AU2003228821B2 - Method and apparatus for spine joint replacement - Google Patents

Description

WO 2004/098465 PCT/US2003/013764 METHOD AND APPARATUS FOR SPINE JOINT REPLACEMENT Reference To Pending Prior Patent Applicatidns This patent application claims benefit of: 5 (1) pending prior U.S. Provisional Patent Application Serial No. 60/273,031, filed 03/02/01 by E. Marlowe Goble et al. for TOTAL SPINE JOINT REPLACEMENT (Attorney's Docket No. MED-3 PROV); (2) pending prior U.S. Patent Application Serial 10 No. 09/726,169, filed 11/29/00 by E. Marlowe Goble et al. for FACET JOINT REPLACEMENT (Attorney's Docket No. MED-1); (3) pending prior U.S. Patent Application Serial No. 09/736,103, filed 12/13/00 by E. Marlowd Goble et 15 al. for MULTIPLE FACET JOINT REPLACEMENT (Attorney's Docket No. MED-2); and (4) pending prior U.S. Patent Application Serial No. 09/797,309, filed 03/01/01 by T. Wade Fllin et al. for PROSTHESIS FOR THE REPLACEMENT OF A POS ERIOR 20 ELEMENT OF A VERTEBRA (Attorney's Docket No. MED-4). The four above-identified patent applications are hereby incorporated herein by reference.

WO 2004/098465 PCT/US2003/013764 -2 Field Of The Invention This invention relates to surgical devices and methods in general, and more particularly tc surgical devices and methods for replacing a damaged, diseased, 5 or otherwise painful spinal joint. Background Of The Invention Traumatic, inflammatory, metabolic, syriovial, neoplastic and degenerative disorders of thl spine can 10 produce debilitating pain that can have severe socioeconomic and psychological effects. One of the most common surgical interv ntions today is arthrodesis, or spine fusion, in w ich two or more adjacent vertebral bodies are fused together in 15 order to alleviate pain associated with the disc(s) located between those vertebral bodies. Approximately 300,000 such procedures are performed annuaJIly in the United States alone. Clinical success varies considerably, depending upon technique and indications, 20 and consideration must be given to the concomitant risks and complications. For example, while spine fusion genera ly helps to eliminate certain types of pain, it has alsc been shown WO 2004/098465 PCT/US2003/013764 -3 to decrease function by limiting the range df motion for patients in flexion, extension, rotation and lateral bending. Furthermore, it is believed that spine fusion creates increased stresses on and, 5 therefore, accelerated degeneration of) adjacent non-fused motion segments. Additionally, pseudoarthrosis, resulting from an incomplete or ineffective fusion, may reduce or even totally eliminate the desired pain relief for the paItient. 10 Also, the fusion device(s) used to effect fusion, whether artificial or biological, may migrate out of the fusion site, thereby creating significar t new problems for the patient. Recently, attempts have been made to r create the 15 natural biomechanics of the spine through tie use of an artificial disc. Artificial discs are interded to restore articulation between vertebral bodies so as to recreate the full range of motion normally allowed by the elastic properties of the natural disc, which 20 directly connects two opposing vertebral bodies. Various artificial discs are described by Stefee et al. in U.S. Pat. No. 5,071,437; Gill et al. in U.S. Pat. No. 6,113,637; Bryan et al. in U.S. Pat. No. 6,001,130; WO 2004/098465 PCT/US2003/013764 -4 Hedman et al. in U.S. Patent No. 4,759,769; Ray in U.S. Patent No. 5,527,312; Ray et al. in U.S~. Pat. 5,824,093; Buttner-Janz in U.S. Patent No. I,401,269; and Serhan et al. in U.S. Patent No. 5,824,094; all 5 which documents are hereby incorporated herein by reference. Still other artificial discs arq known in the art. Unfortunately, however, artificial disds alone do not adequately address all of the mechanics of the 10 motion of the spinal column. In addition to the intervertebral disc, posterior elements called the facet joints help to support axial, torsional and shear loads that act on the spinal column. Furthermore, the facet joints are ciarthroidal 15 joints that provide both sliding articulation and load transmission features. However, the facet Joints can also be a significant source of spinal diso ders and, in many cases, debilitating pain. For exam le, a patient may suffer from arthritic facet joi ts, severe 20 facet joint tropism or otherwise deformed facet joints, facet joint injuries, etc. There is currently a lack of good interventions for facet joint disorders. Facetectomy, or the removal of the facet joints, may WO 2004/098465 PCT/US2003/013764 provide some relief, but it is also believe to produce significant decreases in the stiffness of tfe spinal column (i.e., hypermobility) in all planes of motion: flexion and extension, lateral bending, and rotation. 5 Furthermore, problems with the facet joints can also complicate treatments associated with other portions of the spine. By way of example, contraindications for artificial discs include arthritic facet jo nts, absent facet joints, severe facet joint tropism or otherwise 10 deformed facet joints. A superior vertebra with its inferior acets, an inferior vertebra with its superior facets, the intervertebral disc, and seven spinal ligam nts together comprise a spinal motion segment o functional 15 spine unit. The spinal motion segment provides complex motion along three orthogonal axis, both in rotation (lateral bending, flexion and extension, an axial rotation) and in translation (anterior-post rior, medial-lateral, and cranial-caudal). Furth rmore, the 20 spinal motion segment provides physiological limits and stiffnesses in each rotational and translational direction to create a stable and strong column structure to support physiological loads.

