Intervertebral Spacer
An interbody spacer for insertion between vertebral members. The spacer includes a body having posterior and anterior sides, and inferior and superior faces. The spacer further includes a plurality of teeth to maintain the position of the spacer between the vertebral members. The teeth are aligned in a pattern and have a shape to allow insertion into the space between the vertebral members, and prevent or limit movement once the spacer is positioned in the space.
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The present application is a continuation of application number 10/985,237 filed on Nov. 10, 2004 and herein incorporated by reference in its entirety.
BACKGROUNDA large majority of the population will experience back pain at some point in their lives that results from a spinal condition. The pain may range from general discomfort to disabling pain that immobilizes the individual. The back pain may result from a trauma to the spine, be caused by the natural aging process, or may be the result of a degenerative disease or condition.
Procedures to remedy these problems may require correcting the spacing between vertebral members by inserting a spacer. The spacer is carefully positioned within the disc space and aligned relative to the vertebral members. The spacer is sized to position the vertebral members in a manner to alleviate the back pain.
The spacers often include teeth that extend outward from the body of the spacer to maintain the position of the spacer relative to the vertebral members. Various styles and shapes of teeth have been used previously to prevent movement after insertion into the disc space. Further, the teeth may be located along a single face of the spacer, multiple faces, or along limited areas along one or more faces.
The spacer and teeth should also be designed to facilitate insertion into the disc space. Teeth designs that limit or prevent movement of the spacer relative to the vertebral members may not be practical as they make the spacer too difficult to insert into the disc space.
SUMMARYOne embodiment of the present invention is directed to an interbody spacer for positioning between vertebral members. The spacer may include a body having anterior and posterior walls, and opposing first and second faces. The spacer may further include a plurality of teeth oriented to allow for inserting the spacer into the space between the vertebral members, and prevent or limit movement once the spacer is positioned.
The teeth may be located on one or both of the first and second faces. The teeth may be positioned within a limited section or sections, or across the entirety of the faces.
One embodiment of the present invention is directed to an interbody spacer 10 for insertion between vertebral members. The spacer 10 includes a body having inferior 18 and superior 17 faces. Teeth 30 are positioned along at least of one of the faces 17, 18 to maintain the position relative to the vertebral members. The teeth 30 are aligned in a pattern over all or part of at least one of the faces 17, 18.
A transverse plane is defined as being laterally aligned along the spacer and extending through the side walls 15. The transverse plane is substantially parallel to the transverse center line T-T. A longitudinal plane is defined as being aligned along the spacer 10 and extending through the anterior and posterior walls 14, 13. The longitudinal plane is substantially parallel to a longitudinal center line L-L.
A plurality of teeth 30 are positioned on one or both of the inferior and superior faces 18, 17.
The teeth 30 are ramped in an anterior direction caused by the posterior surfaces 32 having a lesser angle than the anterior surfaces 31 when viewed along the longitudinal plane. Further, the anterior surfaces 31 are curved and undercut the posterior surfaces 32 causing the peak 33 to face in an anterior direction. This configuration provides for inserting the spacer 10 using an anterior approach. The slighter angle of the posterior surfaces 32 and anterior angle of the peak 33 do not catch during the insertion process. Once the spacer 10 is inserted in the disc space between the vertebral members, the greater angle of the anterior surfaces 31 and the anterior facing peak 33 prevent or limit anterior movement of the spacer 10. The embodiments illustrated in
The pathways 34 extend in a crisscross pattern across the face of the spacer 10. The pathways include a series of first parallel pathways extending across the face in a first direction, and a series of second parallel pathways extending in a second direction. Each series of pathways 34 are substantially straight and form an angle relative to the longitudinal and transverse planes. In the embodiment of
The pathways 34 may be flat, angled into the face of the spacer 10, or a combination of both shapes. Specific embodiments include a U-shaped pathway, and a J-shaped pathway. In one embodiment, the first pathway has a first shape, and the second pathway has a second shape different than the first.
