Apparatus for fusion of adjacent bone structures

• US 6,190,414 B1
• Filed: 10/31/1996
• Issued: 02/20/2001
• Est. Priority Date: 10/31/1996
• Status: Expired due to Term

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: Surgical Dynamics Incorporated (Medtronic Plc)
• Inventors: Hinchliffe, Peter W.J., Young, Wayne P.
• Primary Examiner(s): Prebilic, Paul B.
• Application Number:
  US08/741,796
• Time in Patent Office: 1,573 Days
• Field of Search: 606/53, 606/60, 606/61, 606/69, 606/70, 606/71, 623/17, 623/18, 623/20, 623/17.13, 623/17.15, 623/17.16
• US Class Current: 623/17.15
• 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 2/4465 having a circular or kidney shaped cross-section substantially perpendicular to the axis of the spine
• CPC Class Codes: A61F 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• 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 2002/30176 V-shaped
• CPC Class Codes: A61F 2002/30471 connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
• CPC Class Codes: A61F 2002/30538 for adjusting angular orientation
• CPC Class Codes: A61F 2002/3055 for adjusting length
• CPC Class Codes: A61F 2002/30556 for adjusting thickness
• CPC Class Codes: A61F 2002/30565 having spring elements
• CPC Class Codes: A61F 2002/30601 telescopic
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/30787 inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30841 Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• 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 2002/4485 comprising three or more adjacent spinal implants
• CPC Class Codes: A61F 2002/4627 with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2220/0091 connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
• CPC Class Codes: A61F 2230/0054 : V-shaped
• CPC Class Codes: A61F 2250/0006 : for adjusting angular orientation
• CPC Class Codes: A61F 2250/0009 : for adjusting thickness

Abstract

A prosthetic implant for facilitating fusion of adjacent vertebrae includes an implant member dimensioned to be at least partially positioned within an intervertebral space defined between adjacent vertebrae. The implant member includes first and second vertebral engaging plates operatively connected to each other for respectively engaging vertebral end plates of the adjacent vertebrae and having discontinuous surfaces to engage the vertebral end plates and promote bone ingrowth. A displacement member is associated with the engaging plates and is deployable to cause relative movement of the engaging plates to thereby at least laterally displace the engaging plates whereby in a deployed position the engaging plates are in supportive engaged relation with the adjacent vertebrae. The first and second engaging plates are preferably pivotally connected to each other at respective end portions thereof to define a reduced entry profile to facilitate insertion within the intervertebral space. The implant member may also define an interior cavity for accommodating bone growth inducing substances. The first and second engaging plates preferably include apertures extending therethrough to permit communication with the bone growth inducing substances within the interior cavity. The first and second engaging plates may also include projections for engaging the vertebral end plates to assist retention of the implant within the intervertebral space. An apparatus and method for facilitating fusion of adjacent vertebrae are also disclosed.

Claims

1. A prosthetic implant apparatus for facilitating fusion of adjacent vertebrae, comprising an implant member dimensioned to be at least partially positioned within an intervertebral space defined between adjacent vertebrae, the implant member including first and second vertebral engaging plates pivotally connected to each other about a pivot pin extending through corresponding aligned openings of the first and second engaging plates, and adapted for relative pivotal movement to respectively engage vertebral surfaces of the adjacent vertebrae, the implant member defining a longitudinal median plane extending between the engaging plates in equidistant relation therewith, the first and second engaging plates having discontinuous surfaces to engage the vertebral surfaces and promote bone ingrowth, and a displacement member associated with the engaging plates and being movable in a transverse direction relative to the longitudinal median plane, to cause relative movement of the engaging plates, to thereby at least laterally displace the engaging plates to supportingly engage the adjacent vertebrae.

2. The apparatus according to claim 1 wherein the first and second engaging plates are pivotally connected to each other about the pivot pin at respective end portions thereof to define a reduced entry profile to facilitate insertion within the intervertebral space.

