Spine distraction implant
A spine distraction implant alleviates pain associated with spinal stenosis and facet arthropathy by expanding the volume in the spine canal and/or neural foramen. The implant provides a spinal extension stop while allowing freedom of spinal flexion. An interspinous process implant with a selectably expandable spacer can be placed between adjacent spinous processes. a device implanted between the spinous processes of adjacent vertebrae of the spine can be used for relieving pain associated with the vertebrae and surrounding tissues and structures by maintaining and/or adding distraction between adjacent vertebrae. A tissue expander can be adapted to move from a first insertion position, for ease of implantation between spinous processes, to a second retention position that prevents displacement of the implant. An embodiment of a system can include an implant having a spacer with a thickness and a wing, wherein a first configuration of the wing has a first height substantially similar to the thickness and wherein the wing is adapted to be selectably arranged in a second configuration such that the wing has a second height greater than the first height. A periphery of the implant has a shape generally conformal with a shape of an inner surface of a cannula and a cross-sectional diameter smaller than an inner diameter of the cannula. The cannula is inserted such that a proximal end of the cannula is arranged between the adjacent spinous processes. The implant is then urged into position between the adjacent spinous processes by way of the cannula, and subsequently arranged in a second configuration to fix the implant in position.
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The present application is a continuation-in-part of U.S. patent application Ser. No. 11/092,862, filed on Mar. 29, 2005; is a divisional of U.S. patent application Ser. No. 09/842,819, filed on Apr. 26, 2001, now issued as U.S. Pat. No. 7,201,751; which is a continuation-in-part of U.S. patent application Ser. No. 09/579,039, filed on May 26, 2000, now U.S. Pat. No. 6,451,019; which is a continuation-in-part of U.S. patent application Ser. No. 09/473,173, filed on Dec. 28, 1999, now U.S. Pat. No. 6,235,030; which is a continuation of U.S. Ser. No. 09/179,570, filed on Oct. 27, 1998, now U.S. Pat. No. 6,048,342; which is a continuation-in-part of U.S. patent application Ser. No. 08/958,281, filed on Oct. 27, 1997, now U.S. Pat. No. 5,860,977; which is a continuation-in-part of U.S. patent application Ser. No. 08/778,093, filed on Jan. 2, 1997 now U.S. Pat. No. 5,836,948.
The present application is also a continuation-in-part of U.S. patent application Ser. No. 10/684,847, filed on Oct. 14, 2003; which claims priority to U.S. Provisional Application No. 60/421,921, filed on Oct. 29, 2002; both entitled “Interspinous Process Apparatus and Method with a Selectably Expandable Spacer.”
The present application is also a continuation-in-part of U.S. patent application Ser. No. 11/003,555, filed on Dec. 3, 2004; which claims priority to U.S. Provisional Application No. 60/565,910, filed on Apr. 28, 2004.
The present application is also a continuation-in-part of U.S. patent application Ser. No. 11/389,002, filed on Mar. 24, 2006; which claims benefit to U.S. Provisional Application No. 60/672,402, filed Apr. 18, 2005; both entitled “Interspinous Process Implant Having Deployable Wings and Method of Implantation.”
All of the above-listed references are incorporated herein by reference.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENTNot Applicable
REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISKNot Applicable
BACKGROUND OF THE INVENTIONThe spinal column is a bio-mechanical structure composed primarily of ligaments, muscles, vertebrae and intervertebral disks. The bio-mechanical functions of the spine include: (1) support of the body, which involves the transfer of the weight and the bending movements of the head, trunk, and arms to the pelvis and legs, (2) complex physiological motion between these parts, and (3) protection of the spinal cord and the nerve roots.
As the present society ages, it is anticipated that there will be an increase in adverse spinal conditions which are characteristic of older people. By way of example, with aging comes increases in spinal stenosis (including but not limited to central canal and lateral stenosis), the thickening of the bones which make up the spinal column and facet arthropathy. Spinal stenosis results in a reduction foraminal area (i.e., the available space for the passage of nerves and blood vessels) which compresses the cervical nerve roots and causes radicular pain. Humpreys, S. C. et al., Flexion and traction effect on C5-C6 foraminal space, Arch. Phys. Med. Rehabil., vol. 79 at 1105 (September 1998). Another symptom of spinal stenosis is myelopathy, which results in neck pain and muscle weakness. Id. Extension and ipsilateral rotation of the neck further reduces the foraminal area and contributes to pain, nerve root compression and neural injury. Id.; Yoo, J. U. et al., Effect of cervical spine motion on the neuroforaminal dimensions of human cervical spine, Spine, vol. 17 at 1131 (Nov. 10, 1992). In contrast, neck flexion increases the foraminal area. Humpreys, S. C. et al., at 1105.
Spinal stenosis is characterized by a reduction in the available space for the passage of blood vessels and nerves. Pain associated with such stenosis can be relieved by medication and/or surgery. Of course, it is desirable to eliminate the need for major surgery for all individuals and in particular for the elderly.
Accordingly, there needs to be developed procedures and implants for alleviating such condition which are minimally invasive, can be tolerated by the elderly and can be performed preferably on an outpatient basis.
This invention also relates to an apparatus and method for adjustably distracting the spinous process of adjacent vertebrae.
In addition, there are a variety of other ailments that can cause back pain in patients of all ages. For these ailments it is also desirable to eliminate such pain without major surgery.
Accordingly, there is a need for a method for alleviating such conditions that is minimally invasive, can be tolerated by patients of all ages (in particular, the elderly), can be performed on an out-patient basis, and allows adjustments both during and after surgery to minimize patient discomfort. There is a further need for an apparatus with which to apply the method.
BRIEF SUMMARY OF THE INVENTIONThe present invention is directed to providing a minimally invasive implant and method for alleviating discomfort associated with the spinal column.
The present invention provides for apparatus and method for relieving pain by relieving the pressure and restrictions on the aforementioned blood vessels and nerves. Such alleviation of pressure is accomplished in the present invention through the use of an implant and method which distract the spinous process of adjacent vertebra in order to alleviate the problems caused by spinal stenosis and facet arthropathy and the like. While the implant and method particularly address the needs of the elderly, the invention can be used with individuals of all ages and sizes where distraction of the spinous process would be beneficial.
In one aspect of the invention, an implant is provided for relieving pain comprising a device positioned between a first spinous process and a second spinous process. The device includes a spinal column extension stop and a spinal column flexion non-inhibitor.
In another aspect of the invention, the implant is positioned between the first spinous process and the second spinous process and includes a distraction wedge that can distract the first and second spinous processes as the implant is positioned between the spinous processes.
In yet another aspect of the present invention, the implant includes a device which is adapted to increasing the volume of the spinal canal and/or the neural foramen as the device is positioned between adjacent spinous processes.
In yet a further aspect of the present invention, a method is presented for relieving pain due to the development of, by way of example only, spinal stenosis and facet arthropathy. The method is comprised of the steps of accessing adjacent first and second spinal processes of the spinal column and distracting the processes a sufficient amount in order to increase the volume of the spinal canal in order to relieve pain. The method further includes implanting a device in order to maintain the amount of distraction required to relieve such pain.
In yet a further aspect of the invention, the method includes implanting a device in order to achieve the desired distraction and to maintain that distraction.
In yet a further aspect of the invention, the implant includes a first portion and a second portions. The portions are urged together in order to achieve the desired distraction. In still a further aspect of the invention, the implant includes a distracting unit and a retaining unit. The distracting unit includes a body which can be urged between adjacent spinous processes. The body includes a slot. After the distracting unit is positioned, the retaining unit can fit into the slot of the retaining unit and be secured thereto.
In yet a further aspect of the invention, the implant includes a first unit with a central body. A sleeve is provided over the central body and is at least partially spaced from the central body in order to allow for deflection toward the central body.
In a further aspect of the invention, the implant includes a first unit having a central body with a guide and a first wing, with the first wing located at first end of the body. The guide extends from a second end of the body located distally from the first wing. The implant further includes a sleeve provided over said central body. The sleeve is at least partially spaced from the central body in order to allow for deflection of the sleeve toward the central body. The implant further includes a second wing and a device for securing the second wing to the first unit, wherein the sleeve is located between the first and second wings.
