The invention relates to implant for vertebra and spinal applications and more particularly to interspinous process spacers that may be inserted between two vertebrae to replace a damaged or degenerated spinal disc. More particularly, the invention relates to a spacer to be placed between the posterior spinous process of the spine and its method of use.
Degenerative disc disease often results in a loss of disc height, which in turn can cause facet and nerve impingement. One standard of care is to remove the disc and fuse the two vertebrae together. However, this can lead to problems at adjacent vertebra levels as those levels become hypermobile to compensate for the loss of mobility at the fused level. A number of devices have therefore been developed to restore height without fusion. Such known devices include artificial discs, pedicle screws with flexible rods, and spacers which may be implanted between spinous processes, referred to herein as interspinous process spacers. Known interspinous process spacers are inserted between the posterior spinous process and can be made of rigid or flexible material. Typically, known interspinous process spacers are placed in the spine in slight distraction to off load the weight of the disc. Interspinous process spacers also typically serve as a stop for extension, and some have attached straps that limit flexion. Many known interspinous spacers are in the shape of an H, wherein the sides of the H prevent the spacer from sliding out from between the processes. Known spacers also are usually made of a metal or a polymer. Ideally, however, bone would be a more suitable material for a spacer, but typical H-shaped bone spacers may result undesirably in the vertebrae fusing to the spacer.
The present invention provides interspinous process spacers (ISPS), also referred to herein as an a spacer or implant, which may be implanted between spinous processes, for example, to treat patients with spinal stenosis whose symptoms are relieved with flexion.
In one aspect, an interspinous process spacer, or implant, may be inserted laterally into the interspinous space through a small, posterior midline incision, allowing the preservation of the supraspinous ligament. One or more spacers may be placed between spinous processes of adjacent vertebrae, and result in distraction of the spinous processes which may limit extension of the spine. By doing so, implantation of an interspinous process may inhibit or prevent the narrowing of the spinal canal and neural foramen at the level of treatment, thereby relieving pain or other symptoms. Preservation of the supraspinous ligament may provide additional stability, for example by keeping the implant from migrating posteriorly.
The present invention can be better understood by reference to the following drawings, wherein like references numerals represent like elements. The drawings are merely exemplary to illustrate certain features that may be used singularly or in combination with other features and the invention should not be limited to the embodiments shown.
The spacer (100) may include one or more depressions (101) extending laterally across the upper (106) and/or lower face (105). Such depressions (101) are preferably dimensioned and shaped to receive a spinous process and may be curved or substantially flat and planar. In one embodiment of the invention, the lower face (105) has a depression (101) having essentially the same dimensions and position as a corresponding depression (101) of the upper face (106). Advantageously, depressions (101) on the upper and/or lower faces (106, 105) may result in reduced, and preferably minimized, bone contact between the spacer (100) and the vertebrae. Such reduced and minimized bone contact may advantageously lower or reduce, if not eliminate, the potential for bone fusion. The upper and/or lower depressions (101) may have any desired radius and/or depth. For example, in one embodiment the depression (101) on the upper face (106) has a radius of curvature of about 6 mm and a depth of about 0.5 mm. Alternatively, the upper and/or lower depression (101) may have other radiuses and depths and can have radiuses and depths different than each other. The one or more depressions (101) may also be positioned as desired. For example, in one embodiment, the center (101a) of the upper depression (101) is positioned at a distance of about 9 mm from the end side. Alternatively, the one or more depressions (1101) may be positioned at other distances from the end side.
