven-
`tion;
`FIG. 8is a end view of an alignment assembly/cut-
`ting block as aligned upon the drill/reamer as part of
`the method of the present invention;
`FIG 9is a side View of an alignment assembly/cut-
`ting block as aligned upon the drill/reamer as part of
`the method of the present invention;
`FIG. 10'1s a side view or lateral/medial view of the
`femur illustrating a cutting of the distal femur as part of
`the method of the present invention,
`' FIG. 111s a partial end view of the preferred embodi-5
`ment of the apparatus of the present invention illustrat-5
`ing the distal femur With revision anterior/posterior
`cutting block portion attached to the drill/reamer;
`FIG. 121s a partial view of the preferred embodiment
`of the apparatus of the present invention illustrating the
`anterior distal femur with revision anterior/posterior
`cutting block and anterior ledge adapter portions at-
`tached to the drill/reamer;
`FIG. 13 is another partial side view of the preferred ‘
`embodiment of the apparatus of the present invention
`illustrating the medial/lateral distal femur with revision
`anterior/posterior cutting block and anterior ledge
`adapter portions attached to the drill/reamer;
`
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`.The knee prosthesis surgical instrumentation appara-
`tus 10 of the present invention includes a femoral drill
`guide'body 11 (FIG. 1) adapted for placement during
`use 011the distal femur 12. The drill guide 11 includes a
`generally rectangularportion 13 having a flat 14 under
`, fsurface that orients upon the end of the distal femur 12A
`and a flat tOp surface 15 portion that accommodates
`removable collet 16. Collet 16 includes a pair of spaced
`apart handles 17,18 and a central portion 19 having a
`cylindrical opening 20 therethrough which is angularly
`oriented with respect to flat surfaces 14, 15. This angu-
`‘lar orientation of ' opening 20 accommodates for the
`difference between the anatomical axis of the femoral
`intramedullary Canal 12B and the mechanical axis
`which'1s defined bya line that passes through the center
`of the femoral head and the midline of the knee joint
`and ankle joint. The end of the distal femur15 designated
`by the numeral 12A111 FIG. 13.
`In FIGS. 2 and 3, the drill guide 11 is shown in an end
`View andin a anterior view respectively upon femur 12.
`In FIG. 2, the posterior condyles 12C of the femur 12
`can e shown extending beyond the bottom rectangular
`drill guide body 13. Removable collet 16 attaches to
`guide body 11 at an elongated slot 25 that extends trans-
`versely across the rectangular 13 portion of guide body
`_ 11.’ Slot 25 is shaped to receive collet 16. A pair of
`attachment posts 26, 27 receive collet 16 thereon. Collet
`5016 includes openings 28, 29 that register upon posts 26,
`27. The posts 26, 27 can each be provided with a spring
`locking detent, such as a spring loaded ball, for exam-
`ple, to frictionally engage the collet 16 at the openings
`528, 29.An anterior ledge 21 provides a plurality of openings
`522'that define drill or pin openings for preventing rota-
`tional and translational movement of the drill guide 11
`with respect to femur 12. The anterior ledge 21 prefera-
`' bly provides a plurality of, for example, ten (10) open-
`ings 22 as shown in FIGS. 1 and 3. The surgeon can
`select any particular opening 22 forthe placement of a
`pin or drill therethrough into the underlying femur for
`purposes of rigidifying the drill guide 11 and preventing
`rotation and translation.
`In FIGS. 3-4, there can be seen an elongated drill-
`/reamer 30 having a lower cutting 31 portion and a
`smaller diameter shaft 32 portion, a drill/reamer sleeve
`33 manufactured of plastic, for example, provides an
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`
`’
`
`WMT 1019-13
`
`WMT 1019-13
`
`

`

`I
`
`.
`
`.
`
`5,282,803
`
`.
