(12) United States Patent
`12 United States Patent
`Fraser et al.
`Fraser et al.
`
`10 Patent N0.:
`(10) Patent N0.:
`(45) Date of Patent:
`(45) Date of Patent:
`
`US 6 723 097 B2
`9
`9
`US 6,723,097 B2
`Apr. 20, 2004
`Apr. 20, 2004
`
`US006723097B2
`US006723097B2
`
`(54) SURGICAL TRIAL IMPLANT
`(54) SURGICAL TRIAL IMPLANT
`
`Inventors: Robert Fraser, Myrtle Bank
`(75) Inventors: Robert Fraser, Myrtle Bank (AU);
`Mark Boomer Somerville MA (Us)
`Mark
`MA<Us>
`’
`’
`<73) Assigneei D°P“y SPin°= 111°» Raynham» MA (US)
`~
`_
`-
`(73) Asslgnee' DePuy Spme’ Inc" Raynham’ MA (Us)
`(,,) Notice:
`Subject to any disclaimer’ the term Ofthis
`( * ) Notice:
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`U.S.C. 154(b) by 0 days.
`
`(21) AppL NO‘: 10/200’890
`(21) Appl. No‘: 10/200,890
`(22) Filed:
`Jul. 23, 2002
`(22)
`Filed:
`Jul. 23, 2002
`
`(65)
`(65)
`
`Prior Publication Data
`Prior Publication Data
`Us 2004/0019356 A1 Jan 29 2004
`Us 2004/0019356 A1 Jan. 29, 2004
`'
`’
`(51)
`Int. Cl.7 .............................................. .. A61B 17/70
`(51) Int. Cl.7 .............................................. .. A61B 17/70
`(52) U.S. Cl.
`....................................... 606/61; 623/17.11
`(52) US. Cl. ..................................... .. 606/61; 623/1711
`(58) Field of Search ......................... .. 623/17.11-17.16,
`(58) Field of Search ......................... .. 623/17.11—17.16,
`623/16.11; 606/61, 69, 79, 86, 97, 102
`623/1611; 606/61, 69, 79, 86, 97, 102
`
`(56)
`(56)
`
`References Cited
`References Cited
`U.S. PATENT DOCUMENTS
`U.S. PATENT DOCUMENTS
`4,795,463 A *
`1/1989 Gerow ........................ .. 623/8
`4,795,463
`A
`* 1/1989
`Gerow ........................ .. 623/8
`4,834,757 A
`5/1989 Brantigan
`Brantigan
`4,834,757
`5/1989
`A
`4,985,019 A *
`1/1991 Michelson ................ .. 604/180
`4,985,019
`A
`* 1/1991
`Michelson ................ .. 604/180
`5,045,080 A
`9/1991 Dyer et al.
`............... .. 604/362
`5,045,080
`9/1991
`A
`Dyer et al. ............... .. 604/362
`5,071,437 A * 12/1991 Steffee, Arthur D.
`623/17.16
`5,071,437
`Steffee, Arthur D.
`623/17.16
`A
`* 12/1991
`5,133,342 A
`7/1992 Seaton ...................... .. 602/39
`5,133,342
`7/1992
`A
`Seaton ...................... .. 602/39
`
`128/654
`5,361,766 A
`11/1994 Nichols et al.
`.... ..
`5,361,766
`11/1994
`A
`128/654
`Nichols et al. .... ..
`5,383,233 A
`1/1995 Russell ..................... .. 378/162
`5,383,233
`1/1995
`A
`Russell ..................... .. 378/162
`
`5,676,146 A * 10/1997 Scarborough .......... .. 623/16.11
`5,676,146 A * 10/1997 Scarborough .......... .. 623/16.11
`6,041,094 A
`3/2000 Russell . . . . . . . . . . .
`. . . . .. 378/37
`6,041,094 A
`3/2000 Russell ......... ..
`
`A *
`COOPCI et al.
`. . . . . . . . ..
`6,093,201 A * 7/2000 Cooper eta1~ ~
`6,113,639 A
`9/2000 Ray et al. .............. .. 623/17.16
`$2222: , 1?/3888 Emit" tttttttttttttt v~2::¢1:~12
`,
`,
`ay e a .
`.............. ..
`.
`6,132,465 A * 10/2000 Ray et al. .............. .. 623/17.16
`2’$33’2‘§§ 31
`15388? §f§f;°i; ,1.
`................... 600/8
`6,146,422 A 11/2000 Lawson
`6,200,258 B1
`3/2001 Slater 61 a1. ................. .. 600/8
`6,264,695 B1 *
`7/2001 Stoy ...................... .. 623/17.16
`6,264,695 B1 * 7/2001 Stoy ...................... .. 623/17.16
`FOREIGN PATENT DOCUMENTS
`FOREIGN PATENT DOCUMENTS
`WO 96/00539
`1/1996
`W0
`WO 96/00539
`1/1996
`W0
`WO 01/70144
`9/2001
`W0
`WO 01/70144
`9/2001
`W0
`* Cited by examiner
`* Cited by examiner
`
`Primary Examiner—David O. Reip
`Primary Examiner—David O. Reip
`(74) Attorney, Agent, or Firm—Nutter McClennen & Fish
`Attorney, Agent, or FLrm—Nutter McClennen & Fish
`
`LLP
`
`ABSTRACT
`(57)
`ABSTRACT
`(57)
`A trial implant and trial implant kit for assisting a physician
`Atrial implant and trial implant kit for assisting a physician
`in selecting an appropriately sized prosthesis is provided. In
`in selecting an appropriately sized prosthesis is provided. In
`one embodiment, the trial medical implant device includes
`one embodiment, the trial medical implant device includes
`a body formed from a radio-lucent material and having a siZe
`a body formed from a radio-lucent material and having a size
`and shape adapted to fit Within or adjacent to an interstitial
`and shape adapted to ?t Within or adjacent to an interstitial
`space, and at least one marker associated with the body and
`space, and at least one marker associated With the body and
`formed from a radio-opaque material. The at
`least one
`formed from a radio-opaque material. The at least one
`marker is configured to provide an X-ray visible reference to
`marker is con?gured to provide an X-ray visible reference to
`indicate the position and/or alignment of the body with
`indicate the position and/or alignment of the body With
`respect to an anatomical structure when the trial medical
`respect to an anatomical structure When the trial medical
`implant device is positioned Within an interstitial space.
`implant device is positioned Within an interstitial space.
`
`30 Claims, 6 Drawing Sheets
`30 Claims, 6 Drawing Sheets
`
`10\
`
`
`
`MSD 1129
`|PR2013—OO506
`
`|PR2013—OO508
`
`