In yet another aspect of the invention, an implant system includes a cylindrical sleeve which is inwardly deflectable. The system further includes an insertion tool which includes an insertion guide, a central body, a stop and a handle. The guide and the stop extend from opposite sides of the central body and the handle extend from the stop. A sleeve fits over the guide and against the stop preparatory to being positioned between the two adjacent vertebrae with the insertion tool.
In yet a further aspect of the invention, the implant includes central body and first and second wings and a means for selectively positioning one of the first and second wings relative to the other in order to accommodate spinous processes of different sizes.
In yet still a further aspect of the invention, the implant includes a sleeve which is rotatable relative to the wings of the implant in order to be able to accommodate the anatomical structure of spinous processes.
In yet still a further aspect of the invention, the sleeve is formed from bar stock comprised of a super-elastic material.
Other implants and methods within the spirit and scope of the invention can be used to increase the volume of the spinal canal thereby alleviating restrictions on vessels and nerves associated therewith, and pain.
BRIEF DESCRIPTION OF THE DRAWINGS
131A is a right side view of an embodiment of the selectably adjustable spacer in an unexpanded position.
134B is a back view of another embodiment of the spacer similar to that shown in
A first embodiment of the invention is shown in
The second forked end 24 (
For purposes of implantation between adjacent first and second spinous processes of the spinal column, the implant 20 is configured as shown in
It is noted that this implant as well as the several other implants described herein act as an extension stop. That means that as the back is bent backwardly and thereby placed in extension the spacing between adjacent spinous processes cannot be reduced to a distance less than the distance between the lowest point of saddle 26 and the lowest point of saddle 28. This implant, however, does not inhibit or in any way limit the flexion of the spinal column, wherein the spinal column is bent forward.
Preferably, such a device provides for distraction in the range of about 5 mm to about 15 mm. However, devices which can distract up to and above 22 mm may be used depending on the characteristics of the individual patient.
With all the ligaments (such as the superspinous ligament) and tissues associated with the spinous processes left intact, the implant 20 can be implanted essentially floating in position in order to gain the benefits of the aforementioned extension stop and flexion non-inhibitor. If desired, one of the saddles 26 can be laterally pinned with pin 29 to one of the spinous processes and the other saddle can be loosely associated with the other spinous processes by using a tether 31 which either pierces or surrounds the other spinous process and then is attached to the saddle in order to position the saddle relative to the spinous process. Alternatively, both saddles can be loosely tethered to the adjacent spinous process in order to allow the saddles to move relative to the spinous processes.
The shape of the saddles, being concave, gives the advantage of distributing the forces between the saddle and the respective spinous process. This ensures that the bone is not resorbed due to the placement of the implant 20 and that the structural integrity of the bone is maintained.
The implant 20 in this embodiment can be made of a number of materials, including but not limited to, stainless steel, titanium, ceramics, plastics, elastics, composite materials or any combination of the above. In addition, the modulus of elasticity of the implant can be matched to that of bone, so that the implant 20 is not too rigid. The flexibility of the implant can further be enhanced by providing additional apertures or perforations throughout the implant in addition to the holes 40 which also have the above stated purpose of allowing the interbody piece 30 to be rotated in order to expand the distance between the saddle 26, 28.
In the present embodiment, it is understood that the spinous processes can be accessed and distracted initially using appropriate instrumentation, and that the implant 20 can be inserted and adjusted in order to maintain and achieve the desired distraction. Alternatively, the spinous process can be accessed and the implant 20 appropriately positioned. Once positioned, the length of the implant can be adjusted in order to distract the spinous processes or extend the distraction of already distracted spinous processes. Thus, the implant can be used to create a distraction or to maintain a distraction which has already been created.
The placement of implants such as implant 20 relative to the spinous process will be discussed hereinbelow with other embodiments. However, it is to be noted that ideally, the implant 20 would be placed close to the instantaneous axis of rotation of the spinal column so that the forces placed on the implant 20 and the forces that the implant 20 places on the spinal column are minimized.
Further, it is noted that during the actual process of installing or implanting the implant 20, that the method uses the approach of extending the length of the implant 20 a first amount and then allowing the spine to creep or adjust to this distraction. Thereafter, implant 20 would be lengthened another amount, followed by a period where the spine is allowed to creep or adjust to this new level of distraction. This process could be repeated until the desired amount of distraction has been accomplished. This same method can be used with insertion tools prior to the installation of an implant. The tools can be used to obtain the desired distraction using a series of spinal distraction and spine creep periods before an implant is installed.
The embodiment of the invention shown in the above
Another embodiment of the apparatus and method of the invention is shown in
In
An alternative embodiment of the implant can be seen in
The embodiment of implant 130 is not circular in overall outside appearance, as is the embodiment 110 of
If it is desired, and in order to assure that the first member 132 and the second member 134 are aligned, key 148 and keyway 150 are designed to mate in a particular manner. Key 148 includes at least one flattened surface, such as flattened surface 152, which mates to an appropriately flattened surface 154 of the keyway 150. In this manner, the first member is appropriately mated to the second member in order to form appropriate upper and lower saddles holding the implant 130 relative to the upper and lower spinous processes.
The implant 330 as shown in
The first or second wedges 332, 334 have a mating arrangement which includes a channel 344 and a projection of 346 which can be urged into the channel in order to lock the wedges 332, 334 together. The channel 334 is undercut in order to keep the projection from separating therefrom. Further, as in other devices described herein, a detent can be located in one of the channel and the projection, with a complimentary recess in the other of the channel and the projection. Once these two snap together, the wedges are prevented from sliding relative to the other in the channel 344.
While the above embodiment was described with respect to wedges, the wedges could also have been designed substantially as cones with all the same features and advantages.
The implant 370 is comprised of first and second distraction cone 372, 374. These cones are made of a flexible material. The cones are positioned on either side of the spinous processes 376, 378 as shown in
In
Implant 170 can be made of a deformable material so that it can be urged into place and so that it can somewhat conform to the shape of the upper and lower spinous processes. This deformable material would be preferably an elastic material. The advantage of such a material would be that the load forces between the implant and the spinous processes would be distributed over a much broader surface area. Further, the implant would mold itself to an irregular spinous process shape in order to locate the implant relative to spinous processes.
With respect to
As can be seen in
As can be seen in
As can be seen in
Another embodiment of the invention is shown in
The embodiments of
The implant 230 is inserted laterally throughout the opening between upper and lower spinous processes. The first body 238 causes the initial distraction. Each successive conical body distracts the spinous processes a further incremental amount. When the desired distraction has been reached, the spinous processes are locked into position by steps 236. At this point, if desired, the initial nose body 238 of the implant and other bodies 240 can be broken, snapped or sawed off if desired in order to minimize the size of the implant 230. In order for a portion of the implant 230 to be broken or snapped off, the intersection between bodies such as body 238 and 240, which is intersection line 242, would be somewhat weaken with the appropriate removal of material. It is noted that only the intersection lines of the initial conical bodies need to be so weakened. Thus, intersection line 244 between the bodies which remain between the spinous processes would not need to be weaker, as there would be no intention that the implant would be broken off at this point.
Turning to
In the embodiment of
Further, a plurality of cannula can be used instead of one, with each cannula being slightly bigger than one before. In the method of the invention, the first smaller cannula would be inserted followed by successively larger cannula being placed over the previous smaller cannula. The smaller cannula would then be withdrawn from the center of the larger cannula. Once the largest cannula is in place, and the opening of the skin accordingly expanded, the implant, which is accommodated by only the larger cannula, is inserted through the larger cannula and into position.
The precurved implant 270 in
Although only two break lines 280, 282 are depicted, multiple break lines can be provided on implant 270 so that the implant can continue to be fed over the guide wire 278 until the appropriate width of the implant 270 creates the desired amount of distraction. As described hereinabove, the break lines can be created by perforating or otherwise weakening the implant 270 so that the appropriate portions can be snapped or sawed off.
