1. An expansion ring assembly for sealing a gasket against an annular surface, the expansion ring assembly comprising:
a ring having a circumference, said ring including first and second ring bands each having opposite ends;
a ratcheting mechanism joining respective first ends of said ring bands, said ratcheting mechanism allowing incremental expansion of said circumference of said ring by a first distance and preventing contraction of said circumference of said ring; and
a drive mechanism joining respective second ends of said ring bands, said drive mechanism including:
a pair of first threaded members joined to said respective second ends of said ring bands; and
a second threaded member disposed between and threadingly connecting said pair of first threaded members, said drive mechanism allowing non-incremental expansion of said circumference of said ring by a second distance to a fully expanded configuration, said drive mechanism also allowing non-incremental contraction of said circumference of said ring by a third distance, whereby said expansion ring assembly cooperates with the gasket to form a fluid tight seal at the annular surface in the fully expanded configuration.
2. The expansion ring assembly of claim 1, wherein said first distance is greater than said second distance.
3. The expansion ring assembly of claim 1, wherein said ring bands cooperate to form a generally circular profile.
4. The expansion ring assembly of claim 1, wherein one of said first ends of said ring bands overlaps the other first end of said ring bands, whereby said overlap produces a substantially continuous surface at an outside portion of the expansion ring assembly to facilitate a continuous sealing pressure against the gasket.
5. The expansion ring assembly of claim 1, said ratcheting mechanism comprising:
a tooth formed on said second ring band; and
a plurality of apertures formed in said first ring band, each of said apertures sized to receive said tooth therein, whereby said tooth is advanceable from a position within a first aperture to a position within an adjacent second aperture to incrementally expand said circumference of said ring.
6. The expansion ring assembly of claim 5, the expansion ring assembly further comprising tool engagement structures formed on each of said first ring band and said second ring band.
7. The expansion ring assembly of claim 6, wherein said tool engagement structures on said first ring band are formed as holes, said holes spaced from and separate from said plurality of apertures formed in said first ring band.
8. The expansion ring assembly of claim 1, wherein said pair of first threaded members are removably attachable to said respective second ends of said ring bands.
9. The expansion ring assembly of claim 1, wherein:
said second threaded member is a bolt, said bolt includes a first threaded portion and a second, oppositely threaded portion;
said pair of first threaded members are respectively a first block member and a second block member, said first block member and said second block member removably attachable to said respective second ends of said rings bands; and
said first block member is threadingly engaged with said first threaded portion of said bolt, and said second block member is threadingly engaged with said second threaded portion of said bolt, whereby rotation of said bolt in a first rotational direction simultaneously drives said first block member and said second block member away from one another along said bolt to non-incrementally expand said circumference of said ring, and rotation of said bolt in a second rotational direction opposite said first rotational direction simultaneously drives said first block member and said second block member toward one another along said bolt to non-incrementally contract said circumference of said ring.
10. The expansion ring assembly of claim 9, wherein said bolt can be rotated in said first rotational direction by applying a known torque to said bolt, said known torque providing a known pressure of the expansion ring assembly against the gasket.
11. The expansion ring assembly of claim 9, wherein said bolt further comprises a tool receiving structure located between said first threaded portion and said second threaded portion.
12. The expansion ring assembly of claim 9, said expansion ring assembly further comprising:
a sleeve secured to said respective seconds ends of said ring bands, whereby said sleeve prevents lateral movement between said ring bands.
13. A method of installing a gasket against an annular surface, the method comprising:
placing an expansion ring assembly in a contracted configuration proximate the gasket so that the gasket is disposed between the expansion ring assembly and the annular surface;
actuating a first, ratcheting mechanism to incrementally expand the expansion ring assembly to a partially expanded configuration; and
actuating a second mechanism having a pair of threaded members, wherein actuation of the second mechanism simultaneously drives the pair of threaded members away from one another to non-incrementally expand the expansion ring assembly to a fully expanded configuration, the expansion ring assembly cooperating with the gasket to form a fluid tight seal at the annular surface in the fully expanded configuration.
14. The method of claim 13, further comprising, after said second actuation step, the additional steps of:
actuating the second mechanism to contract the expansion ring assembly, wherein actuation of the second mechanism simultaneously drives the pair of threaded members toward one another to non-incrementally contract the expansion ring assembly;
removing the expansion ring assembly in the contracted configuration from the gasket;
repositioning the expansion ring assembly in the contracted configuration proximate another gasket so that the other gasket is disposed between the expansion ring assembly and another annular surface;
re-actuating the first, ratcheting mechanism to incrementally expand the expansion ring assembly to the partially expanded configuration; and
re-actuating the second mechanism having the pair of threaded members, wherein actuation of the second mechanism simultaneously drives the pair of threaded members away from one another to non-incrementally expand the expansion ring assembly to the fully expanded configuration, the expansion ring assembly cooperating with the other gasket to form another fluid tight seal at the other annular surface in the fully expanded configuration.
15. An expansion ring assembly for sealing a gasket against an annular surface, the expansion ring assembly comprising:
a ring having a circumference, said ring including first and second ring bands each having opposite ends;
means for providing incremental expansion of said circumference of said ring by a first distance, said means for providing incremental expansion preventing contraction of said circumference of said ring; and
means for providing non-incremental expansion of said circumference of said ring by a second distance to a fully expanded configuration, said means for providing non-incremental expansion also allowing non-incremental contraction of said circumference of said ring by a third distance, whereby said expansion ring assembly cooperates with the gasket to form a fluid tight seal at the annular surface in the fully expanded configuration.
