Fusion mass constrainer

• US 5,683,394 A
• Filed: 09/29/1995
• Issued: 11/04/1997
• Est. Priority Date: 09/29/1995
• Status: Expired due to Fees

• Current Assignee: Encore Medical Asset Corporation (Enovis Corp.)
• Original Assignee: Advanced Spine Fixation Systems, Inc. (Enovis Corp.)
• Inventors: Rinner, James A.
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): Shai, Daphna
• Application Number:
  US08/537,077
• Time in Patent Office: 767 Days
• Field of Search: 606/86, 606/60, 606/61, 623/17, 623/16
• US Class Current: 606/86.00R
• 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 2/4611 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 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30158 trapezoidal
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30261 parallelepipedal
• CPC Class Codes: A61F 2002/3028 polyhedral different from parallelepipedal and pyramidal
• 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 2002/30372 with additional means for limiting said translation
• 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 2002/30428 made by inserting a protrusion into a slot
• CPC Class Codes: A61F 2002/30576 with extending fixation tabs
• 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 2002/30772 : Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30774 : internally-threaded
• CPC Class Codes: A61F 2002/30777 : Oblong apertures
• CPC Class Codes: A61F 2002/30795 : Blind bores, e.g. of circular cross-section
• CPC Class Codes: A61F 2002/3082 : Grooves
• CPC Class Codes: A61F 2002/30845 : with cutting edges
• CPC Class Codes: A61F 2002/448 : comprising multiple adjacent spinal implants within the same intervertebral space or within the same vertebra, e.g. comprising two adjacent spinal implants
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• 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 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0026 : trapezoidal
• CPC Class Codes: A61F 2230/0063 : Three-dimensional shapes
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0082 : parallelepipedal
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys

Abstract

A bone fusion mass constrainer is useful for promoting fusion between a pair of adjacent vertebrae. The bone fusion mass constrainer includes a generally cylindrical cage assembly having an internal cavity with open top and bottom surfaces. The cage portion is intended to be positioned in contact with the cancellous bone of the adjacent vertebrae. A pair of horizontal platforms extend out from the cage assembly and provide support for the vertebrae by contacting the harder cortical bone of the endplates of the vertebrae. Bone graft is inserted into the cavity where it contacts the cancellous bone of the adjacent vertebrae and promotes fusion between the two vertebrae. An end cap is provided over the proximal opening of the cage assembly to prevent migration of bone graft out from the cage. The bone fusion mass constrainer also includes a pair of blades which can be extended outwardly from the cage assembly and into the cancellous bone of the adjacent vertebrae in order to prevent migration of the device from between the vertebrae.

Claims

1. A bone fusion mass constrainer for insertion between a pair of adjacent vertebrae to promote fusion between the vertebrae comprising:

a cage assembly defining an inner cavity for containing bone graft;

a pair of opposed platforms for providing support to the adjacent vertebrae;

a pair of blades extendable from the cage assembly for anchoring the cage assembly between the adjacent vertebrae; and

an end cap for closing the inner cavity and including means for extending the blades from the cage assembly.

2. A bone fusion mass constrainer for insertion between a pair of adjacent vertebrae to promote fusion between the vertebrae comprising:

a cage assembly defining a longitudinal inner cavity with an open end and further defining a plurality of openings allowing communication between the inner cavity and the vertebrae to be fused;

a pair of opposed platforms extending from the cage assembly; and

an end cap for closing the open end of the cage assembly, the end cap including a pair of blades for extending from the cage assembly into at least one of the vertebrae to be fused upon rotation of the end cap.

3. A bone fusion mass constrainer for insertion between a pair of adjacent vertebrae to promote fusion between the vertebrae comprising:

a generally cylindrical cage assembly, the cage assembly comprising;

a longitudinal inner cavity;

first and second ends, the first end being closed and the second end having a proximal opening in communication with the inner cavity; and

a pair of surface openings through an outer surface of the cage assembly and into the inner cavity;

a pair of platforms extending longitudinally along the outer surface of the cage assembly and outwardly from the cage assembly;

an end cap for closing the proximal opening of the cage assembly; and

a pair of blades integral to the end cap for extending outwardly from the cage assembly upon rotation of the end cap.

4. A method for promoting fusion between a pair of adjacent vertebrae comprising the steps of:

exposing a portion of the cancellous bone of each of the pair of vertebrae;

inserting a bone fusion mass constrainer between the vertebrae, the bone fusion mass constrainer having an inner cavity, and a pair of surface openings in communication with the inner cavity, the bone fusion mass constrainer placed such that the surface openings communicate with the cancellous bone of the pair of vertebrae;

inserting bone graft into the inner cavity; and

extending a pair of blades from the bone fusion mass constrainer into the cancellous bone of the pair of vertebrae to anchor the bone fusion mass constrainer in place.

5. A bone fusion mass constrainer for insertion between a pair of adjacent vertebrae to promote fusion between the vertebrae comprising:

a cage assembly defining a longitudinal inner cavity with an open end and further defining a plurality of openings allowing communication between the inner cavity and the vertebrae to be fused;

a pair of opposed platforms extending from the cage assembly;

at least one blade extendable from the cage assembly into at least one of the vertebrae to be fused; and

an end cap for closing the open end of the cage assembly and including means for extending the at least one blade from the cage.

6. The bone fusion mass constrainer of claim 5 wherein the means for extending the at least one blade comprises a cam.

7. The bone fusion mass constrainer of claim 5 wherein each of the pair of platforms defines a pair of parallel platform surfaces.

8. The bone fusion mass constrainer of claim 5 wherein each of the pair of platforms defines a first platform surface and a second platform surface, the first platform surfaces being at an angle of less than about 10 degrees from parallel to the second platform surfaces.

9. A bone fusion mass constrainer for insertion between a pair of adjacent vertebrae to promote fusion between the vertebrae comprising:

a generally cylindrical cage assembly, the cage assembly comprising;

a longitudinal inner cavity;

first and second ends, the first end being closed and the second end having a proximal opening in communication with the inner cavity;

a pair of surface openings through an outer surface of the cage assembly and into the inner cavity; and

a pair of opposed slots;

a pair of platforms extending longitudinally along the outer surface of the cage assembly and outwardly from the cage assembly;

an end cap for closing the proximal opening of the cage assembly; and

a pair of blades for extending outwardly from the slots of the cage assembly and into the vertebrae.

10. The bone fusion mass constrainer of claim 9 wherein the end cap includes a pair of cams for extending the pair of blades outwardly from the bone cage.

11. The bone fusion mass constrainer of claim 9 wherein each of the pair of platforms defines a first platform surface and a second platform surface, the first platform surfaces being at an angle of less than 10 degrees from parallel to the second platform surfaces.

12. The bone fusion mass constrainer of claim 9 wherein each of the pair of platforms defines a first platform surface and a second platform surface, the first platform surfaces being parallel to the second platform surfaces.