Apparatus and Methods for Inserting an Implant

• US 20080275455A1
• Filed: 01/12/2007
• Published: 11/06/2008
• Est. Priority Date: 08/16/2006
• Status: Active Grant

• Current Assignee: K2M, Inc (Stryker Corporation)
• Original Assignee: Amicus Healthcare Group Limited (Hold LLP)
• Inventors: Berry, Bret M., Lee, Randall F., Zigler, Jack E., Guyer, Richard D., Pike, Adam A.
• Granted Patent: US 8,062,303 B2
• Time in Patent Office: Days
• US Class Current: 606/99
• CPC Class Codes: A61B 17/025 Joint distractors
• 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 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30593 hollow
• 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

Abstract

A system and method for inserting an implant into a cavity is disclosed, which may include advancing an implant insertion instrument toward a pair of adjacent bodies, the implant insertion instrument having two opposed ramps, wherein each ramp has a distal tip and wherein the longitudinal axes of the opposed ramps are separated by an initial angle; inserting the distal tips of the opposed ramps between the adjacent bodies, thereby creating an initial interbody cavity between the adjacent bodies; expanding the interbody cavity while maintaining the initial angle between the longitudinal axes of the opposed ramps; placing the implant in a final location between the adjacent bodies; transferring a compressive force urging the adjacent bodies together from the opposed ramps to the implant; and extracting the implant insertion instrument from the interbody cavity.

Claims

1. An instrument for inserting an implant comprising:

at least two opposed ramps having an initial angle between the respective longitudinal axes thereof, each said ramp having a proximal and a distal end;

at least one distraction guide disposed between the opposed ramps and mobile with respect to the ramps along the longitudinal axes thereof,

wherein advancement of the distraction guide distally along the longitudinal axes of the ramps is operable to separate the ramps while holding the initial angle between the two ramps at least substantially constant.

3. The insertion instrument of claim 1 wherein the distraction guide comprises longitudinal edges configured to interface with respective longitudinal edges of the opposed ramps, and wherein the longitudinal edges of the distraction guide are oriented at a lordotic angle to one another.

4. The insertion instrument of claim 1 wherein the distraction guide and ramps are reversibly assembled to one another to form the insertion instrument.

5. The insertion instrument of claim 1 wherein the distraction guide and ramps are substantially permanently assembled to one another to form the insertion instrument.

6. The insertion instrument of claim 1 wherein the separation of the ramps, while maintaining the initial angle therebetween at least substantially constant, is operable to provide parallel distraction of adjacent bodies when the insertion instrument is positioned within an interbody cavity.

7. The insertion instrument of claim 1 wherein the adjacent bodies are vertebral bodies and the interbody cavity is an intervertebral cavity.

8. The insertion instrument of claim 1 wherein the at least one distraction guide is configured to accommodate the implant for insertion into an interbody cavity.

9. The insertion instrument of claim 8 wherein the distraction guide is configured to receive a compressive force imparted by the interbody cavity on the ramps, thereby avoiding loading the implant with the compressive force during insertion of the instrument into the interbody cavity.

10. The insertion instrument of claim 9 wherein the distraction guide is operable to discontinue receiving the compressive force imparted by the intervertebral cavity once the instrument insertion is complete, thereby transferring the compressive force to the implant.

11. The insertion instrument of claim 1 wherein the at least one distraction guide is operable to move laterally with respect to the longitudinal axes of the ramps.

12. The insertion instrument of claim 11 wherein a geometric interface between the distraction guide and the ramps is configured such that the lateral motion of the distraction guide enables the ramps to approach one another in response to a compressive force acting upon the ramps.

13. The insertion instrument of claim 12 wherein the geometric interface comprises at least one angled surface along a longitudinal edge of the distraction guide.

14. The insertion instrument of claim 13 wherein the geometric interface further comprises at least one angled surface along a longitudinal edge of at least one ramp that engages the angled surface on the distraction guide.

15. The insertion instrument of claim 10 wherein the discontinuation of receipt of the compressive force by the distraction guide is operable to cause the ramps to reduce a separation distance therebetween in response to the compressive force.

16. The insertion instrument of claim 15 wherein the separation distance between the ramps is reduced such that the distance between the outer surfaces of the ramps is less than the thickness of the implant.

17. The insertion instrument of claim 16 wherein the ramps are operable to reduce the separation distance therebetween without contacting the implant.

18. The insertion instrument of claim 17 wherein at least one given ramp of the ramps comprises at least one finger portion that is configured to move along a side of the implant without contacting the implant as the separation distance between the ramps is reduced.

19. The insertion instrument of claim 16 wherein the ramp separation distance reduction is operable to enable removal of the insertion instrument from the interbody cavity in the absence of compressive force on the ramps from the interbody cavity.

20. The insertion instrument of claim 1 wherein the distraction guide has dimensions corresponding to those of the implant.

21. The insertion instrument of claim 1 further comprising:

a plurality of grasping jaws disposed in proximity to the distraction guide and operable to securely grasp the implant within the insertion instrument.

22. The insertion instrument of claim 1 further comprising:

a body

a tube moveable with respect to the body and operable to control a position of the distraction guide with respect to the ramps; and

a locking arm operable to lock a position of the tube with respect to the body.

23. The insertion instrument of claim 1 wherein a direction of insertion of the implant forms a non-zero angle with respect to a longitudinal axis of the insertion instrument about an axis parallel to the direction along which the ramps are separated.

24. The insertion instrument of claim 23 wherein the non-zero angle is between 10 and 90 degrees.

2. The insertion instrument of claim 1 wherein the initial angle is a lordotic angle.

25. The insertion instrument of claim 21 wherein the non-zero angle is between 15 and 45 degrees.

26. The method of claim 24 wherein the expanding step comprises:

maintaining a constant lordotic angle between the two adjacent bodies as the interbody cavity is expanded.

27. The method of claim 24 wherein the expanding step comprises:

providing a distraction guide disposed between the two opposed ramps, wherein the distraction guide is operable to serve as a load bearing element that opposes the compressive force imparted by the adjacent bodies on two opposed ramps; and

moving the distraction guide with respect to the ramps to separate the ramps.

28. The method of claim 27 wherein the transferring step comprises:

causing the distraction guide to stop opposing the compressive force imparted by the adjacent bodies.

29. The method of claim 28 wherein the transferring step further comprises:

allowing the two opposed ramps to approach one another in response to the compressive force.

30. The method of claim 29 wherein the transferring step further comprises:

imparting all of the compressive force from the adjacent bodies to the implant.

31. The method of claim 24 further comprising:

avoiding loading the implant with the compressive force until the implant is in the final location between the adjacent bodies.

32. The method of claim 24 further comprising:

avoiding loading the implant insertion instrument with the compressive force during the extraction of the insertion instrument from the interbody cavity.

24-1. A method for inserting an implant into a cavity, comprising:

advancing an implant insertion instrument toward a pair of adjacent bodies, the implant insertion instrument having two opposed ramps, wherein each ramp has a distal tip and wherein the longitudinal axes of the opposed ramps are separated by an initial angle;

inserting the distal tips of the opposed ramps between the adjacent bodies, thereby creating an initial interbody cavity between the adjacent bodies;

expanding the interbody cavity while maintaining the initial angle between the longitudinal axes of the opposed ramps;

placing the implant in a final location between the adjacent bodies;

transferring a compressive force urging the adjacent bodies together from the opposed ramps to the implant; and

extracting the implant insertion instrument from the interbody cavity.

25-2. The method of claim 24 wherein the transferring step is completed prior to performing the extracting step.