Method and apparatus for intervertebral disc support and repair

[0001] The present invention relates to intervertebral discs and, more particularly, to devices to provide nucleus and annulus support and repair.

[0002] Many people experience back pain. Back pain, however, is a symptom that can occur from a number of different causes, such as, for example, arthritic facets, degenerating discs, pinched nerves, or the like. Determining the source of the back pain is often one of the challenges in treating the symptom.

[0003] Some back pain is caused by degeneration or other deformity of the intervertebral disc (“diseased disc”). Conventionally, surgeons treat diseased discs by surgically removing the diseased disc and inserting an implant in the space vacated by the diseased disc, which implant may be bone or other biocompatible implants. The adjacent vertebrae are then immobilized relative to one another. Eventually, the adjacent vertebrae grow into one solid piece of bone.

[0004] Removing the disc and fusing the vertebrae together generally relieves the back pain. However, the fused segments decrease movement and limits the range of motion of the spine. Moreover, fusing the segments together places additional stress on adjacent vertebral segments. The increased stress may increase or initiate degeneration of the adjacent vertebral segments. Thus, for less severe diseased discs, the conventional treatment of fusion maybe an overly aggressive or traumatic solution.

[0005] Less severe diseased discs still subject the person to some back pain. Typically, the back pain can be associated with inflammation or instability of the disc. Inflammation can arise from numerous factors, including, for example, the proteins in the disc space or disc nucleus. Instability can also arise from numerous factors, including, for example, when the disc annulus wears down, is damaged, or is compromised (through a hole, tear, or the like), the ability of the disc annulus to resist movement results in instability and may cause pain. Dehydration of the disc also can cause back pain or the like.

[0006] In these less severe cases, the treatment may include surgical alternatives. Surgical alternatives include diet, weight control, exercise, stretching, medication, and the like. While helpful, the surgical alternatives frequently only delay the degenerative process and may only partially relieve pain. Thus, it would be desirous to provide other methods and apparatuses to repair, support, or otherwise treat the intervertebral disc.

[0007] The present invention provides an intervertebral disc device. The device comprises an annulus support having an exterior surface to contact a disc annulus and define an interior volume surrounding a disc nucleus and a disc nucleus support residing in the interior volume. The disc nucleus support comprises an elongated wire and at least one expandable material affixed to the elongated wire, wherein the expandable material is expandable in the disc nucleus.

[0008] The present invention also provides for a disc annulus device comprising an elongated, flexible material substantially sized to conform to an interior surface of a disc annulus. The disc annulus device also comprises a disc annulus closure device coupled to the elongated, flexible material to close an insertion point in the disc annulus.

[0009] The present invention also provides for a disc nucleus device comprising an elongated, flexible wire. At least one expandable material affixed to the elongated, flexible wire for insertion into a disc nucleus, whereby the expandable material expands and provides support between a superior vertebrae and an inferior vertebrae.

[0010] The foregoing and other features, utilities and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings.

[0022] The present invention will be described with reference to the figures. Referring first to FIG. 1, a vertebral segment. 100 is shown. Vertebral segment 100 includes a superior vertebral body 102 and an inferior vertebral body 104 separated by an intervertebral disc 106. Intervertebral disc 106 comprises a disc annulus 108′ containing a disc nucleus 110 (which is best seen in FIG. 2). Referring now to FIG. 2, a cross sectional view of intervertebral disc 106 is shown. Disc 106 includes disc annulus 108 and disc nucleus 110. Disc 106 is shown with some degeneration 202 in disc annulus 108. Degeneration 202 could be any number of anatomical conditions, such as, for example, a tear, a bulge, inflammation, or the like.

[0023] Conventional treatments to decrease or remove pain caused by degeneration 202 include, medications, therapy, and the like. Medications, therapy, and the like, while beneficial for a significant number of people, do not ease the pain for everyone. Many people require additional surgical treatment to ease the pain. The conventional treatment, as mentioned above, is fusing superior vertebral body 102 and inferior vertebral body 104 producing a single bone segment without any intervertebral disc 106. This treatment has some significant drawbacks. Other less conventional treatments include cauterizing the natural disc annulus, replacement of the intervertebral disc with an artificial disc, replacing the disc nucleus with a hydrogel, and the like. Each of these procedures, while addressing some of the drawbacks associated with fusion, have drawbacks as well. For example, artificial discs have significant failure rates. Cauterizing the disc annulus reduces the flexibility of the disc. Hydrogels may cause bulging about the annulus or become displaced from the disc space. Other drawbacks also exist.