The plurality of teeth 30 and pathways 34 form a uniform pattern as best seen in
The teeth 30 are each aligned to face in the same direction with the posterior surfaces 32 and common posterior edge 37 having the same orientation. This is best illustrated in
A second embodiment of teeth 30 is illustrated in
Each of the teeth 30 is aligned with the common posterior edges 37 each facing in the same direction. Further, each tooth 30 is aligned with the common anterior edges 36 each facing in the same direction. The teeth 30 may not be parallel to each other due to the overall convexity and angle of the superior and inferior faces 17, 18. In one embodiment, the spacer 10 is substantially uniform in each direction and can be used from a variety of insertion angles.
Anterior and posterior sides 14, 13 are separated by side walls 15 to form an opening 12. Teeth 30 may be positioned on the face in a uniform pattern aligned in a plurality of columns such as along line C and rows such as along line R.
Each of the teeth 30 has four sides that form an overall rectangular shape. A posterior surface 37 is opposed by anterior surface 36 with side surfaces 38 extending along each side. The posterior 37 and anterior 36 surfaces are substantially the same width, as are the side surfaces 38. The posterior surface 37 extends outward from the spacer 10 at a lesser angle than the posterior surface 37. In one embodiment, the posterior surface 37 has an angle of about 70°, and the anterior surface 36 has an angle of about 0° (i.e., the anterior surface 36 is substantially perpendicular to the pathways). In one embodiment, the side surfaces 38 extend outward from the spacer at about 0°. In these embodiments, the angle of the surfaces is determined relative to the substantially flat pathways 34.
The teeth 30 are aligned in columns such as depicted by line C of
Pathways 34 are positioned between each of the columns of teeth 30. In one embodiment, pathways 34 have a width less than the width of the teeth 30 (i.e., less than the width of the anterior 36 and posterior 37 surfaces).
The teeth 30 of the third embodiment are sized and configured to an anterior insertion approach. The angle of the posterior surfaces 37 is set to facilitate movement of the spacer 10 into the disc space from the anterior side. The anterior surface 36 has a steeper angle to prevent the spacer 10 from moving out of the disc space after insertion. As with the other embodiments, the teeth 30 may be aligned in other orientations for other insertion approaches.
The outer edges of the spacer 10 may have a round or curved configuration that prevent a sharp angle that may make the insertion of the spacer 10 more difficult, or cause injury to the patient. In one embodiment as illustrated in
The spacer 10 may be constructed of a single piece with the teeth 30 formed into one or both faces 17, 18. Alternatively, the teeth 30 may be constructed of a separate material and attached to the faces 17, 18.
One embodiment of the spacer (e.g.,
The term vertebral member is used generally to describe the vertebral geometry comprising the vertebral body, pedicles, lamina, and processes. The spacer 10 may be sized and shaped, and have adequate strength requirements to be used within the different regions of the vertebra including the cervical, thoracic, and lumbar regions.
Bone growth material may be positioned within the opening 12 to facilitate bone growth through the spacer 10. The bone growth material may include a sponge, matrix, and/or other carrier impregnated with a protein such as bone morphogenic protein (BMP), LIM mineralization protein (LMP), etc.
The present invention may be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. The teeth 30 may further be spaced inward from the edges of the faces 17, 18. A gap 55 may exist along the edge of the faces that does not include any teeth 30. The spacer 10 may have a variety of shapes and sizes. In one embodiment, the spacer includes an interior wall that closes the opening. In another embodiment, the spacer does not include an opening 12. In embodiments with teeth 30 on both the inferior and superior faces 18, 17, the teeth 30 may be aligned in a common direction on each of the faces. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.
Claims
1. An interbody spacer comprising:
- a member having first and second faces;
- a plurality of first pathways on the first face each extending at an oblique angle relative to a longitudinal centerline of the spacer and a plurality of second pathways on the first face each extending at a mirrored angle relative to the longitudinal centerline, the longitudinal centerline extending through anterior and posterior sides of the member, each of the plurality of first and second pathways being straight;
- teeth extending outward from the first face between the plurality of first and second pathways, each of the teeth including at least one straight side that is parallel with an adjacent one of the plurality of the first pathways and at least a second straight side that is parallel with an adjacent one of the plurality of the second pathways.
