Expandable osteosynthesis cage

• US 6,129,763 A
• Filed: 07/28/1998
• Issued: 10/10/2000
• Est. Priority Date: 09/13/1996
• Status: Expired due to Term

• Current Assignee: Wenzel Spine, Inc.
• Original Assignee: Cage Concepts
• Inventors: Attia, David, Chauvin, Jean-Luc, Attali, David
• Primary Examiner(s): Mancene, Gene
• Assistant Examiner(s): Robert, Eduardo C.
• Application Number:
  US09/117,469
• Time in Patent Office: 805 Days
• Field of Search: 623/16, 623/17, 606/61, 606/62, 606/63, 606/68, 606/73, 606/66, 606/60, 433/173, 433/174, 411/395, 411/396, 411/397, 411/411, 411/418, 411/32, 411/913
• US Class Current: 623/17.11
• CPC Class Codes: A61F 2/30724 Spacers for centering an implant in a bone cavity, e.g. in a cement-receiving cavity
• CPC Class Codes: A61F 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• 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 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• CPC Class Codes: A61F 2/4601 for introducing bone substitute, for implanting bone graft implants or for compacting them in the bone cavity
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2/4637 for connecting or disconnecting two parts of a prosthesis
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30112 Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2002/30115 circular-O-shaped
• CPC Class Codes: A61F 2002/30143 hexagonal
• CPC Class Codes: A61F 2002/30154 square
• CPC Class Codes: A61F 2002/3021 frustoconical
• CPC Class Codes: A61F 2002/30217 hollow cones, e.g. tubular-like cones
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30225 Flat cylinders, i.e. discs
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30253 ellipsoidal or ovoid
• CPC Class Codes: A61F 2002/30332 Conically- or frustoconically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/30367 : with additional means for preventing said rotation
• CPC Class Codes: A61F 2002/3037 : Translation along the common longitudinal axis, e.g. piston
• CPC Class Codes: A61F 2002/30403 : Longitudinally-oriented cooperating ribs and grooves on mating lateral surfaces of a mainly longitudinal connection
• CPC Class Codes: A61F 2002/30405 : made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30421 : Rounded threads
• CPC Class Codes: A61F 2002/305 : Snap connection
• CPC Class Codes: A61F 2002/30538 : for adjusting angular orientation
• CPC Class Codes: A61F 2002/30579 : with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30593 : hollow
• 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 2002/30622 : Implant for fusing a joint or bone material
• CPC Class Codes: A61F 2002/30774 : internally-threaded
• CPC Class Codes: A61F 2002/30795 : Blind bores, e.g. of circular cross-section
• CPC Class Codes: A61F 2002/3085 : with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• 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 2230/0004 : Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2230/0017 : Angular shapes
• CPC Class Codes: A61F 2230/0021 : square
• 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 2250/0006 : for adjusting angular orientation

Abstract

An expandable osteosynthesis implant has branches (5) each connected at one end to a seat (7) which is pierced by an orifice (8), suitable for being slid from a posterior direction between the facing faces of two consecutive vertebrae in order to hold them a given distance apart and restore stability of the spinal column. According to the invention, the branches (5) and the seat (7) define a hollow cage (1) which, in a "rest" position, has an outside general shape that is a cylinder of circular section, and a portion at least of the inside volume (9) of the cage (1) towards the distal ends of the branches (5) is in the form of a circular truncated cone whose large base is towards the seat (7), which implant has at least three branches (5) and, inside the inside volume (9) at least one spacer (2) suitable for passing through the orifice (8) and the large base of the truncated cone.

Claims

1. An expandable osteosynthesis implant comprising at least three branches, each branch having distal and proximal ends and each branch being connected to a seat, the seat having at least two flats each disposed between two successive branches, the seat being pierced by an orifice, the branches and the seat constituting a hollow cage which, in an unexpanded position, has an outside general shape which is quasi-cylindrical of quasi-circular section, and at least a portion of an inside volume of the cage near the distal ends of the branches forming a quasi-circular truncated cone with a base near said seat, and within said inside volume at least one spacer adapted to fit within the base of the truncated cone, such that once the spacer has been placed within the base, a hollow region is created in the space defined by said branches, at least one spacer, and the orifice.

2. An implant according to claim 1, wherein at least one intermediate, second spacer is disposed within said hollow region.

3. An implant according to claim 1, wherein bone material is disposed within said hollow region.

4. An implant according to claim 3, wherein a plug is disposed within said orifice.

5. An implant according to claim 4, wherein said implant comprises at least four branches.

6. An expandable osteosynthesis implant comprising at least three branches, each branch having distal and proximal ends and inside and outside surfaces, and a seat pierced by an orifice, the branches and the seat constituting a hollow cage which, in an unexpanded position, has an outside general shape which is quasi-cylindrical of quasi-circular section, and at least a portion of an inside volume of the cage near the distal ends of the branches forming a quasi-circular truncated cone with a base near said seat, and within said inside volume at least one spacer adapted to fit within the base of the truncated cone, said at least one spacer including at least two splines disposed symmetrically about the axis of the implant, a width e of the splines being no greater than a desired gap distance between the distal ends of two adjacent branches, the inside surfaces of the branches being smooth and defining an inside volume within the cage, said volume having an axial housing at its distal end suitable for receiving the spacer and for holding it by means of a shoulder of diameter greater than a diameter of the inside volume of the cage in an expanded position, such that once the spacer has been placed within the base, a hollow region is created in the space defined by said branches, at least one spacer, and the orifice.

7. An implant according to claim 6, wherein at least one intermediate, second spacer is disposed within said hollow region.

8. An implant according to claim 6, wherein bone material is disposed within said hollow region.

9. An implant according to claim 8, wherein a plug is disposed within said orifice.

10. An implant according to claim 9, wherein said implant comprises at least four branches.