US20080058808A1 - Implant system and method to treat degenerative disorders of the spine - Google Patents

Abstract

An implant has a first hook and a second hook. A connector is coupled to the first and second hooks. The implant is adapted in a preferred embodiment to hook and look onto a spine.

Description

CLAIM OF PRIORITY
• This application claims benefit to U.S. Provisional Application No. 60/801,871, filed Jun. 14, 2006, entitled “Implant Positioned Between the Lamina to Treat Degenerative Disorders of the Spine,” which is incorporated herein by reference and in its entirety.
CROSS REFERENCES TO RELATED APPLICATIONS
• This application relates to, and incorporates herein by reference, each of the following in its entirety: U.S. patent application Ser. No. 11/761,006, filed Jun. 11, 2007, entitled “Implant System and Method to Treat Degenerative Disorders of the Spine,” (Attorney Docket No.: SPART-01018US1); and
• U.S. patent application Ser. No. 11/761,100, filed Jun. 11, 2007, entitled “Implant System and Method to Treat Degenerative Disorders of the Spine,” (Attorney Docket No.: SPART-01018US2).
BACKGROUND OF INVENTION
• The most dynamic segment of orthopedic and neurosurgical medical practice over the past decade has been spinal devices designed to fuse the spine to treat a broad range of degenerative spinal disorders. Back pain is a significant clinical problem and the annual costs to treat it, both surgically and medically, is estimated to be over $2 billion. Motion preserving devices to treat back and extremity pain have, however, created a treatment alternative to fusion for degenerative disc-disease. These devices offer the possibility of eliminating the long term clinical consequences of fusing the spine that is associated with accelerated degenerative changes at adjacent disc levels.
• While total disc replacement is seen as a major advance over fusion, the procedure to implant the devices in the lumbar spine requires a major operation via an anterior approach, subjecting patients to the risk of significant complications. These include dislodgement of the device, which may damage the great vessels, and significant scarring as a consequence of the surgical procedure itself, which makes revision surgery difficult and potentially dangerous. Thus, there are advantages to spinal implants that can be inserted from a posterior approach, a technique with which spine surgeons are much more experienced. The posterior surgical approach also has the benefit of being able to directly address all pathologies that may be impinging the neural elements, which is not possible from an anterior approach. Motion preserving spinal devices that can be implanted with a minimally invasive, posterior procedure offer the benefit of less surgical trauma and faster patient recovery and also offer cost savings to payers with patients staying fewer days in the hospital.
• Motion preserving devices placed posteriorly typically either rely on the spinous processes to support the implant or require pedicle screws to be inserted. However, spinous processes are not load bearing structures and are not rigid. In a population of patients with back pain, the laminae offer a much stronger structure to position an implant, since they consist of significantly stronger bone, and the laminae are also closer to the spine's axis of rotation. Pedicle screws have several disadvantages when used as attachments for motion preservation devices. The procedure to implant them is considered major surgery requiring a wide exposure. The screws are also subject to significant loads and screw loosening is a known consequence over time in these cases. Removing the screws and fusing the spine requires major revision surgery.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective view of an embodiment of the dynamic spine stabilization, motion preservation implant of the invention.
• FIG. 2 is a perspective view of another embodiment of the dynamic spine stabilization, motion preservation implant with pedicle screws of the invention.
• FIG. 3 is a side view of an embodiment of a hook of the invention of the embodiment ofFIG. 2.
• FIG. 4 is a top view of the embodiment of the hook of the embodiment of the invention ofFIG. 3.
• FIG. 5 is an end view of the embodiment of the hook of the embodiment of the invention ofFIG. 3.
• FIG. 6 is a bottom view of the embodiment of the hook of the embodiment of the invention ofFIG. 3.
• FIG. 7 is a side perspective view of the embodiment of the hook of the embodiment of the invention ofFIG. 3.
• FIG. 8 is a side perspective view of another embodiment of the hook of the invention.
• FIG. 9 is a top view of the embodiment of the invention ofFIG. 8.
• FIG. 10 is a side view of the embodiment of the invention ofFIG. 8.
• FIG. 11 is a side partially sectioned view of another embodiment of an implant of the invention.
• FIG. 12 is a side view of an embodiment of a hook of the embodiment of the invention ofFIG. 11.
• FIG. 13 is a perspective view of a hook with barbs of an embodiment of the invention to be used with the embodiment of the invention ofFIG. 11.
• FIG. 14 is a side view of the embodiment of the hook of the invention ofFIG. 13.
• FIG. 15 is a side view of another embodiment of the hook of the invention.