WO 2004/098465 PCT/US2003/013764 -6 As mentioned above, compromised facet joints are a contraindication for disc replacement, due to the inability of the artificial disc (when used with compromised facet joints, or when used with missing 5 facet joints) to properly restore the natural biomechanics of the spinal motion segment. It would therefore be an improvement in the art to provide a spine implant system that facilitates concurrent replacement of the intervertebral disc and sacet joints 10 where both have been compromised due to disease or trauma. U.S. Patent No. Re. 36,758 (Fitz) discloses an artificial facet joint where the inferior fa cet, the mating superior facet, or both, are covered with a cap. 15 This cap requires no preparation of the bone or articular surfaces; it covers and, therefor , preserves the bony and articular structure. The capping of the facet has several potential disadvantages, however. If the facet joint is osteoarthritic, a cap wil1 not 20 remove the source of the pain. Additionally, at least in the case of surface replacements for ost oarthritic femoral heads, the capping of articular bon ends has proven to lead to clinical failure by means of WO 2004/098465 PCT/US2003/013764 -7 mechanical loosening. This clinical failur 1 is hypothesized to be a sequela of disrupting the periosteum and ligamentum teres femoris, both serving a nutrition delivery role to the femoral head, thereby 5 leading to avascular necrosis of the bony support structure for the surface replacement. It is possible that corresponding problems could develop from capping the facet. Another potential disadvantage cf facet capping is that in order to accommodate the wide 10 variability in anatomical morphology of the facets, not only between individuals but also between levels within the spinal column, a very wide range of cap sizes and shapes is required. U.S. Patent No. 6,132,464 (Martin) discloses a 15 spinal facet joint prosthesis that is supported on the lamina (which is sometimes also referred to as the posterior arch). Extending from this suppo t structure are inferior and/or superior blades that replace the cartilage at the facet joint. Like the design of the 20 aforementioned U.S. Patent No. Re. 36,758, he prosthesis of U.S. Patent No. 6,132,464 gen rally preserves existing bony structures and there fore does not address pathologies which affect the bore of the WO 2004/098465 PCT/US2003/013764 -8 facets in addition to affecting the associa ed cartilage. Furthermore, the prosthesis of U.S. Patent No. 6,132,464 requires a secure mating betwIen the prosthesis and the lamina. However, the lanlina is a 5 very complex and highly variable anatomical surface. As a result, in practice, it is very difficlt to design a prosthesis that provides reproducible positioning against the lamina so as to correctly locate the cartilage-replacing blades for the facet 10 joints. Another approach to surgical intervention for spinal facets is disclosed in International Patent Publication No. W09848717A1 (Villaret et al.). While this publication teaches the replacement of spinal 15 facets, the replacement is interlocked in a manner so as to immobilize the joint. Thus it will be seen that previous attempts to provide facet joint replacement have proven inadequate. In some circumstances, additional structures of a 20 vertebra beside the facets may have been compromised by disease or trauma. For example, the lamina, the spinous process and/or the two transverse processes may have been compromised by disease or trauma. In such a WO 2004/098465 PCT/US2003/013764 -9 circumstance, it would be useful to have a prosthesis which would allow the replacement of the sane. Summary Of The Invention 5 One object of the present invention is to provide a spine joint reconstruction assembly that replaces the intervertebral disc and one or more of the facet joints in order to restore the natural biomechanic of a spinal motion segment. 10 Another object of the present invention is to provide a method for reconstructing the spire joint by replacing the intervertebral disc and one oi more of the facet joints in order to restore the na ural biomechanics of a spinal motion segment. 15 Still another object of the present invention is to provide a kit for the reconstruction of m ultiple spine joints to replace intervertebral discs and facet joints in order to restore the natural biomEchanics of a spinal motion segment. 20 In accordance with the present invention, the .preferred embodiment, the intervertebral disc is excised and replaced with an artificial dis This artificial disc may be a device such as is escribed by WO 2004/098465 PCT/US2003/013764 - 10 Stefee et al. in U.S. Pat. No. 5,071,437; Gill et al. in U.S. Pat. No. 6,113,637; Bryan et al. in U.S. Pat. No. 6,001,130; Hedman et al. in U.S. Patent No. 4,759,769; Ray in U.S. Patent No. 5,527,312; Ray et al. 5 in U.S. Pat. 5,824,093; Buttner-Janz in U.S. Patent No. 5,401,269; and Serhan et al. in U.S. Patent No. 5,824,094; all which documents are hereby incorporated herein by reference. Alternatively, the artificial disc may be some other artificial disc of the sort 10 known in the art. In addition to replacing the intervert bral disc, at least one of the facet joints is replace in accordance with the apparatus and methods described hereinafter. Alternatively, the facet join s may be 15 replaced as described by Fitz in U.S. Pat. o. Re. 36,758; Martin in U.S. Pat. No. 6,132,464; and/or Villaret et al. in International Patent Publication No. WO 9848717A1, which documents are hereby inc orporated herein by reference. Or one or more of the facet 20 joints may be replaced by other apparatus arid methods known in the art. The present invention has several adva tages over the prior art. For one thing, the present invention WO 2004/098465 PCT/US2003/013764 - 11 can provide a complete replacement of all o the articulation surfaces of a spine motion segment: the intervertebral disc and the facet joints. Proper disc height is restored while degenerated facet Joints and 5 the underlying painful bone is replaced. The prosthetic disc and prosthetic facet joints work together to reproduce the desired physiological range of motion and to provide low friction articulations, so that adjacent motion segments are returned to 10 physiological levels of stress and strain. Furthermore, osteophytic growth can be concurrently removed, and the artificial disc and facet joint prosthesis together reestablish intervertebral and central foraminal spaces to ensure decompression of any 15 nerve structure. Thus, all sources of pain, such as pain associated with osteoarthritis, instability, and nerve compression, are removed while restoring full function of the spine motion segment. 20 Brief Description Of The Drawings These and other objects and features o the present invention will be more fully disclo ed or rendered obvious by the following detailed description WO 2004/098465 PCT/US2003/013764 - 12 of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein: 5 Fig. 1 is a perspective view of a portion of the spine; Fig. 2 is a dorsal view of the portion of the spine shown in Fig. 1; Fig. 3 is a lateral view of a spine joint 10 reconstructed in accordance with one aspect of the present invention; Fig. 4 is a dorsal view of the facet j Iint shown in Fig. 3; Fig. 5 is a perspective view of the implanted left 15 inferior facet prosthesis shown in Figs. 3 and 4; Fig. 6 is a perspective view of the left inferior facet prosthesis shown in Figs. 3 and 4; Fig. 7 is a cranial view of the implanted left superior facet prosthesis shown in Figs. 3 End 4; 20 Fig. 8 is a perspective view of the lelt superior facet prosthesis shown in Figs. 3 and 4; Fig. 9 is a perspective view of an alternate implanted left superior facet prosthesis; WO 2004/098465 PCT/US2003/013764 - 13 Fig. 10 is a perspective view of an alt-ernate left superior facet prosthesis; Fig. 11 is a lateral view of an alternative reconstructed spine joint; 5 Fig. 12 is a dorsal view of an alternative reconstructed spine joint; Fig. 13 is a perspective view of the implanted left inferior facet prosthesis shown in FigJ. 11 and 12; 10 Fig. 14 is a perspective view of the alternative left inferior facet prosthesis shown in Fig . 11 and 12; Fig. 15 is a cranial view of the alternative implanted left superior facet prosthesis shcwn in Figs. 15 11 and 12; Fig. 16 is a perspective view of the alternative left superior facet prosthesis shown in Fig . 11 and 12; Fig. 17 is a perspective view of an alternate 20 bearing surface for the superior facet prosthesis shown in Fig. 16; Fig. 18 is a perspective view of a spiige motion segment; WO 2004/098465 PCT/US2003/013764 - 14 Fig. 19 is a dorsal view of a bilatera] facet joint reconstructed in accordance with the Iresent invention; Fig. 20 is a lateral view of the bilat ral facet 5 joint prosthesis shown in Fig. 19; Fig. 21 is a dorsal view of the implanted inferior bilateral facet prosthesis shown in Figs. 1S and 20; Fig. 22 is an inferior view of the imp anted inferior bilateral facet prosthesis shown i Figs. 19 10 and 20; Fig. 23 is a ventral view of the inferior bilateral facet prosthesis shown in Figs. 2] and 22; Fig. 24 is a dorsal view of the implanted superior bilateral facet prosthesis shown in Figs. 1S and 20; 15 Fig. 25 is a superior view of the implanted superior bilateral facet prosthesis shown ir Figs. 19 and 20; Fig. 26 is a ventral view of the superior bilateral facet prosthesis shown in Figs. 24 and 25; 20 Fig. 27 is a perspective view of an alternative embodiment of the.superior bilateral facet rosthesis shown in Figs. 24 and 25; WO 2004/098465 PCT/US2003/013764 - 15 Fig. 28 is a dorsal view of a two leve facet joint replacement; Fig. 29 is a lateral view of the two level facet joint replacement of Fig. 28; 5 Fig. 30 is a dorsal view of the implanted four facet prosthesis shown in Figs. 28 and 29; Fig. 31 is a perspective view of the fdur facet prosthesis shown in Fig. 30; Fig. 32 is a perspective view of an al ernative 10 form of inferior bilateral facet prosthesis; Fig. 33 is a perspective view of an implanted superior and inferior unilateral facet pros thesis; Fig. 34 is a perspective view of the unilateral facet prosthesis shown in Fig. 33; 15 Fig. 35 is a perspective view of a lumbar vertebra; Fig. 36 is a perspective view of a novE1 prosthesis that replaces the lamina, the four facets, the spinous process and the two transverse rirocesses of 20 a vertebra; Fig. 37 is an anterior view of the prosthesis shown in Fig. 36; WO 2004/098465 PCT/US2003/013764 - 16 Fig. 38 is a perspective view of a vertebra which has been resected to receive the prosthesis shown in Fig. 36; Fig. 39 is a perspective view of the prosthesis 5 shown in Fig. 36 mounted to the resected ve tebra shown in Fig. 38; Fig. 40 is a dorsal view of the prosthesis shown in Fig. 36 mounted to the resected vertebra shown in Fig. 38; 10 Fig. 41 is a lateral view of the prost esis shown in Fig. 36 mounted to the resected vertebra shown in Fig. 38; Fig. 42 is a perspective view of a nov~l prosthesis that replaces the lamina, the fo r facets 15 and the spinous process of a vertebra; Fig. 43 is a perspective view of a nov1 prosthesis that replaces the lamina, the fotr facets and the two transverse processes of a vertebra; Fig. 44 is a perspective view of a nov 1 20 prosthesis that replaces the lamina and the four facets of a vertebra; Fig. 45 is a perspective view of a novel prosthesis that replaces the two pedicles, the lamina, WO 2004/098465 PCT/US2003/013764 - 17 the four facets, the spinous process and th two transverse processes of a vertebra; Fig. 46 is a lateral view of the prosthesis shown in Fig. 45; 5 Fig. 47 is an anterior view of the pro thesis shown in Fig. 45; Fig. 48 is a perspective view of a vertebra which has been resected to receive the prosthesis shown in Fig. 45; 10 Fig. 49 is a perspective view showing 'he prosthesis of Fig. 45 mounted to the resectqd vertebra shown in Fig. 48; Fig. 50 is a perspective view of a nov 1 l prosthesis that replaces the two pedicles, the lamina, 15 the four facets and the spinous process of a vertebra; Fig. 51 is a perspective view of a novl prosthesis that replaces the two pedicles, the lamina, the four facets and the two transverse processes of a vertebra; 20 Fig. 52 is a perspective view of a novel 1 prosthesis that replaces the two pedicles, the lamina and the. four facets of a vertebra; and WO 2004/098465 PCT/US2003/013764 - 18 Fig. 53 is a, perspective view showing En alternative arrangement for mounting the prosthesis of Fig. 45 to a vertebra. 5 Detailed Description Of The Preferred Embodiments Disc Prosthesis And Single Facet Prosthesis Referring now to Figs. 1 and 2, there is shown a 10 superior vertebra 1 and an inferior vertebrE 3, with an intervertebral disc 2 located in between. Vertebra 1 has superior facets 43, inferior facets 6, posterior arch 35 and spinous process 46. Vertebra 3 has superior facets 7, inferior facets 44, posterior arch 15 36 and spinous process 45. Referring now to Fig. 3, in accordance with one aspect of the present invention, the intervErtebral disc 2 has been replaced by an artificial disc AD. This artificial disc AD may be a device such as is 20 described by Stefee et al. in U.S. Pat. No. 5,071,437; Gill et al. in U.S. Pat. No. 6,113,637; Bryan et al. in U.S. Pat. No. 6,001,130; Hedman et al. in U.S. Patent No. 4,759,769; Ray in U.S. Patent No. 5,527,312; Ray et al. in U.S. Pat. 5,824,093; Buttner-Janz in U.S. Patent WO 2004/098465 PCT/US2003/013764 - 19 No. 5,401,269; and Serhan et al. in U.S. Patent No. 5,824,094; all which documents are hereby ircorporated herein by reference. Alternatively, the artificial disc may be some other artificial disc of tre sort 5 known in the art. In addition to the foregoing, the left inferior facet 6 of vertebra 1 has been resected and an inferior facet prosthesis 4 has been attached to ver ebra 1. Similarly, the left superior facet of verte ra 3 has 10 been resected and a superior facet prosthesj*s 5 has been attached to vertebra 3. Fig. 4 illustrates a dorsal view of thE elements shown in Fig. 3. It can be appreciated tha inferior facet prosthesis 4 replicates the natural anatomy when 15 compared to the contralateral inferior facet 6 of vertebra 1. Similarly, it can be appreciat d that superior facet prosthesis 5 replicates the natural anatomy when compared to the contralateral superior facet 7 of vertebra 3. 