HARD TISSUE ANCHORS AND DELIVERY DEVICES
The present invention provides devices, systems and methods for anchoring medical devices to hard tissues, such as bones or bony structures, particularly vertebrae. By anchoring these medical devices directly to the surrounding hard tissue, the devices are anchored closer to the source of treatment. This provides additional stability and reduces migration of the device at the treatment site. Also, by attaching to hard tissue rather than soft tissue, a stronger attachment is often able to be made.
This application is a continuation of U.S. patent application Ser. No. 13/975,083, filed Aug. 23, 2013, filed Aug. 23, 2013, Publication No. US-2013-0345783-A1, which is a continuation of U.S. patent application Ser. No. 13/175,488, filed Jul. 1, 2011, now U.S. Pat. No. 8,518,092, which is a continuation of U.S. patent application Ser. No. 11/952,081, filed on Dec. 6, 2007, Publication No. US-2008-0183221-A1, now abandoned, which claims priority of U.S. Provisional Patent Application No. 60/873,549, filed on Dec. 6, 2006, each of which is herein incorporated by reference in its entirety.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENTNot Applicable
REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISKNot Applicable
BACKGROUND OF THE INVENTIONA variety of implantable medical devices are used to treat portions of the anatomy which reside near bones or bony structures within the body of a patient. Such devices are typically anchored in place by suturing portions of the device to surrounding soft tissue. Often the device includes suture holes designed specifically for this purpose at predetermined locations along the device. Thus, the device may only be sutured at these locations, limiting the areas and types of tissue available for suturing thereto. Often, the location is far from the treatment site. Such distance and instability of anchoring tissue can contribute to lead migration and pull-out.
For example, conventional spinal cord stimulators (SCS) are positioned along the spinal column to treat pain. A conventional SCS system comprises an implantable lead and an implantable power source or implantable pulse pulse generator IPG. Using fluoroscopy, the lead is implanted into the epidural space of the spinal column and positioned against the dura layer of the spinal cord. The lead extends from the spinal column to the IPG which is remotely implanted. Typically, the lead is sutured to soft tissue remote from the point of entry into the epidural space. And, lead migration and pull-out are common problems associated with SCS.
Therefore, it is desired to provide a more stable anchoring system for implantable devices, such as leads. Such an anchoring system should provide anchoring at desired locations rather than merely at locations along the device which are predesigned for anchoring. Such anchoring should also assist in resisting migration and pull-out. At least some of these objectives will be met by the present invention.
BRIEF SUMMARY OF THE INVENTIONThe present invention provides devices, systems and methods for anchoring medical devices to hard tissues, such as bones or bony structures, particularly vertebrae. A variety of medical devices are used to treat portions of the anatomy which reside near bones or bony structures within the body of a patient. The devices and systems of the present invention are suitable for use with many of such medical devices and specialized devices used for particular treatments. By anchoring these directly to the surrounding hard tissue, the devices are anchored closer to the source of treatment. This provides additional stability and reduces migration of the device at the treatment site. Also, by attaching to hard tissue rather than soft tissue, a stronger attachment is often able to be made.
In a first aspect of the present invention, a hard tissue anchor is provided for securing an element to a hard tissue. In some embodiments, the hard tissue comprises a penetrating end shaped for penetrating the hard tissue, and a head having an aperture, wherein the aperture is configured to receive the element therethrough and wherein the head is configured to secure the element within the aperture. Typically, the element comprises a lead, however catheters or other devices may be used.
In some embodiments, the head includes a channel connected to the aperture, wherein the channel is configured allow passage of the element from outside of the head to the aperture. In some instances, the head is adjustable to close the channel, such as by deformation of the head. Optionally, deformation of the head may secure the element within the aperture. In some embodiments, the head further comprises a grommet disposed within the aperture. The grommet may assist in holding the element within the aperture.
In some embodiments, the penetrating end has a tapered, conical, notched, barbed or serrated shape. In such instances, the hard tissue anchor is considered a tack and is pressed into the hard tissue. In other embodiments, the penetrating end has a shank with a helical thread. In these instances, the hard tissue anchor is considered a screw and is rotated into the hard tissue.