• FIG. 16 is a side view of the another embodiment of the hook of the invention ofFIG. 15 in a different orientation.
• FIGS. 17A, 17B are schematical top views of the embodiment ofFIG. 15.
• FIGS. 18A, 18B are side views of another embodiment of the hook of the invention.
• FIG. 19 depicts an embodiment of the method of implantation of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• In one embodiment of the present invention, an implant is provided that can be placed between the lamina through a posterior, minimally invasive surgical technique and is designed to treat degenerative disorders of the spine. Degenerative disc disease results from the natural process of aging and ultimately affects all structures of the vertebral motion segment. The degenerative process causes loads that are normally borne by the intervertebral disc to be transferred to the articular facet joints, ligaments and other soft tissues of the spine.
• The benefits of this implant are: The articular facets provide an excellent structure to which to attach an implant. They consist of very strong cortical bone, the strongest in the lumbar vertebra. There are no major nerves or vessels in the area approximate to the lateral aspect of facets, making them also a very safe point of attachment.
• Attached to hooks, a crosslink can be positioned as far anterior as is possible without actually impinging on the spinal canal.
• The implant can be inserted through two small incisions on either side of the mid-line, preserving the spinal ligament structures, including the supraspinous ligament and the interspinous ligament and permitting the implant to placed using a minimally invasive procedure.
• An embodiment of theclamp implant system20 of the invention is depicted inFIG. 1.Implant system20 provides for dynamic stabilization and motion preservation of the spine.Implant system20 includesanchor systems22,horizontal rods24,26 andvertical connector system28. Preferably, theanchor systems22 and thevertical connector system28 are made of titanium although stainless steel can also be used. Thehorizontal rods24,26 are preferably made of PEEK or other similar polymer as described below or are made of a super elastic material such as Nitinol which is an alloy of titanium and nickel. Other biocompatible materials can be used and be within the spirit and scope of the invention. Preferably, thevertical system28 is rigid while thehorizontal rods24,26 are flexible. Such asystem20 would accordingly have the horizontal rods made of PEEK or a similar polymer or a super elastic material while the vertical system is comprised of titanium or stainless steel. With such a system, the load that the spine places on the system would be absorbed by the horizontal rods causing the horizontal rods to flex while the vertical system remains rigid.
• FIG. 2 includes another embodiment of theclamp implant system20 which has an additional provision forpedicle screws38 to assist in holding thesystem20 to the spine. Elements of the embodiment ofFIGS. 1, 2 that are the same have similar numerical references.
• Generally, the clamping implant system20 (FIGS. 1, 2) includes opposingclamps30,32 that can wrap around the facets (from posterior to anterior) and hook or angle under the facets to assist in maintaining the clamps in position and resist pull-out forces. Accordingly, theclamps30,32 hook or angle around the outside of the facets and are held in place by the design of theclamps30,32. Thesystem20 also includes opposingclamps34,36 which are the similar to opposingclamps30,32. The clamps30,32,34,36 have setscrews40 as explained below to lock in thehorizontal rods24,26.
• The opposing clamps30,32, and opposingclamps34,36 as can be seen inFIGS. 3, 4,5,6,7, include ahead42 and a foot orhook44. Preferably, the clamps are of one piece construction, however, as described below, the clamps can be of several piece construction with the added advantage of more degrees of freedom in implanting the clamps in the patient. The clamps30,32,34,36 include a threaded set screw bore46 for receiving theset screw40 and a horizontal rod bore48 for receiving thehorizontal rods24,26. Thehead42 also includes a pedicle screw bore50 which is preferably unthreaded and which can receive thepedicle screw38. Thebore50 is angled in order to guide the pedicle screw into the pedicle of the spine. Thehead42, accordingly, accepts in this embodiment a horizontal rod that is transversely mounted in the head and the top mounted setscrew40. As will be discussed below, thehead42 can include a split retainer, such as a split ball retainer that has a central bore for accepting the horizontal rod, and, which split retainer can be compressed by the set screw to retain the horizontal rod in the head of the clamp. Thefoot44, points like a finger away from the head and inFIG. 