Methods and instrumentation for positioning implants in spinal disc space in an anterior lateral approach
Instruments and methods are provided for positioning one or more implants into a spinal disc space. The instruments and methods have application in an anterior lateral approach to the disc space between the L4 and L5 vertebrae. The instruments include a distractor, a housing, a guide member to facilitate positioning of the housing, and a partition member engageable to the housing to facilitate positioning of one or more implants into the disc space.
This application is a divisional of U.S. patent application Ser. No. 10/405,816, filed Apr. 2, 2003, and issuing as U.S. Pat. No. 7,326,216, which application is incorporated herein by reference in its entirety.
BACKGROUNDAccess to the disc space between the L4 and L5 vertebrae can be obstructed or difficult due to anatomical considerations. For example, an anterior approach or an anterior oblique approach requires the surgeon to retract or move, or at least work adjacent to, the major vessels extending along the anterior portion of the spinal column. While an anterior oblique approach may reduce or eliminate the requirement for retraction of these major vessels, access for positioning instruments and implants in the posterior portion of the disc space on the side of the approach can be limited. Further, the instruments can still be adjacent the major vessels during the surgery.
A lateral approach to the disc space anterior of the posterior elements can avoid the major vessels and provide access for disc space preparation and implant insertion, but other anatomical obstructions can be encountered. For example, positioning instruments and implants in the spinal disc space between the L4 and L5 vertebrae from an anterior lateral approach can be obstructed or inhibited by the iliac crest. Instrumentation and methods which facilitate placement of implants in the spinal disc space from an anterior lateral approach are needed to make such procedures a more viable alternative for treatment and correction of spinal deformities.
SUMMARYInstruments and methods are provided for positioning one or more implants into a spinal disc space. The instruments and methods have application in an anterior lateral approach to the disc space between the L4 and L5 vertebrae. The instruments and methods can also have application in other approaches to the spine at any level of the spine.
According to one aspect, instruments are provided that include a distractor, a housing, a guide member to facilitate positioning of the housing, and a partition member engageable to the housing to facilitate positioning of one or more implants into the disc space.
According to another aspect, a surgical instrument insertable in a spinal disc space between an upper vertebra and a lower vertebra is provided. The instrument comprises a head including an upper surface and an opposite lower surface positionable adjacent endplates of the upper and lower vertebrae, respectively. The head defines a disc space distraction height between the upper and lower surfaces. A shaft extends proximally from the head. The shaft includes a distal portion, a proximal portion, and an offset portion therebetween. The distal portion includes a guide portion adjacent the head. The head and the guide portion extend along a first axis and the offset portion extends proximally from the guide portion along a second axis oriented at a first angle relative to the first axis.
According to a further aspect, a surgical instrument assembly provides access to a spinal disc space. The assembly comprises a distractor, a housing and a guide instrument. The distractor includes a head positionable in a spinal disc space and a shaft extending proximally from the head. The shaft includes a guide portion along at least a portion thereof adjacent the head. The guide instrument includes a shaft and a guide member at a distal end of the shaft. The guide member is removably engaged to the housing and moveable along the guide portion of the distractor with the shaft of the guide instrument adjacent to the shaft of the distractor to guide the housing along the distractor to the spinal disc space when the head is positioned in the spinal disc space.
According to another aspect, an instrument assembly for facilitating placement of an implant in a spinal disc space includes a housing and a partition member. The housing includes a frame member defining an opening therethrough between side walls of the housing. The housing is positionable adjacent to the spinal disc space and provides access thereto through the opening. The partition member is engageable to the frame in the opening. The partition member includes an extension extending distally from the frame and positionable in the spinal disc space. The partition member is movable relative to the frame between the side walls.
According to another aspect, a surgical instrument assembly is provided. The assembly includes a body with a portion positionable in a spinal disc space and a mounting member extending from the body. The assembly also includes a shaft assembly removably engageable to the mounting member. The shaft assembly includes an outer shaft defining a distally opening receptacle and an inner shaft movable relative to the outer shaft and extending distally therefrom. The inner shaft includes a distal engagement member engageable to the mounting member. Movement of the engagement member relative to the outer shaft to position the mounting member in the receptacle secures the body to the shaft assembly.