With respect to the precurved implant 272, this implant is similar in design to the implant 230 shown in
A further embodiment of the invention is shown in
In
Implant 310 of
As can be seen in
Alternatively, the insertion tool 326 can be used to insert multiple implants 320, 321 into the space between the spinous processes 322, 324 (
The embodiment of
A variety of materials can be used to make the implant and the fluid which is forced into the implant. By way of example only, viscoelastic substances such as methylcellulose, or hyaluronic acid can be used to fill the implant. Further, materials which are initially a fluid, but later solidify, can be inserted in order to cause the necessary distraction. As the materials solidify, they mold into a custom shape about the spinous processes and accordingly are held in position at least with respect to one of two adjacent spinous processes. Thus, it can be appreciated that using this embodiment and appropriate insertion tools the implant can be formed about one spinous process in such a manner that the implant stays positioned with respect to that spinous process (
It is to be understood that many of the other implants disclosed herein can be modified so that they receive a fluid in order to establish and maintain a desired distraction such in the manner as implant 350 receives a fluid.
The implant 360 as shown in
In this embodiment, the implant 380 is comprised of a plurality of interlocking leaves 382. Initially, a first leaf is positioned between opposed spinous processes 384, 386. Then subsequently, leafs 382 are interposed between the spinous processes until the desired distraction has been built up. The leaves are somewhat spring-like in order to absorb the shock and can somewhat conform to the spinous processes.
The implant 390 of
Implant 410 of
As shown in
The embodiments of
In the embodiment of
The embodiment of
The implant 550 is Z-shaped and includes a central body 552 and first and second arms 554, 556, extending in opposite directions therefrom. The central body 552 of the implant 550 includes first and second saddles 558 and 560. The first and second saddles 558 and 560 would receive upper and lower spinous processes 562, 568. The arms 554, 556 are accordingly located adjacent the distal end 566 (
The second arm 590, projecting from second saddle 586, is located somewhat rearward of the distal end 600, and extends partially along the length of the central body 582. The second arm 590 projects at a compound angle from the central body 582. As can be seen in
In a preferred embodiment, the first and second arms 588, 590 have a length which is about the same as the width of the central body 582. Preferably, the length of each arm is about 10 mm and the width of the central body is about 10 mm. However, the bodies with the widths of 24 mm and greater are within the spirit and scope of the invention, along with first and second arms ranging from about 10 mm to greater than about 24 mm. Further, it is contemplated that the embodiment could include a central body having a width of about or greater than 24 mm with arms being at about 10 mm.
It is to be understood that the embodiment of
The embodiment of
The implant 610 of
Implant 630 is also designed so that it can be inserted from one side of adjacent spinous processes. This insert 630 includes a central body 632 with the first and second arms 634, 636 extending on either side thereof. As can be seen in
For purposes of positioning the implant 630 between adjacent spinous processes, the plunger 638 is pulled outwardly as shown in
Plunger 638 can be spring biased to the position as shown in
Other embodiments of the invention are shown in
Implant 700 includes first and second saddle 706, 708 which are used to receive and spread the load from the upper and lower spinous processes. The saddle 706 is defined by first and second arms 710 and 712. The second saddle 708 is defined by third and fourth arms 714 and 716. As can be seen in
First arm 710 is in addition designed to accommodate the shape of the vertebra. As can be seen in
The second arm 712 is small so that it is easy to insert between the spinous processes, yet still define the saddle 706. The fourth arm 716 is larger than the third arm 714, both of which are smaller than the first arm 710. The third and fourth arms are designed so that they define the saddle 706, guide the spinous processes relative to the implant 700 during movement of the spinal column, and yet are of a size which makes the implant easy to position between the spinous processes.
The procedure, by way of example only, for implanting the implant 700 can be to make an incision laterally between two spinous processes and then initially insert first arm 710 between the spinous processes. The implant and/or appropriate tools would be used to distract the spinous processes allowing the third leg 714 and the central body 702 to fit through the space between the spinous processes. The third leg 714 would then come to rest adjacent the lower spinous processes on the opposite side with the spinous processes resting in the first and second saddle 706, 708. The longer fourth leg 716 would then assist in the positioning of the implant 700.
The implant 760 as shown in
Another embodiment of the invention is shown in
The threaded bore 820 in this embodiment slopes at approximately 45.degree. angle and intersects the slot 806. With the second wing 824 in position, the set screw 822 when it is positioned in the threaded bore 820 can engage and hold the second wing 824 in position in the slot 806.
Turning to
As can be seen in
The implant 800 includes, as assembled, an upper saddle 844 and the lower saddle 846. The upper saddle 844 has an upper width identified by the dimension “UW”. The lower saddle 846 has a lower width identified by the dimension “LW”. In a preferred embodiment, the upper width is greater than the lower width. In other embodiments, the “UW” can be smaller than the “LW” depending on the anatomical requirements. The height between the upper and lower saddles 844, 846 is identified by the letter “h”. These dimensions are carried over into
For the above table, all dimensions are given in millimeters.
For purposes of surgical implantation of the implant 800 into a patient, the patient is preferably positioned on his side (arrow 841 points up from an operating table) and placed in a flexed (tucked) position in order to distract the upper and lower vertebrae.
In a preferred procedure, a small incision is made on the midline of the spinous processes. The spinous processes are spread apart or distracted with a spreader. The incision is spread downwardly toward the table, and the distracting unit 802 is preferably inserted upwardly between the spinous processes 840 and 842 in a manner that maintains the distraction of spinous processes. The distracting unit 802 is urged upwardly until the distracting or bulbous end 808 and the slot 806 are visible on the other wide of the spinous process. Once this is visible, the incision is spread upwardly away from the table and the retaining unit or second wing 824 is inserted into the slot 806 and the screw 822 is used to secure the second wing in position. After this had occurred, the incisions can be closed.
An alternative surgical approach requires that small incisions be made on either side of the space located between the spinous processes. The spinous processes are spread apart or distracted using a spreader placed through the upper incision. From the lower incision, the distracting unit 802 is preferably inserted upwardly between the spinous processes 840 and 842 in a manner that urges the spinous processes apart. The distracting unit 802 is urged upwardly until the distracting or bulbous end 808 and the slot 806 are visible through the second small incision in the patient's back. Once this is visible, the retaining unit or second wing 824 is inserted into the slot 806 and the screw 822 is used to secure the second wing in position. After this has occurred, the incisions can be closed.
The advantage of either of the above present surgical procedures is that a surgeon is able to observe the entire operation, where he can look directly down onto the spinous processes as opposed to having to view the procedure from positions which are to the right and to the left of the spinous processes. Generally, the incision is as small as possible and the surgeon is working in a bloody and slippery environment. Thus, an implant that can be positioned directly in front of a surgeon is easier to insert and assemble than an implant which requires the surgeon to shift from side to side. Accordingly, a top-down approach, as an approach along a position to anterior line is preferred so that all aspects of the implantation procedure are fully visible to the surgeon at all times. This aides in the efficient location of (i) the distracting unit between the spinous processes, (ii) the retaining unit in the distracting unit, and (iii) finally the set screw in the distracting unit.
Another embodiment of the invention is shown in
The end 908 of implant 900 is different in that it is more pointed, having sides 909 and 911 which are provided at about 45.degree. angles (other angles, such as by way of example only, from about 30.degree. to about 60.degree. are within the spirit of the invention), with a small flat tip 913 so that the body 904 can be more easily urged between the spinous processes.
The distracting unit 902 further includes a tongue-shaped recess 919 which extends from the slot 906. Located in the tongue-shaped recess is a threaded bore 920.
As can be seen in
Still a further embodiment of the invention is depicted in
Alternatively, the first wing can be secured to the central body with a press fit and detent arrangement as seen in
In yet another alternative embodiment, the first wing can be designed as shown in
Positioned at the other end of the central body 1002 is a guide 1010. In this particular embodiment, guide 1010 is essentially triangularly-shaped so as to be a pointed and arrow-shaped guide. Alternatively, guide 1010 could be in the shape of a cone with lateral truncated sides along the longitudinal axis 1008. Guide 1010 includes a recess 1012 having a threaded bore 1014. Recess 1012 is for receiving a second wing 1032 as will be described hereinbelow.
Additionally, it is also to be understood that the guide 1010 can be bulbous, cone-shaped, pointed, arrow-shaped, and the like, in order to assist in the insertion of the implant 1000 between adjacent spinous processes. It is advantageous that the insertion technique disturb as little of the bone and surrounding tissue or ligaments as possible in order to (1) reduce trauma to the site and facilitate early healing, and (2) not destabilize the normal anatomy. It is to be noted that with the present embodiment, there is no requirement to remove any of the bone of the spinous processes and depending on the anatomy of the patient, there may be no requirement to remove or sever ligaments and tissues immediately associated with the spinous processes.
