Ball and dual socket joint

• US 20060142862A1
• Filed: 02/15/2005
• Published: 06/29/2006
• Est. Priority Date: 03/02/2004
• Status: Active Grant

• Current Assignee: Joint Synergy LLC
• Original Assignee: Joint Synergy LLC
• Inventors: Doubler, Robert, Diaz, Robert, Hamill, John E.
• Granted Patent: US 7,195,644 B2
• Time in Patent Office: Days
• US Class Current: 623/17.130
• CPC Class Codes: A61F 2/30742 Bellows or hose-like seals; Sealing membranes A61B17/8808 takes precedence; sealing membranes for retaining bone substitute A61F2/2846
• CPC Class Codes: A61F 2/4425 made of articulated components
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30242 spherical
• CPC Class Codes: A61F 2002/30331 made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2002/30426 Bayonet coupling
• CPC Class Codes: A61F 2002/30451 soldered or brazed or welded
• CPC Class Codes: A61F 2002/30462 retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/30495 using a locking ring
• CPC Class Codes: A61F 2002/30563 having elastic means or damping means, different from springs, e.g. including an elastomeric core or shock absorbers
• CPC Class Codes: A61F 2002/30574 with an integral complete or partial collar or flange
• CPC Class Codes: A61F 2002/30578 having apertures, e.g. for receiving fixation screws
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30649 Ball-and-socket joints
• CPC Class Codes: A61F 2002/30662 with rotation-limiting means
• 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 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30904 serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/3097 using laser
• CPC Class Codes: A61F 2002/443 : having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2220/0058 : soldered or brazed or welded
• CPC Class Codes: A61F 2220/0075 : sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2230/0071 : spherical
• CPC Class Codes: A61F 2250/0018 : differing in elasticity, stiffness or compressibility
• 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 2310/00203 : containing alumina or aluminium oxide
• CPC Class Codes: A61F 2310/00281 : containing silicon carbide
• CPC Class Codes: A61F 2310/00317 : containing silicon nitride
• CPC Class Codes: A61F 2310/00395 : Coating or prosthesis-covering structure made of metals or of alloys
• CPC Class Codes: A61F 2310/00592 : Coating or prosthesis-covering structure made of ceramics or of ceramic-like compounds

Abstract

A spinal implant is inserted between adjacent vertebrae to function as an disk prosthesis. The prosthesis has two plates fastened to adjacent vertebrae facing each other. The facing sides of the plates each have a depending skirt formed as concentric arcs of about 90 degrees. The skirts are either bowed or tapered in the axial direction. Depressions are centrally located between the arcs of the plates and a ball is universally movable in the depressions. A spring mechanism is centrally located in the plates to provide axial compression. The plates are oriented to each other with the concentric arcs of each interrupted skirt at 90 degrees and the protrusion is engaged in the depression. The plates are then rotated about 90 degrees and the opposed arcs of one plate interlock with the opposed arcs of the other plate to prevent separation in the axial direction.

Claims

1. A spinal implant for placement between adjacent vertebrae to replace disk material comprising a first plate and a second plate adapted to interlock about a central axis, said first plate having a planar vertebrae engaging side and a disk side, a first interrupted skirt on said disk side extending approximately normal to said plate, said skirt formed as opposing arcs, a depression in said central axis of said disk side of said plate centrally located between said opposing arcs, said second plate having a second planar vertebrae engaging side and a second disk side, a second interrupted skirt on said second disk side extending approximately normal to said second plate, said second skirt formed as opposing arcs, a second depression in said central axis of said second disk side of said second plate centrally located between said opposing arcs and a ball universally mounted in said depressions whereby said first plate is adapted to contact a vertebrae and said second plate is adapted to contact an adjacent vertebrae with said depressions adapted to form bearing surfaces for said ball along said central axis and said first and second interrupted skirts are adapted to interlock forming a universal joint.

2. A spinal implant for placement between adjacent vertebrae of claim 1 wherein a spring in located in said central axis adapted to resiliently flex perpendicularly to said central axis whereby said first plate and said second plate are dynamically associated.

3. A spinal implant for placement between adjacent vertebrae of claim 1 wherein said first interrupted skirt and said second interrupted skirt are concentric in a plane parallel with said first and second plates, said opposed arcs of said first interrupted skirt are adapted to contact said opposed arcs of said second interrupted skirt.

4. A spinal implant for placement between adjacent vertebrae of claim 1 wherein said opposed arcs of said first interrupted skirt and said second interrupted skirt extend approximately 90 degrees relative to each of said first interrupted skirt and said second interrupted skirt, respectively.

5. A spinal implant for placement between adjacent vertebrae of claim 2 wherein said first interrupted skirt and said second interrupted skirt are concentric in a plane parallel with said first and second plates, said opposed arcs of said first interrupted skirt are adapted to contact said opposed arcs of said second interrupted skirt.

6. A spinal implant for placement between adjacent vertebrae of claim 1 wherein said first plate includes a central bore, a sleeve secured in said bore, said depression formed in said sleeve.

7. A spinal implant for placement between adjacent vertebrae of claim 2 wherein said first plate includes a central bore, an insert secured in said bore, said depression formed in said insert, said spring secured in said bore.

8. A spinal implant for placement between adjacent vertebrae of claim 1 wherein said opposed arcs of said first interrupted skirt and said opposed arcs of said second interrupted skirt are concentric segments of a circle in a plane perpendicular to said first and second plates whereby said concentric segments of said first interrupted skirt are adapted to contact said concentric segments of said second interrupted skirt to form an interlocked universal joint.