According to a further aspect, a method for positioning an implant in a spinal disc space of a patient comprises: accessing the spinal disc space between L4 and L5 vertebrae from a lateral approach to the patient; and positioning a distractor in the spinal disc space with a shaft of the distractor oriented laterally to the patient, the shaft comprising a distal portion extending laterally from the spinal disc space and a proximal portion offset relative to the distal portion anteriorly of the iliac crest.
According to another aspect, a method for positioning a spinal implant in a spinal disc space of a patient comprises: positioning a housing adjacent the disc space between the L4 and L5 vertebrae in an anterior lateral approach; positioning a partition member through the housing into the disc space; positioning an implant in the disc space anterior of the partition member; and moving the partition member anteriorly to move the implant anteriorly in the spinal disc space.
These and other aspects are also discussed below.
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates.
Referring to
In surgical procedures for accessing disc space 18, it can be desirable to approach disc space 18 from a lateral approach along the anterior side of iliac crest 20. With such an anterior lateral approach, the major arteries and veins along the anterior portion of the spine can be avoided. Furthermore, the posterior neural elements, musculature, and bony structures can be avoided. With the anterior lateral approach, one or more implants can be positioned in disc space 18 in such a manner that the load of the spinal column transmitted by the implants is evenly distributed about the central axis of the spinal column. However, iliac crest 20, particularly along its outer margin 22, can extend anteriorly relative to disc space 18 such that anterior lateral access to disc space 18 is impeded thereby.
Referring now to
Shaft 34 includes a proximal portion 41 and a distal portion 43 separated by an offset portion 40. Proximal portion 41 includes a first shaft portion 38 extending proximally from offset portion 40 along an axis 39. A handle 36 extends from first shaft portion 38 and is oriented transversely to axis 39. Distal portion 43 includes a guide portion 42 extending distally from offset portion 40 along an axis 44. Head 32 extends distally from guide portion 42. As discussed further below, guide portion 42 can be adapted to guide placement of a housing therealong to a position adjacent disc space 18 when head 32 is positioned in the disc space.
As shown further in
In one embodiment, offset portion 40 is spaced proximally about 60 millimeters from the trailing end of distraction head 32, and offset distance 31 is about 20 millimeters. Other suitable dimensions and offsets are also contemplated so that proximal portion avoids the iliac crest when distractor 30 is inserted in an anterior-lateral approach to the disc space.
In
Upper wall 64 of frame portion 52 includes an upper slot 58 formed therethrough and lower wall 66 includes a lower slot 60 formed therethrough. Slots 58, 60 facilitate coupling of housing 50 to an instrument, such as shaft assembly 126 discussed further below, so that the shaft assembly can remove housing 50 from the disc space. Upper wall 62 includes a leading end 64 curved to conform to the curvature of the vertebral body against which it is positioned in the operative position of housing 50. Similarly, lower wall 66 includes a leading end 68 curved to conform to the curvature of the vertebral body against which it is positioned in the operative position of housing 50. A proximally-opening notch 70 is provided in posterior wall 53.
In
As shown in further detail in
Guide member 86 includes a body 88 defining guide passage 90 extending between a distal end and a proximal end of body 88. Tapered surfaces 92 provide an opening into passage 90 along one side of body 88. Guide passage 90 is sized to receive guide portion 42 of distractor 30 therein in close-fitting and sliding engagement to permit controlled relative movement of guide member 86 along guide portion 42. Body 88 includes a distal portion 96 and a proximal portion 98. Proximal portion 98 includes a flanged wall 99 extending about and forming a lip about distal portion 96. Distal portion 96 is sized for positioning in opening 54 of housing 50 with flanged wall 99 in abutting engagement with the proximal end of housing 50.
In
Shaft 34 of distractor 30 is positioned in passage 90 of guide member 86 proximal of guide portion 42. Guide member 86 and housing 50 are advanced to position guide portion 42 in passage 90. Guide portion 42 can have a cross-section enlarged relative to the proximal portion of shaft 34 for sliding engagement with passage 90. It is contemplated that passage 90 of guide member 86 can be keyed to guide portion 42 to prevent rotation of guide instrument 80 thereabout and to ensure the proper orientation of housing 50 as it is guided to the disc space. Circular cross-sections are also contemplated. Housing 50 is guided along guide portion 42 to position frame 52 adjacent the L4 and L5 vertebrae, and to position posterior extension 56 and anterior extension 57 in the disc space. With housing 50 in its proper position relative to disc space 18, distractor 30 and guide instrument 80 are removed proximally from housing 50 with housing 50 remaining at the operative site. Opening 54 of housing 50 provides access to the disc space for removal of disc material, endplate preparation and implant insertion. It is also contemplated that disc material removal, endplate preparation and other pre-implant insertion procedures can be conducted prior to positioning of housing 50.