20 Turning now to F.g. 5, a perspective view of vertebra 1 with implanted inferior facet prosthesis 4 is provided. Resection at 31 has removed tje natural inferior facet 6 at the bony junction between the WO 2004/098465 PCT/US2003/013764 - 20 inferior facet 6 and the posterior arch 35. In this manner, bone pain associated with a disease, such as osteoarthritis, or trauma may be eliminated as the involved bony tissue has been osteotomized. 5 Fig. 6 illustrates a perspective view cf inferior facet prosthesis 4. Surface 8 replicates the natural articular surface of the replaced inferior facet 6. Post 9 provides a means to affix inferior facet prosthesis 4 to vertebra 1. Post 9 is implanted into 10 the interior bone space of the left pedicle P (Fig. 7) on vertebra 1 and may or may not extend intc the vertebral body of vertebra 1 to provide additional stability. Fig. 7 illustrates a cranial view of v rtebra 3 15 with implanted superior facet prosthesis 5. Resection surface 32 represents the bony junction between the natural superior facet and the posterior arch 35. Fig. 8 illustrates a perspective view cf superior facet prosthesis 5. Surface 36 replicates the natural 20 articular surface of the replaced superior acet 7. Post 37 provides a means for affixing superior facet prosthesis 5 to vertebra 3. Post 37 is implanted into the interior bone space of the left pedicle P (Fig. 7) WO 2004/098465 PCT/US2003/013764 - 21 on vertebra 3 and may or may not extend intc the vertebral body of vertebra 3 to provide additional stability. When the total facet joint is replaced, as shown 5 in Figs. 3 and 4, then surface 8 (Fig. 6) a ticulates with surface 36 (Fig. 8) to recreate the na ural biomechanics of the spine motion segment made up of vertebra 1, vertebra 3, and intervertebral disc 2. Fig. 9 illustrates an alternative inferior facet 10 prosthesis 10 which is implanted into the interior bone space of posterior arch 35. The interior bcne space is accessed from the resaction 31. Fig. 10 shows details of alternative inferior facet prosthesis 10, including the fin 13 that extends 15 into the interior bone 'space of posterior ar ch 35. Surface 12 replicates the natural articular surface of the replaced facet. If desired, a corresponding fin constr ction can be used to form a prosthetic superior facet. 20 The surfaces of post 9 (Fig. 6), post :7 (Fig. 8) and fin 13 (Fig. 10) may or may not include porous coatings to facilitate bone ingrowth to enhance the long term fixation of the implant. Furthermore, such WO 2004/098465 PCT/US2003/013764 - 22 porous coatings may or may not include ostec'inductive or osteoconductive substances to further enhance the bone remodeling into the porous coating. Referring now to Fig. 11, there is shown a lateral 5 view of a superior vertebra 14 and an inferior vertebra 16, with an intervertebral disc 15 located in between is shown. The left inferior facet of vertebra 14 has been resected and an inferior facet prosthesis 18 has been attached to vertebra 14 by means of a crew 10 fastener 17. Similarly, the left superior acet of vertebra 16 has been resected and a superio 4 facet prosthesis 19 has been attached to vertebra 16 by means of a screw fastener 17. Fig. 12 illustrates a dorsal view of the elements 15 of Fig. 11. It can be appreciated that inferior facet prosthesis 18 replicates the natural anatomy when compared to the contralateral inferior facet 22 of vertebra 14. Similarly, it can be appreciated that superior facet prosthesis 19 replicates the natural 20 anatomy when compared to the contralateral superior facet 21 of vertebra 16. Turning now to Fig. 13, there is provi ced a perspective view of vertebra 14 with implan ed inferior WO 2004/098465 PCT/US2003/013764 - 23 facet prosthesis 18. Resection 34 has removed the natural inferior facet at the bony junction between the inferior facet and the posterior arch 37. n this manner, bone pain associated with a disease, such as 5 osteoarthritis, or trauma may be eliminated inasmuch as the involved bony tissue has been osteotomi ed. Fig. 14 illustrates a perspective view of inferior facet prosthesis 18. 'Surface 23 replicates the natural articular surface of the replaced facet. Flange 25 10 contacts the pedicle and hole 24 receives a fastener to attach inferior facet prosthesis 18 to vert bra 14. Fig. 15 illustrates a cranial view of ertebra 16 with implanted superior facet prosthesis 19. Resection surface 35 represents the bony junction between the 15 natural superior facet and the posterior arch 38. Fig. 16 illustrates a perspective view of superior facet prosthesis 19. Surface 27 replicates the natural articular surface of the replaced facet. Faange 39 contacts the pedicle and hole 26 receives a fastener to 20 attach inferior facet prosthesis 19 to vert bra 16. Fig. 17 illustrates an alternative supErior facet prosthesis 40 with an bearing surface 41 that mounts to substrate 42. The bearing surface 41 is a WO 2004/098465 PCT/US2003/013764 ~ 24 biocompatible polymeric material, such as u tra high molecular weight polyethylene. Alternately, the bearing surface can be ceramic, such as zirconia or alumina, or metal. The substrate is a biocompatible 5 metal alloy, such as an alloy of titanium, cobalt, or iron. Disc Prosthesis And Double Facet Prosthesis Referring next to Fig..18, there is shown a 10 superior vertebra 1005 and an inferior vert bra 1010, with an intervertebral disc 1015 located in between. Vertebra 1005 has superior facets 1020, inf rior facets 1025, a lamina (also sometimes referred to s a posterior arch) 1030, a spinous process 103 , and 15- pedicles 1040. Vertebra 1010 has superior Iacets 1045, inferior facets 1050, a posterior arch 1055, a spinous process 1060, and pedicles 1065 (only one of which is seen in Fig. 18). Referring now to-Figs. 19 and 20, in accordance 20 with another aspect of the invention, intervertebral disc 1015 has been replaced by an artificia disc AD. This artificial disc AD may be a device suc4 as is described by Stefee et al. in U.S. Pat. No. 5,071,437; WO 2004/098465 PCT/US2003/013764 - 25 Gill et al. in U.S. Pat. No. 6,113,637; Bry n et al. in U.S. Pat. No. 6,001,130; Hedman et al. in U.S. Patent No. 4,759,769; Ray in-U.S. Patent No. 5,527,312; Ray et al. in U.S. Pat. 5,824,093; Buttner-Janz in U.S. Patent 5 No. 5,401,269; and Serhan et al. in U.S. Patent No. 5,824,094; all which documents are hereby incorporated herein by reference. Alternatively, the ar ificial disc may be some other artificial disc of t e sort known in the art. 10 In addition to the foregoing, the left and right inferior facets 1025 of vertebra 1005 have teen resected at 1070 and a bilateral inferior facet prosthesis 1075 has been attached to vertebra 1005 using screw fasteners 1080. Similarly, the left and 15 right superior facets 1045 of vertebra 1010 have been resected at 1082 (Fig. 24) and a bilateral uperior facet prosthesis 1085 has been attached to vertebra 1010 using screw fasteners 1090. In Fig. 20 it can be appreciated that bilateral 20 inferior facet prosthesis 1075 repli-cates the natural anatomy when compared to the intact inferior facet 1025 of vertebra 1005. Furthermore, bilateral f cet prosthesis 1075 extends from its attachment point in a WO 2004/098465 PCT/US2003/013764 - 26 manner that does not require contact with, 'r mating to, the complex geometry of the lamina (or posterior arch) 1030. Resection surfaces 1070 provide adequate clearance for bilateral inferior facet prosthesis 1075 5 and provide complete removal of the disease$ or traumatized natural inferior facets 1025. Figs. 21 and 22 illustrate how the geometry of the bridge 1095 of bilateral inferior facet prosthesis 1075 matches that of the posterior arch 1030 of vertebra 10 1005 in order to provide adequate clearance for the central foramen 1100. Articular surfaces 1105 articulate with the opposing superior facet 1045 (or their prosthetic replacements) of the vertebra 1010. Fig. 23 illustrates the bilateral inferior facet 15 prosthesis 1075 with flanges 1110 that abut against the pedicles 1040 of vertebra 1005. Bridge 109 connects the articular surfaces 1105. Holes 1115 al low the attachment of bilateral inferior facet pros thesis 1075 to vertebra 1005 by means of screw fasteners 1080. 20 Alternatively, screw fasteners 1080 could bE replaced with staples, pins, tacks, anchors, modular fixation posts, or the like. These alternative fasteners could further include porous coatings to further enhance bony WO 2004/098465 PCT/US2003/013764 - 27 fixation, and could also include osteoconduqtive or osteoinductive substances. In Fig. 24 it can be appreciated that bilateral superior facet prosthesis 1085 replicates tle natural 5 anatomy when compared'to the intact superior facets 1045 of vertebra 1010. Furthermore, bilateral facet prosthesis 1085 extends from its attachment point in a manner that does not require contact with, or mating to, the complex geometry of the lamina (or posterior 10 arch) 1055. Resection surfaces 1082 provide adequate clearance for bilateral superior facet prosthesis 1085 and provide complete removal of the disease or traumatized natural superior facets 1045. Fig. 25 illustrates how the geometry of the bridge 15 1120 of bilateral superior facet prosthesis 1085 matches that of the posterior arch 1055 of vertebra 1010 in order to provide adequate clearance for the central foramen 1125. Articular surfaces 1130 articulate with the opposing inferior facet of the 20 vertebra 1005. Fig. 26 illustrates the bilateral superior facet prosthesis 1085 with flanges 1135 that abut against the pedicles 1065 of vertebra 1010. Bridge 112C connects WO 2004/098465 PCT/US2003/013764 - 28 the articular surfaces 1130 (seen in Fig. 2 but not seen in Fig. 26). Holes 1140 allow the attachment of bilateral superior facet prosthesis 1085 to vertebra 1010 by means of screw fasteners 1090. 5 Fig. 27 illustrates an alternative superior facet prosthesis 1085A with a bearing surface 113CA that mounts to substrate 1131A. The bearing surface 1130A is preferably a biocompatible polymeric material, such as ultra high-molecular weight polyethylene. 10 Alternately, the bearing surface 1130A can he ceramic, such as zirconia or alumina. The substrate 1131A is preferably a biocompatible metal alloy, sucA as an alloy of titanium, cobalt, or iron. Fig. 28 illustrates a superior vertebra 1145, a 15 middle vertebra 1150, and an inferior vertebra 1155. Superior facet prosthesis 1085 articulates with quad-facet prosthesis 1160 to recreate the natural biomechanics of the replaced facet joints. Inferior facet prosthesis 1075 articulates with quad-facet 20 prosthesis 1160 to recreate the natural biomechanics of the replaced facet joints at the next upper level. Thus,.Fig. 28 illustrates a two level recon truction of facet joints. Superior facet prosthesis 10E5, WO 2004/098465 PCT/US2003/013764 - 29 quad-facet prosthesis 1160, and inferior facet prosthesis 1075 are each attached to bone bI means of screw fasteners 1165. In the lateral view of Fig. 29, it can be 5 appreciated that superior facet prosthesis 1085, quad-facet prosthesis 1160, and inferior fa et prosthesis 1075 do not encroach into the in ervertebral foraminal spaces 1167 where nerve roots extend laterally from the spinal cord. 10 Referring next to Fig. 30, it should be appreciated that superior bridge 1170 and inferior bridge 1175 of quad-facet prosthesis 1160 dc not contact any portion of vertebra 1150. Mounting holes 1180 (shown in Fig. 31) are used to secure the flanges 15 1185 against the pedicles of vertebra 1150. In Fig. 32, an alternative inferior bilateral facet prosthesis 1190 is presented. To further stabilize the implant and to counter momentE that act upon the two points of fixation into the pecicles, a 20 set of parallel flanges 1195 extend posteric rly such that the two flanges straddle the spinous process 1035. A bolt 1200 is used to fasten the parallel flanges to the spinous process. -Alternatively, other adjunctive WO 2004/098465 PCT/US2003/013764 - 30 structural features could be added to fourth r stabilize the prosthesis. For example, a strut that extends, and attaches, to the transverse process could b used to further stabilize the prosthesis. 5 Looking next at Figs. 33 and 34, there is shown a superior and inferior unilateral facet pros hesis 1300. Unilateral facet prosthesis 1300 comprises a body 1305 and a stem 1310 extending out of body 1305. A superior element 1315 extends vertically upward from body 1305, 10 and an inferior element 1310 extends vertices lly downward from body 1305. Unilateral facet rosthesis 1300 is configured'so that when its stem 13]0 extends into the pedicle of vertebra 1325, superior element 1315 will replace a resected superior facet, and 15 inferior element 1320 will replace a resect d inferior facet. If desired, stem 1310 could be repl ced with a screw extending through a hole in body 1305 and into the pedicle. 20 Disc Prosthesis And Quadruple Facet Pro thesis Referring next to Fig. 35, there is shcwn a natural lumbar vertebra 2005 comprising a natural vertebral body 2010, a pair of natural pedi les 2015 WO 2004/098465 PCT/US2003/013764 - 31 extending from natural vertebral body 2010, a natural lamina 2020 extending from natural pedicles 2015, a pair of natural superior facets 2025 extending from natural pedicles 2015 and natural lamina 20 0, a pair 5 of natural inferior facets 2030 extending flom natural lamina 2020, a natural spinous process 2035 extending from natural lamina 2020, and a pair of natural transverse processes 2040 extending from natural pedicles 2015. 10 In accordance with another aspect of the invention, the intervertebral disc on one side or the other of vertebral body 2010 is replaced by an artificial disc. This artificial disc may le a device such as is described by Stefee et al. in U.S. Pat. No. 15 5,071,437; Gill et al. in U.S. Pat. No. 6,1]3,637; Bryan et al. in U.S. Pat. No. 6,001,130; Hecman et al. in U.S. Patent No. 4,759,769; Ray in U.S. Patent No. 5,527,312; Ray et al. in U.S. Pat. 5,824,09 ; Buttner Janz in U.S. Patent No. 5,401,269; and Serhan et al. in 20 U.S. Patent No. 5,824,094; all which docume ts are hereby incorporated herein by reference. Alternatively, the artificial disc may be s me other artificial disc of the sort known in the art.

