Expandable vertebral implant and methods of use

• US 20070270964A1
• Filed: 04/27/2006
• Published: 11/22/2007
• Est. Priority Date: 04/27/2006
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Inventors: Veldman, Michael, Strohkirch, Terrance, Taylor, Harold
• Granted Patent: US 8,187,331 B2
• Time in Patent Office: Days
• US Class Current: 623/17.110
• CPC Class Codes: A61B 2017/0256 for the spine
• CPC Class Codes: A61F 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• 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 2/4637 for connecting or disconnecting two parts of a prosthesis
• CPC Class Codes: A61F 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• 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 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30136 undulated or wavy, e.g. serpentine-shaped or zigzag-shaped
• CPC Class Codes: A61F 2002/30171 rosette- or star-shaped
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• 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 2002/30372 with additional means for limiting said translation
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/3052 unrestrained in only one direction, e.g. moving unidirectionally
• CPC Class Codes: A61F 2002/30522 releasable, e.g. using a releasable ratchet
• CPC Class Codes: A61F 2002/30523 by means of meshing gear teeth
• CPC Class Codes: A61F 2002/3054 about a connection axis or implantation axis for selecting any one of a plurality of radial orientations between two modular parts, e.g. Morse taper connections, at discrete positions, angular positions or continuous positions
• CPC Class Codes: A61F 2002/3055 : for adjusting length
• CPC Class Codes: A61F 2002/30571 : Leaf springs
• CPC Class Codes: A61F 2002/30574 : with an integral complete or partial collar or flange
• 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 2002/30601 : telescopic
• CPC Class Codes: A61F 2002/30616 : Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30677 : Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/30772 : Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30777 : Oblong apertures
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30892 : parallel
• 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 2002/4628 : with linear motion along or rotating motion about an axis transverse to the instrument axis or to the implantation direction, e.g. clamping
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2210/0014 : using shape memory or superelastic materials, e.g. nitinol
• 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 2230/005 : Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2310/00011 : Metals or alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00359 : Bone or bony tissue

Abstract

An implant for insertion between vertebral members in which an inner member, intermediate member, and outer member are concentrically disposed. The inner and outer members may comprise end plates to contact the vertebral members. The outer member may include a tapered interior wall. A locking element is movably contained within an opening that extends through a sidewall of the intermediate member. The intermediate member is displaceable longitudinally in first and second directions relative to the outer member. Displacement of the intermediate member in the first direction tends to force the locking element laterally into contact with the inner and outer members. A biasing member may urge the intermediate member in the first direction. Displacement of the intermediate member in the second direction allows the locking element to be laterally displaced out of contact with the inner member.

Claims

1. An implant for insertion between vertebral members in a patient comprising:

an outer member including a first end to contact a first of the vertebral members;

an inner member including a second end to contact a second of the vertebral members;

an intermediate member disposed so as to overlap within the outer member, the intermediate member being displaceable longitudinally in first and second directions relative to the outer member, the intermediate member further having a longitudinal channel to contain the inner member and a lateral opening into the channel; and

a locking element disposed at least partly within the opening and movable with respect thereto;

displacement of the intermediate member in the first direction forces the locking element inward toward the inner member;

displacement of the intermediate member in the second direction allows the locking element to be outwardly displaced away from the inner member.

2. The implant of claim 1, wherein the locking element includes a diameter that is greater than a width of the opening.

3. The implant of claim 2 wherein the locking element includes a spherical shape.

4. The implant of claim 2 wherein the locking element includes a cylindrical shape.

5. The implant of claim 1, wherein a section of the intermediate member is disposed outside of the outer member.

6. The implant of claim 1, wherein the outer member includes a tapered inner wall with displacement of the intermediate member in the first direction moving the locking element into a narrowed section of the outer member and displacement in the second direction moving the locking element into an enlarged section of the outer member.

