EXPANDABLE SPINAL IMPLANTS

• US 20160166396A1
• Filed: 12/10/2015
• Published: 06/16/2016
• Est. Priority Date: 12/11/2014
• Status: Active Grant

• Current Assignee: K2M, Inc (Stryker Corporation)
• Original Assignee: K2M, Inc (Stryker Corporation)
• Inventors: McClintock, Larry
• Granted Patent: US 10,363,142 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61F 2/30771 applied in original prostheses, e.g. holes or grooves
• 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 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 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2002/30538 for adjusting angular orientation
• CPC Class Codes: A61F 2002/30556 for adjusting thickness
• 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 2002/30843 Pyramidally-shaped
• CPC Class Codes: A61F 2002/30904 serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/443 having two transversal endplates and at least one intermediate component
• CPC Class Codes: A61F 2250/0008 for adjusting a position by translation along an axis or two perpendicular axes

Abstract

A spinal implant has a proximal region and a distal region, and includes an upper body and a lower body each having inner surfaces disposed in opposed relation relative to each other. A proximal adjustment assembly is disposed between the upper and lower bodies at the proximal region of the spinal implant and is adjustably coupled to the upper and lower bodies, and a distal adjustment assembly is disposed between the upper and lower bodies at the distal region of the spinal implant and is adjustably coupled to the upper and lower bodies. The proximal and distal adjustment assemblies are independently movable with respect to each other to change a vertical height of at least one of the proximal region or the distal region of the spinal implant.

Claims

1. A spinal implant having a proximal region and a distal region, the spinal implant comprising:

an upper body including an outer surface and an inner surface;

a lower body including an outer surface and an inner surface, the inner surfaces of the upper and lower bodies disposed in opposed relation relative to each other;

a proximal adjustment assembly disposed between the upper and lower bodies at the proximal region of the spinal implant and adjustably coupled to the upper and lower bodies; and

a distal adjustment assembly disposed between the upper and lower bodies at the distal region of the spinal implant and adjustably coupled to the upper and lower bodies,

wherein the proximal and distal adjustment assemblies are independently movable to change a vertical height of at least one of the proximal region or the distal region of the spinal implant.

2. The spinal implant according to claim 1, wherein the proximal adjustment assembly includes a ramp slidably movable along the proximal region of the spinal implant to change the vertical height of the proximal region of the spinal implant.

3. The spinal implant according to claim 2, wherein the ramp includes upper and lower rails that taper from a proximal end towards a distal end of the ramp, and wherein the distal end of the ramp is disposed between the upper and lower bodies, and the ramp is slidable between the upper and lower bodies to increase the vertical height of the proximal region of the spinal implant.

4. The spinal implant according to claim 3, wherein each of the upper and lower rails includes an inner surface having a plurality of grooves extending along a length thereof, and the proximal adjustment assembly further includes:

a first set of pins coupled to the inner surface of the upper body and positioned against the inner surface of the upper rails; and

a second set of pins coupled to the inner surface of the lower body and positioned against the inner surface of the lower rails,

such the first and second sets of pins ride along the plurality of grooves of the upper and lower rails during movement of the ramp.

5. The spinal implant according to claim 1, wherein the distal adjustment assembly includes a pivot linkage assembly including an upper pivot linkage pivotably connected to the inner surface of the upper body and a lower pivot linkage pivotably connected to the inner surface of the lower body, the upper and lower pivot linkages pivotably connected to each other and movable with respect to each other to change the vertical height of the distal region of the spinal implant.

6. The spinal implant according to claim 5, wherein the distal adjustment assembly includes a curved plate having a curved distal surface movable into and out of contact with the pivot linkage assembly to effect movement of the upper and lower pivot linkages with respect to each other.

7. The spinal implant according to claim 6, wherein the distal adjustment assembly includes a threaded post including a distal end retained against a proximal surface of the curved plate, wherein axial movement of the threaded post moves the curved plate.