`

`U.S. Patent
`U.S. Patent
`
`Apr. 20, 2004
`Apr. 20, 2004
`
`Sheet 1 0f 6
`Sheet 1 of 6
`
`US 6,723,097 B2
`US 6,723,097 B2
`
`

`

`U.S. Patent
`U.S. Patent
`
`Apr. 20, 2004
`Apr. 20, 2004
`
`Sheet 2 0f 6
`Sheet 2 of 6
`
`US 6,723,097 B2
`US 6,723,097 B2
`
`
`
`FIG. 2B
`
`[165
`
`146
`
`18p
`we
`
`10\
`
`18a
`18a
`
`14b
`
`K16‘
`
`FIG. 2C
`FIG. 2C
`
`10\
`10\‘
`
`14b
`
`-
`
`14b
`-/
`
`14c
`
`14d
`
`14a
`
`

`

`U.S. Patent
`U.S. Patent
`
`Apr. 20, 2004
`Apr. 20, 2004
`
`Sheet 3 0f 6
`Sheet 3 of 6
`
`US 6,723,097 B2
`US 6,723,097 B2
`
`

`

`U.S. Patent
`U.S. Patent
`
`Apr. 20, 2004
`Apr. 20, 2004
`
`Sheet 4 0f 6
`Sheet 4 of 6
`
`US 6,723,097 B2
`US 6,723,097 B2
`
`FIG. 5A
`
`FIG. 5B
`
`14a\
`14b\
`2
`
`FIG 5C
`
`FIG. 5D
`
`14c\
`
`0
`
`14d\
`
`0
`
`

