Patent Publication Number: US-2005143826-A1

Title: Disk repair structures with anchors

Description:
CLAIM OF PRIORITY  
      U.S. Provisional Patent Application 60/528,954 entitled DISK REPAIR STRUCTURES WITH ANCHORS, by James F. Zucherman et al., filed Dec. 11, 2003 (Attorney Docket No. KLYCD-05005US0).  
     CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application is related to the following U.S. patent application Ser. No. ______, entitled DISK REPAIR STRUCTURES FOR POSITIONING DISK REPAIR MATERIAL, filed XX/XX/04, Attorney Docket No. KLYCD-05005US3, concurrently with the instant application, and incorporated fully by reference. 
    
    
     FIELD OF THE INVENTION  
      This invention relates to a vertebral disk repair implant and method.  
     BACKGROUND OF THE INVENTION  
      The spinal column is a biomechanical structure composed primarily of ligaments, muscles, vertebrae and intervertebral disks. The biomechanical functions of the spine include: (1) support of the body, which involves the transfer of the weight and the bending movements of the head, trunk and arms to the pelvis and legs; (2) complex physiological motion between these parts; and (3) protection of the spinal cord and nerve roots.  
      The intervertebral disk plays an important role in the biomechanical structure of the spine. It cushions the vertebrae and allows for controlled motions of these bones. An intervertebral disk has two components: (1) the nucleus pulposus, or “nucleus”; and (2) the anulus fibrosis, or “anulus.” The disk is positioned between two vertebral endplates located between adjacent vertebrae.  
      Each endplate creates an intermediate zone between the flexible disk and the rigid bone of the vertebrae. An endplate consists of thin cartilage overlying a thin layer of hard cortical bone. The hard cortical bone of the endplate is connected with cancellous bone of the vertebrae, which is spongy and vascularized.  
      The anulus is a tough, fibrous ring that has 15-20 overlapping layers that together are resistant to torsion. The ring connects adjacent vertebrae. It also houses the nucleus pulposus.  
      The nucleus is a gel-like substance that is high in water content. It helps maintain the shape of the anulus without decreasing its flexibility. When a force acts upon adjacent vertebrae, the nucleus moves with the anulus.  
      Trauma or disease may displace or damage the spinal disk. A disk herniation occurs when the anulus fibers are weakened or torn and the nucleus becomes permanently bulged, distended, or extruded out of its normal space within the confines of the anulus. The herniated or so-called “slipped” nucleus can compress a spinal nerve, causing leg pain, loss of muscle control, or even paralysis. Also, as the disk degenerates, the nucleus loses its water binding ability and deflates, which decreases the height of the nucleus. In turn, because of the decrease in height, the anulus buckles. In regions of buckling of the anulus, either circumferential or radial anulus tears may occur, potentially resulting in persistent and disabling back pain. Back pain may be compounded by adjacent, ancillary spinal facet joints which are forced into an overriding position from the buckling of the anulus.  
      Degenerated, diseases, or traumatized disks prevent people from working and can severely impact the lives of patients and their families. The pain associated with such conditions often is treated with medication and/or surgery. Of course, it is desirable to eliminate the need for major surgery for all individuals, particularly the elderly. Therefore, an easily implantable prosthetic is needed for sealing and promoting healing of injuries or defects in the anulus to prevent recurrence of disk herniation, the resulting impingement of nerves, and other effects on the anatomy of the spine. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1A  is a perspective view of an embodiment of the invention including a prosthetic intervertebral disk implant where an anulus patch is not yet connected with the flexible wire structure.  
       FIG. 1B  is a perspective view of a prosthetic intervertebral disk implant with the anulus patch fully connected with the trumpet or cone-shaped flexible wire structure.  
       FIG. 1C  is a perspective view of a prosthetic disk implant with an anulus plug.  
       FIG. 2A  is a side cut-away view of an embodiment of the invention including an implanted intervertebral disk implant, viewed along a sagittal plane, the implant anchored to the top vertebra of two adjacent vertebrae on either side of an injured or defective disk.  