The body of the spacer (100) may also include one or more holes (102) as shown in
The nose (110) of the spacer (100) may have a generally tapered shape, and extend preferably integrally from the upper face (106), lower face (105), front side (104) and back side (103) of the spacer (100). For example, the nose (110) may taper distally and inwardly to form a generally pointed or rounded distal tip (113). The tapered surfaces may be curved or substantially flat planar surfaces. In a preferred embodiment, the nose (110) is asymmetrical, for example including front edge (112) of the nose and back edge (111) of the nose that have different directions and/or radiuses of curvature. For example, as shown in
In other embodiments, the nose (110) may have a generally symmetrical shape, for example as shown in
In some embodiments, the spacer (100) may include one or more engagement, or interface, features (120). For example, as shown in
A spacer (100) may have any desired length, width, and thickness. For example, in one embodiment, the length may be between about 20 and 40 mm, more preferably between about 24 and 35 mm. The width and thickness are preferably dimensionally paired and may be variable depending on the spinal application. Preferably, the spacers (100) are provided in a variety of sizes with thickness increasing in any desired increments, e.g., 2 mm increments. Illustrative, representative thicknesses, or height, could be about 6 mm to about 16 mm, for example. The width of the spacer (100) may be paired to the thickness, for example about 4 mm greater than the thickness. Illustrative, representative widths could be about 10 mm to about 20 mm, for example. Alternatively, the spacers (100) may be of other lengths, widths, and thicknesses.
Preferably, the spacers (100) are made from bone, and more preferably from a single piece of cortical or other bone. Cortical bone may reduce and preferably minimizes the possibility of bone fusion. The spacer (100) may be provided with a coating to minimize, resist, or prevent the possibility of bone fusion. In some embodiments, a spacer (100) is made from allograft bone. In other embodiments, autograft bone may be used. Alternatively the spacer (100) may be made of biocompatible materials such as, for example, PEEK, polycarbonate urethane, silicon polycarbonate urethane, or other polymer and plastic materials. The spacer (100) may also be made of metals, such as, for example, titanium or stainless steel, and may also be made of composites, ceramics, or combinations of materials.
As shown in
As shown in
For example one or more of the units (500) may be fabricated to include male and/or female dovetail connections (150, 140) as shown in
As shown in
The construction in
As shown in
One or more of the following instruments may be utilized with an interspinous process spacer (100), e.g., for implanting one or more spacers, and may be included separately, or in a kit or set.
The surgeon may use a perforator, e.g., such as the perforator (1000) shown in
Next, the surgeon may insert the jaws (3100) of a distractor (3000), e.g., such as the distractor (3000) shown in
After removing the distractor (3000), the surgeon may use an inserter (4000), e.g., such as the inserter (4000) shown in
After the appropriate sized implant has been inserted into the interspinous space, the surgeon may use a flexible cord (e.g., a cable, suture, wire, etc.) to secure the implant (100) to one or more of the spinous processes (11, 21). In order to do so, the surgeon may, for example, pass one end of the cord through the ISL of the neighboring interspinous space to access the opposite side.
The approach and technique described above is only one method for inserting an ISPS. A surgeon may choose to use none or only some of the instruments shown, or may chose to use other instruments that may have some of the same or similar features to those described above. For instance, the surgeon may not need to use the dilator (2000) if the opening created by the perforator (1000) is large enough to accommodate the tips (3111) of the distractor (3000). Similarly, the surgeon may choose not to use the perforator (1000) if the tips (3111) on the distractor (3000) are sharp enough to split the ISL at the desired location.
The previously described exemplary technique called for insertion of the trial (700) and/or ISPS after the distractor (3000) had been removed. However, judicious use of a second distractor may permit the insertion of the trial (700) and/or ISPS while this second distractor (3000) remains in place. After reading the maximum interspinous space on its scale indicator (3400), the first distractor (3000) may be removed. A second distractor, for example with a beak width equal to the reading on the scale indicator, may be inserted such that its jaws (3100) are perpendicular to that of the first distractor (3000) (when it was in place). The second distractor may then be actuated to open the ISL further while maintaining the existing interspinous space distraction. With the jaws of the second distractor opened wide enough to accommodate the width of the implant (100), the trial (700) and/or implant (100) can be safely inserted. This simultaneous insertion while distracting the spinous processes could greatly reduce the insertion load needed to insert the implant (100). Once the implant (100) is in place, the second distractor can be carefully removed.