In a second aspect of the present invention, a method is provided for anchoring an element to a hard tissue in a body: In some embodiments, the method comprises advancing a hard tissue anchor toward the hard tissue, wherein the anchor has a penetrating end and a head having an aperture, positioning the element within the aperture, and applying pressure to the head so as to drive the penetrating end at least partially into the hard tissue.
In some embodiments, applying pressure comprises applying pressure to the head so as to secure the element within the aperture. Optionally, applying pressure comprises deforming the head so as to secure the element within the aperture due to friction.
In some instances, the method further comprises implanting the element in the body. Such implanting may occur before the positioning step of positioning the element within the aperture. This allows the hard tissue anchors to be utilized with existing implanted systems.
In still further embodiments, the anchor includes a channel connected to the aperture and the method further comprises passing a portion of the element through the channel to the aperture. Optionally, applying pressure comprises deforming the head so as to at least partially close the channel.
To deliver a hard tissue anchor of the present invention, such methods may include mounting the head of the anchor on a distal end of an applicator. In some situations, advancing the hard tissue anchor toward the hard tissue comprises advancing the distal end of the applicator through a percutaneous access opening. In such instances, the applicator has a low profile suitable for such percutaneous delivery.
In some embodiments, applying pressure to the head comprises applying pressure to the applicator. Optionally, applying pressure to the applicator may comprise deforming the head by force of the applicator so as to secure the element within the aperture due to friction.
In a third aspect of the present invention, an applicator is provided for delivering a hard tissue anchor. In some embodiments, the applicator comprises an elongate body having a proximal end and a distal end, wherein the distal end is configured to receive a head of the hard tissue anchor, and a handle attached to the proximal end of the elongate body so that force applied to the handle is translatable to the head of the hard tissue anchor. Optionally, the elongate body may be shaped for passage through a percutaneous access opening.
In some embodiments, the applicator further comprises a release button for releasing the hard tissue anchor from the distal end of the elongate body. The distal end may include a recess for receiving the head, from which the hard tissue anchor is releasable.
When the hard tissue anchor comprises a bone tack, the force typically comprises longitudinal force which is translatable to a downward force on the head of the hard tissue anchor. When the hard tissue anchor comprises a bone screw, the force typically comprises rotational force which is translatable to rotation of the head of the hard tissue anchor. In such instances, the distal end may comprise a rotatable member joinable with the head, wherein the rotation force rotates the rotatable member.
Other objects and advantages of the present invention will become apparent from the detailed description to follow, together with the accompanying drawings.
The present invention provides devices, systems and methods for anchoring medical devices to hard tissues, such as bones or bony structures, particularly vertebrae. A variety of medical devices are used to treat portions of the anatomy which reside near bones or bony structures within the body of a patient. For example, spinal cord stimulators (SCS) are positioned along the spinal column to treat pain.
In addition, the devices, systems and methods of the present invention may be used to anchor other types of medical devices, in particular various other types of leads used to selectively stimulate the spinal anatomy, particularly the dorsal root or dorsal root ganglion (DRG).
The hard tissue anchors 600 of the present invention include bone tacks and bone screws.
Other embodiments of the bone tack 601 are particularly suited for anchoring the element 150 at an anchoring location when it is less desirable to pre-load the anchor on the element 150. This may be the case when the element 150 is already implanted or it is not possible to advance an anchor over the element 150, such as from one of the ends of the element 150 to the anchoring location. In some of these embodiments, the head 602 of the bone tack 601 includes a channel 608 which connects to the aperture 607.
In some embodiments, the tack 601 includes a grommet 606, as illustrated in
The head 602 and a penetrating end 604 are typically formed from the same material and may comprise any biocompatible and/or bioresorbable material including but not limited to cobalt chromium, cobalt chromium alloys, titanium, titanium alloys, stainless steel, resorbable PGA or PLA, and PEEK.
The grommet 606 may be comprised of any soft biocompatible and/or bioresorbable material including but not limited to silicone or polyurethane. The grommet 606 could be an assembly or molded onto the tack 606.