       FIG. 2B  is a side cut-away view of an embodiment of the invention including an implanted intervertebral disk implant, viewed along a sagittal plane, the implant anchored to the bottom vertebra of two adjacent vertebrae on either side of an injured or defective disk.  
       FIG. 3  is a perspective view of an embodiment of the invention including an intervertebral disk implant with a flexible wire structure made of mesh and having hooks at the open end that connects with the anulus patch.  
       FIGS. 4A and 4B  are perspective views of embodiments of the invention including intervertebral disk implants.  FIG. 4A  depicts an implant with a flexible wire structure having a single branch of a plurality of wires that flares into a cone shape toward the end that connects with the anulus patch.  FIG. 4B  is similar to  FIG. 4A , except that the cone shaped part of the flexible wire structure is a wire mesh or weave with wires running along an axis that is substantially perpendicular to the axis of the single branch.  
       FIG. 5  is a side cut-away view of an embodiment of the invention including an implanted intervertebral disk implant, viewed along a sagittal plane, the implant anchored to the bottom of two adjacent vertebrae on either side of an injured or defective disk, and having a flexible wire structure consisting of a single branch that connects with the anulus patch, the anulus patch then sutured onto the anulus around the injured or defective site.  
       FIG. 6  is a side cut-away view of an embodiment of the invention including two implanted intervertebral disk implants, viewed along a sagittal plane, with first implant anchored to the bottom of two adjacent vertebrae, and the second implant anchored to the top of the two adjacent vertebrae.  
       FIG. 7  is a side cut-away view of an embodiment of the invention including an implanted intervertebral disk implant, viewed along a sagittal plane, the implant anchored to the bottom of two adjacent vertebrae on either side of an injured or defective disk, and having a spiral-shaped flexible wire structure.  
       FIG. 8  is a perspective view of an embodiment of the invention including an implant having a spiral-shaped flexible wire structure showing that the structure can be made shorter to accommodate the anatomy of the intervertebral space by cutting at a point in between the first end and the second end of the flexible wire structure as, for example, where indicated.  
       FIG. 9  includes a flow chart of an embodiment of the implantation method of the invention.  
       FIGS. 10A and 10B  include a side view of an embodiment of the invention being positioned through a cannula according to the method of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION  
      Embodiments of the present invention relate to a prosthetic intervertebral spinal implant for repairing the anulus of an intervertebral disk. The implant also serves to cushion impact on the spine. Specifically, the embodiments of the present invention concern a flexible structure that can be anchored to a vertebral bone endplate at a first end, and that sustains in place an anulus patch over an injury or defect in the anulus of a disk. Embodiments of the disclosed invention have the added benefit of functioning like the nucleus pulposus material to cushion impact on the spine, prevent further herniation, prevent narrowing of the intervertebral disk space and destabilization of the spine, and promote effective repair and healing of the injured anulus.  
      Embodiments of the present invention include a prosthetic intervertebral disk implant for implantation to repair an injury or defect in the anulus and to prevent narrowing of the intervertebral disk space. The implant is positioned inside the intervertebral disk space, which is defined by the bone endplates of two adjacent vertebrae. The disclosure further provides a method for implanting the implant.  
     Embodiments of the Invention Covering an Implant  
      A flexible wire structure, connected with a bone anchor at a first end and anulus patch at a second end, is implanted by positioning the implant inside the intervertebral disk space after inserting it through the injured or defective site in the anulus. The flexible wire structure can have various shapes. In a preferred embodiment, it is trumpet or cone-shaped with a hollow interior space, and made of wire mesh or wire weave. The trumpet- or cone-shape is narrow at the first end where it is operably connected with the bone anchor, and open at the second end where it is operably connected with the anulus patch.  
      The flexible wire structure may also be made of a plurality of wires oriented in substantially the same direction, i.e., running from the first end of the cone and flaring at the second end. It is also within the scope of this disclosure to have a single branch of wire—either a single wire or a plurality of associated wires in a single branch, which can be contained within a tube or other containing structure. A further embodiment contemplated by the disclosure is a flexible wire structure that at a first end is a single branch, which flares out at the second end into a cone that connects with the anulus patch. An additional embodiment is one where the cone- or trumpet-shaped flexible wire structure is made of a spiral of at least one wire.  