`
`10
`
`30
`
`35
`
`7
`inside diameter cylindrical portion 34A and an outside
`diameter cylindrical portion 34B, and a larger diameter
`..cylindrical portion 35'1n the form of an enlarged collar
`The inside cylindrical portion 34A'is sized to accept and
`centralizethe drill/reamer shaft diameter 32. Thecylin-
`drical portion 34'is sized to snugly fit and centralizein ~
`opening 20of collet 16, as shown1n FIGS. 3 and 4. The
`axis X—X 'of drill/renter 30'rs shownin FIG. 3 as
`being angled with respect to a line normal to theflat
`uppersurface 15 and the flat under surface 14 of drill
`guideportion 13. The flat surfaces 14,15 are preferably 3
`flat plane, and/or parallel to one another.
`In the preferred embodiment, the angle formed bythe 5
`3 drill/reamer 30with respect to aline normal to surfaces
`1'5 '
`14,15is on the order of zero-twenty degrees (0'-20')
`but preferably five-eleven degrees (5'-11‘) which ac-‘
`commodatesthe large majorityof anatomical situations.
`11
`d
`Theco ets 16 are removable an thus each collet pro-
`.vides an opening20 having a different angular orienta-
`' tion. Further, the collets can be provided with openings
`20 of different cylindrical diameter such as 8 millime-
`ters, 9 millimeters, etc. Thus, the removable collets 16
`providean adjustability both with regard to the angle of
`orientation of the drill/reamer 30 and also with regard
`to the diameter of drills/reamers that can be used based
`upon the selection of the diameter of opening 20 and of
`the size of sleeve 33.
`The collet 16 are preferably reversible, as shbwn1n
`FIGS. 1 and 2, havingleft and right sides for accommo-
`”dating left and rightfemurs. The surgeon simplyselects
`the proper collet position so as to Orient the opening 20
`in the direction that will correctly track the intramedul-
`lary canal with the reamer/drill 30.
`The drill guide 11 main rectangular body 13has a pair
`- of Openings 36,37 which are sized based upon the an-
`choring pins of the femoral knee component and lo-
`' cated with respect to the long stem of the femoral co‘mr
`ponent.
`FI.GS 5.10 illustrate the use of the femoral drill;
`/reamer to orient a commercially available alignment
`guide. InFIG. 5, the femur 12'1s illustrated with the flat
`. distal end 12A in a revision case being shown. The
`drill/reamer 30 has been installed with the cutting 31 ’
`45
`portion penetrating the intramedullary canal _123. At
`this point, the drill/reamer 30 provides orientation for
`the aligr'urient guide designated generally by the nu?
`meral 40 and thereafter, for the cutting block 50 portion
`of the present invention (see FIGS. 11——13).
`FIG. 6 shows a top view of the alignment guide,
`whereasin FIG. 7, a side view is shown with the align- .
`ment guide positioned upon the drill/reamer and the
`top 12A of the distal femur. In FIG. 8 and9, the proper
`orientation of the alignment guide 40 with femur 121s
`shonn, andupon drill/reamer 30 whereas FIG. 9 illus-
`trates a side view thereof. A drill or pin 4115 illustrated
`. in _FIG. 9 as entering the anterior femur surface 12B.
`The opening 42 fOrmed by drill or pin 411s shown_1n
`FIG. _10 wherein a blade “is used to dress the end of
`the distal femur 12A- before attachment of the cutting
`'block 50 thereto. It should be understood that the align-
`ment guide illustrated'1n FIGS. 6—10'15 a commercially
`available device sold by Smith & Nephew Richards Inc
`' of Memphis, Tami. The alignment guide 40is shown
`_simply to' illustrate how the drill/reamer 30 is used for
`orientation of the alignment guide 40 and also the cut-
`ting block 50 thereon after the drill/reamer 30 is _in-
`stalled using the femoral drill guide 11.