WO 2004/098465 PCT/US2003/013764 - 32 In addition to the foregoing, and looking next at Figs. 36 and 37, there is shown a novel pro thesis 2100 which is adapted to replace the natural lamina 2020, the two natural superior facets 2025, the two natural 5 inferior facets 2030, the natural spinous process 2035, and the two natural transverse processes 2040. To this end, prosthesis 2100 comprises a pair of prc sthetic mounts 2115, a prosthetic lamina 2120 extending from prosthetic mounts 2115, a pair of prosthetic superior 10 facets 2125 extending from prosthetic mount, 2115 and prosthetic lamina 2120, a pair of prostheti inferior facets 2130 extending from prosthetic lamina 2120, a prosthetic spinous process 2135 extending fiom prosthetic lamina 2120, and a pair of prosthetic 15 transverse processes 2140 extending from prosthetic mounts 2115. In the use of prosthesis 2100, natural lumbar vertebra 2005 is resected at its natural pecicles 2015 so as to remove the natural lamina 2020, th two 20 natural superior facets 2025, the two natural inferior facets 2030, the natural spinous process 20 5, and the two natural transverse processes 2040, leaving a pair of pedicle end surfaces 2041 (Fig. 38). Thqn the WO 2004/098465 PCT/US2003/013764 - 33 prosthesis 2100 may be attached to the natural pedicles 2015, e.g., by placing prosthetic mounts 2115 against pedicle surfaces 2041 and then passing screws 2145 through screw holes 2147 and into natural p dicles 5 2015, as shown in Figs. 39-41. As seen in the drawings, the relative size, shape and positioning of the prosthetic lamina 2120, the two prosthetic superior facets 2125, the two prosthetic inferior fa ets 2130, the prosthetic spinous process 2135, and the two 10 prosthetic transverse processes 2140 essentially mimic the relative size, shape and positioning of the natural lamina 2020, the two natural superior facets 2025, the two natural inferior facets 2030, the natural spinous process 2035, and the.two natural transversE processes 15 2040, whereby to effectively restore the veItebra. If desired, holes 2150 may be provided in the Frosthetic spinous process 2135 and/or the two prosthetic transverse processes 2140 so as to facilitate re-attaching soft tissue to these structureE. 20 Looking next at Fig. 42, there is show a novel prosthesis 2200 which is adapted to replace natural lamina 2020, the two natural superior facets 2025, the two natural inferior facets 2030, and natural spinous WO 2004/098465 PCT/US2003/013764 - 34 process 2035. To this end, prosthesis 2200 comprises a pair of prosthetic mounts 2215, a prosthetid lamina 2220 extending from prosthetic mounts 2215, a pair of prosthetic superior facets 2225 extending from 5 prosthetic mounts 2215 and prosthetic lamina 2220, a pair of prosthetic inferior facets 2230 extending from prosthetic lamina 2220, and a prosthetic spinous process 2235 extending from prosthetic lamina 2220. In the use of prosthesis 2200, natural lumbar 10 vertebra 2005 is resected at its natural pe icles 2015 so as to remove the natural lamina 2020, thE two natural superior facets 2025, the two natural inferior facets 2030, the spinous process 2.035 and tle two natural transverse processes 2040, leaving a pair of 15 pedicle surfaces 2041 (Fig. 38). Then the Frosthesis 2200 may be attached to the natural pedicles 2015, e.g., by placing prosthetic mounts 2215 against pedicle surfaces 2041 and then passing screws 2145 hrough holes 2247 and into natural pedicles 2015. As seen in 20 the drawing, the relative size, shape and positioning of prosthetic lamina 2220, the two prosthetic superior facets 2225, the two prosthetic inferior facets 2230, and the prosthetic spinous process 2235 esse ntially WO 2004/098465 PCT/US2003/013764 - 35 mimic the relative size, shape and positioning of the natural lamina 2020, the two natural superior facets 2025, the two natural.inferior facets 2030, and the natural spinous process 2035, whereby to effectively 5 restore the vertebra. If desired, holes 21 0 may be provided in the prosthetic spinous process 2235 so as to facilitate re-attaching soft tissue to this structure. Looking next at Fig. 43, there is show a novel 10 prosthesis 2300 which is adapted to replace the natural lamina 2020, the two natural superior facetE 2025, the two natural inferior facets 2030, and the two natural transverse processes 2040. To this end, prosthesis 2300 comprises a pair of prosthetic mounts 2315, a 15 prosthetic lamina 2320 extending from prosthetic mounts 2315, a pair of prosthetic superior facets 2325 extending from prosthetic mounts 2315 and prosthetic lamina 2320, a pair of prosthetic inferior acets 2330 extending from prosthetic lamina 2320, and pair of 20 prosthetic transverse processes 2340 extending from prosthetic mounts 2315. In the use of prosthesis 2300, natural lumbar vertebra 2005 is resected at natural pedicls 2015 so WO 2004/098465 PCT/US2003/013764 - 36 as to remove natural lamina 2020, the two n tural superior facets 2025, the two natural inferior facets 2030, the natural spinous process 2035 and he two natural transverse processes. 2040, leaving a pair of 5 pedicle surfaces 2041 (Fig. 38). Then the prosthesis 2300 may be attached to the natural pedicleq 2015, e.g., by placing prosthetic mounts 2315 against pedicle surfaces 2041 and then passing screws 2145 through holes 2347 and into natural pedicles 2015. As seen in 10 the drawing, the relative size, shape and p sitioning of the prosthetic lamina 2320, the two prosthetic superior facets 2325, the two prosthetic in erior facets 2330, and the two prosthetic transve se. processes 2340 essentially mimic the relative size, 15 shape and positioning of the natural lamina 2020, the two natural superior facets 2025, the two natural inferior facets 2030, and the two natural transverse processes 2040, whereby to effectively restore the vertebra. If desired, holes 2150 may be provided in 20 the two prosthetic transverse processes 234C so as to facilitate re-attaching soft tissue to thesq structures.