[0024] Referring now to FIG. 3, a perspective view of disc 106 with annulus support 302 is shown. Disc annulus 108 includes degeneration 202. Also shown in FIG. 3, is an annulus support 302. Annulus support 302 as shown is a loop of material internal to disc 106. Disc nucleus 110 (not specifically shown in FIG. 3) tends to push annulus support 302 against disc annulus 1.08. Annulus support 302 provides structural stability to disc annulus as well as cover degeneration 202, which inhibits further degradation of disc 106. Optionally, a scarring material 304, such as, for example, cotton or the like may reside between annulus support 302 and disc annulus 108 to promote fibrous growth, which would facilitate disc repair. Scarring material 304 could be arranged about the entire annulus support 302 as shown or localized to the area with degradation 202.

[0025] Annulus support 302 may be sized to extend from superior vertebral body 102 to inferior vertebral body 104 as shown. Alternatively, annulus support 302 may be sized to correspond to degeneration 202. Still alternatively, annulus support 302 may be a relatively small wire to deliver scarring material 304 to degeneration 202. Scarring material 304 promotes fibrous growth to repair disc annulus 108.

[0026] Referring now to FIG. 4, a method of delivering annulus support 302 is shown. A delivery mechanism 400 is inserted through disc annulus 108 into disc nucleus 110. Delivery mechanism 400 may be a needle, a dilator, a catheter, or the like. Annulus support 302 is threaded through delivery mechanism 400. Annulus support 302 is threaded into disc nucleus 110 until it bumps or contacts an interior surface 402 of disc annulus 108. Annulus support 302 is further threaded where annulus support 302 bends along the interior surface 402 until it completely travels interior surface 402. Annulus support 302 is either fully threaded at this point, detached by any conventional detachment device, or cut and packed into disc nucleus 110. Delivery mechanism 400 is: removed. To the extent a scarring material 304 is not otherwise provided, a tip 404 of annulus support 302 may be provided with a scarring material 304 such that when fully wrapped about interior surface 402, scarring material 304 is generally aligned with the insertion point of delivery mechanism 400 to promote fibrous growth and healing of the insertion point.

[0027] As one of ordinary skill in the art will now appreciate on reading the above, annulus support 302 should provide sufficient structural support to facilitate disc 106 functionality, but be sufficiently resilient to be directed by disc annulus 108 during insertion. One such material could be a shaped memory alloy (“SMA”), such as, for example, NiTiol. SMAs provide acceptable materials because they have both elastic and inelastic phases. Other polymers, resins, metals, alloys, and the like also could be used. To facilitate wrapping, tip 404 may be beveled or shaped to help guide annulus support 302 around interior surface 402. Generally, to facilitate implantation, support 302 should be an expandable material. However, non-expandable materials are acceptable, but will require additional surgical trauma.

[0028] Referring to FIG. 5, a tail 500 of annulus support 302 is shown adjacent interior surface 402 of disc annulus 108. Tail 500 is shown in a compact insertion format 500c instead of an expanded format as shown by 302. Tail 500 may include scarring material 502 such that material 502 is aligned with the insertion point of delivery mechanism 400. Scarring material 502 on tail 500 can be used in conjunction with or in the alternative to scarring material 304 on tip 404. The insertion point may be covered by a separate closure device 600, shown in FIGS. 6a and 6b. As shown in FIG. 6a, closure device 600 is inserted in a collapsed or compressed package, 600c about insertion point 602 in disc annulus 108. As shown in 6b, closure device 600 has expanded 600e to be larger than insertion point 602 covering the insertion. Closure device 600 may be held about insertion point 602 by annulus support 302 or by an adhesive 604, which could comprise a scarring material 304 to promote fibrous growth. Closure device 600 could be a stand alone device, connectable or integrated with annulus support 302.