Alternatively, the second distractor could be inserted and actuated with the first distractor (3000) in place. This may require the beak (3110) width of the second distractor to be slightly smaller than the opening between the first distractor jaws (3100). With the jaws of the second distractor opened wide enough to accommodate the ISPS width (e.g., which is equal to or larger than the ISPS height), the jaws (3100) on the first distractor (3000) can be safely closed and removed.
In still another embodiment, a direct posterior insertion approach of the ISPS may be employed as an alternative to a lateral insertion approach. In such a technique, the surgeon may take down the supraspinous ligament and/or the interspinous ligament.
Many variations to the implant design are possible. Although the preferred embodiment uses holes for flexible attachment means, such may not be necessary. For example,
After the main body (910) has been inserted between the spinous processes (11, 21), the locking pin (920) may be assembled, for example as shown in
In other embodiments, the locking pin may be a threaded pin, while the hole and slot configuration may be replaced a corresponding by a threaded hole. The high wall on the main body could also be replaced by another locking pin. The slot in the hole and slot configuration could permit the addition of flexible attachment methods (e.g., a cable, suture, wire, etc.). The flexible attachment cord may provide interference with the locking pin, insuring it did not disassemble from the main body. Interspinous process spacers with various combinations of the features previously described above are envisioned.
Having a large mismatch in mechanical properties between implant and surrounding bone can often lead to resorption of the surrounding bone. One of the advantages of making the interspinous process spacer from bone is that its mechanical properties may be similar to that of the surrounding bone and thus minimize the likelihood of this occurring. Other materials, like PEEK for example, that have mechanical properties similar to bone could also be used. In other embodiments, other common implantable materials like titanium, stainless steel, ceramics, and composites could also be used.
The application of this implant design and insertion method is not limited the lumbar spine as shown, but could easily be adapted for other areas of the spine or other joints or body parts.
While it is apparent that the illustrative embodiments of the invention disclosed herein fulfill the objectives stated above, it will be appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Features and structures, such as, for example, the size, shape, and location of the spacer depressions can be used singularly or in combination with other features and structures. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments which come within the spirit and scope of the invention.
Many modifications and variations of this invention can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. In particular, it will be clear to those skilled in the art that the invention may be embodied in other specific forms, structures, arrangements, proportions, and with other elements, materials, and components, without departing from the spirit or essential characteristics thereof. The specific embodiments described herein are offered by way of example only, and the invention is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled.
