Prostheses for Spine Facets

Claim 2

1 . A prosthesis for the replacement of at least a portion of the bone of a facet located on a host mammalian vertebra, comprising: a posterior arch structure having a plurality of bearing attachment surfaces; a plurality of facet bearing buttons releasably engaged with the bearing attachment surfaces; and a plurality of bioresorbable attachment screws to secure the posterior arch structure to the posterior vertebral articular process of the mammalian vertebra.

Claim 3

2 . The prosthesis of claim 1 , wherein the posterior arch structure further comprises, at least one pedicle extending from the posterior arch structure, the at least one pedicle to mate with at least one fenestra of the mammalian vertebra and to receive at least one of the plurality of bioresorbable attachment screws.

Claim 4

3 . The prosthesis of claim 1 , wherein the pedicles are cylindrical in shape.

Claim 5

4 . The prosthesis of claim 1 , wherein the posterior arch structure further comprises a posterior protrusion in a shape approximating a spinous process.

Claim 6

5 . The prosthesis of claim 4 , wherein the posterior protrusion further comprises an attachment location to resect a bone piece originating from the spinous process of the mammalian vertebra.

Claim 7

6 . The prosthesis of claim 4 , wherein the posterior protrusion is capable of bioincorporation into the spinous process of the mammalian vertebra.

Claim 8

7 . The prosthesis of claim 4 , wherein the posterior protrusion is fabricated comprising a plurality of volumetric voids to establish volumetric porosity of the posterior protrusion.

Claim 9

8 . The prosthesis of claim 7 , wherein the volumetric voids establishing the volumetric porosity of the posterior arch structure are between about 75 μm and 500 μm in diameter.

Claim 10

9 . The prosthesis of claim 4 , wherein the posterior protrusion further comprises at least a portion of osteoinductive materia.

Claim 11

10 . The prosthesis of claim 9 , wherein the osteoinductive material is hydroxyapitite.

Claim 12

11 . The prosthesis of claim 4 , wherein the posterior portion further comprises at least a portion of osteoconductive materia.

Claim 13

12 . The prosthesis of claim 11 , wherein the osteoconductive material is bone morphogenic protein.

Claim 14

13 . The prosthesis of claim 1 , wherein the plurality of bearing attachment surfaces further comprises, at least one superior prosthetic facet to contact an inferior facet of a superior vertebral body of the vertebra, the at least one superior prosthetic facet to receive at least one of the plurality of facet bearing buttons.

Claim 15

14 . The prosthesis of claim 1 , wherein the plurality of bearing attachment surfaces further comprises, at least one inferior prosthetic facet to contact a superior facet of an inferior vertebral body of the vertebra, the at least one inferior prosthetic facet to receive at least one of the plurality of facet bearing buttons.

Claim 16

15 . The prosthesis of claim 1 , wherein the posterior arch structure is fabricated of a material selected from the group consisting of ceramic, glass reinforced polymer and carbon reinforced polymer.

Claim 17

16 . The prosthesis of claim 1 , wherein the posterior arch structure is capable of bioincorporation into the host vertebra.

Claim 18

17 . The prosthesis of claim 1 , wherein the posterior arch structure is fabricated comprising a plurality of volumetric voids to establish volumetric porosity of the posterior arch structure.

Claim 19

18 . The prosthesis of claim 17 , wherein the volumetric voids establishing the volumetric porosity of the posterior arch structure are between about 75 μm and 500 μm in diameter.

Claim 20

19 . The prosthesis of claim 1 , wherein the posterior arch structure further comprises at least a portion of osteoinductive materia.

Claim 21

20 . The prosthesis of claim 19 , wherein the osteoinductive material is hydroxyapitite.

Claim 22

21 . The prosthesis of claim 1 , wherein the posterior arch structure further comprises at least a portion of osteoconductive materia.

Claim 23

22 . The prosthesis of claim 21 , wherein the osteoconductive material is bone morphogenic protein.

Claim 24

23 . The prosthesis of claim 1 , wherein the plurality of bearing attachment surfaces are substantially planar and positioned at a predetermined angle with respect to a sagittal plane of the host.

Claim 25

24 . The prosthesis of claim 13 , wherein the at least one of the superior bearing attachment surfaces is positioned to face substantially medially relative to the posterior arch structure.

Claim 26

25 . The prosthesis of claim 13 , wherein the at least one of the superior bearing attachment surfaces is positioned at substantially a 30 degree angle relative to the sagittal plane of the host.

Claim 27

26 . The prosthesis of claim 13 , wherein the at least one of the superior bearing attachment surfaces is positioned at substantially a 45 degree angle relative to the sagittal plane of the host.

Claim 28

27 . The prosthesis o claim 13 , wherein the at least on of the inferior bearing attachment surfaces is positioned to face substantially laterally relative to the posterior arch structure.

Claim 29

28 . The prosthesis of claim 14 , wherein the at least one of the inferior bearing attachment surfaces is positioned at substantially a 35 degree angle relative to the sagittal plane of the host.

Claim 30

29 . The prosthesis of claim 14 , wherein the at least one of the inferior bearing attachment surfaces is positioned at substantially a 50 degree angle relative to the sagittal plane of the host.

Claim 31

30 . The prosthesis of claim 1 , wherein the plurality of facet bearing buttons are fabricated from ultra-high molecular weight polyethylene.

Claim 32

31 . The prosthesis of claim 1 , wherein the plurality of facet bearing buttons further comprises a button cap and a button stem, the button stem adapted to allow releasable engagement with an aperture of the plurality of bearing attachment surfaces.

Claim 33

32 . The prosthesis of claim 31 , wherein the button cap of the facet bearing button is fabricated to have a contour selected from the contours consisting of substantially convex, substantially concave and substantially flat.

Claim 34

33 . The prosthesis of claim 31 , wherein the button stem further comprises a locking barb to secure the facet bearing button within the aperture of the bearing attachment surface.

Claim 35

34 . The prosthesis of claim 1 , wherein the bioresorbable attachment screws are fabricated of a polymer material.

Claim 36

35 . A prosthesis for the replacement of at least a portion of the bone of a facet located on a host mammalian vertebra, comprising: a posterior arch structure having two superior bearing attachment surfaces and two inferior bearing attachment surfaces; two pedicles extending from the posterior arch structure, the two pedicles dimensioned to engage with two fenestra provided in the host vertebra; two superior facet bearing buttons releasably engaged with the two superior bearing attachment surfaces; two inferior facet bearing buttons releasably engaged with the two inferior bearing attachment surfaces; and two bioresorbable attachment screws to secure the posterior arch structure to the posterior vertebral articular process of the mammalian vertebra through the two pedicles.

Claim 37

35 . A prosthesis for the replacement of at least a portion of the bone of a facet located on a host mammalian vertebra, comprising: a posterior arch structure having two superior bearing attachment surfaces and two inferior bearing attachment surfaces; two pedicles extending from the posterior arch structure, the two pedicles dimensioned to engage with two fenestra provided in the host vertebra; two superior facet bearing buttons releasably engaged with the two superior bearing attachment surfaces; two inferior facet bearing buttons releasably engaged with the two inferior bearing attachment surfaces; and two bioresorbable attachment screws to secure the posterior arch structure to the posterior vertebral articular process of the mammalian vertebra through the two pedicles.