3. The apparatus according to claim 1 wherein the implant member defines an interior cavity for accommodating bone.

4. The apparatus according to claim 3 wherein the first and second engaging plates include apertures extending therethrough to permit communication with bone within the interior cavity.

5. The apparatus according to claim 4 wherein the first and second engaging plates include projections for engaging the vertebral end plates.

6. The apparatus according to claim 1 wherein the displacement member is a telescoping jack member, the telescoping jack member deployable with a remotely operable applier instrument.

7. The apparatus according to claim 6 wherein the telescoping jack member is a screw jack having a threaded portion cooperatively engageable with a threaded component wherein rotational movement of one of the screw jack and the threaded component causes corresponding telescoping motion of the screw jack and displacing movement of the first and second engaging plates.

8. The apparatus according to claim 7 wherein the threaded component is rotatable and has a spur gear associated therewith, the spur gear engageable with corresponding structure of an applier instrument.

16. An implant for facilitating fusion of adjacent vertebrae, comprising an implant member including first and second members pivotally connected and pivotally moveable relative to each other, and having first and second supporting surfaces for engaging respective vertebral surfaces of the adjacent vertebrae, the implant member defining a longitudinal median plane disposed between the first and second members in equidistant relation therewith, the first member having a threaded portion cooperatively engageable with a threaded portion of the second member, one of the threaded portions of the first and second members being rotatable about an axis which is generally transverse relative to the longitudinal plane to thereby cause corresponding relative movement of the first and second members through the cooperation of the respective threaded portions to thereby move the implant member to a deployed position wherein the first and second supporting surfaces are in oblique angular relation and contact the vertebral surfaces to maintain the adjacent vertebrae in predetermined spaced relation during healing.

17.The implant according to claim 16 wherein the first member includes an external threaded portion and the second member includes an internal threaded bore cooperatively engageable with the threaded portion of the first member to thereby cause relative movement of the first and second members upon rotation of the one of the first and second members.

18.The apparatus according to claim 1 wherein the first and second engaging plates are deployable to a deployed position such that contacting surfaces of the first and second engaging plates are in angular relation.

21. The apparatus according to claim 16 wherein the first and second members are pivotally connected about a pivot pin.

22. The apparatus according to claim 23 wherein the pivot pin is stationary relative to the first and second engaging plates.

23. The apparatus according to claim 1 wherein the pivot pin is stationary relative to the first and second engaging plates.

24. The apparatus according to claim 22 wherein the pivot pin is stationary relative to the first and second engaging plates.

9. An apparatus for facilitating fusion of adjacent vertebrae, which comprises:

an elongated member having proximal and distal ends and defining a longitudinal axis;

an implant member releasably mounted to the distal end of the elongated member, the implant member configured for insertion within an intervertebral space defined between adjacent vertebrae, the implant member including first and second separate and independent vertebral engaging plates pivotally connected to each other about a fixed pivot pin received within corresponding aligned openings defined in the first and second engaging plates, the first and second engaging plates adapted for relative pivotal movement between a retracted position and an extended position, the first and second engaging plates defining an internal cavity for reception of bone growth inducing substances and having contacting surfaces with apertures extending therethrough for communicating with the internal cavity; and

a manually operable actuator operatively connected to the implant member, the actuator moveable to cause movement of the first and second engaging plates to the extended position thereof.

10. The apparatus according to claim 9 including a displacement mechanism associated with the implant member for moving the implant member to the extended position, the displacement mechanism operatively engageable with the actuator.

17. The apparatus according to claim 9 wherein the first and second engaging plates are in angular relation when in the extended position thereof.