The implant 1000 further includes a sleeve 1016 which fits around and is at least partially spaced from the central body 1002. As will be explained in greater detail below, while the implant may be comprised of a bio-compatible material such as titanium, the sleeve is comprised preferably of a super-elastic material which is by way of example only, a nickel titanium material (NiTi), which has properties which allow it to withstand repeated deflection without fatigue, while returning to its original shape. The sleeve could be made of other materials, such as for example titanium, but these materials do not have the advantages of a super-elastic material.
In this particular embodiment, the central body 1002 includes elongated grooves 1018, along axis 1008, which receives elongated spokes 1020 extending from the internal surface of the cylinder 1016.
In a preferred embodiment, both the cross-section of the central body and the sleeve have a major dimension along axis 1022 and a minor dimensional along axis 1024 (
Alternatively as can be seen in
In other embodiments, the sleeve can have minor and major dimensions as follows:
In one preferred embodiment, said sleeve has a cross-section with a major dimension and a minor dimension and said major dimension is greater than said minor dimension and less than about two times said minor dimension. In said embodiment, said guide has a cross-section which is adjacent to said sleeve with a guide major dimension about equal to said sleeve major dimension and a guide minor dimension about equal to said sleeve minor dimension. Further in said embodiment, said guide extends from said central body with a cross-section which reduces in size in a direction away from said central body.
In another preferred embodiment, said guide is cone-shaped with a base located adjacent to said sleeve. Further, said guide has a base cross-section about the same as the oval cross-section of said sleeve.
Thus, from the above, it is evident that preferably a major dimension of the sleeve correspond with a major dimension of the central body and a minor dimension of the sleeve corresponds with a minor dimension of the central body. Additionally, it is evident that the major dimension of the sleeve 1016 is substantially perpendicular to a major dimension of the first wing 1004 along longitudinal axis 1030 (
As indicated above, the preferred material for the sleeve 1016 is a super-elastic material and more preferably one comprised of an alloy of nickel and titanium. Such materials are available under the trademark Nitinol. Other super-elastic materials can be used as long as they are bio-compatible and have the same general characteristics of super-elastic materials. In this particular embodiment, a preferred super-elastic material is made up of the following composition of nickel, titanium, carbon, and other materials as follows:
In particular, this composition of materials is able to absorb about 8% recoverable strain. Of course, other materials which can absorb greater and less than 8% can come within the spirit and scope of the invention. This material can be repeatably deflected toward the central body and returned to about its original shape without fatigue. Preferably and additionally, this material can withstand the threshold stress with only a small amount of initial deforming strain and above the threshold stress exhibit substantial and about instantaneous deformation strain which is many times the small amount of initial deforming strain. Such a characteristic is demonstrated in
Preferably, the above super-elastic material is selected to allow deformation of up to about, by way of example only, 8%, at about 20 lbs. to 50 lbs. force applied between a spinous processes. This would cause a sleeve to deflect toward the central body absorbing a substantial amount of the force of the spinous processes in extension. Ideally, the sleeves are designed to absorb 20 lbs. to 100 lbs. before exhibiting the super-elastic effect (threshold stress level) described above. Further, it is possible, depending on the application of the sleeve and the anatomy of the spinal column and the pairs of spinous processes for a particular individual, that the sleeve can be designed for a preferable range of 20 lbs. to 500 lbs. of force before the threshold stress level is reached. Experimental results indicate that with spinous processes of an older individual, that at about 4400 pounds force, the spinous process may fracture. Further, such experimental results also indicate that with at least 100 pounds force, the spinous process may experience some compression. Accordingly, ideally the super-elastic material is designed to deform or flex at less than 100 pounds force.
In a preferred embodiment, the wall thickness of the sleeve is about 1 mm or 40/1000 of an inch (0.040 in.). Preferably the sleeve is designed to experience a combined 1 mm deflection. The combined 1 mm deflection means that there is ½ mm of deflection at the top of the minor dimension and a ½ mm deflection at the bottom of the minor dimension. Both deflections are toward the central body.
In a particular embodiment where the sleeve is more circular in cross-section, with an outer dimension of 0.622 in. and a wall thickness of 0.034 in., a 20 lb. load causes a 0.005 in. deflection and a 60 lb. load causes a 0.020 in. deflection (approximately ½ mm). A 100 lb. load would cause a deflection of about 0.04 in. or approximately 1 mm.
Thus in summary, the above preferred super-elastic material means that the sleeve can be repeatedly deflected and returned to about its original shape without showing fatigue. The sleeve can withstand a threshold stress with a small amount of deforming strain and at about said threshold stress exhibit about substantially instantaneous deformation strain which is many times the small amount of the forming strain. In other words, such super-elastic qualities mean that the material experiences a plateau stress where the material supports a constant force (stress) over very large strain range as exhibited in
It is to be understood that for this particular embodiment, bar stock of the super-elastic material is machined into the appropriate form and then heat treated to a final temperature to set the shape of the material by increasing the temperature of the material to 932° F. and holding that temperature for five (5) minutes and then quickly quenching the sleeve in water. It is also to be understood that preferably the present nickel titanium super-elastic alloy is selected to have a transition temperature A, of about 59° Fahrenheit (15° C.). Generally for such devices the transition temperature can be between 15° C. to 65° C. (59° F. to 149° F.), and more preferably 10° C. to 40° C. (50° F. to 104° F.). Preferably, the material is maintained in the body above the transition temperature in order to exhibit optimal elasticity qualities.
Alternatively, and preferably, the sleeve can be fabricated by wire Electrical Discharge Machining (EDM) rather than machined. Additionally, the sleeve can be finished using a shot blast technique in order to increase the surface strength and elasticity of the sleeve.
Top and side views of the second wing 1032 are shown in
An alternative configuration of the second wing 1032 is depicted in
With respect to the alternative second wing 1032 depicted in
Implant 1050 of
Implant 1060 is depicted in
Another embodiment of the invention can be seen in
As with implant 1000, implant 1100 includes a central body 1002 (
In this particular embodiment, the sleeve 1016 is preferably oval or elliptical in shape as can be seen in
It is to be understood that the sleeve in this embodiment has all the characteristics and advantages described hereinabove with respect to the above-referenced super-elastic sleeves.
The second wing as discussed above, can come in a variety of shapes in order to provide for variations in the anatomical form of the spinous processes. Such shapes are depicted in
Alternative embodiments of second wings, as shown in
It is to be understood that in this embodiment, if desired, the second wing may not have to be used, depending on the anatomy of the spinal column of the body, and this embodiment still has the significant advantages attributable to the guide 1010 and the functionality of the sleeve 1016.
The implant 1120 as shown in
An additional embodiment of the implant 1150 is shown in
Implant 1150 includes a central body 1152 with a first wing 1154, where central body 1152 includes elongated groove 1156 which extends to the guide 1158. A screw 1160 is received in a threaded bore located in the elongated groove 1156.
The second wing 1162 includes a central body 1164 which is substantially perpendicular to the second wing 1162.
The central body 164 includes a plurality of bores 1166 provided therein. These bores are formed adjacent to each other in order to define a plurality of scallops, each scallop capable of retaining bolt 1160 therein. As can be seen in
It is to be understood that preferably during the surgical process, the central body 1152 is urged between spinous processes. After this has occurred, the second wing is guided by the other sides of the spinous processes from a path which causes the plane of the second wing to move substantially parallel to the plane of the first wing until the central body 1164 associated with the second wing 1162 is received in the groove of 1156 of the central body 1152 associated with the first wing 1154. After this has occurred, the bolt 1160 is positioned through aligned bores associated with the second wing 1162 and the central body 1152 in order to secure the second wing to the central body.
While embodiment 1150 does not depict a sleeve such as sleeve 1016, such a sleeve 1016 could be placed over body 1152 and be within the spirit of the invention.
Implant 1200 of the invention is depicted in
As can be seen in
As can be seen in
As can be seen in
The sleeve 1204 is received over the central body 1210 of the implant 1200 and can rotate thereon about the longitudinal axis 1214 of the central body 1210. When this particular embodiment is assembled, the grooves 1222 have received therein the pins 1212 that extend from the first wing 1202. Accordingly, the pins inserted in the grooves 1222 assist in the positioning of the sleeve relative to the remainder of the implant 1200. With the pins 1212 received in the curved grooves 1222, the pins limit the extent of the rotation of the sleeve about the central body and relative to the first wing.