8. The spinal implant according to claim 7, wherein the distal adjustment assembly includes a bracket including a threaded opening and a pair of legs extending distally therefrom, wherein the threaded post is threadingly engaged with the threaded opening of the bracket and is axially movable therethrough, and wherein the curved plate is slidably disposed between the pair of legs of the bracket, and the upper and lower pivot linkages are pivotable connected to each other by a pin extending through the upper and lower pivot linkages and a distal end of the pair of legs of the bracket.

9. The spinal implant according to claim 5, wherein the distal adjustment assembly includes a threaded post including a distal end movable into and out of contact with the pivot linkage assembly to effect movement of the upper and lower pivot linkages with respect to each other.

10. The spinal implant according to claim 9, wherein the distal adjustment assembly includes an expander including a body portion defining a cavity therein and a distal end including a double ramped inner surface, wherein the pivot linkage assembly extends through the cavity of the expander such that the upper and lower pivot linkages contact the double ramped inner surface of the expander when moved by the threaded post.

11. The spinal implant according to claim 10, wherein the expander includes a shaft extending proximally from the body portion, the shaft including a threaded opening defined therein, and wherein the threaded post is threadingly engaged with the threaded opening of the shaft and axially movable therethrough into the cavity of the expander.

12. The spinal implant according to claim 9, wherein each of the inner surfaces of the upper and lower bodies includes a pair of proximal fins defining angled slots therethrough, and wherein the proximal adjustment assembly includes:

a linkage body including a pair of arms extending along lateral sides thereof, each arm of the pair of arms including a distal hole; and

a first set of pins disposed within the distal holes of the linkage body and into the angled slots of the upper and lower bodies,

such that movement of the linkage body causes the first set of pins to translate within the angled slots to change the vertical height of the proximal region of the spinal implant.

13. The spinal implant according to claim 12, wherein the proximal adjustment assembly includes a flange nut having a threaded opening defined therethrough that is threadingly engaged with the threaded post of the distal adjustment assembly, and the linkage body includes a recess in which a distal flange of the flange nut is disposed, such that axial movement of the flange nut along the threaded post effects movement of the linkage body.

14. The spinal implant according to claim 13, wherein the pair of proximal fins of the upper and lower bodies defines vertical slots therethrough, and wherein the proximal adjustment assembly includes a coupler that includes a pair of nubs extending from lateral sides thereof that is slidably disposed within the vertical slots of the upper and lower bodies.

15. The spinal implant according to claim 9, wherein side surfaces of the upper and lower bodies include angled slots defined therethrough, and wherein the proximal adjustment assembly includes a bracket assembly including a plurality of nubs slidably disposed within the angled slots of the upper and lower bodies, such that movement of the bracket assembly causes the plurality of nubs to translate within the angled slots to change the vertical height of the proximal region of the spinal implant.

16. The spinal implant according to claim 15, wherein the proximal adjustment assembly includes a nut having a threaded opening defined therethrough that is threadingly engaged with the threaded post of the distal adjustment assembly, such that axial movement of the nut along the threaded post effects movement of the bracket assembly.

17. The spinal implant according to claim 1, wherein at least one of the outer surfaces of the upper and lower bodies includes a wing portion that is movable from a retracted position in which the wing portion is aligned with the outer surface of the upper body or the lower body, and a deployed position in which the wing portion is rotated at an angle relative to the outer surface of the upper body or the lower body.

18. The spinal implant according to claim 1, wherein at least one of the outer surfaces of the upper body or the lower body includes a plurality of retaining features.

19. A method of spacing vertebral bodies, comprising:

implanting a spinal implant into a disc space defined between first and second endplates of respective first and second vertebral bodies such that an upper body of the spinal implant is adjacent the first end plate and a lower body of the spinal implant, disposed in opposed relation relative to the upper body, is adjacent the second end plate, the spinal implant including proximal and distal adjustment assemblies disposed between the upper and lower bodies, the proximal and distal adjustment assemblies independently and adjustably coupled to proximal and distal regions, respectively, of the spinal implant; and

adjusting a vertical height of at least one of the proximal region or the distal region of the spinal implant via one of the proximal or distal adjustment assemblies such that at least one of the outer surfaces of the upper or lower bodies of the spinal implant matches an anatomical shape of the first or second endplates of the first or second vertebral bodies.