LOW PRESSURE DELIVERY SYSTEM AND METHOD FOR DELIVERING A SOLID AND LIQUID MIXTURE INTO A TARGET SITE FOR MEDICAL TREATMENT

• US 20070233146A1
• Filed: 01/26/2007
• Published: 10/04/2007
• Est. Priority Date: 01/27/2006
• Status: Active Grant

• Current Assignee: Stryker Corporation
• Original Assignee: Stryker Corporation
• Inventors: Henniges, Bruce, Tyler, Douglas, Huyser, Richard
• Granted Patent: US 9,301,792 B2
• Time in Patent Office: Days
• US Class Current: 606/91
• CPC Class Codes: A61B 17/3472 for bones, e.g. intraosseus injections
• CPC Class Codes: A61B 17/7094 Solid vertebral fillers; devices for inserting such fillers
• CPC Class Codes: A61B 17/7095 the filler comprising unlinked macroscopic particles
• CPC Class Codes: A61B 17/8805 for introducing fluid filler into bone or extracting it A61B17/7097, A61B17/8833 take precedence
• CPC Class Codes: A61B 17/8811 characterised by the introducer tip, i.e. the part inserted into or onto the bone
• CPC Class Codes: A61B 17/8816 characterised by the conduit, e.g. tube, along which fluid flows into the body or by conduit connections
• CPC Class Codes: A61B 17/8822 characterised by means facilitating expulsion of fluid from the introducer, e.g. a screw pump plunger, hydraulic force transmissions, application of vibrations or a vacuum

Abstract

A system for forming an implant to stabilize an interior of a vertebral body is provided. The system includes a delivery cannula. A plurality of elements are disposed adjacent to one another in the delivery cannula with void spaces defined between the elements. A fluent material, capable of setting to a hardened condition, is disposed within at least a portion of the void space in the delivery cannula. A push rod is movably disposed within the delivery cannula to apply a force to move the elements through the delivery cannula and into the interior of the vertebral body. Upon application of the force, the elements simultaneously carry the fluent material through the delivery cannula and into vertebral body to delivery the fluent material at a low pressure. The fluent material sets to the hardened condition to secure the elements and form the implant.

Claims

1. A system for forming an implant to stabilize a vertebral body having an interior of cancellous bone, said system comprising:

a delivery cannula defining a delivery passage for providing access to the interior of the vertebral body;

a plurality of elements disposed adjacent to one another in said delivery passage of said delivery cannula with a void space defined between said adjacent elements, said plurality of elements including a first element adjacent to a second element;

a fluent material capable of setting to a hardened condition disposed within at least a portion of said void space in said delivery passage; and

a push rod movably disposed within said delivery passage of said delivery cannula to apply a force to said first element and transfer the force through said first element to said second element to move said elements through said delivery passage and into the interior of the vertebral body, said elements simultaneously carrying said fluent material therewith through said delivery passage and into the interior of the vertebral body upon application of said force to said first element whereby said fluent material sets to the hardened condition to secure said elements and form the implant.

2. A system as set forth in claim 1 wherein said delivery passage has an inner diameter ID and said elements have an outer diameter OD substantially equal to said inner diameter ID of said delivery passage.

3. A system as set forth in claim 1 wherein said delivery cannula includes a delivery wall surrounding said delivery passage and said delivery wall defines at least one groove open to said delivery passage for holding said fluent material.

4. A system as set forth in claim 1 including a ratio of a volume of said elements in said delivery passage to a volume of said fluent material in said delivery passage of from about 0.1:

1 to about 10;

1.

5. A system as set forth in claim 4 wherein said ratio of said volume of said elements in said delivery passage to said volume of said fluent material in said delivery passage is from about 2:

1 to about 5;

1.

6. A system as set forth in claim 5 wherein said ratio of said volume of said elements in said delivery passage to said volume of said fluent material in said delivery passage is about 2:

1.