7. The implant of claim 1, wherein the opening is substantially perpendicular to the channel.

8. The implant of claim 1, wherein the outer, intermediate, and inner members each include a cylindrical body.

9. The implant of claim 1, wherein the outer, intermediate, and inner members each include an asymmetric cross section within a plane substantially perpendicular to a longitudinal axis of the implant.

10. The implant of claim 1 wherein the first end is oriented at a first angle relative to a longitudinal axis of the implant.

11. The implant of claim 1 wherein the second end is oriented at a second angle relative to a longitudinal axis of the implant.

12. An implant for insertion between vertebral members in a patient comprising:

a first member including a first end to contact a first of the vertebral members;

a second member concentrically coupled to the first member and including a second end to contact a second of the vertebral members; and

a locking element movably contained within the implant and disposed in contact with the second member and a tapered surface of the first member;

the second member being displaceable longitudinally in first and second directions relative to the first member with displacement of the second member in the first direction forcing the locking element to move relative to the tapered surface to provide a clearance between the first member, the second member, and the locking element, and

displacement of the second member in the second direction forcing the locking element to move relative to the tapered surface to create an interference between the first member, the second member, and the locking element.

13. The implant of claim 12, wherein the second member is at least partially disposed within the first member.

14. The implant of claim 12, wherein the first and second members each include an asymmetric cross section within a plane substantially perpendicular to the first and second directions.

15. The implant of claim 12, further comprising a third member sized to fit at least partially within the first member, the locking element disposed in an opening in the third member that extends through a sidewall of the third member.

16. The implant of claim 15, wherein the third member is displaceable longitudinally in the first and the second directions, displacement of the third member in the first direction allows the locking element to be displaced out of contact with the second member, and displacement of the third member in the second direction forcing the locking element laterally into contact with the second member.

17. The implant of claim 12, wherein the tapered surface is disposed at an interior wall of the first member.

18. The implant of claim 12, wherein the tapered surface is formed by a slanted opening in the first member that extends through a sidewall of the first member.

19. An implant for insertion between vertebral members in a patient comprising:

a first member including a first end to contact a first of the vertebral members, the first member including an interior section formed by a sidewall, the interior section having a tapered portion that extends between a first level having a first width and a second level having a reduced second width;

a second member movably disposed within the interior section and having a channel;

a third member including a second end to contact a second of the vertebral members, the third member movably disposed within the channel;

a locking element sized to move within an opening in the second member, the locking element having a width greater than the opening;

the second member movable relative to the first member between an unlocked position with the opening positioned in proximity to the first level with the locking element freely movable within the opening, and a locked position with the opening positioned in proximity to the second level with the locking element being forced into contact with the sidewall and the third member.

20. The implant of claim 19, further comprising a biasing member operatively connected to the first member to maintain the second member positioned within the interior section of the first member.

21. The implant of claim 19, further comprising a biasing member operatively connected to the first member to bias the second member towards the locked position.

22. The implant of claim 19, further comprising a second locking element positioned within a second opening in the second member, the second locking element positioned in a common vertical plane with the locking element.

23. The implant of claim 19, wherein the locking element includes a spherical shape.

24. The implant of claim 19, wherein the locking element includes a cylindrical shape.

25. The implant of claim 19, wherein a portion of the second member extends outward from the first member in both the locked and unlocked positions.

26. The implant of claim 19, wherein the first, second, and third members each include a cylindrical body.

27. The implant of claim 19, wherein the first, second, and third members each include an asymmetric cross section within a plane substantially perpendicular to a longitudinal axis.

28. A method of inserting an implant between vertebral members in a patient, the method comprising the steps of:

inserting the vertebral implant between the vertebral members;

compressing an inner member longitudinally relative to a concentric outer member and moving a locking element laterally toward the inner member; and

distracting the inner member longitudinally relative to the outer member and moving the locking element laterally away from the inner member.

29. The method of claim 28, wherein the step of moving a locking element laterally toward the inner member comprises contacting the locking element against a tapered section of the outer member.

