Human spinal disc prosthesis

• US 6,156,067 A
• Filed: 05/15/1997
• Issued: 12/05/2000
• Est. Priority Date: 11/14/1994
• Status: Expired due to Fees

• Current Assignee: Medtronic Sofamor Danek Incorporated (Medtronic Plc)
• Original Assignee: Spinal Dynamics Corporation (Medtronic Plc)
• Inventors: Kunzler, Alex, Bryan, Vincent
• Primary Examiner(s): Isabella, David J.
• Assistant Examiner(s): Nguyen, Tram A.
• Application Number:
  US08/856,846
• Time in Patent Office: 1,300 Days
• Field of Search: 623/16.11-18.11, 606/61, 606/72, 606/73
• US Class Current: 623/17.15
• CPC Class Codes: A61B 17/686 Plugs, i.e. elements forming interface between bone hole and implant or fastener, e.g. screw
• CPC Class Codes: A61B 17/7059 Cortical plates A61B17/7007, A61B17/7058 take precedence
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable or resorptive
• CPC Class Codes: A61F 2/08 Muscles; Tendons; Ligaments sutures A61B17/04
• 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 2/30771 applied in original prostheses, e.g. holes or grooves
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2/4425 made of articulated components
• CPC Class Codes: A61F 2002/30016 differing in hardness, e.g. Vickers, Shore, Brinell
• CPC Class Codes: A61F 2002/30069 elastomeric
• CPC Class Codes: A61F 2002/30113 circular
• CPC Class Codes: A61F 2002/30168 L-shaped
• CPC Class Codes: A61F 2002/302 toroidal, e.g. rings
• CPC Class Codes: A61F 2002/30214 having tapered sections of different conicities
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30253 ellipsoidal or ovoid
• 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 2002/30405 made by screwing complementary threads machined on the parts themselves
• 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 2002/30451 : soldered or brazed or welded
• CPC Class Codes: A61F 2002/30461 : sutured, ligatured or stitched
• CPC Class Codes: A61F 2002/30462 : retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/30469 : using band clamps
• CPC Class Codes: A61F 2002/30474 : using an intermediate sleeve interposed between both prosthetic parts to be coupled
• CPC Class Codes: A61F 2002/30487 : Circumferential cooperating grooves and beads on cooperating lateral surfaces of a mainly longitudinal connection
• CPC Class Codes: A61F 2002/30495 : using a locking ring
• CPC Class Codes: A61F 2002/30507 : using a threaded locking member, e.g. a locking screw or a set screw
• 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 2002/30576 : 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 2002/30594 : slotted, e.g. radial or meridian slot ending in a polar aperture, non-polar slots, horizontal or arcuate slots
• CPC Class Codes: A61F 2002/30599 : stackable
• CPC Class Codes: A61F 2002/30624 : Hinged joint, e.g. with transverse axle restricting the movement
• 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 2002/30772 : Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/443 : having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2002/449 : comprising multiple spinal implants located in different intervertebral spaces or in different vertebrae
• 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 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2220/005 : using adhesives
• 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 2230/0006 : circular
• CPC Class Codes: A61F 2230/0043 : L-shaped
• CPC Class Codes: A61F 2230/0065 : toroidal, e.g. ring-shaped, doughnut-shaped
• CPC Class Codes: A61F 2230/0067 : conical
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0076 : ellipsoidal or ovoid
• CPC Class Codes: A61F 2250/0019 : differing in hardness, e.g. Vickers, Shore, Brinell
• CPC Class Codes: A61F 2250/0063 : Nested prosthetic parts
• 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: Y10S 606/907 : Composed of particular material or coated
• CPC Class Codes: Y10S 606/91 : Polymer

Abstract

The invention relates to a spinal disc endoprosthesis. The endoprosthesis has a resilient body formed of one or more materials which may vary in stiffness from a relatively stiff exterior annular gasket portion to a relatively supple central nucleus portion. Concaval-convex elements at least partly surround that nucleus portion so as to retain the nucleus portion and gasket between adjacent vertebral bodies in a patient'"'"'s spine. Assemblies of endoprosthetic discs, endoprosthetic vertebral bodies, and endoprosthetic longitudinal ligaments may be constructed. To implant this endoprosthesis assembly, information is obtained regarding the size, shape, and nature of a patient'"'"'s damaged spine. Thereafter, one or more prosthetic vertebral bodies and disc units are constructed in conformity with that information. Finally, the completed and conformed vertebral body and disc assembly is implanted in the patient'"'"'s spine.

Claims

1. A vertebral disc endoprosthesis comprising relatively rigid superior and inferior concaval-convex elements, each element having an outer surface of predetermined convexity and unreticulated surface roughness for engaging adjacent bone structure which has been milled to mate with said outer convex surface for encouraging bone ingrowth into the mating outer convex surface, each concaval-convex element also having a continuous, smooth non-porous inner concave surface extending substantially across the entire concaval-convex element, and disposed to confront the opposed concaval-convex element smooth concave surface;

the endoprosthesis also comprising a solid but relatively resilient convex nuclear body located between the confronting concave surfaces of the adjacent concaval-convex elements, the nuclear body engaging but being separate from the adjacent concave surfaces to permit sliding arcuate movement of the concave surfaces over the resilient nuclear body.

2. The vertebral disc endoprosthesis according to claim 1 wherein each concaval-convex element is of relatively constant cross-sectional thickness.

3. The vertebral disc endoprosthesis according to claim 1 wherein said resilient nuclear body comprises a relatively resilient central body, wherein the endoprosthesis further includes a gasket surrounding a circumference of the central body, the resilient nuclear body snugly engaging the adjacent, mating concave surfaces of the concaval-convex elements.

4. The vertebral disc endoprosthesis according to claim 3 wherein the gasket is stiffer than the resilient nuclear body.

5. The vertebral disc endoprosthesis according to claim 3 wherein the concaval-convex elements do not engage one another.

6. The vertebral disc endoprosthesis according to claim 1 wherein the resilient convex nuclear body is shaped and sized, relative to the concave surfaces of the concaval-convex elements, so as to be inhibited from expulsion from the endoprosthesis.