      The wire of the flexible wire structure can be made of nitinol, aluminum, stainless steel, nylon, polypropylene, or another flexible, biocompatible material.  
      In a preferred embodiment, the bone anchor is a bone screw, connected with the first end of the flexible wire structure. However, other bone anchors are also within the scope of this disclosure. The bone anchor is used to anchor the implant in the intervertebral disk space, after the implant is positioned inside that space so that the second end of the flexible wire structure is sustained in place over the injury or defect in the anulus. A screwdriver can be used to drive a bone screw into the vertebral bone endplate and into the cortical bone. Other varieties of bone anchors will employ other appropriate tools. For the screwdriver or other tool to be able to reach the bone screw or anchor, the anulus patch either can be unattached until after anchoring, or partially attached to allow the tool to reach the bone screw or anchor, or partially folded back.  
      However, in certain embodiments, it may be possible to pre-attach the anulus patch if the tool used to drive the bone anchor into the vertebral bone endplate can be used without damaging the patch or the rest of the implant. One such embodiment has a single branch of at least one wire that connects with the anulus patch at its second end, i.e., the end distal to the first end that connects with the bone screw.  
      The anulus patch can be attached all at once after anchoring, or attached partially before anchoring with the remainder waiting until after the anchoring step. The flexible wire structure can engage the anulus patch with hooks at the second end of the implant that are either connected with the wires at the second end, or continuous with them. The hooks further secure the patch and flexible wire structure to the healthy anulus tissue around the injury or defect. Alternatively, the patch can associate with the flexible wire structure via loops connected with the second end of the flexible wire structure which are adapated to receive sutures. The sutures penetrate the anulus patch and the anulus tissue.  
      The anulus patch can remain on the outside of the anulus, once the implant is positioned with the patch connected with the flexible wire structure. However, a patch that is positioned on the interior wall of the injured or defective anulus is also within the scope of this disclosure. Further, the disclosure contemplates the use of a patch that promotes tissue growth over and around the patch to permanently repair the injury or defect. For instance, the patch can be made of a wire or plastic mesh, or other scarring agent, and/or other appropriate agent that promotes tissue growth.  
     Embodiments of the Invention Covering a Method of Implantation  
      The preferred method of an embodiment of this invention for implanting the prosthetic intervertebral disk implant uses the actual injury site as the point of insertion and positioning of the implant. This approach obviates the need to damage the anulus further with additional incisions for inserting the implant. A cannula with a stylet is first inserted through an incision in the skin. Alternatively, nested cannula can be used, gradually to expand the point of insertion so that the point of insertion is able to accommodate a cannula of sufficiently large diameter to house the implant and any tools necessary in the disclosed method of implantation.  
      A device, such as an automated Nucleotome® hand-operated tissue cutter, is inserted through the cannula and used to cut and remove any herniated nucleus material. The device is then withdrawn and the implant is placed inside the cannula, with the bone anchor end positioned to be inserted first, followed by the flexible wire structure. A plunger is used to urge the implant through the cannula and through the insertion side. The plunger is withdrawn and a tool, such as a screwdriver is used to drive the bone achor into a vertebral bone endplate. This disclosure contemplates using either the upper or lower bone endplate of two adjacent vertebrae on either side of an injured or defective disk.  
      Once the screwdriver or other tool is withdrawn, the anulus patch is introduced into the cannula and hooked onto the hooks in the ends of the wires of the flexible wire framework. The hooks are then allowed to engage the healthy anulus tissue around the defect or injury. This is done by removing the cannula used to insert the implant into the invertebral disk space. Alternatively, the anulus patch can be sutured onto the tissue around the injury or defect through loops in the ends of the wires at the second, open end of the flexible wire structure.  
      Embodiments of this invention further contemplate insertion of a flexible wire structure already fully attached to the anulus patch, so long as a tool can be inserted to drive the bone anchor into the vertebral bone endplate without damaging the anulus patch.  