[0029] Referring back to FIG. 3, annulus support 302 provides support for disc annulus 108 and could also deliver biologic or pharmaceuticals (generally referred to as either biologics or pharmaceuticals) to either disc annulus 108 or disc nucleus 110. For example, inner surface 306 of annulus support 302 could be loaded with biologics 308 designed to assist in re-growth or repair of disc nucleus material 110. Moreover, biologics 308 could be contained on outer surface 308 or loaded in scarring material 304 if used. Types of biologics that could be delivered include, for example, FGF-beta, BMP-12, OP-1, TGF-betal, cultured autologous annular fibrosis or nuclear pulposes cells or other biologics that aid the repair of the annulus or the nucleus, or the like.

[0030] Referring now to FIG. 7, disc 106 (shown in phantom) is shown with a disc nucleus support 700. Disc nucleus support 700 could be used to augment or replace the biological disc nucleus 110. Moreover, disc nucleus support 700 could be used separately or in conjunction with an annulus support. Disc nucleus support 700 includes a wire 702 carrying several capsules 704 of expandable material. The number of capsules 704 will depend, in part, on the size of the disc space as well as whether the entire disc nucleus is being replaced or whether the disc nucleus is being augmented. Spacers 706 (of which only one is shown for convenience), such as coils wrapped about wire 702, may be placed between capsules to maintain separation for proper expansion of the capsules.

[0031] Wire 702 may be any biocompatible wire. Wire 702 could be constructed from titanium, platinum, SMAs, plastics, composites, resins, polymers, or the like. Capsules 704 can be any biocompatible expandable material. For example, capsules 704 could be hydrophilic foam or gel material that swells. One such material is described in U.S. Pat. No. 5,570,585, issued to Park et al., the disclosure of which is incorporated herein by reference as if set out in full. Other suitable materials are described in U.S. Pat. No. 6,602,261, issued to Creene, Jr. et al., the disclosure of which is incorporated herein by reference as if set out in full. Other suitable, materials include polymers, resins, composites, SMAs, spring metals, and other expandable biocompatible materials. Ideally, the amount, of expansion is controllable and/or predictable so a sufficient number of capsules 704 can be implanted into disc nucleus 110 to provide sufficient support to alleviate pain. For, example capsules 704 may be as described in U.S. Pat. No. 6,878,384, issued to Curise et al., which is incorporated herein by reference as if set out in full, described materials that swell or expand in a predictable manner.

[0032] Referring now to FIG. 8a, another nucleus support 800 is provided. Nucleus support 800 provides a wire 802 or filament. Expandable material 804 extends over substantially the entire wire 802. Optionally, an over coil 806 for expansion control, expansion direction, trackability, or durability is provided. In the unexpanded state, over coil 806 resides a distance from an outer surface 808 of expandable material 804. Over coil 806 provides a number of gaps 810 to allow limited or directed expansion of expandable material 804. FIG. 8b shows nucleus support 800 in the expanded state and FIG. 8a shows nucleus support 800 in the non-expanded state.

[0033] Referring now to FIG. 9, a biologics delivery mechanism 900 is provided. Biologics delivery mechanism 900 includes a wire 902 with one or more capsules 904 including biologics or the like, as described above. Biologics delivery mechanism 900 optionally may include capsules 704 or expandable material 804 interspersed with the one or more biologics capsules 904 such that biologics delivery mechanism 900 also functions as a nucleus support mechanism. Optionally, biologics mechanism 900 may have spacers, such as spacers 706 described above, or an expansion control attachment 806.

[0034] Devices 700, 800, and 900 could be delivered to the disc nucleus 110 in a manner similar to annulus support 302. The expandable material should sufficiently impinge on the insertion point to sufficient close the insertion point, but a closure mechanism such as closure device 600 could also be used. Closure device 600 may be seated against the disc annulus by the expandable material.

[0035] Wires 702, 802, and 902 should be sufficiently elastic to be able to pack into disc nucleus without piercing disc annulus 108. They could be comprised from, for example, SMAs, such as, nitinol, polymers, resins, platinum, titanium, or the like.

[0036] While the invention has been particularly shown and described with reference to some embodiment thereof, it will be understood by those skilled in the art that various other changes in the form and details may be made, without departing from the spirit and scope of the invention.