As can be seen in
It is to be understood that the sleeve can be comprised of biologically acceptable material such as titanium. Additionally, it can be comprised of super-elastic material such as an alloy of nickel and titanium, much as described hereinabove with respect to other embodiments.
The great advantage of the use of the sleeve 1204 as depicted in the embodiment of
In
An alternative embodiment is shown in
A further embodiment, it is shown in
The embodiments of
An alternative embodiment of the invention is shown in
From the above, it is evident that the present invention can be used to relieve pain caused by spinal stenosis in the form of, by way of example only, central canal stenosis or foraminal (lateral) stenosis. These implants have the ability to flatten the natural curvature of the spine and open the neural foramen and the spacing between adjacent vertebra to relieve problems associated with the above-mentioned lateral and central stenosis. Additionally, the invention can be used to relieve pain associated with facet arthropathy. The present invention is minimally invasive and can be used on an outpatient basis.
The following description is presented to enable any person skilled in the art to make and use the invention. Various modifications to the embodiments described will be readily apparent to those skilled in the art, and the principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of the present invention as defined by the appended claims. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. To the extent necessary to achieve a complete understanding of the invention disclosed, the specification and drawings of all patents and patent applications cited in this application are incorporated herein by reference.
As required, implant 2100 can include a second wing 2132 which fits over the guide 2110 and is secured by a bolt 2130 placed through aperture 2134 of the second wing 2132 to the threaded bore 2112 located in the guide 2110. As implanted, the first wing 2104 is located adjacent to first sides of the spinous processes and the second wing 2132 is located adjacent to second sides of the same spinous processes.
The spacer 2150 is rotatably mounted about a shaft 2102. The spacer 2150 is positioned between the first wing 2104 and the guide 2110. The tissue expander 2110 guides the spacer 2150 into position between the spinous process of adjacent vertebrae. The spacer 2150 includes a slotted sphere 2151 that when rotated is positioned along a lead-screw, expanding or collapsing the spacer.
FIGS. 130F, 131A-B, 132A-B, and 133 illustrate a preferred embodiment of the spacer 2150 wherein the shape of the spacer 2150 is oval or elliptical in cross-section, although it can alternatively be circular or ovoid or race-track shaped in cross-section. It is to be understood that the spacer 2150 can have other shapes as described throughout the specification and be within the spirit and scope of the invention. In a preferred embodiment, the spacer 2150 includes a bore 2152 extending the length of the spacer 2150. The bore 2152 of the spacer 2150 is received over the shaft 2102 of the implant 2100 so that, as described above, the spacer can be rotated about the shaft 2102. In these embodiments, the spacer 2150 can have minor and major dimensions as follows:
One advantage of the use of the spacer 2150, as depicted in the embodiment of
In another embodiment, the spacer 2150 has a cross-section with a major dimension and a minor dimension, wherein the major dimension is greater than the minor dimension, and, for example, less than about two times the minor dimension. It is to be understood that the spacer 2150 can be fabricated from somewhat flexible and/or deflectable material.
In this embodiment the spacer is made out of a polymer, more specifically, the polymer is a thermoplastic. Still more specifically, the polymer is a polyketone known as polyetheretherketone (PEEK™). Still more specifically, the material is PEEK 450G, which is an unfilled PEEK approved for medical implantation available from Victrex of Lancashire, Great Britain. (Victrex is located at www.matweb.com or see Boedeker www.boedeker.com). Other sources of this material include Gharda located in Panoli, India (www.ghardapolymers.com).
The spacer 2150 can be formed by extrusion, injection, compression molding and/or machining techniques. This material has appropriate physical and mechanical properties and is suitable for carrying and spreading the physical load between the spinous process. For example, in this embodiment, the PEEK has the following approximate properties:
It should be noted that the material selected may also be filled. For example, other grades of PEEK are also available and contemplated, such as 30% glass-filled or 30% carbon-filled, provided such materials are cleared for use in implantable devices by the FDA, or other regulatory body. Glass-filled PEEK reduces the expansion rate and increases the flexural modulus of PEEK relative to that which is unfilled. The resulting product is known to be ideal for improved strength, stiffness, or stability. Carbon-filled PEEK is known to enhance the compressive strength and stiffness of PEEK and lower its expansion rate. Carbon-filled PEEK offers wear resistance and load carrying capability.
In this embodiment, as described above, the spacer 2150 is manufactured from polyetheretherketone (PEEK™), available from Victrex. As will be appreciated, other suitable similarly biocompatible thermoplastic or thermoplastic polycondensate materials that resist fatigue, have good memory, are flexible, and/or deflectable, have very low moisture absorption, and good wear and/or abrasion resistance, can be used without departing from the scope of the invention. The spacer can also be comprised of polyetherketoneketone (PEKK).
Other materials that can be used include polyetherketone (PEK), polyetherketoneetherketoneketone (PEKEKK), and polyetheretherketoneketone (PEEKK), and generally a polyaryletheretherketone. Further other polyketones can be used as well as other thermoplastics. The spacer can also be made of titanium.
Reference to appropriate polymers that can be used in the spacer can be made to the following documents, all of which are incorporated herein by reference. These documents include: PCT Publication WO 02/02158 A1, dated Jan. 10, 2002, entitled “Bio-Compatible Polymeric Materials;” PCT Publication WO 02/00275 A1, dated Jan. 3, 2002, entitled “Bio-Compatible Polymeric Materials;” and, PCT Publication WO 02/00270 A1, dated Jan. 3, 2002, entitled “Bio-Compatible Polymeric Materials.”
Other materials such as Bionate®, polycarbonate urethane, available from the Polymer Technology Group, of Berkeley, Calif., may also be appropriate because of the good oxidative stability, biocompatibility, mechanical strength and abrasion resistance. Other thermoplastic materials and other high molecular weight polymers can be used.
A preferred embodiment of the spacer is illustrated in
The first and second portions of the spacer 2150 in combination, can have a cross-section that is elliptical, oval, ovoid, football-shaped, circular-shaped, rectangular with rounded ends (where the cross-section has two somewhat flattened surfaces and two rounded surfaces similar to the effect of a flattened ellipse) or race-track shaped. Further, the first and second portions can have different cross-sectional shapes relative to each other. At least the minor dimension (the height) of the spacer is between 6 mm and 14 mm. Typically, the minor outer dimension is one of 6 mm, 8 mm, 10 mm, 12 mm, and 14 mm. The different sizes and selectable expandability enable the spacer to accommodate different sized patients.
As discussed above, the spacer 2150 and its components, including either the first or second portions, or both, can be made of a number of materials. Suitable materials can include polymers, such as, for example, polyetheretherketone (PEEK™), as well as other materials described above, including titanium. Such materials can be deflectable and flexible depending on the configuration of the spacer 2150.
Further, the deflectable or flexible material can have a graduated stiffness to help gradually distribute the load when the spinous processes place a force upon the exterior surface of the spacer. This can be accomplished by forming multiple layers of the deflectable or flexible material with decreasing stiffness or hardness from the center of the spacer outwardly. Alternatively, the material can have a higher stiffness or hardness in the center of the inner spacer.
Referring to
A hinge 2463 couples a first portion 2260 with a second portion 2261, such that the two portions pivot about the hinge 2463, expanding or collapsing the gap 2465.
A perspective view is provided in
The bore 2252 provides a sleeve for the shaft 2102, and also limits the rotation of the spacer 2150 about the shaft 2102. Limiting the rotation of the spacer 2150 can be accomplished, for example, by providing a slot 2255 in the bore 2252 and a key on the shaft 2102, or vice-versa. One of skill in the art can appreciate that different mechanisms and geometries can be used to limit spacer rotation. Reference is also made to a copending U.S. patent application Ser. No. 09/799,470, filed on Mar. 5, 2001, entitled “Spinal Implants, Insertion Instruments, and Methods of Use,” (Atty Docket No. KLYC-1027 US1), which is incorporated herein by reference and which discloses an implant which has a spacer with a slot and an implantation tool that includes a probe that engages the slot in order to position the spacer relative to the implantation tool for desirable initial positioning of the space relative to the spinous processes. Such a mechanism can be used by itself or in addition to the above discussed keyway and key for purposes of positioning the sphere 2151 so that the height of the spacer 2150 can be selectively adjusted during the initial surgical procedure or, thereafter, should such adjustment be desirable due, for example, to the need for more distraction between the spinous processes.