3 looks much like an index finger of a right hand of a human extending from the rest of the hand, with the fingers and thumb of the rest of the hand folded down into the palm of the human hand. Stated another way there is an L-shaped junction between thehead42 and the foot orhook44. As is evident from the figures, there is in this preferred embodiment, a continuous transition from thehead42 to the foot orhook44. The inner surface of thefoot44 can be comprised of a textured surface to provide for bony ingrowth of the spine bone into thefoot44. Also the inner surface can be coated with bone growth inducing materials such as bone morphogenetic proteins or BMPs. The inner surface of thefoot44 in this preferred embodiment, is comprised of a compound surface that can accommodate the anatomical shape of the facets in order to secure the clamps about the facets. In this embodiment, thefoot44 has a first radius of curvature52 (FIG. 5) which defines the first curve of the foot along the length of the foot. Thefoot44 also includes a second radius of curvature54 (FIG. 6) which defines the second curve of the foot across the width of the foot with the first curve and the second curve in this embodiment being about perpendicular to each other. The first curve runs about vertically and the second curve runs about horizontally. In this embodiment the first radius of curvature is about 0.625 inches and the second radius of curvature is about 0.785 inches. These curves allow the foot orhook44 to optimally conform to the anatomical shape of the outside of the facet with a contour for maximum contact area. In this preferred embodiment, theclamps30,32,34,36 have about up to 40 degrees of adjustment upon implantation relative to the coronal orientation of the spine and up to about 10 degrees of adjustment upon implantation relative to the sagittal orientation of the spine.
• As can be seen inFIGS. 3, 5,6, spikes56 extend from the inner surface of the foot orhook44 of theclamps30,32,34,36. Thesespikes56 are used to also secure the foot orhook44 to the outer surface of the facets. The tips of thespikes56 are designed to cut and penetrate the facet bone and not to compress the facet bone. The spikes haveflat surfaces58 that increase lateral resistance to lateral movement of theclamps30,32,34,36, and, thus, assist in preventing the clamps from working themselves out of engagement with the facets. Thespines58 are arranged down the length of thefoot44 and across the base of thefoot44, where thefoot44 transitions to thehead42. As depicted, thespikes56 are arrayed in the foot in order to obtain optimal stability of the clamp as secured to the facets. The smooth transition between thehead42 and thefoot44 allows for, in this embodiment, continuous sagittal adjustment. This additionally allows for optimal positioning and orientation of thehorizontal rods24,26 upon implantation of thesystem20. The shape and radii of the foot and the transition from the head to the foot allow the clamp to match the anatomical variations in the junction between the transverse process and articular processes of the spine.
• FIGS. 8, 9,10, depict alternative embodiments of theclamps30,32,34,36, which have lamina articular process hooks60,62 which have ahook element64,66, respectively, that is curved to fit around the lamina and assist in holding the clamp in place in the spine. Thehooks60,62 includeadjustable arms68,70 that can adjust to the size of the lamina of the spine. As is evident fromFIGS. 8, 9,10, eacharm68,70 includes an elongate slot such asslot72 with a set screw such asset screw74, provided through saidslot72. Theset screw74 is mounted in a threaded bore in theclamp30 and thearm68 can slide relative to the rest of the clamp to adjust to the spine and then thearm68 can be locked into position by the set screw. It is evident from the depiction that clamp30 inFIGS. 8, 9,10, has a different head than the head depicted in the prior embodiment of theclamp30. In order to accommodate the laminar hooks60,62, the embodiments of theclamp30 inFIGS. 1-7 can be modified in a number of ways. For example, the top of the head of the clamp in these figures can be widened to accept thearm68 and theset screw74, and, thus, both theset screw40 and theset screw74, can be tightened from the top of the head of the clamp. Alternatively, theslot72 of the arm can be rotated by about ninety degrees so that the set screw can lock the arm to the clamp along the outside of the clamp, opposite to the surface of the clamp that has the spines and conforms to the surface of the facet. It is also to be understood that theclamps30, as they appear inFIGS. 8, 9,10, can be used by themselves to repair fractures of the pars interarticularis on the lamina of the spine.
• Thehorizontal rods24,26 can have variable lengths and diameters in order accommodate the shape of the spine. Preferably, the diameters of thehorizontal rods24,26 can be selected to adjust the dynamic stabilization, motion preservation feature afforded by these embodiments. Larger diameter, generally, will provide for a stiffer system while smaller diameters will provide for a less stiff system. For the same diameter, rods made of PEEK will provide for a stiffer system than rods made of a super elastic material. Also rods made of stainless steel will be stiffer than rods made of titanium. PEEK rods will be less stiff than rods made of titanium or stainless steel. Accordingly, the rods can be selected to give the degree of flex desired, and, thus, the degree of dynamic stabilization desired in response to dynamic loads placed on thesystem20 by the spine in motion. It is to be understood that the horizontal rods can also be bent or bowed out in order to accommodate the anatomical structures of the spine.