16. The expansion ring assembly of claim 15, wherein said first distance is greater than said second distance.
17. The expansion ring assembly of claim 15, wherein said ring bands cooperate to form a generally circular profile.
18. The expansion ring assembly of claim 15, wherein one of said first ends of said ring bands overlaps the other first end of said ring bands, whereby said overlap produces a substantially continuous surface at an outside portion of the expansion ring assembly to facilitate a continuous sealing pressure against the gasket.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An intervertebral implant for insertion into an intervertebral disc space between first and second vertebral bodies, the implant comprising:
a spacer portion including first and second blade receiving channels; and
first and second blade elements configured to retain the intervertebral implant with respect to the first and second vertebral bodies, each of the first and second blade elements including a superior portion configured to engage the first vertebral body, an inferior portion configured to engage the second vertebral body and an intermediate portion configured to operatively couple the superior and inferior portions, the intermediate portion being adapted for insertion into one of the first and second blade receiving channels.
2. The intervertebral implant of claim 1, wherein the implant is configured to be inserted into the intervertebral disc space between the first and second vertebral bodies along an insertion direction, and wherein the spacer portion has a top surface configured to contact the first vertebral body, a bottom surface configured to contact the second vertebral body, a first side surface, a second side surface, a leading surface, and a trailing surface, the leading surface spaced from the trailing surface in the insertion direction.
3. The intervertebral implant of claim 2, wherein the spacer portion includes a longitudinal axis extending between the top and bottom surfaces, each of the first and second blade elements being obliquely angled at a first blade angle with respect to the longitudinal axis, the superior and inferior portions of the first and second blade elements are selected from the group consisting of a substantially flat blade and a cylindrical pin.
4. The intervertebral implant of claim 2, wherein the first and second blade elements are comprised of first and second cylindrical pins.
5. The intervertebral implant of claim 2, wherein the superior portion, the inferior portion and the intermediate portion of the first blade element are integrally formed and the superior portion, the inferior portion and the intermediate portion of the second blade element are integrally formed.
6. The intervertebral implant of claim 2, wherein the superior portion of the first and second blade elements extend superiorly of the top surface of the spacer portion and the inferior portion of the first and second blade elements extend inferiorly of the bottom surface of the spacer portion in an assembled configuration.
7. The intervertebral implant of claim 2, wherein the first and second blade receiving channels are at least partially defined in the trailing end surface of the spacer portion.
8. The intervertebral implant of claim 7, further comprising:
a blocking element having a fastener hole therein;
a fastener configured to be mounted in the fastener hole; and
a recess formed in the spacer portion configured to receive at least a portion of the first and second blade elements after the blade elements have been inserted into the first and second blade receiving channels in an assembled configuration, the blocking element being coupled to the plate portion by the fastener.
9. The intervertebral implant of claim 2, wherein the spacer portion includes an anterior-posterior axis extending between the first and second side surfaces, and wherein the spacer the superior portion of at least one of the first and second blade elements includes a trailing portion and a leading portion, the at least one of the first and second blade elements extending from the trailing portion toward the leading portion at an oblique angle with respect to the anterior-posterior axis.
10. The intervertebral implant of claim 2, wherein the spacer portion includes a longitudinal axis extending between the top and bottom surfaces, and the first and second blade elements are coupled to implant along a pair of curved paths with respect to longitudinal axis.
11. The intervertebral implant of claim 10, wherein the pair of curved paths are divergent with respect to each other.
12. The intervertebral implant of claim 3, wherein the superior portion of at least one of the first and second blade elements includes a trailing portion and a leading portion that is separated from the trailing portion along the insertion direction, and wherein the first blade angle is different at the leading portion than at the trailing portion of the at least one of the first and second blade elements.
13. The intervertebral implant of claim 12, wherein first blade angle is greater at the leading portion than at the trailing portion of the at least one of the first and second blade elements.
14. The intervertebral implant of claim 3, wherein the first blade angle is between about 10 degrees and about 80 degrees.
15. The intervertebral implant of claim 2, wherein the superior portion of at least one of the first and second blade elements includes a trailing portion, a leading portion that is separated from the trailing portion along the insertion direction, and a superior intermediate trailing portion extending from the leading portion to the trailing portion, and the intermediate trailing portion is obliquely angled with respect to the trailing portion.
16. The intervertebral implant of claim 15, wherein the leading portion of the superior portion of the at least one of the first and second blade elements is obliquely angled with respect to intermediate trailing portion.
17. The intervertebral implant of claim 16, wherein the trailing portion extends in the insertion direction towards the leading portion and terminates prior to the leading portion of blades such that the superior portion, the inferior portion and the trailing portion collectively define a cavity that is configured to receive at least a portion of the spacer portion when the intermediate portion of the first and second blade elements is inserted into one of the first and second blade receiving channels.
18. The intervertebral implant of claim 2, wherein the first and second blade elements are configured to be inserted into the first and second vertebral bodies without the use of bone removing instrumentation.
19. The intervertebral implant of claim 2, wherein the first and second blade elements are configured to form a channel in the first and second vertebral bodies during insertion of the implant into the intervertebral space.
20. The intervertebral implant of claim 2, wherein at least one of the first and second blade elements define opposed superior and inferior inner edges, and the inner edges are spaced apart from the top and bottom surfaces of the spacer portion when the blade elements are received in the first and second blade receiving channels.