The following U.S. Patent Applications are cross-referenced and incorporated herein by reference: ARTIFICIAL VERTEBRAL DISK REPLACEMENT IMPLANT WITH TRANSLATING PIVOT POINT AND METHOD, U.S. Provisional Patent Application No. 60/422,039, Inventor: James F. Zucherman et al., filed on Oct. 29, 2002; ARTIFICIAL VERTEBRAL DISK REPLACEMENT IMPLANT WITH TRANSLATING PIVOT POINT AND METHOD, U.S. patent application Ser. No. 10/684,669, Inventor: James F. Zucherman et al., filed on Oct. 14, 2003; ARTIFICIAL VERTEBRAL DISK REPLACEMENT IMPLANT WITH CROSSBAR SPACER AND METHOD, U.S. Provisional Patent Application No. 60/422,021, Inventor: Steve Mitchell, filed on Oct. 29, 2002; ARTIFICIAL VERTEBRAL DISK REPLACEMENT IMPLANT WITH CROSSBAR SPACER AND METHOD, U.S. patent application Ser. No. 10/684,668, Inventor: Steve Mitchell, filed on Oct. 14, 2003; ARTIFICIAL VERTEBRAL DISK REPLACEMENT IMPLANT WITH A SPACER AND METHOD, U.S. Provisional Patent Application No. 60/422,022, Inventor: Steve Mitchell, filed on Oct. 29, 2002; ARTIFICIAL VERTEBRAL DISK REPLACEMENT IMPLANT WITH A SPACER AND METHOD, U.S. patent application Ser. No. 10/685,011, Inventor: Steve Mitchell, filed on Oct. 14, 2003.
The present invention relates to spinal disks and spinal disk replacement devices.
A common procedure for handling pain associated with degenerative spinal disk disease is the use of devices for fusing together two or more adjacent vertebral bodies. The procedure is known by a number of terms, one of which is vertebral interbody fusion. Interbody fusion can be accomplished through the use of a number of devices and methods known in the art. These include screw arrangements, solid bone implant methodologies, and fusion devices which include a cage or other mechanism which is packed with bone and/or bone growth inducing substances. All of the above are implanted between adjacent vertebral bodies in order to fuse the vertebral bodies together, alleviating associated pain.
There are a number of drawbacks to undergoing interbody fusion. One drawback is that interbody fusion at one or more levels of the spine may cause decreased motion of the spine. Another drawback is that having interbody fusion at one or more levels of the spine may cause more stress to be transferred to adjacent levels. Transferred stress may cause new problems to develop at other levels of the spine, which may lead to additional back surgery.
Alternatives to interbody fusion surgery have been proposed including the use of artificial spinal disks. Such artificial spinal disks act like cushions or “shock absorbers” between vertebrae and may contribute to the flexibility and motion of the spinal column. Thus a purpose and advantage of such artificial spinal disks is to replace a degenerated spinal disk, while preserving the range of motion of the spine. Replacement of a spinal disk with an artificial disk may treat underlying back pain, while protecting patients from developing problems at an adjacent level of the spine.
A number of different artificial disks have been proposed. For example, one such proposal includes an artificial disk primarily comprising two metal metallic plates between which is a core that allows for motion. Another proposal includes two spinal disk halves connected at a pivot point. Other artificial disks have been proposed in the art.
Further details of embodiments of the present invention are explained with the help of the attached drawings in which:
Systems and methods in accordance with the present invention can comprise one or more artificial spinal disks for replacing a degenerated spinal disk.
In one embodiment, a cross-section of each of the upper housing 102 and the lower housing 104 along a sagittal plane can have inner cavities or recesses 120, 122 that varies from an anterior end to a posterior end of the housing 102,104 and that have ramps 124, 126 and 128,130 respectively, such that when the upper and lower housing 102,104 are urged together, for example by a compressive or torsional force applied to the artificial spinal disk 100, spacer 106, slides toward spacer 108. It is to be understood that in an alternative embodiment that both spacers 106, 108 can be movably mounted on shaft 110 and thus when a load is placed on artificial spinal disk 100, both spacers 106, 108 can slide towards each other. Accordingly can be seen in
As can be seen in
In the embodiment of
In the embodiment shown the keels include ports 148 and 150. Bone from, for example, the vertebral bodies can grow thorough the ports and aid in securing the keels and the artificial disk 100 with respect to the vertebral bodies. In addition the keels and the surfaces of the artificial spinal disk 100 can be roughened in order to promote bone in growth into the surfaces of the artificial spinal disk 100. By way of example only, such surfaces can be coated with a bone growth substance such as for example bone morphogenic protein, BMP or hyaluronic acid, HA, or other substance which promotes growth of bone relative to and into the keel, keel ports, and other external surfaces of the disk 100. In addition in another embodiment these surfaces can be coated with cobalt chrome in order to provide a surface for bone-in growth relative to the replacement disk 100.