`

`U.S. Patent
`U.S. Patent
`
`Apr. 20, 2004
`Apr. 20, 2004
`
`Sheet 5 0f 6
`Sheet 5 of 6
`
`US 6,723,097 B2
`US 6,723,097 B2
`
`
`
`14d
`14d
`
`10d\
`
`FIG. 6B
`
`14d
`
`12d
`
`14d
`14d
`
`14d
`14d
`
`14d
`
`FIG. 6C 8)
`
`

`

`U.S. Patent
`U.S. Patent
`
`Apr. 20, 2004
`Apr. 20, 2004
`
`Sheet 6 6f 6
`Sheet 6 of 6
`
`US 6,723,097 B2
`US 6,723,097 B2
`
`
`
`FIG. 78
`FIG. 7B
`1ac\ Md
`10c \
`1
`
`14g
`14g
`
`FIG. 7C
`FIG. 7C
`/@\1’’9
`
`14d
`
`

`

`US 6,723,097 B2
`US 6,723,097 B2
`
`1
`1
`SURGICAL TRIAL IMPLANT
`SURGICAL TRIAL IMPLANT
`
`FIELD OF THE INVENTION
`FIELD OF THE INVENTION
`
`The present invention relates to a trial medical implant
`The present invention relates to a trial medical implant
`device, and more particularly,
`to a trial medical implant
`device, and more particularly, to a trial medical implant
`device for evaluating the size, shape, and alignment of the
`device for evaluating the siZe, shape, and alignment of the
`implant with respect to an anatomical structure. The present
`implant With respect to an anatomical structure. The present
`invention also relates to a method of manufacturing a trial
`invention also relates to a method of manufacturing a trial
`implant device.
`implant device.
`BACKGROUND OF THE INVENTION
`BACKGROUND OF THE INVENTION
`Advancing age, as well as injuries, can lead to changes in
`Advancing age, as Well as injuries, can lead to changes in
`the various bones, discs, joints and ligaments of the body. In
`the various bones, discs, joints and ligaments of the body. In
`particular,
`these changes can manifest themselves in the
`particular, these changes can manifest themselves in the
`form of damage or degeneration of an intervertebral disc, the
`form of damage or degeneration of an intervertebral disc, the
`result of which is mild to severe chronic back pain. Inter-
`result of Which is mild to severe chronic back pain. Inter
`vertebral discs serve as “shock” absorbers for the spinal
`vertebral discs serve as “shock” absorbers for the spinal
`column, absorbing pressure delivered to the spinal column.
`column, absorbing pressure delivered to the spinal column.
`Additionally, they maintain the proper anatomical separation
`Additionally, they maintain the proper anatomical separation
`between two adjacent vertebra. This separation is necessary
`betWeen tWo adjacent vertebra. This separation is necessary
`for allowing both the afferent and efferent nerves to exit and
`for alloWing both the afferent and efferent nerves to exit and
`enter, respectively, the spinal column.
`enter, respectively, the spinal column.
`Treatment for a diseased or damaged disc can involve the
`Treatment for a diseased or damaged disc can involve the
`removal of the natural, damaged disk tissue, and the subse-
`removal of the natural, damaged disk tissue, and the subse
`quent replacement of the disc with an implant, such as an
`quent replacement of the disc With an implant, such as an
`interbody cage or fusion device, or a disc prosthesis. The
`interbody cage or fusion device, or a disc prosthesis. The
`implant should have an appropriate size and shape to
`implant should have an appropriate siZe and shape to
`complement the normal height of the disc and to contour the
`complement the normal height of the disc and to contour the
`vertebral endplates adjacent the disc space to provide sta-
`vertebral endplates adjacent the disc space to provide sta
`bility and, if a fusion device is being implanted, to promote
`bility and, if a fusion device is being implanted, to promote
`fusion. If the shape of the vertebral endplates does not match
`fusion. If the shape of the vertebral endplates does not match
`the shape of the implant, shifting can occur resulting in
`the shape of the implant, shifting can occur resulting in
`misalignment of the vertebrae. Accordingly, it is important
`misalignment of the vertebrae. Accordingly, it is important
`for the implant to correspond as closely as possible to the
`for the implant to correspond as closely as possible to the
`region of the intradiscal space that is receiving the implant.
`region of the intradiscal space that is receiving the implant.
`Selection of a properly sized implant can be difficult due
`Selection of a properly siZed implant can be dif?cult due
`to the enclosed nature of the nucleus cavity. X-rays generally
`to the enclosed nature of the nucleus cavity. X-rays generally
`reveal very little about the particular size and shape of the
`reveal very little about the particular siZe and shape of the
`intradiscal space, and thus surgeons often have to rely on an
`intradiscal space, and thus surgeons often have to rely on an
`estimated shape and size based on physiological factors,
`estimated shape and siZe based on physiological factors,
`such as the patient’s height, weight, etc., as well as the
`such as the patient’s height, Weight, etc., as Well as the
`position of the vertebrae. While this method can be
`position of the vertebrae. While this method can be
`sufficient, the selection of an improperly sized implant can