One of skill in the art can also appreciate the different expansion mechanisms that can be employed to expand the spacer 2150. For example, an expansion mechanism could include: pistons, ratchets, cams, jacks, or other machines.
The preferred method for inserting the implant between adjacent vertebrae is block-diagramed in
The implant can subsequently be readjusted with the insertion of a cannula through which a tool is inserted for operating the expansion mechanism.
Embodiments of the present invention relate to an interspinous process implant including a first wing for implant retention after placement, a spacer for maintaining and/or causing additional distraction, and a tissue expander for converting from a first position for insertion to a second position for retention of the implant after placement between adjacent spinous processes. In the second position, the tissue expander acts like a second wing to prevent displacement of the implant. The disclosed invention further claims a method for lateral insertion of the disclosed implant of the invention.
The spacer 3016 has a first or proximal end 3018 and a second or distal end 3020. At the first end 3018, the spacer 3016 is connected with a first wing 3022. The first wing 3022 functions as a first retaining unit. That is, the first wing 3022 prevents displacement of the implant 3100 once the implant 3100 is positioned in the spine, with the spacer 3016 between adjacent spinous processes. From the first wing 3022 extends a shaft 3017 upon which the rotatable spacer 3016 is rotatably mounted, so that the spacer 3016 can rotate independently from the first wing 3022 for positioning of both elements of the implant 3100. Alternatively, the first wing 3022 can be fixedly connected with, or integral to the spacer 3016.
The second end 3020 of the spacer 3016 is located adjacent to a tissue expander 3024. The tissue expander 3024 has a wedge-shaped first end 3026 that is distal to the spacer 3016, and a second end 3028 that is adjacent the spacer 3016. As discussed below, the tissue expander 3024 can be rotated about the axis 3034. When the tissue expander 3024 is rotated about the rotation axis 3034, it is converted from a first insertion position 3036 (shown in
In
In one embodiment, the tissue expander 3024 rotates about 90° to be reconfigured into the second retention position 3042, which alters the orientation of the wedge-shaped first end 3026 of the tissue expander 3024 and the elongated base element 3032. In the second retention position 3042, the tissue expander 3024 is rotated about 90° so that the elongated element 3032 (
The tissue expander 3024 can be locked into the second retention position 3042, as depicted in
The implant 3200 has a tissue expander 3224 having a wedge-shaped distal end 3226 and a proximal end 3228 that is located adjacent to rotatable spacer 3216 at a second distal end 3220 of a rotatable spacer 3216. A first wing 3222 is located adjacent to a proximal first end 3218 of spacer 3216. Focusing first on the tissue expander 3224, the wedge-shaped distal end 3226 is oriented in the first insertion position 236 to accommodate insertion between spinous processes 3212, 3214, with the flat distal part of the wedge 3226 oriented in an anterior-to-posterior direction in a patient. Also in the first insertion position 3236, the elongated base element 3232 of the tissue expander 3224, located adjacent to the spacer 3216, is oriented so that it is elongated in a direction that is anterior-to-posterior when the implant 3200 is implanted laterally in a patient.
With respect to the first wing 3222, when the tissue expander 3224 is oriented in the first insertion position 3236, the first wing 3222 is oriented, like the tissue expander 3224, in an anterior-to-posterior direction relative to a patient. As with the tissue expander 3226 rotation of the shaft 3248 causes the first wing 3222 to rotate so that is about perpendicular to an anterior-posterior direction.
In this embodiment, as indicated above, the first wing 3222 and the tissue expander 3224 are joined together by the shaft 3248 which has a longitudinal axis 3234. The spacer 3216 can rotate upon shaft 3248. Shaft 3248 includes a head 3250 which has a slot 3252 that can accept a rotation tool such as a screwdriver. Rotation of the shaft 3248 causes the first wing 3222 as well as the tissue expander 3224 to rotate. Thus, once the implant 3200 is positioned between spinous processes, a screwdriver can be used to rotate the tissue expander 3224 and the first wing 3222 from the insertion position 3236 as seen in
Although the patient's tissue will hold the first wing 3222 and the tissue expander 3224 in the rotated position, if desired, a mechanism can be included to fix the shaft 3248 in the rotated position. Such mechanism can include a detent extending from the shaft 3248 which can lock into a recess in the spacer 3216. Accordingly, in the second retention position 3242, both the first wing 3222 and the tissue expander 3224 are rotated about 90° and can be locked into place.
In this embodiment 3300, the first wing 3322 is positioned adjacent to a spacer 3316 at a first end 3318 of the spacer. As above with the implants 3100 and 3200, the spacer 3316 is rotatably mounted over a hollow spacer-mounting shaft 3317 extending from the first wing 3322. The spacer 3316 can be cylindrical, or it can have other shapes, including but not limited to elliptical or tear-drop shape in cross-section.
The tissue expander 3324 of implant 3300 comprises an upper segment 3380 that is pivotally connected via a pivoting joint 3382, or other pivoting means, with a lower segment 3384. That is, a second end 3381 of the upper segment 3380 meets a second end 3383 of the lower segment 3384 via the pivoting joint 3382. A coiled spring 3321 is provided around pivoting joint 3382 and biases both the upper segment 3380 and the lower segment 3384 of the tissue expander 3324 against the spacer 3316. The pivoting joint 3382 is connected with a first end 3388 of a rod 3386. Rod 3386 is slidably disposed in a bore 3319 which runs the entire length of the spacer 316, and is located within hollow spacer-mounting shaft 3317.
The pivoting joint 3382 and the rod 3386 provide the mechanism whereby the tissue expander 3324 is converted from the first insertion position 3336 to the second retention position 3342. In the first insertion position 3336, depicted in
Rod 3386 includes a head 3350 at the end of the rod 3386 distal from the tissue expander 3324. The head 3350 has a slot 3352 that can accept a tool adapted to be used to rotate and pull the rod 3386 through a bore 3319 of shaft 3317 toward the first wing, causing the upper segment 3380 and lower segment 3384 of the tissue expander 3324 to become aligned, such that the tissue expander 3324 is no longer wedge-shaped in the first insertion position 3336 (
In contrast, in another embodiment, the tissue expander 3324 in the first insertion position 3336 is not wedge-shaped in a top view during lateral insertion, as discussed above. Instead, the wedge-shape of the tissue expander 3324 in the first insertion position 3336 is wedge-shaped looking into the spine from a posterior to anterior direction. As such, merely pulling without rotating rod 3386 causes upper segment 3380 of the tissue expander 3324 and the lower segment 3384 of the tissue expander 3324 to pivot about the pivoting joint 3382, as above. Thus without rotating the tissue expander 3324, the tissue expander 3324 after reconfiguration will be oriented as depicted in
A rotating tool, such as a hook mounted on the end of a rod, can be used to pull the rod 3386 through the bore 3319, and can be used to rotate the tissue expander 3324 so that it is generally parallel to the first wing 3322. In a preferred embodiment, the rod 3386 can rotate the tissue expander about 90°. Alternatively, different amounts of rotation can be accomplished as needed to adapt to the anatomical structure of a patient.
Although the patient's tissue will hold the tissue expander 3324 in the rotated position 3242, if desired, a mechanism can be included to fix the rod 3386 in the rotated position. Such mechanism can include a detent extending from head 3350 which can lock into a recess in the first wing 3322 as the rod 3386 is pulled toward the first wing 3322 and rotated when the head 3350 is adjacent to the first wing 3322. Another mechanism can include ridges extending from the head 3350 of the rod 3386 which can lock into recesses in the first wing 3322.
One of ordinary skill in the art will appreciate that the locking components need not be limited to a detent and recess. The invention contemplates any locking mechanism that can secure the implant 3300 in a second retention position 3342 with the tissue expander 3324 reconfigured to a second wing.
First, an implant as in, by way of example only, embodiment 3100, is provided 3420, and the spine is accessed 3430. Access can be accomplished laterally or postero-laterally. The implant with the tissue expander 3034 in the first insertion position 3036 then is inserted 3440 between the spinous processes, either from the right lateral side, or the left lateral side.