The anterior spacer 106 stops sliding when a component of the bending force urging the anterior spacer 106 to slide along the ramp is balanced by a component of force of the spring 112 on the shaft 110 urging the anterior spacer 106 apart from the posterior spacer 108, or until the upper housing 102 contacts the lower housing 104 and the gap is eliminated. When the bending force is removed from the anterior end of the artificial spinal disk 100, the force of the spring 112 on the shaft 110 causes the anterior spacer 106 to slide toward the anterior end of the artificial spinal disk 110, urging the upper housing 102 and the lower housing 104 apart as the anterior spacer 106 slides on the ramps. The original gap can be restored in this manner by removing the bending force applied to the anterior end of the artificial spinal disk 100. Similarly, as the patient bends backward, a bending force can be applied to the posterior end of the artificial spinal disk 100, causing the posterior spacer 108 and shaft 110 to slide toward the spacer 106 and the anterior end of the artificial spinal disk 100.
The cross-section of the artificial spinal disk 100 shown in
As shown in
The artificial spinal disk 100 are generally anchored or fixed to the vertebrae. Fixation can be achieved, for example, as previously described by, with one or both of the upper and lower housings 102, 104 including a keel 140, 142 which extend therefrom, which keels can include teeth 144, 146 respectively. Appropriate channels can be cut in the upper and lower adjacent vertebrae to receive the keels 140, 142 in order to retain the artificial spinal disk 100 relating to the vertebrae. Fixation can also be accomplished (1) by anchoring using one or more teeth, pegs, or posts extending from the upper and/or lower housing 102,104 and inserted into the vertebrae (2) by promotion of bone-in growth by means of a porous contact surface of each housing 102, 104, or (3) by fixation with screws through ports in the upper and/or lower housings 102, 104. In one embodiment, the top surface of the upper housing 102 can include teeth which can penetrate into the top vertebra, fixing the artificial spinal disk 100 with respect to the top vertebra. Similarly, the bottom surface of the lower housing 104 can include teeth which can penetrate into the bottom vertebra, fixing the artificial spinal disk 100 with respect to the bottom vertebra.
As shown in
The spacers 106, 108 and housings 102, 104 can be of various shapes and sizes. Thus for example, using imaging prior to surgery, the anatomy of the individual patent can be determined and the artificial spinal disk 100 selected to suit the particular patient. Additionally, during surgery the physician can be provided with a kit having different sized artificial spinal disks 100 to fit the anatomy of the patient.
The upper housing 102 and lower housing 104 and the spacers 106, 108 and shaft 110 can be made of stainless steel, titanium, and/or other bio-compatible metal or metal composite. Each component can be cast, milled, or extruded, for example. Alternatively, the upper housing 102 and lower housing 104 and the spacers 106, 108 and the shaft 110 can be made of a polymer such as polyetheretherketone (PEEK), (as defined below) or other biologically acceptable material. A material can be selected based on desired characteristics. For example, a metal can be selected based on high relative fatigue strength. Many patients with back pain are in their lower forties in age. In such cases, it may be desired that an artificial spinal disk have a fatigue life of at least forty years, extending beyond a patients octogenarian years.
As indicated above, each spacer 106, 108 can be made of a polymer, such as a thermoplastic, and can be formed by extrusion, injection, compression molding and/or machining techniques. Specifically, the spacer 106, 108 can be made of a polyketone such as PEEK.
One type of PEEK is PEEK 450G, which is an unfilled PEEK approved for medical implantation available from Victrex of Lancashire, Great Britain. Other sources of this material include Gharda located in Panoli, India. PEEK 450G has appropriate physical and mechanical properties and is suitable for carrying the physical load exerted by the upper housing 102 and lower housing 104 while providing a smooth, slidable surface. For example in this embodiment PEEK has the following approximate properties:
The material selected may also be filled. For example, other grades of PEEK available and contemplated include 30% glass-filled or 30% carbon-filled PEEK, provided such materials are cleared for use in implantable devices by the FDA or other regulatory body. Glass-filled PEEK reduces the expansion rate and increases the flexural modulus of PEEK relative to unfilled PEEK. The resulting product is known to be ideal for improved strength, stiffness, or stability. Carbon-filled PEEK is known to enhance the compressive strength and stiffness of PEEK and lower its expansion rate. Carbon-filled PEEK offers wear resistance and load carrying capability.