     Embodiments of FIGS.  1 A,  1 B, and  1 C  
      One preferred embodiment of a prosthetic intervertebral spinal implant for repairing the anulus of an intervertebral disk is shown in  FIGS. 1A and 1B . Both figures show a perspective view of an implant with a bone anchor  40 , flexible wire structure  30 , and anulus patch  20 . The bone anchor  40  depicted is a bone screw, but the disclosure encompasses other types of bone anchors including, by way of example only, bone pins and bone sutures that can penetrate the vertebral bone endplate and into the cortical bone. The bone anchor  40  can be made of a biocompatible metal, including nitinol, titanium, and stainless steel.  
      One purpose of the flexible wire structure  30  is to position and sustain an anulus patch  20  over the injured or defective anulus tissue. A further purpose is to serve as a cushion in the space otherwise occupied by the nucleus pulposus to absorb shocks to the spine and maintain flexibility. The flexible wire structure  30  in both  FIGS. 1A and 1B  is comprised of wires  80  with a common point of origin which forms the closed end  70  of the cone- or trumpet-shaped structure  30 . However, other forms of the flexible wire structure  30  also are within the scope of the disclosure, and are illustrated in additional figures included herein.  
      At its first closed end  70 , the flexible wire structure  30  meets and connects with the bone anchor  40 . It is within the scope of this disclosure that the bone anchor  40  can be connected with the flexible wire structure  30  by having the ends of the wires  80  at the first end  70  loop around the head of the bone anchor  40 . It should be understood, however, that any connecting means is contemplated by this disclosure to the extent that it allows the bone anchor  40  to be driven into the bone without entangling the flexible wire structure  30  or otherwise interfering with its positioning or damaging its physical integrity.  
      At the second end  60  of the flexible wire structure  30 , the wires  80  flare out relative to the first closed end  70 . The wires  80  have hooks  50  extending from the second end  60  of the flexible wire structure  30  that engage the anulus patch  20  and that can engage the healthy tissue surrounding the injury or defect in the anulus.  FIG. 1A  shows the anulus patch  20  completely separate from the rest of the implant  100 . The anulus patch  20  is left off until after the bone anchor  40  has been driven into the vertebral bone endplate, so that the bone anchor can be reached with a tool, such as a screwdriver, without damaging the anulus patch  20 . It should be understood, however, that the anulus patch  20  also can be partially attached to several of the hooks  50  before anchoring the implant  10  because the partial attachment would permit use of a tool to drive the bone anchor  40  into the bone without having to puncture or otherwise damage the anulus patch  20 . Further, the anulus patch can be fully attached to the structure  30  and then folded back out the way of a tool.  FIG. 1B  depicts the implant  100  with the anulus patch  20  fully connected with the flexible wire structure  30  with hooks  50  extending from the ends of the wires  80  at the second end  60  of the flexible wire structure  30 .  FIG. 1C  depicts the implant  100  with a plug  25  substituted for an anulus patch  20 . The plug  25  serves substantially similar functions as the anulus patch. It can be made of a hydrogel core or cushion contained in a constraining jacket. Alternatively, the constraining jacket can be made of a patient&#39;s hair, treated for example as described in Shamie, U.S. Pat. No. 6,416,776. The hydrogel further can contain therapeutic materials. Alternatively, the plug can be made of other appropriate biocompatible material that will remain for a period of time sufficient to ensure promotion of tissue formation over the damage to the anulus. One such example is to use a keratin hydrogel, which has also been described and will not be discussed in detail here.  
      It is also within the scope of the disclosure that the second, open end  60  of the flexible wire structure  30 , rather than having hooks  50 , would have loops  455  (see  FIG. 5 ). The anulus patch  20  would then be sutured to the healthy tissue around the anulus and also connected with the flexible wire structure  30  through the loops  455  at the second end  60  of the flexible wire structure  30 .  