The tissue expander 3024 is wedge-shaped in the first insertion position 3036, as described above, and is used to distract the vertebrae somewhat to facilitate the lateral insertion of the spacer 3016 between the adjacent spinous processes. This level of distraction may suffice to fully insert the implant 3100. However, if additional distraction is necessary prior to insertion of the tissue expander, distraction can be added prior to insertion 3435, by methods already well-known in the art.
Once the implant 3100 is positioned 3450 with the spacer maintaining distraction of the adjacent spinous processes, the tissue expander 3024 is moved from the first insertion position to the second retention position 3460. For implant 2100, moving the tissue expander 3024 involves rotating 3470 the tissue expander 3024 to the second retention position 3042. The rotation in one embodiment is preferably about 90°. However, varying degrees of rotation are also possible. The tissue expander 3024 locks into the second retention position 3042, as described above. The base element 3032 in the second retention position 3042 is parallel to the first wing 3022, which also serves to retain the implant 2100 in position and prevent displacement.
For an implant as in embodiment 3200, both the first wing 3222 and the tissue expander 3224 are rotated together 3470, because in embodiment 3200, the spacer 3216 is connected with the first wing 3222.
For an implant as in embodiment 3300, the tissue expander 3324 is moved 3460 from a wedge-shaped first insertion position 3336 to a retaining arm or second wing second retention position 3342.
After the converting step 3460 the incision is closed 3470.
As can be seen in
As can be seen in
In other embodiments, the implant 4100 can include two wings, with a second wing 4160 (shown in
As can be seen in
It is to be understood that the implant can be made in two pieces. The first piece can include the first wing 4130, the spacer 4120, and the distraction guide 4110. The second piece can include the second wing 4160. Each piece can be manufactured using technique known in the art (e.g., machining, molding, extrusion). Each piece, as will be more fully discussed below, can be made of a material that is bio-compatible with the body of the patient. An implant can be formed with multiple pieces and with the pieces appropriately joined together, or alternatively, an implant can be formed as one piece or joined together as one piece.
Further embodiments of implants in accordance with the present invention are depicted in
With respect to the prior embodiments which have first and second wings 4130, 4160, the second wing 4160, can be designed to be interference-fit onto the spacer 4120 (where the spacer is fixed) or a portion of the distraction guide 4110 adjacent to the spacer 4120 (where the spacer is rotatable). Where the second wing 4160 is interference-fit, there is no additional attachment device to fasten the second wing 4160 relative to the remainder of the implant. Alternatively, various fasteners can be used to secure the second wing relative to the remainder of the implant. For example,
As described above in reference to
Systems and methods in accordance with the present invention can include devices that can be used in cooperation with implants of the present invention.
Implants Having Deployable Wings
In other embodiments, implants in accordance with the present invention can comprise a “matchbox”-like structure having a first configuration (as shown in
Referring to
As mentioned above, the support structure 4722 extends from the spacer 4720 toward the distal end of the implant 4700. The spacer 4720 and the support structure 4722 include a bore or other cavity through which the rod 4715 can travel. Applying resistive force to the support structure 4722 can fix the spacer 4720 in place between spinous processes when drawing the rod 4715 through the bore. As the rod 4715 is drawn through the bore, the hinged structures 4752, 4753 with which the proximal end of the rod 4715 is connected are drawn with the rod 4715. As the rod 4715 is drawn through the spacer 4720, the hinged structures 4752,4753 are drawn toward the spacer 4720. The hinged structures 4750-4753 pivot outward to accommodate the relative movement between the rod 4715 and the spacer 4720. Accordingly, the second wing 4760 has been satisfactorily deployed.
The hinged structures 4756, 4757 of the first wing 4730 can cause deployment of the first wing 4730 by applying resistive force to the hinged structures 4756, 4757 while drawing the spacer 4720 (via the support structure 4722), or by urging the hinged structures 4756, 4757 toward the spacer 4720. The resistive force or urging can be applied by a second stop 4784 that can fit around the support structure 4722 and can be interference fit or otherwise selectively fixed with the support structure 4722. As the second stop 4784 is pushed along the longitudinal axis 4725, along the support structure 4722, the hinged structures 4754-4757 pivot outward to accommodate the relative movement between the second stop 4784 and the spacer 4720. Accordingly, the first wing 4730 has been satisfactorily deployed.
It should be noted that with implants as described above in reference to
Referring to
The flexible straps 4890 can be made from a biocompatible material. In an embodiment, the flexible straps 4890 can be made from a braided polyester suture material. Braided polyester suture materials include, for example, Ethibond, Ethiflex, Mersilene, and Dacron, and are non-absorbable, having high tensile strength, low tissue reactivity and improved handling. In other embodiments, the flexible straps 4890 can be made from stainless steel (i.e., surgical steel), which can be woven into a strap, for example. In still other embodiments, flexible straps 4890 can be made from some other material (or combination of materials) having similar properties.
Referring to
The cross-section of the implant 4900 in a first configuration is generally consistent along the implant's length, having a diameter generally the thickness of a spacer 4920 of the implant 4900. The implant 4900 can comprise a distraction guide 4910 at a proximal end of the implant 4900, the distraction guide 4910 having a rounded (as shown) or tapered shape to pierce and/or distract a space between adjacent spinous processes. However, where a cannula is employed to deliver an implant to a surgical site, the implant 4900 can optionally include a distraction guide 4910 at the proximal end. The surgical site, and associated tissues and structures can be distracted and repositioned by the cannula, allowing substantially unobstructed access to the surgical site by the implant 4900. In such circumstance a distraction guide 4910 may not be necessary.
The implant 4900 can further comprise a plurality of hinged structures 4950-4957, the hinged structures 4950-4957 being collapsed so as to facilitate the substantially collapsed profile. The hinged structures 4950-4957 are pivotally connected with the spacer 4920 and extend from both sides of the spacer 4920. A rod 4915 (or alternatively some other mechanism such as a tab) can be connected with the proximal end of the implant 4900 and can extend through the hinged structures 4950-4953, and through the spacer 4920 so that the rod 4915 is accessible to a physician.
Referring to
Embodiments as described above in reference to
Once the second wing 4960 is deployed, the cannula 995 can be retracted from the surgical site, thereby allowing the hinged structures 956, 4957 of the first wing 4930 to deploy by urging the hinged structures 4956, 4957 toward the spacer 4920. The urging can be applied by a stop 4982 that can fit around the rod 4915 and can be interference fit or otherwise selectively fixed with the rod 4915. As the stop 982 is pushed along the longitudinal axis 4925, along the rod 4915, the hinged structures 4954-4957 pivot outward to accommodate the relative movement between the stop 4982 and the spacer 4920. Accordingly, the first wing 4930 has been satisfactorily deployed.
Once the second wing 4960 and the first wing 4930 are deployed, the rod 4915 can be fixed in position relative to the spacer 4920. As above, this can be accomplished using myriad different mechanisms. For example, as shown a stop 4982 can be interference fit to the rod 4915 and positioned against the first wing 4930 along the rod 4915. The stop 4982 can grip the rod 4915 so that the rod 4915 is prevented from moving by a friction fit between the stop 4982 and the rod 4915. In other embodiments, some other mechanism can be used, such as a pin (e.g., a cotter pin), a latch system, etc. One of ordinary skill in the art will appreciate the myriad different mechanisms for fixing a rod 4915 in position relative to the spacer 4920. With the first wing 4930 and the second wing 4960 deployed, movement of the implant 4900 along the longitudinal axis 4925 can be limited or blocked, thereby resisting undesirable displacement of the implant 4900.
It should be noted that with implants as described above in reference to
Referring to
As with the flexible straps 4890 above, the cord 4996 can be made from a biocompatible material. In an embodiment, the cord 4996 can be made from a braided polyester suture material. Braided polyester suture materials include, for example, Ethibond, Ethiflex, Mersilene, and Dacron, and are non-absorbable, having high tensile strength, low tissue reactivity and improved handling. In other embodiments, the cords 4996 can be made from stainless steel (i.e., surgical steel), which can be woven into a strap, for example. In still other embodiments, the cords 4996 can be made from some other material (or combination of materials) having similar properties.