As will be appreciated, other suitable bio-compatible thermoplastic or thermoplastic polycondensate materials that resist fatigue, have good memory, are flexible and/or deflectable, have very low moisture absorption and have good wear and/or abrasion resistance, can be used without departing from the scope of the invention. Other materials that can be used include polyetherketoneketone (PEKK), polyetherketone (PEK), polyetherketoneetherketoneketone (PEKEKK), and polyetheretherketoneketone (PEEKK), and generally a polyaryletheretherketone. Further, other polyketones can be used, as well as other thermoplastics.
Reference to appropriate polymers that can be used in the spacer can be made to the following documents, all of which are incorporated herein by reference: PCT Publication WO 02/02158 A1, dated Jan. 10, 2002 and entitled Bio-Compatible Polymeric Materials; PCT Publication WO 02/00275 A1, dated Jan. 3, 2002 and entitled Bio-Compatible Polymeric Materials; and PCT Publication WO 02/00270 A1, dated Jan. 3, 2002 and entitled Bio-Compatible Polymeric Materials. Other materials such as Bionate®, polycarbonate urethane, available from the Polymer Technology Group, Berkeley, Calif., may also be appropriate because of the good oxidative stability, biocompatibility, mechanical strength and abrasion resistance.
Other thermoplastic materials and other high molecular weight polymers can be used. One of ordinary skill in the art can appreciate the many different materials with which a spacer 106, 108 having desired characteristics can be made.
First and second artificial spinal disks 100 can be connected together at one or more locations, preferably along opposing surfaces, preventing shifting of one artificial spinal disk 100 relative to the other. The artificial spinal disks 100 can be connected using one or more snaps, pins, screws, hinges or other fastening device 111. One of ordinary skill in the art can appreciate the methods for connecting multiple artificial spinal disks 100 after each disk 100 is separately implanted between adjacent vertebrae.
By way of example, an incision can be made posteriorly from the left or right of the spinous processes. The disk space can be cleaned and tissue removed as required. Then disk 100 can be inserted through the incision. Thereafter, the second disk can be inserted into the disk space through the disk space through the incision. Once the second disk 100 is positioned the two disks can be secured together by for example inserting a pin or screw between aligned eyelets extending form the disks 100 as seen in
As can be seen in
Also it is to be understood that as described below, an artificial spinal disk can be inserted laterally into a disk space between two adjacent vertebral bodies. In this method the spine is approached laterally and disk tissue is removed as is appropriate. Then the disk 100 is inserted along a lateral direction.
Other methods of insertion include having the disk 100 disassembled prior to insertion. For this method, an upper or a lower housing 102, 104 can first be inserted and either loosely positioned or fixed to a vertebra, followed by a first spacer 106, a shaft 110, and a second spacer 108. The housing 102, 104 can then be joined or snapped together using the mechanism shown in
In these embodiments, elements that are similar to the elements of prior embodiments are similarly numbered. In
As can be seen in
The upper and lower housings 802, 804 further include keels 840 and 842 which can be similar in design as keels 140 and 142. In this embodiment, however, the keels 840, 842 are provided along a lateral orientation with respect to the spine. In order words, the keels are provided on disk 800 so that after disk 800 is implanted, the keels are substantially perpendicular to the sagittal plane of the spine. The keels 802, 804 are preferably provided parallel to and over the shaft 810 in order to balance the load of the spine on the disk 800. Such an arrangement provides stability to the disk 800 with respect to bending of the spine from flexion to extension in the sagittal plane.
The present embodiment is preferably implanted laterally or substantially perpendicular to the sagittal plane of the spine. Accordingly the method of implantation is similar to that described in
As can be seen in
With respect to
It is to be noted that in a number of these Figures the implants are illustrated against a kidney-shaped background that is representative of the plan view shape of the disk space between vertebral bodies.
The foregoing description of preferred embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations will be apparent to one of ordinary skill in the relevant arts. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications that are suited to the particular use contemplated. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims. It is intended that the scope of the invention be defined by the claims and their equivalence.
This Application is a Divisional of U.S. patent application Ser. No. 10/730,717, filed Dec. 8, 2003, entitled “System and Method for Replacing Degenerated Spinal Disks”, and is hereby incorporated herein by reference.