The bone tacks 601 of the present invention are driven into a portion of bone B by mechanical force, such as tapping or pressing. Referring to
In some embodiments, the distal end 304 is comprised of an insert that is inserted into the elongate body 300.
Example methods of installing a bone tack 601 of the present invention are described herein. In one embodiment, a tack 601 of the present invention is mounted in an applicator 620 as described above. An element, such as a lead 610, is threaded through the aperture 607 of the tack 601 while the tack 601 is held in the applicator 620. The tack 601 is inserted into a percutaneous access site, locating the target bone or bony structure via fluoroscopy or other imaging method. The lead 610 is positioned as desired for its intended therapeutic purpose. The bone tack 601 is then tapped into place so that the penetrating end 604 sufficiently penetrates the target bone or bony structure and the head crimps the lead. The applicator 620 is then removed.
Thus, the bone tacks 601 of the present invention can be used to secure various devices without the use of sutures. Further, such securing or anchoring can be achieved in percutaneous procedures without the need for a large surgical exposure. And, such securing and anchoring is easily achievable without excessive manipulation, particularly with the use of the deformable head which secures the lead during insertion of the tack into bone. Likewise, this action is assisted by the use of the applicator which is able to hold the tack and deform the head while inserting the tack into the bone.
The head 602 includes an aperture 657 through which the element 152 can be threaded prior to implantation of the element 152 in a manner similar to the bone tack 601 of
The head 652 and a penetrating end 654 of the bone screws 650 are typically formed from the same material and may comprise any biocompatible and/or bioresorbable material including but not limited to cobalt chromium, cobalt chromium alloys, titanium, titanium alloys, stainless steel, resorbable PGA or PLA, and PEEK.
The bone screws 650 of the present invention are driven into a hard tissue, such as a portion of bone B, by rotational force. Referring to
One challenge of a twisting or screw-type penetration is that the orientation of the aperture 657 depends on how the screw 650 is screwed in. Also, placing the lead into the aperture 657 after delivery may be difficult due to its orientation. These challenges are overcome by the bone screws 650 of the present invention. The bone screw 650 may be screwed in place at a desired location first and then the element, such as a lead, is loaded through the channel 658 in the head 652. The lead is then advanced to a desired position for the therapeutic application and secured in place by crimping of the head 652.
Although the foregoing invention has been described in some detail by way of illustration and example, for purposes of clarity of understanding, it will be obvious that various alternatives, modifications and equivalents may be used and the above description should not be taken as limiting in scope of the invention.
Claims
1. (canceled)
2. An applicator for delivering a hard tissue anchor, the applicator comprising:
- an elongate body having a proximal end and a distal end, wherein the distal end is configured to receive a head of the hard tissue anchor; and
- a handle attached to the proximal end of the elongate body so that a force applied to the handle is translatable to the head of the hard tissue anchor.
3. The applicator of claim 2, wherein the elongate body is shaped for passage through a percutaneous access opening.
4. The applicator of claim 2, further comprising a release button for releasing the hard tissue anchor from the distal end of the elongate body.
5. The applicator of claim 2, wherein the distal end includes a recess for receiving the head.
6. The applicator of claim 2, wherein the force comprises longitudinal force which is translatable to a downward force on the head of the hard tissue anchor.
7. The applicator of claim 2, wherein force comprises rotational force which is translatable to rotation of the head of the hard tissue anchor.
8. The applicator of claim 2, wherein the distal end comprises a rotatable member joinable with the head, wherein the rotation force rotates the rotatable member.
9. The applicator of claim 5 wherein the depth of the recess is selected so that when the elongate body is removed after the force is applied to a target hard tissue implant location the head of the hard tissue anchor extends beyond the surface of the target hard tissue implant location.
10. The applicator of claim 5 wherein the depth of the recess is selected so that a portion of the distal end configured to receive the head of the hard tissue anchor contacts a portion of the target hard tissue implant location after the force is applied to a the head of the hard tissue anchor.