      The anulus patch  20  is intended to repair damage, such as an injury or defect, to the anulus. It should not only patch the injury or defect, but also promote healing at the site. Patching and scarring can be promoted using a scarring agent, such as wire mesh, plastic mesh, or another inert synthetic mesh of a biocompatible material. Alternatively, a hydrogel plug inside a constraining jacket can be positioned inside the flexible wire structure, with or without a patch over the plug. The hydrogel also can be made of keratin supplied and prepared from the patient&#39;s own hair, substantially as described in Zucherman et al., U.S. patent application Ser. No. 10/218,100, which is incorporated herein by reference, or with other hydrogels as taught in the art.  
     Embodiments of FIGS.  2 A and  2 B  
      As can be seen in  FIGS. 2A and 2B , the disclosed implant  100  can be implanted to repair an injury or defect in the anulus of an intervertebral disk  90 , by anchoring the implant  100  into either the top ( FIG. 2A ) or bottom ( FIG. 2B ) vertebral bone endplate of two adjacent vertebrae  80 . It is to be realized that any of the disclosed embodiments to be described herein can be anchored as depicted in  FIGS. 2A and 2B .  
     Embodiment of FIG.  3   
      A further embodiment  200  is shown in  FIG. 3 . In this embodiment, the flexible wire structure  230  is composed of a wire mesh or weave, with hooks  250  extending from the second, flared end  260  of the cone- or trumpet-shaped wire structure  230 , from the wires extending substantially along the axis defined by A-A′. Alternatively, the hooks  250  need not be continuous with the wires. Instead, they may be fixed separately to the wires or mesh at the open end  260  running substantially along the axis defined by B-B′, at the open end  260  of the flexible wire structure  230 . A combination of both types of hooks  250  also is contemplated. Preferably, the wire mesh and the hooks  250  disclosed are made of nitinol, titanium, or stainless steel. They can further be made of nylon, polypropylene, or other flexible biologically inert material.  
      The hooks  250  engage the anulus patch  220 , after the implant  200  is anchored at its first end  270  with a bone anchor  240  to either a first or second vertebral bone endplate, as depicted in  FIGS. 2A and 2B . The anulus patch  220  depicted is a mesh. The mesh can either be of wire or plastic, or another inert synthetic biocompatible material that will promote and/or permit tissue growth over the anulus patch  220 , or any other material that can have tissue growth-encouraging properties. Alternatively, the anulus patch  220  can be placed over a hydrogel plug encased in a constraining jacket.  
      The bone anchor  240  depicted in  FIG. 3  is a bone screw. However, it is within the scope of this disclosure to employ any type of appropriate bone anchor  240  that can penetrate the vertebral bone endplate and into the cortical bone to anchor the implant  200 .  
     Embodiment of FIGS.  4 A and  4 B  
      A further embodiment is depicted in  FIG. 4A . In this embodiment  300 , part of the flexible wire structure  330  is made of a plurality of wires associated as a single branch  335  originating at the first end  370  of the flexible wire structure  330 . The single branch  335  is depicted as appearing encased inside a tube  345 . The tube  345  has its point of origin near the bone anchor  340 , where the plurality of wires are connected, and a second end  375  intermediate between the bone anchor  340  and the second, open end  360  of the flexible wire structure  330 . Thus, the tube  345  does not run the full length of the flexible wire structure  330 , and the plurality of wires emerges where the tube ends  375  to form a cone or mini-trumpet shape  385 , as detailed below.  
      The tube  345  functions to prevent the single branch of wires  335  from fraying or dissociating, and otherwise to protect them. It also serves to brace the single branch of wires  345  so that is sufficiently rigid to sustain the anulus patch  320  in place at the injury or defect in the anulus. The tube  345  can be made of a plurality of flexible biocompatible materials, including plastics and metals such as nitinol, titanium, and stainless steel. It is also within the scope of this disclosure to use fibrous materials and other non-brittle materials for the tube  345 . It is also contemplated that the single branch  335  need not be encased by a tube  345 .  