WO 2004/098465 PCT/US2003/013764 - 37 Looking next at Fig. 44, there is show a novel prosthesis 2400 which:is adapted to replace the natural lamina 2020, the two natural superior facet 2025, and the two natural inferior facets 2030. To this end, 5 prosthesis 2400 comprises a pair of prosthetic mounts 2415, a prosthetic lamina 2420 extending from prosthetic mounts 2415, a pair of prosthetic superior facets 2425 extending from prosthetic mount 2415 and prosthetic lamina 2420, and a pair of prosthetic 10 inferior facets 2430 extending from prosthetic lamina 2420. In the use of prosthesis 2400, natural lumbar vertebra 2005 is rejected at pedicles 2015 Jo as to remove the natural lamina 2020, the two nat ral 15 superior facets 2025, the two natural inferior facets 2030, the natural spinous process 2035, and the two natural transverse processes 2040, leaving E pair of pedicle surfaces 2041 (Fig. 38). Then the rosthesis 2400 may be attached to the natural pedicleE 2015, 20 e.g., by placing prosthetic mounts 2415 against pedicle surfaces 2041 and then passing screws 2145 through holes 2447 and into natural pedicles 2015. As seen in the drawing, the relative size, shape and positioning WO 2004/098465 PCT/US2003/013764 - 38 of prosthetic lamina 2420, the two prosthetic superior facets 2425, and the two prosthetic inferior facets 2430 essentially mimic the relative size, shape and positioning of the natural lamina 2020, the two natural 5 superior facets 2025 and the two natural interior facets 2030, whereby to effectively restore the vertebra. Looking next at Figs. 45-47, there is shown a novel prosthesis 2500 which is adapted to replace a 10 pair of natural pedicles 2015, the natural lamina 2020, the two natural superior facets 2025, the two natural inferior facets 2030, the natural spinous process 2035, and the two natural transverse processes 2040. To this end, prosthesis 2500 comprises a pair of prosthetic 15 pedicles 2515, a prosthetic lamina 2520 extending from prosthetic pedicles 2515, a pair of prosthetic superior facets 2525 extending from prosthetic pedicles 2515 and prosthetic lamina 2520, a pair of prosthetic inferior facets 2530 extending from prosthetic laminE 2520, a 20 prosthetic spinous process 2535 extending fiom prosthetic lamina 2520, and a pair of prosthetic transverse processes 2540 extending from prosthetic pedicles 2515.