11. An apparatus for facilitating fusion of adjacent vertebrae, which comprises:

an elongated member having proximal and distal ends and defining a longitudinal axis;

an implant member releasably mounted to the distal end of the elongated member, the implant member configured for insertion within an intervertebral space defined between adjacent vertebrae, the implant member including first and second vertebral engaging plates pivotally connected to each other and adapted for relative pivotal movement between a retracted position and an extended position, the implant member defining a median longitudinal plane extending between the first and second engaging plates in equidistant relation therewith, the first and second engaging plates defining an internal cavity for reception of bone growth inducing substances and having contacting surfaces with apertures extending therethrough for communicating with the internal cavity and a spring operatively engageable with at least one of the first and second engaging plates to normally bias the implant member to the retracted position;

a displacement mechanism associated with the implant member for moving the implant member between the retracted and extended positions, the displacement mechanism being actuable in a direction having a transverse component relative to the longitudinal plane; and

a manually operable actuator operatively connected to the displacement mechanism, the manually operable actuator adapted for rotational movement such that rotational movement of the actuator causes movement of the displacement mechanism to thereby move the implant member between the retracted and extended positions.

12. The apparatus according to claim 11 wherein the elongated member includes a drive shaft, the drive shaft operatively connected to the actuator and the displacement mechanism, the drive shaft adapted for rotational movement upon rotation of the actuator to thereby cause movement of the displacement mechanism and corresponding movement of the implant member between the retracted and extended positions.

13. The apparatus according to claim 12 wherein the displacement mechanism includes a telescopic jack disposed between the first and second engaging plates of the implant member and operatively engageable with the drive shaft, the telescopic jack adapted for telescoping motion to cause relative movement of the first and second engaging plates between the retracted and extended positions.

14. The apparatus according to claim 13 wherein the telescopic jack is a screw jack, the screw jack cooperating with a threaded component associated with the implant such that rotational movement of one of the screw jack and threaded component causes telescopic movement of the screw jack relative to the threaded component.

15. The apparatus according to claim 14 wherein the screw jack has a spur gear associated therewith, the spur gear cooperating with a spur gear associated with the distal end of the drive shaft such that rotation of the drive shaft causes corresponding rotation of each spur gear and telescopic movement of the screw jack.

25. The apparatus according to claim 11 wherein the displacement mechanism is actuable in a transverse direction relative to the longitudinal plane.

18. A prosthetic implant for facilitating fusion of first and second adjacent vertebral portions, which comprises an implant member dimensioned to be at least partially positioned within an intervertebral space defined between adjacent vertebrae, the implant member including first and second separate and independent members pivotally connected about a fixed pivot pin extending through corresponding aligned openings of the first and second members, the first and second members having contacting surfaces for respectively engaging first and second adjacent vertebral portions, the first and second members pivotally movable about a fixed axis of rotation defined by the pivot pin from an initial position to facilitate insertion between the first and second vertebral portions to a deployed position wherein the contacting surfaces of the first and second members are in oblique angular relation and support the first and second vertebral portions in spaced relation.

20. The apparatus according to clam 11 wherein the first and second engaging plates are pivotally connected about a pivot pin received within corresponding aligned openings of the first and second engaging plates.

19. The implant according to claim 20 wherein the first and second members each include apertures extending therethrough to permit communication with an interior space defined between the first and second members when in the deployed position thereof.

26. A prosthetic implant for positioning between adjacent vertebrae, which comprises an implant member dimensioned to be at least partially positioned within an intervertebral space defined between adjacent vertebrae, the implant member including first and second members, each member having contacting surfaces for respectively engaging first and second adjacent vertebral portions, and means for pivotally mounting the first and second members to permit pivotal movement of the first and second members between an initial position to facilitate insertion between the first and second vertebral portions to a deployed position wherein the contacting surfaces of the first and second members are in oblique angular relation and support the first and second vertebral portions in spaced relation, wherein the means for pivotally mounting includes a pivot pin, the pivot pin defining a fixed axis of rotation, the first and second members being pivotally movable about the first axis of rotation of the pivot pin.

27. The prosthetic implant according to claim 28 wherein the pin is mounted with respect to the first and second members wherein movement of the first and second members is solely restricted to pivotal movement about the fixed axis of rotation.