Spinal facet implant with spherical implant apposition surface and bone bed and methods of use

• US 7,914,560 B2
• Filed: 09/29/2008
• Issued: 03/29/2011
• Est. Priority Date: 02/17/2004
• Status: Active Grant

• Current Assignee: Globus Medical, Inc.
• Original Assignee: Gmedelaware 2 LLC (Globus Medical, Inc.)
• Inventors: Hoy, Robert W., Fallin, T. Wade, Justin, Daniel F., Triplett, Daniel J., Chervitz, Alan
• Primary Examiner(s): Robert; Eduardo C
• Assistant Examiner(s): HAMMOND, ELLEN CHRISTINA
• Application Number:
  US12/240,047
• Publication Number:
  US 20090030459A1
• Time in Patent Office: 911 Days
• Field of Search: 606/246, 606/247, 606/279
• US Class Current: 606/279
• CPC Class Codes: A61B 17/7049 Connectors, not bearing on the vertebrae, for linking longitudinal elements together A61B17/7055, A61B17/7053, A61B17/7019 take precedence
• CPC Class Codes: A61B 17/7064 Devices acting on, attached to, or simulating the effect of, vertebral facets; Tools therefor
• CPC Class Codes: A61B 17/7067 Devices bearing against one or more spinous processes and also attached to another part of the spine; Tools therefor
• CPC Class Codes: A61B 17/8625 Shanks, i.e. parts contacting bone tissue
• CPC Class Codes: A61B 17/8695 Washers surrounding screw head in plate hole A61B17/8047, between bone plate and bone A61B17/8028
• CPC Class Codes: A61B 2017/8655 with special features for locking in the bone
• CPC Class Codes: A61F 2/30771 applied in original prostheses, e.g. holes or grooves
• CPC Class Codes: A61F 2/4405 for apophyseal or facet joints, i.e. between adjacent spinous or transverse processes devices implanted between spinous or transverse processes A61B17/7062
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30125 elliptical or oval
• CPC Class Codes: A61F 2002/30154 square
• CPC Class Codes: A61F 2002/30156 triangular
• CPC Class Codes: A61F 2002/30171 rosette- or star-shaped
• CPC Class Codes: A61F 2002/30179 X-shaped
• CPC Class Codes: A61F 2002/30426 Bayonet coupling
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30448 using adhesives
• CPC Class Codes: A61F 2002/30514 using a locking washer
• CPC Class Codes: A61F 2002/30574 with an integral complete or partial collar or flange
• CPC Class Codes: A61F 2002/30576 with extending fixation tabs
• CPC Class Codes: A61F 2002/30578 : having apertures, e.g. for receiving fixation screws
• CPC Class Codes: A61F 2002/30579 : with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30616 : Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30663 : multiaxial, e.g. biaxial; multipolar, e.g. bipolar or having an intermediate shell articulating between the ball and the socket
• CPC Class Codes: A61F 2002/3082 : Grooves
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/3085 : with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/30934 : Special articulating surfaces
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2220/005 : using adhesives
• CPC Class Codes: A61F 2230/0008 : elliptical or oval
• CPC Class Codes: A61F 2230/0021 : square
• CPC Class Codes: A61F 2230/0023 : triangular
• CPC Class Codes: A61F 2230/005 : Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00131 : Tantalum or Ta-based alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00203 : containing alumina or aluminium oxide
• CPC Class Codes: A61F 2310/00239 : containing zirconia or zirconium oxide ZrO2
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite
• CPC Class Codes: A61F 2310/00928 : Coating or prosthesis-covering structure made of glass or of glass-containing compounds, e.g. of bioglass

Abstract

Superior and/or inferior facets of one or more facet joints may be replaced by superior and/or inferior facet joint prostheses. In one embodiment, a kit of superior or inferior prostheses is provided, in which the prostheses have at least two dimensions that vary among members of the kit independently of each other. Each prosthesis may have a bone engaging surface having a surface that is polyaxially rotatable against a corresponding resection of a vertebra. Each prosthesis may also have an articulating surface shaped such that, after attachment to the spine, the replaced or partially replaced facet joints provide a larger medial-lateral range of motion when the spine is flexed than when the spine is extended. Crosslinks may be used to connect left and right prosthesis together in such a manner that they are stabilized in a position in which they are seated directly against the vertebra.