Number | Name | Date | Kind |
---|---|---|---|
2677369 | Knowles | May 1954 | A |
3648691 | Lumb | Mar 1972 | A |
3867728 | Stubstad et al. | Feb 1975 | A |
3875595 | Froning | Apr 1975 | A |
3904226 | Smalley | Sep 1975 | A |
4309777 | Patil | Jan 1982 | A |
4349921 | Kuntz | Sep 1982 | A |
4759766 | Büttner-Janz et al. | Jul 1988 | A |
4759769 | Hedman et al. | Jul 1988 | A |
4772287 | Ray et al. | Sep 1988 | A |
4863476 | Shepperd | Sep 1989 | A |
4863477 | Monson | Sep 1989 | A |
4874389 | Downey | Oct 1989 | A |
4878915 | Brantigan | Nov 1989 | A |
4904260 | Ray et al. | Feb 1990 | A |
4911718 | Lee et al. | Mar 1990 | A |
4932969 | Frey et al. | Jun 1990 | A |
4946378 | Hirayama et al. | Aug 1990 | A |
4997432 | Keller | Mar 1991 | A |
5002576 | Fuhrmann et al. | Mar 1991 | A |
5011484 | Breard | Apr 1991 | A |
5035716 | Downey | Jul 1991 | A |
5047055 | Bao et al. | Sep 1991 | A |
5071437 | Steffee | Dec 1991 | A |
5108438 | Stone | Apr 1992 | A |
5122130 | Keller | Jun 1992 | A |
5123926 | Pisharodi | Jun 1992 | A |
5171280 | Baumgartner | Dec 1992 | A |
5171281 | Parsons et al. | Dec 1992 | A |
5192326 | Bao et al. | Mar 1993 | A |
5246458 | Graham | Sep 1993 | A |
5258031 | Salib et al. | Nov 1993 | A |
5258043 | Stone | Nov 1993 | A |
5306307 | Senter | Apr 1994 | A |
5306308 | Gross et al. | Apr 1994 | A |
5306309 | Wagner et al. | Apr 1994 | A |
5314477 | Marnay | May 1994 | A |
5320644 | Baumgartner | Jun 1994 | A |
5370697 | Baumgartner | Dec 1994 | A |
5375823 | Navas | Dec 1994 | A |
5390683 | Pisharodi | Feb 1995 | A |
5401269 | Büttner-Janz et al. | Mar 1995 | A |
5425773 | Boyd et al. | Jun 1995 | A |
5458642 | Beer et al. | Oct 1995 | A |
5458643 | Oka et al. | Oct 1995 | A |
5496318 | Howland | Mar 1996 | A |
5507816 | Bullivant | Apr 1996 | A |
5514180 | Heggeness et al. | May 1996 | A |
5534028 | Bao et al. | Jul 1996 | A |
5534029 | Shima | Jul 1996 | A |
5534030 | Navarro et al. | Jul 1996 | A |
5545229 | Parsons et al. | Aug 1996 | A |
5549679 | Kuslich | Aug 1996 | A |
5554191 | Lahille et al. | Sep 1996 | A |
5556431 | Büttner-Janz | Sep 1996 | A |
5562736 | Ray et al. | Oct 1996 | A |
5562738 | Boyd et al. | Oct 1996 | A |
5609634 | Voydeville | Mar 1997 | A |
5645596 | Kim et al. | Jul 1997 | A |
5645597 | Krapiva | Jul 1997 | A |
5658335 | Allen | Aug 1997 | A |
5665122 | Kambin | Sep 1997 | A |
5674294 | Bainville et al. | Oct 1997 | A |
5674295 | Ray et al. | Oct 1997 | A |
5674296 | Bryan et al. | Oct 1997 | A |
5676701 | Yuan et al. | Oct 1997 | A |
5676702 | Ratron | Oct 1997 | A |
5683465 | Shinn et al. | Nov 1997 | A |
5702450 | Bisserie | Dec 1997 | A |
5702454 | Baumgartner | Dec 1997 | A |
5716416 | Lin | Feb 1998 | A |
5755796 | Ibo et al. | May 1998 | A |
5755798 | Papavero et al. | May 1998 | A |
5782832 | Larsen et al. | Jul 1998 | A |
5824093 | Ray et al. | Oct 1998 | A |
5824094 | Serhan et al. | Oct 1998 | A |
5827328 | Buttermann | Oct 1998 | A |
5865845 | Thalgott | Feb 1999 | A |
5865846 | Bryan et al. | Feb 1999 | A |
5865848 | Baker | Feb 1999 | A |
5885299 | Winslow et al. | Mar 1999 | A |
5888226 | Rogozinski | Mar 1999 | A |
5893889 | Harrington | Apr 1999 | A |
5895428 | Berry | Apr 1999 | A |