9. A spinal implant for placement between adjacent vertebrae of claim 2 wherein said opposed arcs of said first interrupted skirt and said opposed arcs of said second interrupted skirt are concentric segments of a circle in a plane perpendicular to said first and second plates whereby said concentric segments of said first interrupted skirt are adapted to contact said concentric segments of said second interrupted skirt to form an interlocked universal joint.

10. A spinal implant for placement between adjacent vertebrae of claim 1 wherein said first plate includes a cavity between said depression and said vertebrae side, an O-ring spring secured in said cavity, said ball adapted to flex said spring resulting in resilient compression.

11. A spinal implant for placement between adjacent vertebrae of claim 9 wherein said second plate includes a cavity between said second depression and said vertebrae side, a O-ring spring secured in said cavity, said protrusion adapted to flex said spring resulting in resilient compression.

12. A spinal implant for placement between adjacent vertebrae of claim 1 wherein said second plate includes a cavity between said second depression and said vertebrae side, a O-ring spring secured in said cavity, said protrusion adapted to flex said spring resulting in resilient compression.

13. A spinal implant for placement between adjacent vertebrae of claim 1 wherein a plurality of first plates of different sizes, a plurality of balls of different sizes and a plurality of second plates of different sizes comprise a kit whereby a proper sized spinal implant can be selected from said kit.

14. A spinal implant for placement between adjacent vertebrae of claim 1 wherein an elastic membrane extends between said first plate and said second plate about the periphery of said first plate and said second plate.

15. A spinal implant for placement between adjacent vertebrae of claim 14 wherein said elastic membrane is continuous and a viscous polymeric composition is located within said membrane.

16. A spinal implant for placement between adjacent vertebrae for resilient axial support comprising a first plate and a second plate, said first plate having a planar vertebrae engaging side and a disk side, a first fastener on said planar side for engaging a vertebrae, a first interrupted skirt on said disk side extending approximately normal to said plate, said first interrupted skirt formed as opposing arcs, a first centrally located bore in said first plate, an slidable insert in said bore, a depression in said disk side of said insert centrally located between said opposing arcs, said second plate having a second planar vertebrae engaging side and a second disk side, a second fastener on said second planar side for engaging a vertebrae, a second interrupted skirt on said second disk side extending approximately normal to said second plate, said second skirt formed as opposing arcs, a second centrally located bore in said second plate, a second insert in said second bore, a second depression on said second disk side of said second plate centrally located between said opposing arcs, a second centrally located bore in said second plate, a second slidable insert in said second bore, a second depression in said disk side of said second insert centrally located between said opposing arcs, a universally movable ball inserted in said depression and said second depression, said ball, said depression and said second depression forming a bearing surface, a first cover plate mounted on said planar side of said first plate closing said bore and secured to said first plate, an O-ring spring for resilient compression between said insert and said cover plate, a second cover plate mounted on said planar side of said second plate closing said second bore and secured to said second plate, a second O-ring spring for resilient compression between said second insert and said second cover plate, said first interrupted skirt and said second interrupted skirt being concentric in a plane parallel with said first and second plates, said opposed arcs of said first interrupted skirt contacting said opposed arcs of said second interrupted skirt, said opposed arcs of said first interrupted skirt and said opposed arcs of said second interrupted skirt being concentric segments of a circle in a plane perpendicular to said first and second plates whereby said concentric segments of said first interrupted skirt contact said concentric segments of said second interrupted skirt to form an interlocked universal joint.

17. A method of assembly of a resiliently spinal implant comprising the steps of:

a) providing a first plate, said first plate having a planar vertebrae engaging side and a disk side, a first interrupted skirt on said disk side extending approximately normal to said plate, said skirt formed as opposing arcs, a depression in said disk side of said plate centrally located between said opposing arcs,

b) providing a second plate having a second planar vertebrae engaging side and a second disk side, a second interrupted skirt on said second disk side extending approximately normal to said second plate, said second skirt formed as opposing arcs, a second depression in said second disk side of said second plate centrally located between said opposing arcs,

c) providing a ball and placing said ball in said depression,

d) orienting said first plate and said second plate parallel with each other with said interrupted skirt of said first plate located between said opposing arcs of said second plate,

e) moving said interrupted skirt of said first plate between said opposing arcs of said second plate and engaging said protrusion in said depression in axial alignment, and

f) rotating said first plate and said second plate about the axis relative to each other until said interrupted skirt of said first plate contacts said opposing arcs of said second plate and said ball contacts said first plate and said second plate.

18. A method of manufacture of a spinal prosthesis comprising the steps of:

a) forming a plate having a planar surface and a periphery in the general shape of the end wall of a vertebra;

b) forming a central through bore in said plate;

c) forming a depending skirt on one side of said plate between said through bore and said periphery;

d) forming an elongated sleeve having a depression in one end;

e) inserting said sleeve in said through bore with said skirt being concentric with said depression;

f) inserting a cover plate in said through bore and bonding said cover plate to said planar surface.

19. A method of manufacture of a spinal prosthesis of claim 18 comprising the steps of:

a) forming a cavity on the other end of said sleeve; and

b) inserting a spring in said cavity whereby said sleeve is resiliently movable relative to said plate.

20. A method of manufacture of a spinal prosthesis of claim 18 comprising the steps of:

a) forming a second plate having a second planar surface and a second periphery in the general shape of the end wall of a vertebra;

b) forming a second central through bore in said second plate;

c) forming a second depending skirt on one side of said second plate between said second through bore and said second periphery, said second depending skirt having a lesser diameter than said depending skirt, said depending skirt and said second depending skirt being in contact with each other;

d) forming a second elongated sleeve having a second depression in one end;

e) inserting said second sleeve in said second through bore with said second skirt being concentric with said second depression;

f) inserting a second cover plate in said second through bore and bonding said second cover plate to said second planar surface; and

g) forming a ball of a size closely approximating the size of said depression and said second depression.