      At or near the point  375  where the single branch of wires  335  emerges from the tube  345 , the wires flare out individually to form a cone or mini-trumpet  385  at the second, open end  360  of the flexible wire structure  330 , as in  FIG. 4A . Alternatively, the wires can be interwoven with wires in a direction substantially perpendicular or at an angle to the direction of the wires emerging from the tube  345 , as depicted by axis B-B′ in  FIG. 4B . The wires at the open end  360  of the flexible wire structure  330  can have a plurality of hooks  350  adapted to engage the anulus patch  320  with the flexible wire structure  330  and also to engage it with the healthy tissue around the damage, caused by an injury or defect, to the anulus. In the wire weave or mesh depicted in  FIG. 4B , the wires in the mini-trumpet  385  can have hooks  350  that are continuous with the wires at the open end  360  of the flexible wire structure  330 , and/or the wires substantially parallel or at an angle relative to the axis B-B′ can have separate hooks  350  that are connected with the wires to function as the hooks  350  made from the ends of the wires which are parallel to axis A-A′.  
      The single branch  335  of the flexible wire structures  330  in  FIGS. 4A and 4B , respectively, are connected with a bone anchor  340  at the first end  370 , which is depicted in  FIGS. 4A and 4B , respectively, as a bone screw. However, as in previous and other embodiments in this disclosure, the bone anchor  340  can be any type of bone anchoring device that can engage the vertebral bone endplate to sustain the implant in position in the intervertebral space.  
     Embodiment of FIG.  5   
      A further embodiment is depicted in  FIG. 5 . In this embodiment  400 , the flexible wire structure  430  is composed of a single branch of at least one wire that extends continuously from the first end  470  of the flexible wire structure  430  that connects with the bone anchor  440  to the second end  460  of the flexible wire structure  430  that connects with the anulus patch  420 . The single branch flexible wire structure  430  is adapted to brace the anulus patch  420  and sustain it in place over and around the injury or defect in the anulus. It also maintains the flexibility of the spine and cushions the shock to the spine.  
      The single branch of the flexible wire structure  430  can either be a single thick wire, or a plurality of wires that are associated or woven together as a branch. The flexible wire structure  430 , whether made of a single wire or a plurality of wires, can be encased in a tube (not shown) that is substantially similar to the tube  345  in embodiment  300  depicted in  FIGS. 4A and 4B .  
      The flexible wire structure  430  connects with the anulus patch  420  at the second end  460  of the flexible wire structure  430 , which second end is distal from the first end  470  that connects with the bone anchor  440 . The connection between the second end  460  and the anulus patch  420  can be made using a plurality of hooks  450  at the second end  460 , which extend from the second end  460  of at least one of the wires. The hooks  450  should pierce the anulus patch  420  at an area substantially at its center, and emerge through to the side of the anulus patch  420  facing out from the intervertebral disk. The hooks  450  should then be made to puncture the anulus patch  420  near the site from where it emerged, to emerge again on the side facing the intervertebral disk space.  
      It should be understood that the means for connecting the anulus patch  420  with the single branch of the flexible wire structure  430  may also include means that do not require piercing the anulus patch  420 . By way of example only, the wires in the single branch of the flexible wire structure  430  may be unraveled near the second end  460 , and then flared out in a plane that is substantially parallel to the faces of the anulus patch  420 , forming a plate that can be adhered to the anulus patch  420  using a biocompatible adhesive or using biocompatible ties. The single branch of the flexible wire structure  430  also may be sutured to the anulus patch  420 , or woven into the anulus patch  420 .  
      A plurality of sutures  445  can be used to engage the anulus patch  420  with the anulus tissue surrounding the damaged site. In this embodiment, the sutures do not engage the tissue and anulus patch  420  with the flexible wire structure  430 . Rather, the sutures only connect the anulus patch  420  with the anulus tissue. The flexible wire structure  430  sustains the patch in place only from inside the intervertebral disk space, unlike other embodiments described here, where the flexible wire structure  430  also is used to engage the anulus patch  420  with the anulus tissue.  
      As in the other embodiments, the bone anchor  440  depicted is a bone screw, but other bone anchors  440  are also within the scope of the disclosure. Also, the anulus patch  420  can be composed, if desired, of any of a wire mesh, a plastic mesh or other scarring agent made from an inert synthetic biocompatible material, adapted to promote growth of scar tissue around and over the anulus patch so that the result is sealing of the damage to the anulus resulting from an injury or defect.  