7. A system as set forth in claim 1 wherein said plurality of elements are disposed in said delivery passage in a linear array and include at least three elements and at least two void spaces.

8. A system as set forth in claim 1 wherein said delivery passage of said delivery cannula extends along a delivery axis and said delivery cannula further defines an exit port open to said delivery passage for allowing said elements and said fluent material to exit said delivery cannula and enter the interior of the vertebral body.

9. A system as set forth in claim 8 wherein said exit port opens at a delivery angle of less than 180 degrees to said delivery axis for allowing said elements and said fluent material to exit said delivery cannula at said delivery angle relative to said delivery passage.

10. A system as set forth in claim 9 wherein said delivery angle is about 90 degrees to said delivery axis for allowing said elements and said fluent material to exit said delivery cannula perpendicular to said delivery passage.

11. A system as set forth in claim 1 including a connecting member interconnecting said first and second elements.

12. A system as set forth in claim 11 wherein said connecting member is flexible.

13. A system as set forth in claim 11 further including an access cannula defining an access passage for accessing the interior of the vertebral body wherein said delivery cannula is sized for inserting in said access passage of said access cannula and said access cannula extends to a distal end and includes a cutter disposed on said distal end for cutting said connecting member as said access cannula is moved relative to said delivery cannula.

14. A system as set forth in claim 1 further including an access cannula defining an access passage for accessing the interior of the vertebral body wherein said delivery cannula is sized for insertion in said access passage of said access cannula.

15. A system as set forth in claim 1 wherein said push rod extends to a distal end and includes a pusher fixed to said distal end, said pusher being movably disposed within said delivery passage and having a maximum dimension S for applying said force to said first element.

16. A system as set forth in claim 15 wherein said maximum dimension S of said pusher is substantially equal to said inner diameter ID of said delivery passage.

17. A system as set forth in claim 15 wherein said pusher and said delivery cannula define at least one gap therebetween for allowing said fluent material to backflow through said gap as said pusher is moved along said delivery passage of said delivery cannula.

18. A system as set forth in claim 15 wherein said pusher defines a hole for allowing said fluent material to back flow through said hole as said pusher is moved along said delivery passage of said delivery cannula.

19. A system as set forth in claim 1 wherein said push rod has a minimum dimension T and said push rod and said delivery cannula define a space therebetween for allowing said fluent material to back flow through said space as said push rod is moved along said delivery passage of said delivery cannula.

20. A system as set forth in claim 1 further including a delivery mechanism adapted to engage said push rod and said delivery cannula to provide said force of said push rod while holding said delivery cannula to allow relative movement between said push rod and said delivery cannula and move said elements and said fluent material along said delivery passage and into the interior of the vertebral body.

21. A system as set forth in claim 20 wherein said delivery mechanism includes:

a housing;

a connector extending from said housing for engaging said delivery cannula;

a force applying mechanism supported by said housing for applying a force to said push rod; and

a trigger mechanism for actuating said force applying mechanism.

22. A system as set forth in claim 1 wherein said fluent material is bone cement.

23. A system as set forth in claim 1 wherein said plurality of elements are further defined as having a generally spherical shape.

24. A method of delivering a plurality of elements and a fluent material capable of setting into a hardened condition into a vertebral body having an interior of cancellous bone to form an implant using a system comprising a delivery cannula and a push rod, said method comprising the steps of:

disposing the elements in a delivery passage of the delivery cannula adjacent to one another to define a void space between the elements;

disposing the fluent material within at least a portion of the void space in the delivery passage;

inserting the push rod in the delivery passage of the delivery cannula;

moving the push rod along the delivery passage to apply a force to a first of the elements and transfer the force through the first element to a second of the elements disposed in the delivery passage to move the elements through the delivery passage and into the interior of the vertebral body; and

simultaneously carrying the fluent material with the elements as the elements move through the delivery passage and into the interior of the vertebral body upon application of the force whereby the fluent material sets to the hardened condition to secure the elements and form the implant.