Claims

1. A method for replacing a facet of a mammalian vertebra, the method comprising the steps of:

resecting at least a portion of the facet;

implanting a fixation element into a pedicle of the resected facet, the fixation element having a distal end with a bone engaging surface and a proximal end extending outward from the pedicle,

after the implanting step, introducing a connecting element over the proximal end of the fixation element, the connecting element allowing polyaxial adjustment of a prosthetic facet relative to the fixation element;

polyaxially rotating the prosthetic facet relative to the fixation element such that the prosthetic facet is positioned to articulate against a second facet; and

fixedly attaching the prosthetic facet to the fixation element to inhibit polyaxial movement of the prosthetic facet relative to the fixation element.

2. The method of claim 1, wherein polyaxially rotating the prosthetic facet comprises triaxially rotating the prosthetic facet.

3. The method of claim 2, wherein the connecting element comprises a bone engaging surface, wherein attaching the connecting element to the fixation element comprises positioning the bone engaging surface to protrude into the vertebra to engage an inversely-shaped portion of a resection formed by resecting at least a portion of the facet.

4. The method of claim 3, wherein the bone engaging surface has a generally semispherical shape and the inversely-shaped portion of the resection comprises a generally semispherical shape.

5. The method of claim 3, further comprising actuating a component selected from the group consisting of the fixation element and a nut coupled to the fixation element to fix a position and orientation of the bone engaging surface with respect to the resection.

6. A method for establishing a disposition of an implant for replacing a portion of a facet of a mammalian vertebra, the implant comprising an articulating surface, a coupling portion and a fixation element, the coupling portion having a bone engaging surface and a fixation element engaging surface, wherein the articulating surface is shaped to articulate against a second facet surface, the method comprising:

forming a semispherical resection in the vertebra;

securing the fixation element to the vertebra, the fixation element having an end extending outward from the vertebra;

after the securing step, introducing the fixation element engaging surface of the coupling portion over the outward extending end of the fixation element, and positioning the bone engaging surface against the semispherical resection such that the articulating surface is positioned to articulate against a second facet; and

securing the fixation element engaging surface to the outward extending end of the fixation element, thereby affixing the bone engaging surface against the semispherical resection.

7. The method of claim 6, wherein the step of securing the fixation element engaging surface to the fixation element comprises tightening a component selected from the group consisting of the fixation element and a nut coupled to the fixation element.

8. The method of claim 6, wherein forming the rounded resection comprises forming a rounded concave resection.

9. A method for establishing a disposition of an implant for replacing a facet of a mammalian vertebra, the implant comprising an articulating surface and a coupling portion, the coupling portion having a bone engaging surface, wherein the articulating surface is shaped to articulate against a second facet surface, the method comprising:

forming a rounded resection in the vertebra;

forming a substantially flat resection in the vertebra, proximate the rounded resection;

implanting a fixation element into the vertebra, a portion of the fixation element extending outward from the vertebra in a relatively posterior direction;

introducing the bone engaging surface over the outward extending portion of the fixation element and positioning the bone engaging surface against the rounded resection such that the articulating surface is positioned to articulate against the second facet surface; and

securing the coupling portion to the outward extending portion of the fixation element to affix the bone engaging surface against the rounded resection.

10. The method of claim 9, wherein the securing step comprises tightening a component selected from the group consisting of the fixation element and a nut coupled to the fixation element.

11. The method of claim 9, wherein forming the rounded resection comprises forming a rounded concave resection.

12. The method of claim 9, wherein forming the rounded resection comprises forming a semispherical resection.

13. The method of claim 9, wherein forming the substantially flat resection comprises positioning the substantially flat resection contiguous with the rounded resection.

14. The method of claim 13, wherein the implant comprises an angled flat, wherein positioning the bone engaging surface against the rounded resection comprises positioning the angled flat to lie against the substantially flat resection.