This application claims the benefit of International Application No. PCT/US2007/002791, filed Jan. 31, 2007, entitled “Interspinous Process Spacer.” This application also claims the benefit of priority of U.S. Provisional Application Ser. No. 60/764,069, filed Feb. 1, 2006. The entire disclosure of these applications is incorporated herein by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/US2007/002791 | 1/31/2007 | WO | 00 | 12/29/2008 |
Publishing Document | Publishing Date | Country | Kind |
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WO2007/089905 | 8/9/2007 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
4298993 | Kovaleva et al. | Nov 1981 | A |
4904261 | Dove et al. | Feb 1990 | A |
4917704 | Frey et al. | Apr 1990 | A |
5011484 | Breard | Apr 1991 | A |
5059193 | Kuslich | Oct 1991 | A |
5496318 | Howland et al. | Mar 1996 | A |
5836948 | Zucherman et al. | Nov 1998 | A |
5980572 | Kim et al. | Nov 1999 | A |
6111164 | Rainey et al. | Aug 2000 | A |
6235030 | Zucherman et al. | May 2001 | B1 |
6261586 | McKay | Jul 2001 | B1 |
6332882 | Zucherman et al. | Dec 2001 | B1 |
6332883 | Zucherman et al. | Dec 2001 | B1 |
6419676 | Zucherman et al. | Jul 2002 | B1 |
6451019 | Zucherman et al. | Sep 2002 | B1 |
6500177 | Martinelli et al. | Dec 2002 | B1 |
6579318 | Varga et al. | Jun 2003 | B2 |
6613090 | Fuss et al. | Sep 2003 | B2 |
6626944 | Taylor | Sep 2003 | B1 |
6652527 | Zucherman et al. | Nov 2003 | B2 |
6695842 | Zucherman et al. | Feb 2004 | B2 |
6699246 | Zucherman et al. | Mar 2004 | B2 |
6699247 | Zucherman et al. | Mar 2004 | B2 |
6699288 | Moret | Mar 2004 | B2 |
6733534 | Sherman | May 2004 | B2 |
6749636 | Michelson | Jun 2004 | B2 |
6761720 | Senegas | Jul 2004 | B1 |
6949123 | Reiley | Sep 2005 | B2 |
6974480 | Messerli et al. | Dec 2005 | B2 |
7018413 | Kruger | Mar 2006 | B2 |
7029473 | Zucherman et al. | Apr 2006 | B2 |
7048762 | Sander et al. | May 2006 | B1 |
7060073 | Frey et al. | Jun 2006 | B2 |
7060096 | Schopf et al. | Jun 2006 | B1 |
7137997 | Paul | Nov 2006 | B2 |
7201751 | Zucherman et al. | Apr 2007 | B2 |
7479160 | Branch et al. | Jan 2009 | B2 |
7686832 | Jackson | Mar 2010 | B2 |
7771456 | Hartmann et al. | Aug 2010 | B2 |
D625821 | Goncalves et al. | Oct 2010 | S |
7837688 | Boyer et al. | Nov 2010 | B2 |
7879109 | Borden et al. | Feb 2011 | B2 |
7892261 | Bonutti | Feb 2011 | B2 |
8034079 | Bruneau et al. | Oct 2011 | B2 |
8070777 | Soboleski et al. | Dec 2011 | B2 |
8070778 | Zucherman et al. | Dec 2011 | B2 |
8147554 | Hansell et al. | Apr 2012 | B2 |
20010012938 | Zucherman et al. | Aug 2001 | A1 |
20020029039 | Zucherman et al. | Mar 2002 | A1 |
20030093153 | Banick et al. | May 2003 | A1 |
20040162616 | Simonton et al. | Aug 2004 | A1 |
20040186572 | Lange et al. | Sep 2004 | A1 |
20040210222 | Angelucci et al. | Oct 2004 | A1 |
20040220568 | Zucherman et al. | Nov 2004 | A1 |
20050027360 | Webb et al. | Feb 2005 | A1 |
20050055031 | Lim | Mar 2005 | A1 |
20050090829 | Martz et al. | Apr 2005 | A1 |
20050143738 | Zucherman et al. | Jun 2005 | A1 |
20050177238 | Khandkar et al. | Aug 2005 | A1 |
20050187625 | Wolek et al. | Aug 2005 | A1 |
20050203512 | Hawkins et al. | Sep 2005 | A1 |