     Embodiment of FIG.  6   
      A further embodiment of the disclosure is depicted in  FIG. 6 . In this embodiment  500 , two implants  501  and  502 , which can be any of the embodiments described above, are used from within the intervertebral disk space to brace an anulus patch  520  and sustain it in place over a defect or injury to the anulus, while also cushioning impact on the spine. A first implant  501  is anchored to a first vertebral bone endplate  515 , and a second implant  502  is anchored to a second vertebral bone endplate  517 .  
      Essentially, two flexible wire structures  530 , one from each implant  501  and  502  connect with a single anulus patch  520  that seals a damaged site in the anulus. A plurality of hooks  550  extend from the second ends  560  of the two flexible wire structures  530  and connect with the anulus. Alternatively, loops  555  may be formed from or attached to the second ends  560  of the flexible wire structures  530  and adapted to receive sutures to engage the anulus patch  520  with the anulus.  
      As with other embodiments, the bone anchor  540  is depicted as a bone screw, but other bone anchors  540  are within the scope of the disclosure. The anulus patch  520  also has been described in other embodiments.  
     Embodiment of FIGS.  7  and  8   
      A further embodiment is depicted in  FIGS. 7 and 8 . In this embodiment  600 , the flexible wire structure  630  is in the shape of a spiral cage with a hollow interior space  632 . The spiral cage wire structure  630  is open at its second end  660  and is substantially closed at its first end  670 , substantially similar to the cone- or trumpet-shape of other embodiments already described. The spiral cage wire structure  630  comprises at least one wire that is connected at the first end  660  with a bone anchor  640 , and is adapted to connect, after anchoring, with an anulus patch  620 .  
      The spiral cage  630  connects with the anulus patch  620  by a plurality of hooks  650  that are adapted to connect with the rim of the open end  620  of the spiral cage  630  and with the periphery of the anulus patch  620  and the tissue surrounding the defect in the anulus. The anulus patch  620  can be connected completely with the spiral cage  630  and positioned over and around the injury or defect in the anulus after the implant  600  is anchored in the vertebral bone endplate. The anulus patch  620  can remain unattached entirely until after anchoring. Alternatively, the anulus patch  620  can initially be partially attached to the hooks  650  on the rim of the spiral cage  630  before anchoring and, once any tools needed for engaging the bone anchor  640  with the vertebral bone endplate are removed from between the vertebrae, the anulus patch  620  can be fully connected with the rim of the spiral cage wire structure  630 .  
      It is to be realized that other means of engaging the anulus patch  620  with the spiral cage  630  are also within the scope of the disclosure. By way of example only, wire loops  555  (shown in FIGS.  5  AND  6 ) can be used to connect the rim of the spiral cage  630  with the anulus patch  620 . Such loops  555  are adapted to receive sutures that will engage the anulus patch  20  with the healthy tissue around the defect or injury to the anulus.  
       FIG. 8  shows that this spiral wire structure  630  can be adjusted to accommodate intervertebral disk space anatomy of different dimensions. The physician can use known means for measuring the dimensions of the patient&#39;s intervertebral disk space and determine the proper dimensions for an implant as disclosed herein. The physician can then adjust the size of the implant  600  accordingly by cutting the implant  600  as depicted  690  in  FIG. 8 .  
     Embodiment of FIG.  9   
      An embodiment of a method for implanting a spinal disk repair implant is depicted in flow chart format in  FIG. 9 . First, an incision or puncture is made using a posterior approach  900 . A cannula is inserted with a stylus  906  and the cannula moved into position at the site of the injury or defect to the anulus  908 . The stylus is then removed  910 , and a Nucleotome® tool is inserted into the cannula  912 . The Nucleotome® tool includes a guillotine blade that can be used to excise herniated nucleus pulposus material  914 .  
      As an alternative to a cannula/stylus, nested cannulae and a guidewire  902  can be used to position the cannulae and widen gradually the incision and to access the intervertebral disk space. The guidewire is inserted first, followed by successively wider-bore cannulae  904 . The smaller interior cannulae are then removed, as well as the guidewire, and a larger operating space is available through the broadest cannula. The Nuceotome is then inserted  912  and applied to remove herniated disk material, as above  914 .  