5899941 | Nishijima et al. | May 1999 | A |
5919235 | Husson et al. | Jul 1999 | A |
5928284 | Mehdizadeh | Jul 1999 | A |
5964807 | Gan et al. | Oct 1999 | A |
5976186 | Bao et al. | Nov 1999 | A |
6001130 | Bryan et al. | Dec 1999 | A |
6022376 | Assell et al. | Feb 2000 | A |
6039763 | Shelokov | Mar 2000 | A |
6080193 | Hochshuler et al. | Jun 2000 | A |
6093205 | McLeod et al. | Jul 2000 | A |
6110210 | Norton et al. | Aug 2000 | A |
6113637 | Gill et al. | Sep 2000 | A |
6132465 | Ray et al. | Oct 2000 | A |
6136031 | Middleton | Oct 2000 | A |
6139579 | Steffee et al. | Oct 2000 | A |
6146421 | Gordon et al. | Nov 2000 | A |
6146422 | Lawson | Nov 2000 | A |
6156067 | Bryan et al. | Dec 2000 | A |
6162252 | Kuras et al. | Dec 2000 | A |
6165218 | Husson et al. | Dec 2000 | A |
6176882 | Biedermann et al. | Jan 2001 | B1 |
6190414 | Young et al. | Feb 2001 | B1 |
6368351 | Glenn et al. | Apr 2002 | B1 |
6454806 | Cohen et al. | Sep 2002 | B1 |
6517580 | Ramadan et al. | Feb 2003 | B1 |
6582437 | Dorchak et al. | Jun 2003 | B2 |
6723126 | Berry | Apr 2004 | B1 |
6755841 | Fraser et al. | Jun 2004 | B2 |
6770095 | Grinberg et al. | Aug 2004 | B2 |
6835206 | Jackson | Dec 2004 | B2 |
6905512 | Paes et al. | Jun 2005 | B2 |
7018415 | McKay | Mar 2006 | B1 |
7052515 | Simonson | May 2006 | B2 |
7147665 | Bryan et al. | Dec 2006 | B1 |
7273496 | Mitchell | Sep 2007 | B2 |
7291171 | Ferree | Nov 2007 | B2 |
7331995 | Eisermann et al. | Feb 2008 | B2 |
7377921 | Studer et al. | May 2008 | B2 |
7473276 | Aebi et al. | Jan 2009 | B2 |
7476238 | Panjabi, Manohar M. | Jan 2009 | B2 |
7485134 | Simonson | Feb 2009 | B2 |
7531001 | De Villiers et al. | May 2009 | B2 |
7604654 | Fallin et al. | Oct 2009 | B2 |
7611538 | Belliard et al. | Nov 2009 | B2 |
7632314 | Dietz | Dec 2009 | B2 |
7641692 | Bryan et al. | Jan 2010 | B2 |
7682376 | Trieu | Mar 2010 | B2 |
7699875 | Timm | Apr 2010 | B2 |
7708778 | Gordon et al. | May 2010 | B2 |
7722674 | Grotz | May 2010 | B1 |
7727280 | McLuen | Jun 2010 | B2 |
20020022887 | Huene | Feb 2002 | A1 |
20020035400 | Bryan et al. | Mar 2002 | A1 |
20020040243 | Attali et al. | Apr 2002 | A1 |
20020107574 | Boehm et al. | Aug 2002 | A1 |
20020128716 | Cohen et al. | Sep 2002 | A1 |
20030040801 | Ralph et al. | Feb 2003 | A1 |
20040024461 | Ferree | Feb 2004 | A1 |
20040039448 | Pisharodi | Feb 2004 | A1 |
20040106998 | Ferree | Jun 2004 | A1 |
20040138750 | Mitchell | Jul 2004 | A1 |
20040143332 | Krueger et al. | Jul 2004 | A1 |
20040172135 | Mitchell | Sep 2004 | A1 |
20050278026 | Gordon et al. | Dec 2005 | A1 |
20060276899 | Zipnick et al. | Dec 2006 | A1 |
20080077244 | Robinson | Mar 2008 | A1 |
20090270992 | Gerber et al. | Oct 2009 | A1 |
20100114318 | Gittings et al. | May 2010 | A1 |
Number | Date | Country |
---|---|---|
3113142 | Jan 1982 | DE |
0322334 | Jun 1989 | EP |
2705227 | Nov 1994 | FR |
2722088 | Jan 1996 | FR |
2722980 | Feb 1996 | FR |
2724554 | Mar 1996 | FR |
780652 | Aug 1957 | GB |
WO 0101893 | Jan 2001 | WO |
Number | Date | Country | |
---|---|---|---|
20070191955 A1 | Aug 2007 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 10730717 | Dec 2003 | US |
Child | 11734681 | US |