2. The interbody spacer of claim 1, wherein each of the teeth include a rectangular shape.
3. The interbody spacer of claim 1, wherein each of the straight sides of the teeth are aligned towards the anterior side of the member.
4. The interbody spacer of claim 1, wherein each of the teeth are capped with a relatively flat surface.
5. The interbody spacer of claim 1, wherein the first plurality of pathways extend on the first face at an angle of about 45° relative to the longitudinal centerline, and the second plurality of pathways extend on the first face at an angle of about −45° relative to the longitudinal centerline.
6. The interbody spacer of claim 1, wherein the oblique angle is an acute angle relative to the longitudinal centerline.
7. The interbody spacer of claim 1, further comprising a second plurality of teeth extending outward from the second face.
8. An interbody spacer comprising:
- a body with opposing first and second faces and opposing anterior and posterior sides that extend between the first and second faces;
- a plurality of teeth on the first face, each of the plurality of teeth having a rectangular shape;
- first and second angled pathways positioned between each of the plurality of teeth, the first pathways oriented at an acute angle relative to a longitudinal centerline extending through the anterior and posterior sides, and the second pathways oriented at a mirrored acute angle relative to the longitudinal centerline;
- opposing first and second straight edges of each of the plurality of teeth being parallel with the first pathways and opposing third and fourth straight edges of each of the plurality of teeth being parallel with the second pathways.
9. The interbody spacer of claim 8, wherein the acute angle is about 45° and the mirrored angle is about −45°.
10. The interbody spacer of claim 8, wherein the plurality of teeth extend across a limited portion of the first face.
11. The interbody spacer of claim 8, wherein each of the plurality of teeth have a square shape.
12. The interbody spacer of claim 8, wherein the spacer has an annular shape with a central opening.
13. The interbody spacer of claim 12, wherein the spacer has a D-shape with the anterior side being curved and the posterior side being substantially straight.
14. The interbody spacer of claim 8, wherein each of the plurality of teeth are capped with a relatively flat surface.
15. An interbody spacer comprising:
- a body having anterior and posterior sides, and first and second faces;
- teeth on the first face of the body, each of the teeth being substantially rectangular in shape and having two anterior edges facing towards the anterior side and two posterior edges facing towards the posterior side, the teeth also including a relatively flat top;
- the teeth aligned in a pattern of rows and columns, a center point of each of the teeth aligned in a first row being centered with a gap formed between each of said plurality of teeth in an adjacent second row, and the center point of each of said plurality of teeth in a first column being centered within the gap formed between each of said plurality of teeth in an adjacent second column, the rows and columns being substantially perpendicular to each other;
- the columns each being parallel with a longitudinal centerline of the body and each of the rows being perpendicular to the longitudinal centerline of the body.
16. The interbody spacer of claim 15, further comprising a plurality of first pathways on the first face each extending at an oblique angle relative to the longitudinal centerline, a plurality of second pathways on the first face each extending at a mirrored angle relative to the longitudinal centerline, each of the plurality of first and second pathways being straight.
17. The interbody spacer of claim 16, wherein the first plurality of pathways extend on the first face at an angle of about 45° relative to the longitudinal centerline, and the second plurality of pathways extend on the first face at an angle of about −45° relative to the longitudinal centerline.
18. The interbody spacer of claim 15, further comprising second teeth extending outward from the second face.
19. The interbody spacer of claim 15, wherein each of the plurality of teeth have a square shape.
20. The interbody spacer of claim 15, wherein the teeth extend across an entirety of the first face.
Type: Application
Filed: Dec 28, 2010
Publication Date: Apr 21, 2011
Applicant: Warsaw Orthopedic, Inc. (Warsaw, IN)
Inventors: Rolando Puno (Prospect, KY), Michael O'Brien (Pinecrest, FL), Wiliam J. Albans (Southaven, MS), Scott Gareiss (Cordova, TN)
Application Number: 12/979,937
International Classification: A61F 2/44 (20060101);