11. The applicator of claim 2 the head of the hard tissue anchor further comprising an aperture wherein when the elongate body is removed from the hard tissue anchor after applying the force the aperture remains open.
12. The applicator of claim 2 the head of the hard tissue anchor further comprising an aperture and a channel through a portion of the head in communication with the aperture wherein when the elongate body is removed from the hard tissue anchor after applying the force the aperture and the channel both remain open.
13. The applicator of claim 11 further comprising an opening in the sidewalls of the distal end of the elongate body adapted and configured to permit passage of an element positioned within the aperture.
14. The applicator of claim 12 further comprising an opening in the sidewalls of the distal end of the elongate body adapted and configured to permit passage of an element positioned within a grommet disposed within the aperture.
15. The applicator of claim 2 further comprising an opening in the sidewalls of the distal end of the elongate body adapted and configured to permit passage of an element within the head of the hard tissue anchor disposed within the elongate body distal end.
16. The applicator of claim 15 wherein the element is generally transverse to the elongate body distal end and disposed within an aperture of the hard tissue anchor or a grommet.
17. The applicator of claim 16 wherein the element is an implantable lead.
18. The applicator of claim 2 wherein the hard tissue anchor has a distal penetrating end.
19. The applicator of claim 18 wherein the distal penetrating end has a tapered, conical, notched, barbed or serrated shape.
20. An applicator for percutaneous delivery of a hard tissue anchor to a portion of a bony structure, the applicator comprising:
- an elongate body having a proximal end and a distal end;
- a recess within the distal end adapted and configured to receive a head of the hard tissue anchor;
- a first opening in a sidewall of the elongate body distal end adjacent to the recess and a second opening in a sidewall of the elongate body distal end adjacent to the recess wherein an element positioned in an aperture of the head of the hard tissue anchor passes through the first opening and the second opening when the head of the hard tissue anchor is within the recess;
- a handle attached to the proximal end of the elongate body so that a force applied to the handle is translatable to the head of the hard tissue anchor.
21. The applicator of claim 20, wherein the elongate body is shaped for passage through a percutaneous access opening from a position outside of the body to a bony structure on a portion of a spinal vertebra.
22. The applicator of claim 21 wherein the element is a lead and the bony structure on the portion of the spinal vertebra is adjacent to a dorsal root ganglion.
23. The applicator of claim 20 further comprising a grommet adapted and configured to be positioned within the aperture of the head and to receive the element.
24. The applicator of claim 23 wherein the grommet forms a friction fit with a portion of the elongate body when the head is within the recess.
25. The applicator of claim 23 wherein the grommet and base may be aligned to provide a channel shaped to accommodate the lead.
26. The applicator of claim 23 wherein when a force is applied to the handle until the distal end of the elongate body contacts the portion of the bony structure and thereafter the applicator is removed, only the head of the hard tissue anchor protrudes from the portion of the bony structure.
27. The applicator of claim 26 wherein the head of the hard tissue anchor extends about 0.009″ above the surface of the bony structure.
28. The applicator of claim 26 wherein the portion of the distal end of the hard tissue anchor extends about 0.025″ into the bony structure.
29. The applicator of claim 20 wherein the handle is configured for use with a hard tissue anchor distal end adapted for being tapped into engagement with a portion of the bony structure comprising a portion of a vertebral foramen.
30. The applicator of claim 20 wherein the handle is configured for use with a hard tissue anchor distal end adapted for being rotated into engagement with a portion of the bony structure comprising a vertebral foramen.
31. The applicator of claim 20 wherein the hard tissue anchor distal end adapted for being tapped into engagement with the bony structure.
32. The applicator of claim 20 wherein the hard tissue anchor distal end adapted for being rotated into engagement with the bony structure.
33. The applicator of claim 20 wherein the hard tissue anchor has a distal penetrating end.
34. The applicator of claim 33 wherein the distal penetrating end has a tapered, conical, notched, barbed or serrated shape.
Type: Application
Filed: Feb 26, 2015
Publication Date: Dec 3, 2015
Inventor: Albert G. BURDULIS (San Francisco, CA)
Application Number: 14/633,060