25. A method as set forth in claim 24 further comprising the step of delivering the elements and the fluent material at a volumetric ratio of the elements to the fluent material of from about 0.1:

1 to about 10;

1.

26. A method as set forth in claim 24 further comprising the step of delivering the elements and the fluent material at a volumetric ratio of the elements to the fluent material of from about 0.2:

1 to about 5;

1.

27. A method as set forth in claim 24 further comprising the step of delivering the elements and the fluent material at a volumetric ratio of the elements to the fluent material of about 2:

1.

28. A method as set forth in claim 24 further comprising the step of delivering the elements and the fluent material from an exit port radially from the delivery cannula into the interior of the vertebral body.

29. A method as set forth in claim 24 further comprising the step of inserting an access cannula into the vertebral body to provide access to the interior of the vertebral body.

30. A method as set forth in claim 29 further comprising the step of inserting the delivery cannula through an access passage in the access cannula and into the interior of the vertebral body.

31. A method as set forth in claim 30 further comprising the step of flexibly connecting the elements to one another with a connecting member.

32. A method as set forth in claim 31 further comprising the step of moving the access cannula within the interior of the vertebral body to sever the connecting member with a cutter disposed on a distal end of the access cannula.

33. A method as set forth in claim 24 further comprising the steps of measuring a linear distance the push rod travels along the delivery passage of the delivery cannula and estimating a volume of the elements and the fluent material delivered into the interior of the vertebral body based on the linear distance the push rod traveled.

34. A method as set forth in claim 24 further comprising the step of attaching a delivery mechanism to the push rod.

35. A method as set forth in claim 34 further comprising the step of actuating a trigger mechanism of the delivery mechanism to move the push rod along the delivery passage of the delivery cannula.

36. A method as set forth in claim 35 further comprising the step of attaching the delivery mechanism to the delivery cannula to hold the delivery cannula while moving the push rod along the delivery passage relative to the delivery cannula.

37. A method of loading a plurality of elements and a fluent material capable of setting into a hardened condition into a delivery passage of a delivery cannula using a fill system having a container defining a loading chamber and a mover for inserting into the loading chamber, said method comprising the steps of:

disposing the elements and the fluent material in the loading chamber of the container;

inserting the mover in the loading chamber;

coupling the container to the delivery cannula; and

moving the elements and the fluent material from the loading chamber into the delivery passage of the delivery cannula such that the elements and fluent material are loaded into the delivery cannula and define void spaces between adjacent elements with the fluent material at least partially filling the void spaces in the delivery passage.

38. A method of loading a plurality of elements and a fluent material capable of setting to a hardened condition into a delivery passage of a delivery cannula using a fill system having a container defining a loading chamber, said method comprising the steps of:

disposing the elements in the delivery passage of the delivery cannula in a staggered arrangement with gaps defined between the elements and the delivery cannula;

disposing the fluent material in the loading chamber of the container;

coupling the container to the delivery cannula; and

transferring the fluent material from the loading chamber into the delivery passage of the delivery cannula and at least partially filling void spaces defined between adjacent elements with the fluent material by moving the fluent material through the gaps defined between the elements and the delivery cannula and into the void spaces.

39. A method of loading a fluent material capable of setting to a hardened condition in void spaces defined between a plurality of elements in a delivery cannula while simultaneously delivering the elements and the fluent material to an interior of a vertebral body, said method comprising the steps of:

disposing the elements in a delivery passage defined by the delivery cannula in a linear array to define the void spaces between the elements in the delivery passage;

inserting a push rod in the delivery passage of the delivery cannula;

moving the push rod along the delivery passage to apply a force to the elements to move the elements through the delivery passage and into the interior of the vertebral body; and

introducing the fluent material within at least a portion of the void spaces as the elements move through the delivery passage and before the elements exit the delivery cannula and enter the interior of the vertebral body.