Referring to
In
Partition member 110 can be attached to shaft assembly 126 and positioned through opening 54 of housing 50 so that central extension 112 extends into the disc space between posterior extension 56 and anterior extension 57. When inserted through opening 54 of housing 50, upper flange member 116 is positioned along upper wall 62, and lower flange member 118 is positioned along lower wall 66. Mounting member 122 extends upwardly from upper wall 62 so that shaft assembly 126 is located above the iliac crest at its proximal end when secured to mounting member 122. Spacing 132 between the flange members 116, 118 and body 114 can be provided to receive the thickness of the upper and lower walls 62, 66 for sliding engagement therewith as partition member 110 is moved relative to housing 50. Upper and lower walls 62, 66 can be parallel to one another to facilitate the sliding movement of partition member 100 therealong.
In
In
In use, displacer wedge 150 of wedge displacer instrument wedge 140 can be been inserted between partition member 110 and posterior extension 56 of housing 50 to provide an initial separation. With wedge displacer instrument 140 removed, second displacer instrument 170 is positioned with leading end 182 of displacer head 180 between posterior extension 56 of housing 50 and partition member 110. Leading end 182 can provide a separation between the distal ends of posterior extension 56 and partition member 110 that corresponds to the width of leading end 182.
With reference to
Housing 50 is mounted to guide member 86 of guide instrument 80 and then positioned about shaft 34 of distractor 30. Guide member 86 and thus housing 50 are guided along guide portion 42 to position posterior extension 56 laterally along the posterior portion P of disc space 18 and anterior extension 57 laterally along the anterior portion A of disc space 18. Frame 52 is positioned adjacent the vertebrae 14, 16 outside disc space 18 so that opening 54 can provide access to disc space 18 while extensions 56, 57 maintain disc space distraction.
Referring now to
In
Tapered leading end 152 of wedge displacer instrument 140 may not position central extension 112 and implant 250 anteriorly far enough so that implant 250 extends in a medial-lateral orientation in disc space 18, particularly at the distal end of central extension 112. In
With implant 250 in a desired position in disc space 18, partition member 110 can be removed by, for example, attaching shaft assembly 126 thereto and withdrawing partition member 110 from disc space 18 and housing 50. In
The instruments and methods of the present invention facilitate placement of implants 250, 270 in disc space 18 in a medial lateral orientation to provide bilateral support of the adjacent vertebrae 14, 16 in the anterior and posterior areas of disc space 18. It is further contemplated that only a single implant may be inserted in disc space 18. Bone graft, bone growth inducing material, and/or therapeutic agents can be positioned in, around or integrated into the one or more implants positioned in disc space 18. It is further contemplated that the one or more implants positioned in disc space 18 can be fusion devices, bone support devices, artificial disc devices, or other suitable device for implantation between vertebrae. The one or more implants can be provided with an outer surface structure to engage the vertebral endplates, and one or more chambers, cavities and/or recesses for receiving bone growth material. The one or more implants can also be flexible, or include one or more articulating components, to provide segmental motion between the adjacent vertebrae.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character. All changes, modifications and equivalents that come within the spirit of the invention as defined by the following claims are desired to be protected
Claims
1. A surgical instrument insertable in a spinal disc space between an upper vertebra and a lower vertebra, comprising:
- a head including an upper surface positionable adjacent an endplate of the upper vertebra and an opposite lower surface positionable adjacent an endplate of the lower vertebra; and
- a shaft extending proximally from said head, said shaft including a distal portion, a proximal portion, and an offset portion therebetween, said distal portion including a guide portion adjacent said head and engageable to guide an instrument therealong to the spinal disc space, said head and said guide portion extending along a first axis and said offset portion extending proximally from said guide portion and transversely oriented thereto.
2. The instrument of claim 1, wherein said proximal portion extends along a second axis generally parallel to said first axis.
3. The instrument of claim 2, wherein said proximal portion includes a handle oriented transversely to said second axis.
4. The instrument of claim 2, wherein said offset portion extends along a third axis oriented at an angle to said first axis.
5. The instrument of claim 1, wherein said guide portion includes a cross-sectional dimension along a length thereof that is greater than a cross-sectional dimension along a length of said proximal portion.