• Thevertical connector system28 inFIGS. 1, 2, connect adjacenthorizontal rods24,26, which horizontal rods are associated with different vertebral levels. In this embodiment thevertical connector system28 is about U-shaped. Thevertical connector system28 includes anupper half connector76 joined to alower half connector78, along thesplit line86, by a lockingscrew80. With the upper connector and the lower connector joined, thesystem28 defines a first horizontal rod capture bore82 and a second horizontal rod capture bore84. Thevertical connector systems28 are curved at the midpoint or apex of the curve in order to accommodate, and, thus, preserve the spinous processes and the associated ligaments. In this particular embodiment, the lockingscrew80 is located at the midpoint and is used to lock thesystem28 about the first and secondhorizontal rods24,26. It is to be appreciated that anothervertical connector system28 can be used with thesystem20 in order to impart additional stiffness. If twosystems28 were used, one would be closer to the first clamp30 (also clamp34) and the other would be closer to the second clamp32 (also clamp36) in order to accommodate the spinous processes and ligament structures of the spine. If twosystems28 were used, theset screws80 and the midpoint or apex of each system would be closer to the respective clamps in order to define a large opening between the twovertical connector systems20 to accommodate the spinous processes and associated ligaments. If desired, the vertical connector system can be made of a less stiff biocompatible material as discussed herein, should additional flexibility be desired.
• Referring toFIGS. 11, 12, another embodiment of the present invention is an implant, generally denoted as100, with afirst hook102, asecond hook104 and a cross-link orhorizontal rod106 coupled to the first andsecond hooks102 and104. The first andsecond hooks102 and104 have geometries that conform to a lateral border of a superior articular facet.
• In various embodiments, the implant (i) engages the laminae to stabilize the spine in a dynamic manner, and (ii) can be made stiff enough to rigidly stabilize the spine as an aid to a fusion.
• In one embodiment, the first and second hooks have radii to provide conformance with the spine. As discussed below, the first andsecond hooks102 and104 can be symmetrical in a sagittal orientation and free to rotate around a coronal axis. The first andsecond hooks102 and104, can provide an ability to adjust to, and be affixed to, the articular facets. In one embodiment, the first andsecond hooks102 and104 include at least one member to engage with the articular facet. This member can be a fin, stud, spike, and the like, as discussed above with respect to other embodiments.
• Further as seen inFIGS. 11, 12, the hooks include a ventral or lowerhooked section108 and an dorsal orupper head section110. The hookedsection108 can conform to the spine as described herein and thehead section110 can mount the cross-link orhorizontal rod106. Thehead sections110 can include atop bore112 that is threaded and can accept a set screw to lock thehorizontal rod106 in place. Thehead section110 also includes either (1) arecess114 that can receive an end of thehorizontal rod106 such that the set screw can lock therod106 in place, or (2) abore116 through which therod106 can be received so that the spacing between thehooks102,104 can be adjusted. Once therod106 is received in thebore116 and the spacing of thehooks102,104 is adjusted by sliding thehook102 on therod106, a set screw can be used to lock therod106 in place. It is to be understood, that procedurally and preferably, thehooks102,104 are placed adjacent to the facets and the length between the hooks is adjusted prior to the tightening of the set screws to lock therod106 and thehooks102,106 together. Alternatively, therod106 can be telescoping such that afirst portion118 of therod106 can slide into asecond portion120 of therod106 in order to adjust the length of therod106. If desired, an additional set screw can be mounted on thesecond portion120 of therod106 to lock the first portion to the second portion of the rod.
• As illustrated inFIGS. 13, 14,15,16,17A,17B the first and second hooks such ashook102 can have a ventral orlower section108 and dorsal orupper sections110 that can move and in this embodiment, rotate relative to each other. The ventral or lowerhooked sections108 has a freedom of motion about an axial plane to allow for variations in anatomy of the articular facet. The dorsal orupper section110 accepts thehorizontal rod106. The dorsal orupper section110, as previously discussed, includes a recess or bore to accept thehorizontal rod106. In this embodiment, thehorizontal rod106 rests in the saddle or head orupper portion110 and a set screw locks the horizontal rod in place in the head.