WO 2004/098465 PCT/US2003/013764 - 39 In the use of prosthesis 2500, natural lumbar vertebra 2005 is resected at the bases of natural pedicles 2015 so as to remove to two natura pedicles 2015, the natural lumina 2020, the two natu al superior 5 facets 2025, the two natural inferior facet 2030, the natural spinous process 2035, and the two n-tural transverse processes 2040, leaving a verteb al body end face 2042 (Fig. 48). Then the prosthesis 2 00 may be attached to the natural vertebral body 2010, e.g., by 10 placing prosthetic pedicles 2515 against vertebral body end face 2042 and then passing screws 2145 through holes 2547 and into natural vertebral body 2010, as shown in Fig. 49. As seen in the drawings, the relative size, shape and positioning of the two 15 prosthetic pedicles 2515, the prosthetic lanina 2520, the two prosthetic superior facets 2525, thE two prosthetic inferior facets 2530, the prosth tic spinous process 2535, and the two prosthetic transverse processes 2540 essentially mimic the relative size, 20 shape and positioning of the two natural pe icles 2015, the natural lamina 2020, the two natural superior facets 2025, the two natural inferior facets 2030, the natural spinous process 2035, and the two natural WO 2004/098465 PCT/US2003/013764 - 40 transverse processes 2040, whereby to effectively restore the vertebra. If desired, holes 21 0 may be provided in prosthetic spinous process 25351and the two prosthetic transverse processes 2540 so as to 5 facilitate re-attaching soft tissue to these structures. Looking next at Fig. 50, there is show a novel prosthesis'2600 which is adapted to replace the two natural pedicles 2015, the natural lamina 2020, the two 10 natural superior facets 2025, the two natural inferior facets 2030, and the natural spinous process 2035. To this end, prosthesis 2600 comprises a pair cf prosthetic pedicles 2615, a prosthetic lamira 2620 extending from prosthetic pedicles 2615, a Tair of 15 prosthetic superior facets 2625 extending from prosthetic pedicles 2615 and prosthetic lamina 2620, a pair of prosthetic inferior facets 2630 ext e nding from prosthetic lamina 2620, and a prosthetic spinous process 2635 extending from prosthetic lamira 2620. 20 In the use of prosthesis 2600, natural lumbar vertebra 2005 is resected at the bases of natural pedicles 2015 so as to remove the two natural pedicles 2015, the natural lamina 2020, the two natural superior WO 2004/098465 PCT/US2003/013764 - 41 facets 2025, the two natural inferior facet 2030, the natural spinous process 2035 and the two natural transverse processes 2040, leaving a verteb al body end face 2042 (Fig. 48) . Then the prosthesis 2 00 may be 5 attached to the natural vertebral body 2010, e.g., by placing prosthetic pedicles 2615 against vertebral body end face 2042 and then passing screws 2145 through holes 2647 and into natural vertebral body 2010. As seen in the drawing, the relative size, sha e and 10 positioning of the two prosthetic pedicles 2615, the prosthetic lamina 2620, the two prosthetic uperior facets 2625, the two prosthetic inferior facets 2630, and the prosthetic spinous process 2635 ess ntially mimic the relative size, shape and positioning of the 15 two natural pedicles 2015, the natural lamira 2020, the two natural superior facets 2025, the two natural inferior facets 2030, and the natural spinods process 2035, whereby to effectively restore the vertebra. If desired, holes 2150 may be provided in pros hetic 20 spinous process 2635 so as to facilitate re attaching soft tissue to this structure. Looking next at Fig. 51, there is show a novel prosthesis 2700 which'is adapted to replace the two WO 2004/098465 PCT/US2003/013764 - 42 natural pedicles 2015, the natural lamina 2C20, the two natural superior facets 2025, the two natural inferior facets 2030, and the two natural transverse processes 2040. To this end, prosthesis 2700 comprises a pair of 5 prosthetic pedicles 2715, a prosthetic lamira 2720 extending from prosthetic pedicles 2715, a pair of prosthetic superior facets 2725 extending f om prosthetic pedicles 2715 and prosthetic lamina 2720, a pair of prosthetic inferior facets 2730 extending from 10 prosthetic lamina 2720, and a pair of prosthetic transverse processes 2740 extending from prosthetic pedicles 2715. In the use of prosthesis 2700, natural lumbar vertebra 2005 is resected at the bases of natural 15 pedicles 2015 so as to remove the two natural pedicles 2015, the natural lamina 2020, the two natu al superior facets 2025, the two natural inferior facetE 2030, the natural spinous process 2035, and the two natural transverse processes 2040, leaving a vertebial body end 20 face 2042 (Fig. 48). Then the prosthesis 2~00 may be attached to the natural vertebral body 2010, e.g., by placing prosthetic pedicles 2715 against ve tebral body end face 2042 and then passing screws 2145 hrough WO 2004/098465 PCT/US2003/013764 - 43 holes 2747 and into vertebral body 2010. A seen in the drawing, the relative size, shape and positioning of the two prosthetic pedicles 2715, the prosthetic lamina 2720, the two prosthetic superior facets 2725, 5 the two prosthetic inferior facets 2730, anc the two prosthetic transverse processes 2740 essentially mimic the relative size, shape and positioning of the two natural pedicles 2015, the natural lamina 2020, the two natural superior facets 2025, the two natural inferior 10 facets 2030, and the two natural transverse processes 2040, whereby to effectively restore the vertebra. If desired, holes 2150 may be provided in the two prosthetic transverse processes 2740 so as to facilitate re-attaching soft tissue to thesE 15 structures. Looking next at Fig. 52, there is show a novel prosthesis 2800 which is adapted to replace the two natural pedicles 2015, the natural lamina 2C20, the two natural superior facets 2025, and the two n tural 20 inferior facets 2030. To this end, prosthe is 2800 comprises a pair of prosthetic pedicles 281 , a prosthetic lamina 2820 extending from prosthetic pedicles 2815, a pair of prosthetic superior facets WO 2004/098465 PCT/US2003/013764 - 44 2825 extending from prosthetic pedicles 281 and prosthetic lamina 2820, and a pair of prosthetic inferior facets 2830 extending from prosthetic lamina 2820. 5 In the use of prosthesis 2800, natural lumbar vertebra 2005 is resected at the bases of natural pedicles 2015 so as to remove the two natural pedicles 2015, the natural lamina 2020, the two natu al superior facets 2025, the two natural inferior facet 2030, the 10 natural spinous process 2035, and the two natural transverse processes 2040, leaving a vertebral body end face 2042 (Fig. 48). Then the prosthesis 2E00 may be attached to natural vertebral body 2010, e.c., by placing prosthetic pedicles 2715 against ve tebral body 15 end face 2042 and then passing screws 2145 hrough holes 2847 and into natural vertebral body 1010. As seen in the drawing, the relative size, shape and positioning of the two prosthetic pedicles 815, the prosthetic lamina 2820, the two prosthetic uperior 20 facets 2825, and the two prosthetic inferior facets 2830 essentially mimic the relative size, shape and positioning of the two natural pedicles 201 , the natural lamina 2020, the two natural superior facets WO 2004/098465 PCT/US2003/013764 - 45 2025, and the two natural inferior facets 2930, whereby to effectively restore the vertebra. It should also be appreciated that prostheses 2100, 2200, 2300, 2400, 2500, 2600, 2700 and 2800 may 5 be attached to natural vertebra 2005 with apparatus other than the screws 2145 discussed above. Thus, for example, prostheses 2100, 2200, 2300, 2400, 2500, 2600, 2700 and 2800 may be attached to natural ve tebra 2005 with rods or posts, etc. See, for example, Fig. 53, 10 where prosthesis 2500 is shown attached to riatural vertebra 2005 with rods 2146 which pass through, and snap into engagement with, prosthetic pedicles 2515. Having thus described preferred embodiments of the invention with reference to the accompanying drawings, 15 it is to be understood that the embodiments shown herein are provided by way of example only, and that various changes and modifications may be ef ected by one skilled in the art without departing frcm the scope or spirit of the invention as defined in thE claims. 20