30. The method of claim 28, wherein the step of moving a locking element laterally comprises confining the locking element within an intermediate member disposed between the inner and outer members.

31. The method of claim 30 further comprising moving the intermediate member in a longitudinal direction out of the outer member and moving the locking element laterally away from the inner member.

32. The method of claim 28, further comprising forcing the locking element laterally toward the inner member and into contact with both the outer member and the inner member to prevent compression of the inner and outer members.

33. A method of inserting an implant between vertebral members in a patient, the method comprising the steps of:

inserting the vertebral implant between the vertebral members, the vertebral implant including a longitudinal axis and including a inner member, an intermediate member, and an outer member disposed concentrically;

moving the inner member longitudinally out of the outer member to expand the device; and

moving the intermediate member longitudinally out of the outer member and simultaneously forcing the inner member longitudinally into the outer member to compress the implant.

34. The method of claim 33, wherein the step of moving the inner member longitudinally out of the outer member comprises moving a locking element laterally away from the inner member.

35. The method of claim 33, wherein the step of moving the intermediate member longitudinally out of the outer member comprises moving a locking element laterally away from the inner member.

36. An implant for insertion between vertebral members in a patient comprising:

an outer member including a first end to contact a first of the vertebral members and a tapered inner diameter;

an inner member including a second end to contact a second of the vertebral members, each of the inner and outer members including a cross section shape with a linear sidewall;

an intermediate member disposed at least partially within the outer member and around the inner member with each of the members being aligned along a common longitudinal axis;

a locking element disposed at least partly within an opening within the intermediate member and movable with respect thereto, the locking element including a flattened shape that is complementary to the linear sidewalls;

the intermediate member being displaceable along the longitudinal axis in first and second directions relative to the outer member, displacement of the intermediate member in the first direction forces the locking element against the tapered inner diameter of the outer member and radially inward toward the inner member, displacement of the intermediate member in the second direction allows the locking element to be outwardly displaced away from the inner member.

37. The implant of claim 36, wherein the locking element includes a cylindrical shape with first and second substantially straight sides.

38. The implant of claim 36, wherein cross section shapes of the inner and outer members are substantially D-shaped.

39. The implant of claim 36, wherein cross section shapes of the inner and outer members are substantially polygonal.

40. The implant of claim 36, further comprising a second locking element positioned at least partly within a second opening in the intermediate member,

41. The implant of claim 36, wherein the intermediate member includes a cross section shape that is substantially similar to the inner and outer members.

42. An implant for insertion between vertebral members in a patient comprising:

a first cylindrical member including a first end to contact a first of the vertebral members and including a tapered inner diameter;

a second cylindrical member concentrically coupled to the first member and including a second end to contact a second of the vertebral members, each of the first and second members including a cross section shape with a linear section; and

a locking element movably contained between the first and second cylindrical members and positioned to contact the linear sections of the first and second members;

the second member being displaceable longitudinally in first and second directions relative to the first member with displacement of the second member in the first direction forcing the locking element to contact a reduced section of the tapered inner diameter of the first cylindrical member to create an interference between the first member, the second member, and the locking element, and

displacement of the second member in the second direction positions the locking element at an enlarged section of the tapered inner diameter of the first cylindrical member to provide a clearance between the first member, the second member, and the locking element.

43. The implant of claim 42, wherein the second member is at least partially disposed within the first member.

44. The implant of claim 42, wherein the locking element is substantially cylindrical.

45. The implant of claim 42, wherein the cross section shape of the first and second cylindrical members is substantially D-shaped.

46. The implant of claim 42, wherein the cross section shape of the first and second cylindrical members is substantially rectangular.

47. The implant of claim 42, wherein the cross section shape of the first and second cylindrical members is substantially triangular.

48. The implant of claim 42, wherein the cross section shape of the first and second cylindrical members is substantially polygonal.