20050203624 | Serhan et al. | Sep 2005 | A1 |
20050209603 | Zucherman et al. | Sep 2005 | A1 |
20050228383 | Zucherman et al. | Oct 2005 | A1 |
20050261768 | Trieu | Nov 2005 | A1 |
20060084988 | Kim | Apr 2006 | A1 |
20060085069 | Kim | Apr 2006 | A1 |
20060085070 | Kim | Apr 2006 | A1 |
20060129243 | Wong et al. | Jun 2006 | A1 |
20060184247 | Edidin et al. | Aug 2006 | A1 |
20060184248 | Edidin et al. | Aug 2006 | A1 |
20060224159 | Anderson | Oct 2006 | A1 |
20060235532 | Meunier et al. | Oct 2006 | A1 |
20060241601 | Trautwein et al. | Oct 2006 | A1 |
20060241613 | Bruneau et al. | Oct 2006 | A1 |
20060247623 | Anderson et al. | Nov 2006 | A1 |
20060247634 | Warner et al. | Nov 2006 | A1 |
20060264938 | Zucherman et al. | Nov 2006 | A1 |
20060271049 | Zucherman et al. | Nov 2006 | A1 |
20060271194 | Zucherman et al. | Nov 2006 | A1 |
20060293662 | Boyer et al. | Dec 2006 | A1 |
20060293663 | Walkenhorst et al. | Dec 2006 | A1 |
20070010813 | Zucherman et al. | Jan 2007 | A1 |
20070043361 | Malandain et al. | Feb 2007 | A1 |
20070043362 | Malandain et al. | Feb 2007 | A1 |
20070043363 | Malandain et al. | Feb 2007 | A1 |
20070049934 | Edidin et al. | Mar 2007 | A1 |
20070049935 | Edidin et al. | Mar 2007 | A1 |
20070055237 | Edidin et al. | Mar 2007 | A1 |
20070055373 | Hudgins et al. | Mar 2007 | A1 |
20070093830 | Zucherman et al. | Apr 2007 | A1 |
20070129804 | Bentley et al. | Jun 2007 | A1 |
20070149972 | Nakajima et al. | Jun 2007 | A1 |
20070173832 | Tebbe et al. | Jul 2007 | A1 |
20070203493 | Zucherman et al. | Aug 2007 | A1 |
20070203497 | Zucherman et al. | Aug 2007 | A1 |
20070203501 | Zucherman et al. | Aug 2007 | A1 |
20070208347 | Zucherman et al. | Sep 2007 | A1 |
20070219552 | Zucherman et al. | Sep 2007 | A1 |
20070225706 | Clark et al. | Sep 2007 | A1 |
20070270951 | Davis et al. | Nov 2007 | A1 |
20070270963 | Melkent et al. | Nov 2007 | A1 |
20080021562 | Huppert | Jan 2008 | A1 |
20080058937 | Malandain et al. | Mar 2008 | A1 |
20080065219 | Dye | Mar 2008 | A1 |
20080077247 | Murillo et al. | Mar 2008 | A1 |
20080154377 | Voellmicke | Jun 2008 | A1 |
20080249622 | Gray | Oct 2008 | A1 |
20080269904 | Voorhies | Oct 2008 | A1 |
20080294263 | Altarac et al. | Nov 2008 | A1 |
20080312695 | Sybert et al. | Dec 2008 | A1 |
20080312741 | Lee et al. | Dec 2008 | A1 |
20090248076 | Reynolds et al. | Oct 2009 | A1 |
20090265008 | Thibodeau | Oct 2009 | A1 |
20100057130 | Yue | Mar 2010 | A1 |
20100198263 | Siegal et al. | Aug 2010 | A1 |
20100211102 | Belliard et al. | Aug 2010 | A1 |
20100241166 | Dwyer et al. | Sep 2010 | A1 |
20100256760 | Hansell | Oct 2010 | A1 |
20110022091 | Anderson et al. | Jan 2011 | A1 |
20120165942 | Khanna | Jun 2012 | A1 |
Number | Date | Country |
---|---|---|
1330987 | Jul 2003 | EP |
1 334 703 | Aug 2003 | EP |
2 722 980 | Feb 1996 | FR |
WO 0207624 | Jan 2002 | WO |
WO 03007791 | Jan 2003 | WO |
WO 2005009300 | Feb 2005 | WO |
WO 2006064356 | Jun 2006 | WO |
Entry |
---|
International Search Report, completed Jul. 31, 2007 for International Application No. PCT/US2007/002791, filed Jan. 31, 2007. |
International Preliminary Report on Patentability dated Aug. 5, 2008. |
Number | Date | Country | |
---|---|---|---|
20090306715 A1 | Dec 2009 | US |
Number | Date | Country | |
---|---|---|---|
60764069 | Feb 2006 | US |