      Once the herniated nucleus material is removed, the Nucleotome® tool is extracted from the cannula  916  and the implant can be anchored. An implant essentially as described above is inserted into the cannula with the bone anchor inserted first  918 , so that the bone anchor is the first part to penetrate through the defect in the anulus that is to be repaired. Inserting the implant through the same part of the anulus that already has been damaged is beneficial to the patient, since it may avoid further injury to the anulus, which may result from making additional incisions in it. For example, cutting flaps out of the anulus could cause a loss of integrity of its fibrous layers. Further injury may result from any weakening in the anulus, and the possibility of its healing completely would be reduced.  
      The implant with the anulus patch pre-attached  922  can be urged down the cannula toward the injury or defect using an instrument that serves as a plunger. Alternatively, it can be moved through the cannula with a rigid tool to push the implant along and maintaining the proper orientation—bone anchor first—as it travels down the cannula. The plunger or other tool is then removed.  
      Once the bone anchor is in the intervertebral disk space, a tool is inserted into the cannula to cause the bone anchor to engage with a vertebral bone endplate  920 . If the bone anchor is a bone screw, then the tool is a screw driver with a head adapted to engage the bone screw and drive it into the bone endplate. Alternatively, the bone anchor can be a type of anchor or bone suture that is able to penetrate the bone endplate.  
      After the bone anchor is engaged, the tool used to drive the bone anchor into the bone endplate is removed from the cannula. The flexible wire structure of the implant is left in position to receive the anulus patch at the site of the injury or defect to the anulus  926 .  
      In certain embodiments, the anulus patch is attached completely at this point  922 . As described for the various embodiments, the connecting means can be hooks at or near the ends of the wires at the second end of the flexible wire structure, or loops that can receive sutures to engage the anulus patch with the healthy tissue around the defect or injury in the anulus and with the flexible wire structure.  
      Other embodiments will require the anulus patch to be attached, either partially or entirely, after anchoring the implant in the intervertebral space  924 . At this point, hooks or loops and/or sutures are used to make this connection  928 . It is within the scope of this disclosure for a tool, such as a small forceps or other effective tool, to be used to position the anulus patch and pierce it with the hooks that are to hold it in position and engage the anulus tissue around the defect or injury. Alternatively, the forceps or other effective tool can be used to manipulate loops into position to receive sutures that will hold the patch to the anulus and the flexible wire structure.  
      Alternatively, an anulus patch fully attached to the second end of the flexible wire structure can spring out of the end of the cannula prior to the bone screw being attached to the bone. The bone screw can then be used to secure the flexible wire structure to the vertebra. Thereafter, the anulus patch and hook of the flexible wire structure can be manipulated into engaging with the tissue surrounding the tear in the anulus.  
      The cannula is then removed from the incision and the incision is surgically closed  930 .  
     Embodiment of FIG.  10   
      An embodiment of a method for implanting a spinal disk repair implant is depicted in  FIG. 10 . In this embodiment, as depicted in flowchart format in  FIG. 9 , a cannula  1002  is inserted toward the damaged site on the annulus and the implant is inserted with the bone anchor  40  end first. The implant is pushed through the cannula  1002  and toward the damaged site. The anchor is engaged using an appropriate tool. Here, a bone screw is depicted and the appropriate tool is a screw driver  1004 . Other tools and bone anchoring devices are within the scope of this disclosure.  
      Once the implant is anchored, an anulus patch  20  is engaged with the flexible wire structure and the tissue surrounding the damaged site on the anulus, using methods described in detail above. If the anulus patch  20  already is attached to the flexible wire structure, as with embodiments having a flexible wire structure comprising a single branch of wires or a wire, then all that remains is to ensure that the connecting means for engaging the patch further are manipulated to engage the tissue of the anulus surrounding the damaged site.  
      The foregoing description of 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 the practitioner skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its pratical application, thereby enabling others skilled in the art to understand the invention and the various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and its equivalence.