`sufficient, the selection of an improperly siZed implant can
`lead to problems. An oversized implant, for example, will be
`lead to problems. An oversiZed implant, for example, Will be
`difficult to position between the adjacent vertebrae and can
`dif?cult to position betWeen the adjacent vertebrae and can
`lead to long term problems once implanted. Moreover, due
`lead to long term problems once implanted. Moreover, due
`to the enclosed nature of the nucleus cavity, it is virtually
`to the enclosed nature of the nucleus cavity, it is virtually
`impossible for a surgeon to accurately evaluate the size and
`impossible for a surgeon to accurately evaluate the siZe and
`shape of the cavity, much less the matching of the implant
`shape of the cavity, much less the matching of the implant
`with the vertebral endplates. Unfortunately, the sizing prob-
`With the vertebral endplates. Unfortunately, the siZing prob
`lem is not always discovered until the surgeon attempts to
`lem is not alWays discovered until the surgeon attempts to
`position the implant between the vertebrae. As a result, the
`position the implant betWeen the vertebrae. As a result, the
`implant will have been in direct contact with bodily fluids
`implant Will have been in direct contact With bodily ?uids
`and will be contaminated. Some implants can be virtually
`and Will be contaminated. Some implants can be virtually
`impossible to resterilize due to the nature of the materials
`impossible to resteriliZe due to the nature of the materials
`from which they are made. In such cases, it is necessary to
`from Which they are made. In such cases, it is necessary to
`discard an expensive device.
`discard an expensive device.
`To overcome this problem, trial implants and trial implant
`To overcome this problem, trial implants and trial implant
`kits have been developed to assist surgeons in selecting an
`kits have been developed to assist surgeons in selecting an
`implant having the appropriate size and shape. U.S. Pat. No.
`implant having the appropriate siZe and shape. US. Pat. No.
`6,113,639 of Ray et al. discloses, for example, a trial implant
`6,113,639 of Ray et al. discloses, for example, a trial implant
`kit containing several trial implants, each sized and shaped
`kit containing several trial implants, each siZed and shaped
`to simulate the size and shape of an available prosthetic
`to simulate the siZe and shape of an available prosthetic
`implant. The surgeon can select an implant from the kit to
`implant. The surgeon can select an implant from the kit to
`temporarily position within the disc space to evaluate the
`temporarily position Within the disc space to evaluate the
`
`2
`2
`size of the intradiscal space and the fit of a sample prosthe-
`siZe of the intradiscal space and the ?t of a sample prosthe
`sis. A contrast material can be injected into the nucleus
`sis. A contrast material can be injected into the nucleus
`cavity to view the trial implant with respect to the intradiscal
`cavity to vieW the trial implant With respect to the intradiscal
`space via a fluoroscope.
`space via a ?uoroscope.
`While fluoroscopy or x-ray can be effective to verify the
`While ?uoroscopy or x-ray can be effective to verify the
`placement of a trial implant, the image produced can be
`placement of a trial implant, the image produced can be
`distorted by the large, opaque implant. This distortion can
`distorted by the large, opaque implant. This distortion can
`either shield or completely obscure the anatomical matching
`either shield or completely obscure the anatomical matching
`that the surgeon desires to verify. It can also be difficult to
`that the surgeon desires to verify. It can also be dif?cult to
`accurately assess whether the implant is in close contact
`accurately assess Whether the implant is in close contact
`with the complex geometries of the adjacent vertebral end-
`With the complex geometries of the adjacent vertebral end
`plates.
`plates.
`Accordingly, there is a need for a trial implant that can be
`Accordingly, there is a need for a trial implant that can be
`used to accurately and effectively evaluate the size, shape,
`used to accurately and effectively evaluate the siZe, shape,
`and alignment of the implant with respect to an anatomical
`and alignment of the implant With respect to an anatomical
`structure.
`structure.
`
`SUMMARY OF THE INVENTION
`SUMMARY OF THE INVENTION
`The present invention provides a trial implant and trial
`The present invention provides a trial implant and trial
`implant kit for assisting a physician in selecting an appro-
`implant kit for assisting a physician in selecting an appro
`priately sized prosthesis. In one embodiment, the trial medi-
`priately siZed prosthesis. In one embodiment, the trial medi
`cal implant device includes a body formed from a radio-
`cal implant device includes a body formed from a radio
`lucent material and having a size and shape adapted to fit
`lucent material and having a siZe and shape adapted to ?t
`within or adjacent to an interstitial space, and at least one