`
`8
`In FIGS. 11—13, the revision femoral anterior/post-
`erior cutting block 50 is shown, comprising a generally
`rectangular cutting block portion 51 having an upper
`generally flat surface 52 and a lower flat surface 53 with
`' an anterior ledge 54 being removably attached at bolted
`connectiOn 55. The anterior ledge 54 can be shaped
`correspondingly to the ledge 21 of femoral drill guide
`11, having the same plurality of openings to accommo-
`date a drill or pin as the openings 22 of anterior ledge
`21. Thus, the plurality of openings 56'm anterior ledge
`54 can be correspondingly placed to the plurality of
`openings 22in anterior ledge 21 of drill guide 11.
`The cutting block 50 provides a plurality of guide
`slots 56459 and guide surface 59A which are parallel
`and which accommodate a cutting blade for making
`posterior femoral cuts. The guide surface 61A accom-
`:
`modates a cutting blade to make the anterior femoral
`:._ .‘
`Cut. A plurality of diagonal slots 60, 61 (FIG. 13) are
`. provided for
`g diagonal cuts to the distal end of
`20
`femur 12 when the cutting block 50 is positioned, as
`shown'In FIG. 13.. The cutting block 50 is preferably
`provided with _a pair of permanent angled openings 62,
`.. 63, (or openings carried'1n collets) each of which is
`angled by a measure equal to the anatomical offset of
`25
`the intr'amedullarycanal as defined by the positibn of
`the drill/reamer 30 when occupying the intramedullary
`'canal of the femur. The surgeon simply selects the de-
`gree of orientation of the cutting block 50 for a given
`anatomical offset by selecting from a plurality of cutting
`blocks 50, or by means of removable collets. The cut-
`ting block 50. can provide a pair of spaced apart pegs 64,
`'65 that register- in cavities 74 that were made through
`~ openings 36, 37 of femoral drill guide 11 or left in the
`distal femur by the previous femoral component for the
`knee prosthesis.
`In FIG. 14, the femur 12'15 illustrated with the cuts
`having been made using cutting block 50 and prior to
`the installation of a new long stem component 70 that
`includesan elongated stem 71 and a pair of spaced apart
`40 ,
`pegs 72, the stem 71 registering in the opening 73 that
`has been formed'1n the intramedullary canal using drill-
`/reamer 30. The pair of cavities 74 represents openings
`in the femur 12 for accommodating the pair of pegs 72.
`FIGS. 15—19 illustrate the method of the present
`invention for implanting knee prosthesis component 70
`having stem 71 that registers with the patient’s tibia 75
`i and more particularly the intramedullary canal 78 por-
`tion as more fully described hereinafter.
`The method of the present invention first requires the
`placement of a selected reamer/drill 30 which is se-'
`lected’frOm a group of reamers 30. Each of the reamers
`if of an increasingly largerexternal cutting diameter and
`isused to preliminarily ream the intramedullary canal
`78 of the patient’s tibia 75 and to a desired depth and
`internal diameter which corresponds to the length and
`external diameter of the stem 71 of a knee prosthesis
`component70. Typically, the reamers 30 would be
`providedin a range of diameters beginning for example
`at ten (10) millimeters1n cutting diameter and up to for
`example twenty-two millimeters'in diameter and one
`millimeter apart in diameter from one reamer 30 to the
`next, for example.
`.
`The surgeon begins the method of the present inven-
`tion by selecting the smallest diameter reamer 30 that is
`provided in the set of reamers ten through twenty-two
`(10-22) millimeters in cutting diameter, for example.
`The surgeon then progresses up by inserting one reamer
`30 at a time into the intramedullary canal 78 until the
`
`>
`
`55
`
`60
`
`65
`
`WMT 1019-14
`
`WMT 1019-14
`
`

`

`5,282,803
`
`l0
`
`'
`
`_ openings 89. This affixes the position of block 81 with
`respect to the patient’s tibial condylar surface 79. The
`surgeon then simplyplaces the cutting blade 91 upon
`the flat upper surface 86 of cutting block 81. In this
`fashion, the proxima