Apparatus and method for stylet-guided vertebral augmentation

Patent metadata

Field	Value
Publication number	US-9526551-B2
Application number	US-201514873947-A
Country	US
Kind code	B2
Filing date	Oct 2, 2015
Priority date	Nov 10, 2009
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

A stylet-guided balloon vertebroplasty system, as well as methods for bone augmentation using same are provided. In certain embodiments, a pre-curved stylet with an overlying delivery tube may be used to target an approximately centered target site within a bone structure, facilitating direction thereto of an expandable member useful for creating a cavity that may receive curable material to restore bone height and/or to reinforce the bone structure.

First claim

We claim:

1. A method for stabilizing a bone structure of a patient, the method comprising steps of:
identifying a target site for locating an expandable member within a bone structure at a predetermined location,
directing a distal end of a generally straight access cannula into the bone structure near the target site;
providing a guide stylet assembly that comprises
a stylet including memory metal and having a distal pre-set
stylet curved portion; and
an overlying flexible polymeric delivery tube through which the stylet snugly and slidably extends, where the stylet and the delivery tube have sufficient length to extend through and be operable beyond the distal end of the access cannula, and where the pre-set curved portion is held generally longitudinally straight when the stylet is constrained by the access cannula;

directing the stylet and overlying delivery tube simultaneously and coaxially through the access cannula and out the distal end of the access cannula, where the pre-set stylet curved portion, no longer constrained by the access cannula, curves toward and forms a path into the target site as it is extended out of the access cannula distal end;
withdrawing the stylet from the overlying delivery tube;
thereafter removing the delivery tube;
directing a coated expandable member in a contracted state via the access cannula into the target site;
expanding the expandable member to form a cavity at the target site; and,
thereafter, delivering a curable material into the cavity.

2. The method of claim 1 , further comprising, executing steps of:
as part of the step of directing a distal end of a generally straight access cannula into the bone structure near the target site, determining a desired curvature path between the distal end of the access cannula and the approximate center of the target site;
where the desired curvature path is determined by the curvature of the distal preset curved portion; and
where the step of directing a distal end of a generally straight access cannula into the bone structure near the target site includes desirably locating and orienting the generally straight access cannula so that, during the step of directing the stylet and overlying delivery tube includes directing a distal end of the stylet and overlying delivery tube to an approximate center of the target site.

3. The method of claim 1 , where the access cannula is located and oriented relative to the target site so that the pre-set curved portion of the stylet is oriented to transit from the distal end of the access cannula to approximately the center of the target site.

4. The method of claim 1 , where the cavity formed is generally symmetrical within the target site.

5. The method of claim 1 , where the cavity formed is generally symmetrical within the bone structure relative to boundaries of the bone structure.

6. The method of claim 1 , further comprising, before the step of delivering curable material, removing the expandable member.

7. The method of claim 1 , where the step of delivering curable material into the cavity comprises directing a curved delivery cannula through the access cannula into the cavity and directing curable material through the curved delivery cannula into the cavity.

8. The method of claim 1 , where the expandable member comprises a silicone-coated balloon.

9. The method of claim 1 , where the curable material is delivered through a delivery tube that may be the same or different than the removed delivery tube.

10. The method of claim 1 , where the delivery tube comprises at least one radio-opaque marker.

11. The method of claim 1 , where the step of delivering curable material into the cavity comprises directing a curved delivery cannula through the access cannula into the cavity and directing curable material through the curved delivery cannula into the cavity, where the delivery cannula curvature is temperature-dependent.

12. The method of claim 1 , where the step of delivering curable material into the cavity comprises directing a curved delivery cannula through the access cannula into the cavity and directing curable material through the curved delivery cannula into the cavity, and where the curvature of the curved delivery cannula is about the same as the curvature of the pre-set stylet curved portion.

13. The method of claim 1 , further including providing radio-opaque contrast material into the cavity, internal to or external of the expandable member.

14. The method of claim 1 , where the stylet includes a distalmost straight length that is distal of the preset curved portion.

15. A system configured for stabilizing a bone structure of a patient, the system comprising:
an access cannula configured for penetrating into a bone structure;
a guide stylet assembly that comprises
a stylet including a distal memory metal pre-set curved portion; and
an overlying flexible polymeric delivery tube through which the stylet coaxially, snugly, and slidably extends, where the stylet and the delivery tube have sufficient length to extend through and be operable beyond the distal end of the access cannula, and where the pre-set curved portion is held generally longitudinally straight when the stylet is constrained by the access cannula;

a silicone-coated expandable member dimensioned and operable for passage through and deployment outside a distal end of the delivery tube in a manner displacing bone material; and
a curved delivery cannula configured for delivering curable material into a bone.

16. The system of claim 15 , where the delivery cannula includes a closed distal end terminus and a side-facing opening near the terminus, where the opening is oriented along an outside surface of the curved portion of the delivery cannula near the closed distal end terminus.

17. The system of claim 16 , further comprising proximal end indicia showing the direction of curvature of the curved delivery cannula.

18. The system of claim 15 , further comprising proximal end indicia showing the direction of curvature of the stylet's pre-set curve and indicating when a distal end terminus of the stylet is aligned with and ready to exit the distal end of the delivery tube.

19. The system of claim 15 , where the expandable member is embodied 5 as a fluid-inflatable balloon configured to create a cavity by displacing cancellous bone.

20. The system of claim 15 , further comprising a curved delivery cannula configured for passage through the access cannula and including a pre-set curved portion corresponding to the curvature of the stylet pre-curved portion, the delivery cannula containing pre-loaded, but not-yet-cured, curable material.

Assignees

• Stryker Corp

Inventors

• Linderman Evan D
• Krueger John A

Classifications

• A61B17/1642

  for producing a curved bore · CPC title

• A61B17/8811

  characterised by the introducer tip, i.e. the part inserted into or onto the bone · CPC title

• A61B90/08

  Accessories or related features not otherwise provided for · CPC title

• A61B2090/062

  penetration depth · CPC title

• A61B2017/00867

  shape memory effect · CPC title