6. A surgical instrument for spinal surgery having an operative orientation including an anterior lateral approach to a spinal disc space between L4 and L5 vertebrae of a patient, comprising:
- a distal end portion positionable adjacent the spinal disc space and a proximal portion offset from said distal portion to avoid an iliac crest of the patient when the surgical instrument is the operative orientation.
7. The instrument of claim 6, wherein the instrument is a distractor including a head at said distal portion positionable in the spinal disc space and said proximal portion includes a shaft extending distally from said head, said proximal portion being offset anteriorly of the iliac crest in the operative orientation.
8. The instrument of claim 6, wherein the instrument is a guide instrument including a guide member at said distal portion and said proximal portion includes a shaft extending distally from said head, said proximal portion being offset cephaladly of the iliac crest in the operative orientation.
9. A surgical instrument assembly for providing access to a spinal disc space, comprising:
- a distractor including a head positionable in a spinal disc space and a shaft extending proximally from said head, said shaft including a guide portion along at least a portion thereof adjacent said head;
- a housing including an opening therethrough for providing access to the spinal disc space when positioned adjacent thereto; and
- a guide instrument including a shaft and a guide member at a distal end of said shaft, said guide member removably engaged to said housing, said guide member moveable along said guide portion of said distractor with said shaft of said guide instrument in side-by-side relation to said shaft of said distractor to guide said housing along said distractor to the spinal disc space when said head is positioned in the spinal disc space.
10. The assembly of claim 9, wherein said housing includes a frame portion defining said opening therethrough, said housing further including a first extension along one side of said opening extending distally from said frame portion and a second extension along an opposite side of said opening extending distally from said frame portion, said first and second extensions positionable in the spinal disc space to maintain a disc space distraction when said head is removed from the spinal disc space.
11. The assembly of claim 10, wherein said first extension is longer than said second extension.
12. The assembly of claim 10, wherein said frame portion includes an upper wall positionable adjacent an upper vertebra and a lower wall positionable adjacent a lower vertebra, said upper and lower walls each including a distal end curvature corresponding to a curvature of a lateral profile of the upper and lower vertebrae, respectively.
13. The assembly of claim 9, wherein said opening includes a rectangular shape.
14. The assembly of claim 9, wherein said guide member includes a distal portion positionable in said opening to engage said guide member in said opening and a proximal portion forming a lip around said distal portion, said lip in abutting engagement with a proximal end of said housing when said distal portion is positioned in said opening.
15. The assembly of claim 14, wherein said housing includes a proximally-opening notch in a wall thereof and said guide member includes a protrusion positionable in said notch.
16. The assembly of claim 9, wherein said guide member includes a passage extending between a distal end and a proximal end of said guide member and said guide portion of said distractor is movably received in said passage.
17. The assembly of claim 16, wherein said guide member includes tapered surfaces forming an opening into said passage along one side thereof.
18. The assembly of claim 16, wherein said passage extends along a center of said guide member and said shaft of said guide instrument is offset from said passage.
19. The assembly of claim 18, wherein said shaft of said guide instrument includes a distal portion, a proximal portion, and an offset portion therebetween, said offset portion positioning said proximal portion cephaladly of said distal portion in an operative orientation of said guide instrument.
20. The assembly of claim 18, wherein said shaft is offset posteriorly of said passage in said operative orientation of said guide instrument.
21. The assembly of claim 9, wherein said shaft of said distractor includes a distal portion, a proximal portion, and an offset portion therebetween, said distal portion including said guide portion, said head and said guide portion extending along a first axis and said offset portion extending proximally from said guide portion along a second axis oriented at a first angle relative to said first axis.
22. The assembly of claim 21, wherein said proximal portion extends along a third axis generally parallel to said first axis.
23. The instrument of claim 22, wherein said proximal portion includes a handle oriented transversely to said third axis.
24. The instrument of claim 21, wherein said guide portion includes a cross-sectional dimension along a length thereof that is greater than a cross-sectional dimension along a length of said proximal portion.
25-56. (canceled)
Type: Application
Filed: Feb 4, 2008
Publication Date: Jun 5, 2008
Inventors: Rudolf Bertagnoli (Vienna), Mingyan Liu (Bourg la Reine), Loic Josse (Denens)
Application Number: 12/012,558
International Classification: A61B 17/58 (20060101);