Claims (34)

1. A spinal joint kit for replacement of a portion of a mammalian spine comprising a spinal motion segment comprising two adjacent vertebrae, the intervertebral disc, and other interposed soft tissues, the kit comprising: an artificial disc adapted to be incorporated into the spinal motion segment, the artificial disc comprising opposing end plates adapted to engage the adjacent vertebrae and an articulating structure therebetween; and a prosthesis comprising a pair of articular surfaces formed separately from each other, wherein the pair of articular surfaces is securable to one of the adjacent vertebrae to provide complementary interoperation with the artificial disc to help restore the natural biomechanics of the spinal motion segment, wherein the pair of articular surfaces is selected from the group consisting of a pair of prosthetic superior facets securable to the inferior of the two adjacent vertebrae to replace the corresponding natural superior facets, and a pair of prosthetic inferior facets securable to the superior of the two adjacent vertebrae to replace the corresponding natural inferior facets.

2. The kit of claim 1, wherein the prosthesis is adapted to be secured to one of the vertebrae without requiring removal of substantially all of a lamina of the vertebra.

3. The kit of claim 1, wherein the prosthesis further comprises a bone contacting surface, the kit further comprising a fixation member configured to urge the prosthesis against one of the vertebrae such that the bone contacting surface abuts the vertebra.

4. The kit of claim 1, wherein each articular surface of the pair of articular surfaces is shaped to mimic the position and shape of the corresponding -47 natural articular surface such that the prosthesis operates as part of a partially or fully prosthetic facet joint to mimic the articulation present in a natural facet joint.

5. The kit of claim 1, wherein the artificial disc and the prosthesis are configured to allow undamped flexion.

6. A spinal joint kit for replacement of a portion of a mammalian spine comprising a spinal motion segment comprising two adjacent vertebrae, the intervertebral disc, and other interposed soft tissues, the kit comprising: an artificial disc adapted to be incorporated into the spinal motion segment, the artificial disc comprising opposing end plates adapted to engage the adjacent vertebrae and an articulating structure therebetween; and a prosthesis comprising a pair of prosthetic inferior facets securable to the superior of the two adjacent vertebrae to replace the corresponding natural superior facets and provide complementary interoperation with the artificial disc to help restore the natural biomechanics of the spinal motion segment without requiring removal of substantially all of a lamina of the superior of the two adjacent vertebrae.

7. The kit of claim 6, wherein the prosthesis further comprises a bone contacting surface, the kit further comprising a fixation member configured to urge the prosthesis against the superior of the two adjacent vertebra such that the bone contacting surface abuts the vertebra.

8. The kit of claim 6, wherein the pair of prosthetic inferior facets comprises a pair of articular surfaces, wherein the pair of articular surfaces is shaped to mimic the shape of a pair of natural inferior articular surfaces such that the prosthesis operates as part of a partially or fully -48 prosthetic facet joint to mimic the articulation present in a natural facet joint.

9. The kit of claim 6, wherein the artificial disc and the prosthesis are configured to function independently of any extra-discal damping member.

10. A spinal joint kit for replacement of a portion of a mammalian spine comprising a spinal motion segment comprising two adjacent vertebrae, the intervertebral disc, and other interposed soft tissues, the kit comprising: an artificial disc adapted to be incorporated into the spinal motion segment; and a prosthesis comprising at least one prosthetic facet securable to one of the adjacent vertebrae to replace the corresponding natural facet and provide complementary interoperation with the artificial disc to help restore the natural biomechanics of the spinal motion segment, the prosthesis comprising a bone contacting surface; and a fixation member configured to urge the prosthesis against the vertebra such that the bone contacting surface abuts the vertebra.

11. The kit of claim 10, wherein the prosthetic facet further comprises an articular surface, wherein the articular surface is shaped Ito mimic the shape of a natural articular surface on a natural facet such that the prosthesis operates as part of a partially or fully prosthetic facet joint to mimic the articulation present in a natural facet joint.

12. The kit of claim 10, wherein the artificial disc and the prosthesis are configured to function independently of any extra-discal damping member.

13. A method for replacing a portion of a mammalian spine comprising a spinal motion segment comprising two adjacent vertebrae, the -49 intervertebral disc, and other interposed soft tissues, the method comprising: implanting an artificial disc adjacent to the vertebra; and securing a prosthesis to one of the adjacent vertebrae such that the prosthesis complements the artificial disc to help restore the natural biomechanics of the spinal motion segment, the prosthesis comprising a pair of articular surfaces formed separately from each other, wherein the pair of articular surfaces is selected from the group consisting of a pair of prosthetic superior facets, such that securing the prosthesis to one of the adjacent vertebrae comprises securing the prosthesis to the inferior of the two adjacent vertebrae to replace the corresponding natural superior facets, and a pair of prosthetic inferior facets, such that securing the prosthesis to one of the adjacent vertebrae comprises securing the prosthesis to the superior of the two adjacent vertebrae to replace the corresponding natural inferior facets.

14. The method of claim 13, wherein the prosthesis is adapted to be secured to one of the vertebrae without requiring removal of substantially all of a lamina of the vertebra.