`Within or adjacent to an interstitial space, and at least one
`marker associated with the body and formed from a radio-
`marker associated With the body and formed from a radio
`opaque material. The at least one marker is configured to
`opaque material. The at least one marker is con?gured to
`provide an x-ray visible reference to indicate the position
`provide an x-ray visible reference to indicate the position
`and alignment of the body with respect to an anatomical
`and alignment of the body With respect to an anatomical
`structure when the trial medical implant device is positioned
`structure When the trial medical implant device is positioned
`within an interstitial space.
`Within an interstitial space.
`The markers can be disposed on an outer surface of the
`The markers can be disposed on an outer surface of the
`body and/or embedded in the body. In one embodiment, the
`body and/or embedded in the body. In one embodiment, the
`implant includes several markers, each of which can be
`implant includes several markers, each of Which can be
`selectively positioned to intersect
`to form one or more
`selectively positioned to intersect to form one or more
`reference points on the body. Thus, when implanted in the
`reference points on the body. Thus, When implanted in the
`body, an x-ray image can be used to determine the exact
`body, an x-ray image can be used to determine the exact
`position of the implant with respect to an anatomical struc-
`position of the implant With respect to an anatomical struc
`ture. In another embodiment, the implant can include first
`ture. In another embodiment, the implant can include ?rst
`and second markers that are selectively distinguishable on
`and second markers that are selectively distinguishable on
`an x-ray image. Each marker can have a variety of shapes,
`an x-ray image. Each marker can have a variety of shapes,
`and can be in the form of a tube, cross, sphere, plate, ring,
`and can be in the form of a tube, cross, sphere, plate, ring,
`rod, T-shape, and combinations thereof.
`rod, T-shape, and combinations thereof.
`In further aspects of the present invention, the body of the
`In further aspects of the present invention, the body of the
`implant has a shape and size adapted to fit between adjacent
`implant has a shape and siZe adapted to ?t betWeen adjacent
`vertebral bodies. By way of non-limiting example, the body
`vertebral bodies. By Way of non-limiting example, the body
`can be a disc-shaped member having a superior, bone-
`can be a disc-shaped member having a superior, bone
`contacting surface and an inferior, bone-contacting surface.
`contacting surface and an inferior, bone-contacting surface.
`The at least one marker is preferably effective to indicate the
`The at least one marker is preferably effective to indicate the
`alignment of the superior and inferior bone-contacting sur-
`alignment of the superior and inferior bone-contacting sur
`faces of the body with respect
`to superior and inferior
`faces of the body With respect to superior and inferior
`endplates of adjacent vertebral bodies when the implant is
`endplates of adjacent vertebral bodies When the implant is
`positioned between adjacent vertebral bodies.
`positioned betWeen adjacent vertebral bodies.
`In another embodiment of the present invention, a trial
`In another embodiment of the present invention, a trial
`spinal implant is provided having a trial implant member
`spinal implant is provided having a trial implant member
`formed from a radio-lucent material and having a size and
`formed from a radio-lucent material and having a siZe and
`shape configured to fit between adjacent vertebral bodies.
`shape con?gured to ?t betWeen adjacent vertebral bodies.
`The trial
`implant member
`includes a superior bone-
`The trial implant member includes a superior bone
`contacting surface and an inferior bone-contacting surface.
`contacting surface and an inferior bone-contacting surface.
`At least one marker formed from a radio-opaque material is
`At least one marker formed from a radio-opaque material is
`associated with the trial implant member such that, when the
`associated With the trial implant member such that, When the
`trial implant is positioned between adjacent vertebral bodies,
`trial implant is positioned betWeen adjacent vertebral bodies,
`the at least one marker provides at least one x-ray visible
`the at least one marker provides at least one x-ray visible
`reference to indicate the position and/or alignment of the
`reference to indicate the position and/or alignment of the
`implant with respect to the adjacent vertebral bodies. In a
`implant With respect to the adjacent vertebral bodies. In a
`preferred embodiment,
`the superior and inferior bone-
`preferred embodiment, the superior and inferior bone
`contacting surfaces of the trial implant member each have a
`contacting surfaces of the trial implant member each have a
`
`5
`
`10
`10
`
`15
`15
`
`20
`
`25
`25
`
`30
`
`35
`35
`
`40
`
`45
`45
`
`50
`
`55
`55
`
`60
`
`65
`65
`
`