• As depicted inFIGS. 15, 16,17A,17B, the lowerhooked portion108 can rotate relative to theupper head portion110. The rotation occurs atsplit line122. Preferably, theupper portion110 can snap into thelower portion108 and be captured under a lip of the cylindrical recess of thelower portion108. Thus, theupper portion110 can rotate in therecess122 of thelower portion108 at thesplit line122. If desired the rotation can be limited by alimit rod126 that is mounted on thelower portion108 and projects through thecylindrical recess122. The upper portion includes anenlarged bore128 through which thelimit rod126 is received, when the upper portion is assembled with the lower portion of thehook102. In a preferred embodiment, the limit rod allows the upper portion of thehook102 to rotate about 15 degrees on each side of a central axis, for a total of about 30 degrees of rotation. It is to be understood that 360 degrees of rotation is possible with thelimit rod126 removed, and also that changes to the size of thebore128 can be made to adjust the degree of rotation of the upper portion to the lower portion or thehook102. Accordingly, the first andsecond hooks102 and104 illustrated inFIGS. 15, 16 are adjustable and can be re-adjusted after thehooks102 and104 are initially implanted.
• In the embodiment ofFIGS. 18A, 18B, thehorizontal rod106 is configured to be fixed with compression applied by a set screw received thoughbore112 in head1110. The set screw can fix an orientation of the ventral orupper section108 of thehooks102 andhorizontal rod106, as well as, lock the upper portion of the hook to thelower portion108 at the same time. In this embodiment, thehorizontal rod106 can be received in acompression block130 that is received in thebore112. Generally, the compression block is cylindrical and can be comprised of two pieces which mate with facing recesses that can receive thehorizontal rod106. Alternatively, the compression block can be a one piece construction with a slit. In either embodiment, the set screw, when turned down in thebore112, causes thecompression block130 to compress about, and without causing damage to, thehorizontal rod106 to lock the rod in place.
• In one embodiment, thehorizontal rod106 has a flat surface that conforms to a laminar anatomy or a contoured surface to match the laminar anatomy.
• In another embodiment of the present invention, theimplant100 includes an artificial ligament attached to thehorizontal rod106. The artificial ligament can be looped around the superior spinous process and then re-attached to thehorizontal rod106. The artificial ligament provides a limit to flexion and increases rigidity of the implant. The artificial ligament can be made of a biocompatible material.
• In another embodiment of the present invention, an implant assembly is provided that has first andsecond implants100. The first andsecond implants100 can be coupled by at least one vertically running rod configured to provide rigid stability as an aid in fusing the spine.
• It is to be understood that the various features, designs and functions of the various embodiments can be selected for and or combined in other embodiments as is advantageous.
• With respect to the method of implantation (FIG. 19), the hooks can be placed adjacent to the facets, and then the position of the horizontal rod relative to the hooks can be adjusted. The hooks can be pressed into the bone and the set screws can be tightened to hold the hooks and horizontal rod in place. With two such configurations in the spine, the configurations can be connected with vertical rods and the like. Alternatively, the implant, including the hooks and the horizontal rod loosely coupled together, can be inserted as an assembly and then once positioned, the set screws can be tightened to lock thesystem100 in place in the spine.
• Materials for use with the implant include the following:
• As indicated above, the implant can be made of titanium, stainless steel, super elastic materials and/or polymers such as PEEK.
• In addition to Nitinol or nickel-titanium (NiTi) other super elastic materials include copper-zinc-aluminum and copper-aluminum-nickel. However for biocompatibility the nickel-titanium is the preferred material.
• Other suitable material include, by way of example, only polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetherketone (PEK), polyetherketoneetherketoneketone (PEKEKK), and polyetheretherketoneketone (PEEKK). Still, more specifically, the material can be PEEK 450G, which is an unfilled PEEK approved for medical implantation available from Victrex of Lancashire, Great Britain. (Victrex is located at www.matweb.com or see Boedeker www.boedeker.com). Other sources of this material include Gharda located in Panoli, India (www.ghardapolymers.com).
• Preferably, the horizontal rods are made of PEEK or a similar polymer or a super elastic material, which materials are flexible, or the rods are made of another flexible material, and the anchors and the vertical systems are made of titanium or stainless steel which are stiff or made of another stiff material.
• Further, it should be apparent to those skilled in the art that various changes in form and details of the invention as shown and described may be made. It is intended that such changes be included within the spirit and scope of the claims appended hereto. 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 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. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims (19)