15. The method of claim 13, wherein the prosthesis further comprises a bone contacting surface, wherein securing the prosthesis to one of the vertebrae comprises securing the prosthesis against the vertebra such that the bone contacting surface abuts the vertebra.

16. The method of claim 13, wherein the pair of articular surfaces is shaped to mimic the shape of a pair of natural articular surfaces such that the prosthesis operates as part of a partially or fully prosthetic facet joint to mimic the articulation present in a natural facet joint. - 50

17. The method of claim 13, wherein the artificial disc and the prosthesis are configured to function independently of any extra-discal damping member.

18. A method for replacing a portion of a mammalian spine comprising a spinal motion segment comprising two adjacent vertebrae, the intervertebral disc, and other interposed soft tissues, the method comprising: implanting an artificial disc adjacent to the vertebra; and securing a prosthesis to the superior of the adjacent vertebrae such that the prosthesis replaces the corresponding natural inferior facets arid complements the artificial disc to help restore the natural biomechanics of the spinal motion segment without removal of substantially all of a lamina of the vertebra, the prosthesis comprising a pair of prosthetic inferior facets.

19. The method of claim 18, wherein the prosthesis further comprises a bone contacting surface, wherein securing the prosthesis to the vertebra comprises securing the prosthesis against the vertebra such that the bone contacting surface abuts the vertebra.

20. The method of claim 18, wherein the pair of prosthetic inferior facets comprises a pair of articular surfaces, wherein the pair of articular surfaces is shaped to mimic the shape of a pair of natural articular surfaces such that the prosthesis operates as part of a partially or fully prosthetic facet joint to mimic the articulation present in a natural facet joint.

21. The method of claim 18, wherein the artificial disc and the prosthesis are configured to function independently of any extra-discal damping member. - 51

22. A method for replacing a spine joint, comprising the steps of: replacing an intervertebral disc with an artificial disc comprising opposing end plates and articulating structure therebetween; resecting at least a portion of a bone of a vertebra facet; attaching a prosthetic facet to the remaining bone of the vertebra such that no portion of the prosthetic facet contacts a posterior arch of the vertebra; wherein said prosthetic facet is adapted to articulate with another facet; with the artificial disc and the prosthetic facet cooperating so as to restore the natural biomechanics of a spinal motion segment.

23. A method for replacing a spine joint, comprising the steps of: replacing an intervertebral disc with an artificial disc comprising opposing end plates and articulating structure therebetween; resecting at least a portion of a bone of a first facet on a first vertebra; attaching a first prosthetic facet to the remaining bone of the first vertebra such that no portion of the prosthetic facet contacts a posterior arch of the vertebra; resecting at least a portion of the bone of a second facet on a second vertebra; and attaching a second prosthetic facet to the remaining bone of the second vertebra such that no portion of the prosthetic facet contacts the posterior arch of the vertebra; wherein the first prosthetic facet is adapted to articulate with the second prosthetic facet; with the artificial disc and the prosthetic facet cooperating so as to restore the natural biomechanics of a spinal motion segment.

24. A method for replacing a spine joint, comprising the steps of: -52 replacing an intervertebral disc with an artificial disc comprising opposing end plates and articulating structure therebetween; resecting a pair of facets on the vertebra; and attaching a prosthesis to the vertebra so that a pair of bearing surfaces on the prosthesis are positioned in place of the resected facets, wherein the prosthesis is configured so that no portion of the prosthesis is supported by the lamina of the vertebra; with the artificial disc and the prosthesis cooperating so as 'to restore the natural biomechanics of a spinal motion segment.

25. A method for replacing a mammalian spine joint, comprising the steps of: replacing an intervertebral disc with an artificial disc comprising opposing end plates and articulating structure therebetween; resecting at least a bony portion of the inferior facets of a superior vertebra; attaching a first prosthesis that replaces the inferior facets of the superior vertebra; resecting at least a bony portion of the superior facets of an inferior vertebra; and attaching a second prosthesis that replaces the superior facets of the inferior vertebra; wherein no portion of the first prosthesis is supported by the lamina of the superior vertebra, and further wherein no portion of the second prosthesis is supported by the lamina of the inferior vertebra; with the artificial disc and the first prosthesis and the second prosthesis cooperating so as to restore the natural biomechanics of a spinal motion segment.

26. A method for replacing a mammalian spine joint, comprising the steps of: - 53 replacing an intervertebral disc with an artificial disc comprising opposing end plates and articulating structure therebetween; resecting at least a bony portion of the inferior facets of a most superior vertebra; attaching a first prosthesis that replaces the inferior facets of the most superior vertebra; resecting at least a bony portion of the superior facets of a most inferior vertebra; attaching a second prosthesis that replaces the superior facets of the most inferior vertebra; resecting at least a bony portion of all of the facets of at least one intermediate vertebra located between the most superior vertebra and the most inferior vertebra; wherein, for each of the at least one intermediate vertebra, a prosthesis is attached that replaces all facets of the intermediate vertebra; with the artificial disc and the prostheses cooperating so as to restore the natural biomechanics of a spinal motion segment.

27. A method for replacing a spine joint, wherein the natural vertebra comprises a natural vertebral body, a pair of natural pedicles extending from the natural vertebral body, a natural lamina extending from the two natural pedicles, a pair of natural superior facets extending from the two natural pedicles and the natural lamina, a pair of natural inferior facets extending from the natural lamina, a natural spinous process extending from the natural lamina and a pair of natural transverse processes extending from the two natural pedicles, said method comprising the steps of: replacing an intervertebral disc with an artificial disc comprising opposing end plates and articulating structure therebetween; making a resection at the most dorsal aspect of the two natural pedicles; and -54 attaching a prosthesis to the resected vertebra, the prosthesis comprising two prosthetic mounts, a prosthetic lamina extending from the two prosthetic mounts, a pair of prosthetic superior facet extending from the two prosthetic mounts and the prosthetic lamina, and a pair of prosthetic inferior facets extending from the prosthetic lamina; with the artificial disc and the prosthesis cooperating so as to restore the natural biomechanics of a spinal motion segment.

28. A method according to claim 27 wherein the prosthesis further comprises a prosthetic spinous process extending from the prosthetic lamina.

29. A method according to claim 27 wherein the prosthesis further comprises a pair of prosthetic transverse processes extending from the two prosthetic mounts.

30. A method according to claim 27 wherein the prosthesis further comprises a prosthetic spinous process extending from the prosthetic lamina and a pair of prosthetic transverse processes extending from the two prosthetic mounts and the prosthetic lamina.

31. A method for replacing a spine joint, wherein the natural vertebra comprises a natural vertebral body, a pair of natural pedicles extending from the natural vertebral body, a natural lamina extending from the two natural pedicles, a pair of natural superior facets extending from the two natural pedicles and the natural lamina, a pair of natural inferior facets extending from the natural lamina, a natural spinous process extending from the natural lamina, and a pair of natural transverse processes extending from the natural pedicles, said method comprising the steps of: replacing an intervertebral disc with an artificial disc comprising opposing end plates and articulating structure therebetween; - 55 making a resection at the junction of the natural vertebral body and the two natural pedicles; and attaching a prosthesis to the resected vertebra, the prosthesis comprising two prosthetic pedicles, a prosthetic lamina extending from the prosthetic pedicles, a pair of prosthetic superior facets extending from the two prosthetic pedicles and the prosthetic lamina, and a pair of prosthetic inferior facets extending from the prosthetic lamina; with the artificial disc and the prosthesis cooperating so as to restore the natural biomechanics of a spinal motion segment.

32. A method according to claim 31 wherein the prosthesis further comprises a prosthetic spinous process extending from the prosthetic lamina.

33. A method according to claim 31 wherein the prosthesis further comprises a pair of prosthetic transverse processes extending from the two prosthetic pedicles.

34. A method according to claim 31 wherein the prosthesis further comprises a prosthetic spinous process extending from the prosthetic lamina and two prosthetic transverse processes extending from the two prosthetic pedicles and the prosthetic lamina.