`

`US 6,723,097 B2
`US 6,723,097 B2
`
`3
`3
`shape adapted to conform to an endplate of an adjacent
`shape adapted to conform to an endplate of an adjacent
`vertebral body. Thus, when implanted in the body, the at
`vertebral body. Thus, When implanted in the body, the at
`least one marker indicates, on an x-ray image, the alignment
`least one marker indicates, on an x-ray image, the alignment
`of the superior and inferior bone-contacting surfaces of the
`of the superior and inferior bone-contacting surfaces of the
`trial implant member with respect to the endplates of adja-
`trial implant member With respect to the endplates of adja
`cent vertebral bodies.
`cent vertebral bodies.
`In yet another embodiment of the present invention, a trial
`In yet another embodiment of the present invention, a trial
`implant system is provided having a plurality of implantable
`implant system is provided having a plurality of implantable
`trial prostheses. Each implantable prosthesis includes a body
`trial prostheses. Each implantable prosthesis includes a body
`formed from a radio-lucent material and having a size and
`formed from a radio-lucent material and having a siZe and
`shape adapted to fit within or adjacent to an anatomical
`shape adapted to ?t Within or adjacent to an anatomical
`structure, and at least one marker associated with the body
`structure, and at least one marker associated With the body
`and formed from a radio-opaque material. The at least one
`and formed from a radio-opaque material. The at least one
`marker is configured to provide an x-ray visible reference to
`marker is con?gured to provide an x-ray visible reference to
`indicate the position and alignment of the body with respect
`indicate the position and alignment of the body With respect
`to the anatomical structure when the implantable trial pros-
`to the anatomical structure When the implantable trial pros
`thesis is positioned within or adjacent
`to an anatomical
`thesis is positioned Within or adjacent to an anatomical
`structure.
`structure.
`In other aspects of the present invention, a method for
`In other aspects of the present invention, a method for
`manufacturing a trial
`implant
`is provided. The method
`manufacturing a trial implant is provided. The method
`includes the steps of providing at least one marker formed
`includes the steps of providing at least one marker formed
`from a radio-opaque material, providing a mold having a
`from a radio-opaque material, providing a mold having a
`desired size and shape for a medical implant, strategically
`desired siZe and shape for a medical implant, strategically
`placing each of the at least one markers in the mold such that
`placing each of the at least one markers in the mold such that
`the markers are configured to provide at least one x-ray
`the markers are con?gured to provide at least one x-ray
`visible reference to indicate the size and shape of the
`visible reference to indicate the siZe and shape of the
`medical implant, and injecting a radio-lucent material into
`medical implant, and injecting a radio-lucent material into
`the mold to form a trial implant.
`the mold to form a trial implant.
`BRIEF DESCRIPTION OF THE DRAWINGS
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The invention will be more fully understood from the
`The invention Will be more fully understood from the
`following detailed description taken in conjunction with the
`folloWing detailed description taken in conjunction With the
`accompanying drawings, in which:
`accompanying draWings, in Which:
`FIG. 1 is a anterior perspective view of a trial implant
`FIG. 1 is a anterior perspective vieW of a trial implant
`member according to one embodiment of the present inven-
`member according to one embodiment of the present inven
`tion;
`tion;
`FIGS. 2A—2C are top, lateral side, and anterior side views,
`FIGS. 2A—2C are top, lateral side, and anterior side vieWs,
`respectively, of the trial implant of FIG. 1;
`respectively, of the trial implant of FIG. 1;