1. A method of implanting an implant in a spine including the steps of:

locating a first hook relative to a part of the spine;

locating a second hook relative to a part of the spine;

locating a connector between the first hook and the second hook;

adjusting the first hook, the second hook and the connector to fit relative to the spine; and

locking the connector to the first hook and the second hook in order to lock the implant in the spine.

2. The method ofclaim 1 wherein

the first locating step locates the first hook adjacent to a facet of the spine; and

the second locating step locates the second hook adjacent to a facet of the spine and locking step locks the implant about the opposite facets on lateral sides of the spine.

3. The method ofclaim 1 including the step of causing spikes, fins or stubs of at least one of the first and second hooks to penetrate the bone of the spine to assist in securing the implant to the spine.

4. The method ofclaim 1 wherein said first locating step locates the first hook about and under a first facet of a vertebra of the spine, and the second locating step locates the second hook about and under a second facet of the spine on the same vertebra.

5. The method ofclaim 1 wherein said first locating step locates the first hook about and under a first facet of a vertebra of the spine on one side of a spinous process of the same vertebra, and the second locating step locates the second hook about and under a second facet of the spine on an opposite side of the same spinous process on the same vertebra.

6. The method ofclaim 1 including the step of selecting a connector that is flexible and can support and absorb and be deflected with respect to the load that the spine places on the connector.

7. The method ofclaim 1 including the step of selecting a connector make of PEEK.

8. The method ofclaim 1 including selecting a first hook that conforms to the shape of a facet and selecting a second hook that conforms to the shape of a facet.