`FIG. 3 is a posterior perspective view illustrating the
`FIG. 3 is a posterior perspective vieW illustrating the
`radio-lucent marking strips of a trial
`implant member
`radio-lucent marking strips of a trial implant member
`according to another embodiment of the present invention;
`according to another embodiment of the present invention;
`FIG. 4 is a side view illustration of a trial implant member
`FIG. 4 is a side vieW illustration of a trial implant member
`positioned between adjacent vertebrae;
`positioned betWeen adjacent vertebrae;
`FIGS. 5A—5H illustrate several embodiments of markers
`FIGS. 5A—5H illustrate several embodiments of markers
`for use with an implant according to the present invention;
`for use With an implant according to the present invention;
`FIG. 6A illustrates a perspective view of another embodi-
`FIG. 6A illustrates a perspective vieW of another embodi
`ment of a trial implant having several radio-lucent sphere
`ment of a trial implant having several radio-lucent sphere
`markers positioned around and/or within the implant;
`markers positioned around and/or Within the implant;
`FIG. 6B illustrates a top view of the implant of FIG. 6A;
`FIG. 6B illustrates a top vieW of the implant of FIG. 6A;
`FIG. 6C illustrates two misaligned sphere markers;
`FIG. 6C illustrates tWo misaligned sphere markers;
`FIG. 7A illustrates a perspective view of yet another
`FIG. 7A illustrates a perspective vieW of yet another
`embodiment of a trial implant having several radio-lucent
`embodiment of a trial implant having several radio-lucent
`markers positioned around and/or within the implant;
`markers positioned around and/or Within the implant;
`FIG. 7B illustrates a front view of the trial implant of FIG.
`FIG. 7B illustrates a front vieW of the trial implant of FIG.
`7A; and
`7A; and
`FIG. 7C illustrates a ring marker and a cross marker being
`FIG. 7C illustrates a ring marker and a cross marker being
`misaligned with respect to each other.
`misaligned With respect to each other.
`DETAILED DESCRIPTION OF THE
`DETAILED DESCRIPTION OF THE
`INVENTION
`INVENTION
`The present invention provides a trial implant and trial
`The present invention provides a trial implant and trial
`implant kit for assisting a physician in selecting an appro-
`implant kit for assisting a physician in selecting an appro
`priately sized prosthesis. The trial implant is effective to
`priately siZed prosthesis. The trial implant is effective to
`indicate, on an x-ray image, the shape, size, and/or position
`indicate, on an x-ray image, the shape, siZe, and/or position
`
`10
`10
`
`15
`15
`
`20
`
`25
`25
`
`30
`
`35
`35
`
`40
`
`45
`45
`
`50
`
`55
`55
`
`60
`
`65
`65
`
`4
`4
`of the implant with respect to an anatomical structure when
`of the implant With respect to an anatomical structure When
`the implant is positioned within or adjacent the anatomical
`the implant is positioned Within or adjacent the anatomical
`structure. As shown in FIG. 1,
`the implant 10 generally
`structure. As shoWn in FIG. 1, the implant 10 generally
`includes a body 12 formed from a radio-lucent material, and
`includes a body 12 formed from a radio-lucent material, and
`at least one marker 14 associated with the body 12 and
`at least one marker 14 associated With the body 12 and
`formed from a radio-opaque material.
`formed from a radio-opaque material.
`The body of the trial
`implant can have virtually any
`The body of the trial implant can have virtually any
`configuration, depending on the intended use. The body
`con?guration, depending on the intended use. The body
`should, however, have a size and shape adapted to fit within
`should, hoWever, have a siZe and shape adapted to ?t Within
`an interstitial space, and more preferably the size and shape
`an interstitial space, and more preferably the siZe and shape
`of the body should be identical or at least similar to the size
`of the body should be identical or at least similar to the siZe
`and shape of a prosthesis desired to be implanted into a
`and shape of a prosthesis desired to be implanted into a
`patient. FIG. 1 illustrates one example of a trial implant 10
`patient. FIG. 1 illustrates one example of a trial implant 10
`having a disc-shaped body 12 adapted to be positioned
`having a disc-shaped body 12 adapted to be positioned
`between adjacent vertebral bodies. The body includes supe-
`betWeen adjacent vertebral bodies. The body includes supe
`rior and inferior surfaces 16s, 16i, posterior and anterior
`rior and inferior surfaces 16s, 16i, posterior and anterior
`sides 18p, 18a, first and second lateral sides 20a, 20b,
`sides 18p, 18a, ?rst and second lateral sides 20a, 20b,
`respectively, and a perimeter P (FIG. 2A). While the body 12
`respectively, and a perimeter P (FIG. 2A). While the body 12
`can have any shape, the posterior side 18p of the illustrated
`can have any shape, the posterior side 18p of the illustrated
`body 12 is preferably substantially fiat, while the anterior
`body 12 is preferably substantially ?at, While the anterior
`side 18a and the first and second lateral sides 20a, 20b
`side 18a and the ?rst and second lateral sides 20a, 20b
`preferably form a curved convex portion of the perimeter P
`preferably form a curved convex portion of the perimeter P
`between opposite ends 18171, 18172 of the flattened posterior
`betWeen opposite ends 18171, 18172 of the ?attened posterior
`side 18p.
`side 18p.
`A person having ordinary skill in the art will appreciate
`A person having ordinary skill in the art Will appreciate
`that the superior and inferior surfaces 16s, 161' of the body
`that the superior and inferior surfaces 16s, 16i of the body
`12 can have a variety of shapes, sizes, and/or features
`12 can have a variety of shapes, siZes, and/or features
`present on one of both of the surfaces 16s, 161'. By way of
`present on one of both of the surfaces 16s, 16i. By Way of
`non-limiting example, one or both of the surfaces 16s, 161'
`non-limiting example, one or both of the surfaces 16s, 16i
`can have a wedge-like shape (not shown) wherein one side
`can have a Wedge-like shape (not shoWn) Wherein one side
`(e.g., posterior) of the body 12 member has a height less than
`(e.g., posterior) of the body 12 member has a height less than
`a height of the opposed side (e.g., anterior) of the body 12.
`a height of the opposed side (e.g., anterior) of the body 12.
`Other profiles include,
`for example, a supine shape, a
`Other pro?les include, for example, a supine shape, a
`converging portion, and a domed or convex-like profile. One
`converging portion, and a domed or convex-like pro?le. One
`of ordinary skill
`in the art will appreciate that various
`of ordinary skill in the art Will appreciate that various
`combinations of these profiles may be used as well.
`combinations of these pro?les may be used as Well.
`Moreover, the trial implant can be adapted to be used with
`Moreover, the trial implant can be adapted to be used With
`either unprepared or prepared bony endplates of adjacent
`either unprepared or prepared bony endplates of adjacent
`vertebrae.
`vertebrae.
`The trial implant 10 further includes one or more markers
`The trial implant 10 further includes one or more markers
`that are effective to indicate, on an x-ray image, the size,
`that are effective to indicate, on an x-ray image, the siZe,
`shape, and/or position of the implant 10 with respect to
`shape, and/or position of the implant 10 With respect to
`adjacent bone structures. The markers are formed from a
`adjacent bone structures. The markers are formed from a
`radio-opaque material and can have virtually any shape and
`radio-opaque material and can have virtually any shape and
`size. FIG. 1 illustrates one example of a trial implant 10
`siZe. FIG. 1 illustrates one example of a trial implant 10
`having several marker strips 14 that extend around the body
`having several marker strips 14 that extend around the body
`12. As shown, the marker strips 14 are formed from gener-
`12. As shoWn, the marker strips 14 are formed from gener
`ally elongate strip-li