9. The method ofclaim 1 including the steps of:

selecting the connector to be a flexible rod;

and said first locking step locks the implant in the spine relative to a first vertebra;

locating a third hook relative to a part of the spine;

locating a fourth hook relative to a part of the spine;

selecting anther connector to be a flexible rod;

locating said another connector between the third hook and the fourth hook;

adjusting the third hook, the fourth hook and the another connector to fit relative to a first vertebra of the spine; and

locking the connector to the third hook and the fourth hook in order to lock the implant in the spine relative to the second vertebra; and

connecting a rigid vertical connector between the connector and the another connector so that any spinal load that the implant carries causes a deflection of one or both of the connector and the another connector.

10. A method of implanting an implant in the spine comprising the steps of:

selecting a first hook that conforms to the outer lateral side of a facet on a first vertebra and locating the first hook adjacent to the lateral side of the facet;

selecting a second hook that conforms to the outer lateral side of an opposite facet on the same first vertebra and locating the second hook adjacent to the lateral side of the opposite facet;

place a horizontal rod through the first hook and through the second hook so that the horizontal rod is about parallel to the first vertebra;

adjusting the position of the first hook relative to the facet;

adjusting the position of the second hook relative to the opposite facet; and

securing the first hook to the rod and securing the second hook to the rod in order to secure the implant to the spine.

11. The method ofclaim 10 including the step of causing spikes, fins or stubs of at least one of the first and second hooks to penetrate the bone of the spine to assist in securing the implant to the spine.

12. The method ofclaim 10 wherein said first locating step locates the first hook about and under a first facet of a vertebra of the spine, and the second locating step locates the second hook about and under a second facet of the spine on the same vertebra.

13. The method ofclaim 10 wherein said first locating step locates the first hook about and under a first facet of a vertebra of the spine on one side of a spinous process of the same vertebra, and the second locating step locates the second hook about and under a second facet of the spine on an opposite side of the same spinous process on the same vertebra.

14. The method ofclaim 10 including the step of selecting a horizontal rod that is flexible and can support and absorb and be deflected with respect to the load that the spine places on the connector.

15. The method ofclaim 10 including the step of selecting a horizontal rod that is make of PEEK.

16. A method to implant an implant in a spine comprising the steps of:

placing a first anchor in a first vertebra on one side of a spinous process;

placing a second anchor in the first vertebra on the opposite side of a spinous process;

in any order connecting a flexible horizontal rod to the first anchor and to the second anchor and positioning the flexible horizontal rod to be about parallel to the first vertebra as connected to and between the first and second anchors, wherein said connecting step causes the flexible horizontal rod to be received through a first head of the first anchor and causes the flexible horizontal rod to be received through a second head the second anchor;

locking the first anchor to the flexible horizontal rod and locking the second anchor to the flexible horizontal rod in order to secure the implant in the spine and to allow the horizontal rod to absorb and deflect with respect to motion of the spine.

17. The method ofclaim 16 including the step of selecting a horizontal rod that is flexible and can support and absorb and be deflected with respect to the load that the spine places on the implant.

18. The method ofclaim 16 including the step of selecting a horizontal rod that is make of PEEK.

19. The method ofclaim 16 including the steps of:

placing a third anchor in a second vertebra on one side of another spinous process;

placing a fourth anchor in the second vertebra on the opposite side of the another spinous process;

in any order connecting another flexible horizontal rod to the third anchor and to the fourth anchor and positioning the another flexible horizontal rod to be about parallel to the second vertebra as connected to and between the third and fourth anchors, wherein said connecting step causes the another flexible horizontal rod to be received through a third head of the third anchor and causes the flexible horizontal rod to be received through a fourth head the fourth anchor;

locking the third anchor to the another flexible horizontal rod and locking the fourth anchor to the another flexible horizontal rod in order to secure the implant in the spine; and

in any order securing a rigid vertical rod to the flexible horizontal rod and the another flexible horizontal rod to allow the horizontal rods to absorb and deflect with respect to motion of the spine.

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