Materials for Use in Implants of the Present Invention
In some embodiments, the implant can be fabricated from medical grade metals such as titanium, stainless steel, cobalt chrome, and alloys thereof, or other suitable implant material having similar high strength and biocompatible properties. Additionally, the implant can be at least partially fabricated from a shape memory metal, for example Nitinol, which is a combination of titanium and nickel. Such materials are typically radiopaque, and appear during x-ray imaging, and other types of imaging. Implants in accordance with the present invention, and/or portions thereof can also be fabricated from somewhat flexible and/or deflectable material. In these embodiments, the implant and/or portions thereof can be fabricated in whole or in part from medical grade biocompatible polymers, copolymers, blends, and composites of polymers. A copolymer is a polymer derived from more than one species of monomer. A polymer composite is a heterogeneous combination of two or more materials, wherein the constituents are not miscible, and therefore exhibit an interface between one another. A polymer blend is a macroscopically homogeneous mixture of two or more different species of polymer. Many polymers, copolymers, blends, and composites of polymers are radiolucent and do not appear during x-ray or other types of imaging. Implants comprising such materials can provide a physician with a less obstructed view of the spine under imaging, than with an implant comprising radiopaque materials entirely. However, the implant need not comprise any radiolucent materials.
One group of biocompatible polymers are the polyaryl ester ketones which has several members including polyetheretherketone (PEEK), and polyetherketoneketone (PEKK). PEEK is proven as a durable material for implants, and meets the criterion of biocompatibility. Medical grade PEEK is available from Victrex Corporation of Lancashire, Great Britain under the product name PEEK-OPTIMA. Medical grade PEKK is available from Oxford Performance Materials under the name OXPEKK, and also from CoorsTek under the name BioPEKK. These medical grade materials are also available as reinforced polymer resins, such reinforced resins displaying even greater material strength. In an embodiment, the implant can be fabricated from PEEK 450G, which is an unfilled PEEK approved for medical implantation available from Victrex. Other sources of this material include Gharda located in Panoli, India. PEEK 450G has the following approximate properties: TABLE-US-00001 Property Value Density 1.3 g/cc Rockwell M 99 Rockwell R 126 Tensile Strength 97 MPa Modulus of Elasticity 3.5 GPa Flexural Modulus 4.1 GPa
PEEK 450G has appropriate physical and mechanical properties and is suitable for carrying and spreading a physical load between the adjacent spinous processes. The implant and/or portions thereof can be formed by extrusion, injection, compression molding and/or machining techniques.
It should be noted that the material selected can also be filled. Fillers can be added to a polymer, copolymer, polymer blend, or polymer composite to reinforce a polymeric material. Fillers are added to modify properties such as mechanical, optical, and thermal properties. For example, carbon fibers can be added to reinforce polymers mechanically to enhance strength for certain uses, such as for load bearing devices. In some embodiments, other grades of PEEK are available and contemplated for use in implants in accordance with the present invention, such as 30% glass-filled or 30% carbon-filled grades, provided such materials are cleared for use in implantable devices by the FDA, or other regulatory body. Glass-filled PEEK reduces the expansion rate and increases the flexural modulus of PEEK relative to unfilled PEEK. The resulting product is known to be ideal for improved strength, stiffness, or stability. Carbon-filled PEEK is known to have enhanced compressive strength and stiffness, and a lower expansion rate relative to unfilled PEEK. Carbon-filled PEEK also offers wear resistance and load carrying capability.
As will be appreciated, other suitable similarly biocompatible thermoplastic or thermoplastic polycondensate materials that resist fatigue, have good memory, are flexible, and/or deflectable, have very low moisture absorption, and good wear and/or abrasion resistance, can be used without departing from the scope of the invention. As mentioned, the implant can be comprised of polyetherketoneketone (PEKK). Other material that can be used include polyetherketone (PEK), polyetherketoneetherketoneketone (PEKEKK), polyetheretherketoneketone (PEEKK), and generally a polyaryletheretherketone. Further, other polyketones can be used as well as other thermoplastics. Reference to appropriate polymers that can be used in the implant can be made to the following documents, all of which are incorporated herein by reference. These documents include: PCT Publication WO 02/02158 A1, dated Jan. 10, 2002, entitled “Bio-Compatible Polymeric Materials-” PCT Publication WO 02/00275 A1, dated Jan. 3, 2002, entitled “Bio-Compatible Polymeric Materials;” and, PCT Publication WO 02/00270 A1, dated Jan. 3, 2002, entitled “Bio-Compatible Polymeric Materials.” Other materials such as Bionate®., polycarbonate urethane, available from the Polymer Technology Group, Berkeley, Calif., may also be appropriate because of the good oxidative stability, biocompatibility, mechanical strength and abrasion resistance. Other thermoplastic materials and other high molecular weight polymers can be used.
As described above, the binder can be made from a biocompatible material. In an embodiment, the binder can be made from a braided polyester suture material. Braided polyester suture materials include, for example, Ethibond, Ethiflex, Mersilene, and Dacron, and are nonabsorbable, having high tensile strength, low tissue reactivity and improved handling. In other embodiments, the binder can be made from stainless steel (i.e., surgical steel), which can be braided into a tether or woven into a strap, for example. In still other embodiments, the binder can be made from some other material (or combination of materials) having similar properties.
It is to be understood that embodiments in accordance with the present invention can be constructed without a pliant material. It is also to be understood that the embodiments in accordance with the present invention can have other dimensions
Methods for Implanting Interspinous Implants
A minimally invasive surgical method for implanting an implant 4400 in the cervical spine is disclosed and taught herein. In this method, as shown in
Once the implant 4400 is satisfactorily positioned, a second wing 4460 can be optionally inserted along a line that is generally co-linear with the line over which the implant 4400 is inserted but from the opposite side of the neck. The anatomy of the neck is such that it is most convenient and minimally invasive to enter the neck from the side with respect to the implant 4400 and the second wing 4460. The second wing 4460 is mated to the implant and in this particular embodiment, the second wing 4460 is attached to the implant 4400 by the use of a fastener, for example by a screw 4442. Where a screw is used, the screw 4442 can be positioned using a screw driving mechanism that is directed along a posterior to anterior line somewhat parallel to the guide wire 4080. This posterior to anterior line aids the physician in viewing and securing the second wing 4460 to the implant. The second wing 4460 is positioned so that a bore 4463 formed in a lip 4461 of the second wing 4460 is aligned with a bore 4440 of the implant 4400, as described above. The screw 4442 is positioned within both bores and secured, at least, to the bore 4440 of the implant 4400. In other embodiments, the second wing can be interference fit with the implant, as described above, or fastened using some other mechanism, such as a flexible hinge and protrusion.
A minimally invasive surgical method for implanting an alternative embodiment of an implant 4700 in the cervical spine is disclosed and taught herein. In this method, as shown in
Once the implant 4700 is satisfactorily positioned, the first wing 4730 and the second wing 4760 can be deployed. As described above, the second wing 4760 can be deployed by urging the rod 4715 in a direction opposite the direction of insertion along the longitudinal axis 4725. As the rod 4715 travels through the spacer 4720, hinged structures 4750-4753 contact the spacer 4720, buckle and extend away from the rod 4715 two form an upper end 4762 of the second wing and a lower end 4764 of the second wing. When second wing 4760 is satisfactorily deployed, the rod 4715 can be fixed in place relative to the spacer 4720 using a first stop 4782, a pin, or some other mechanism. The first wing 4730 can be deployed by urging the hinged structures 4754-4757 toward the spacer 4720, causing the hinged structures 4754-4757 to buckle and extend away from one another to form an upper end 4732 of the second wing and a lower end 4734 of the second wing. The anatomy of the neck is such that it is most convenient and minimally invasive to enter the neck from the side with respect to the implant 4700.
A minimally invasive surgical method for implanting an alternative embodiment of an implant 4900 in the cervical spine is disclosed and taught herein. In this method, as shown in
The foregoing description of embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations will be apparent to the practitioner skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention and the various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalence.
Additional aspects, objects and advantages of the invention can be obtained through a review of the appended claims and figures.
Claims
1.-21. (canceled)
22. An interspinous device for stabilizing at least one spinal motion segment comprising:
- a first vertebra having a first spinous process and a second vertebra having a second spinous process, the device comprising: an expandable member having an unexpanded configuration and an expanded configuration, wherein the expandable member in an expanded configuration has a size and shape configured for positioning between and providing distraction of the first and second spinous processes.
23. The device of claim 22, wherein the expandable member is a non-compliant balloon.
24. The device of claim 22, wherein the expandable member is a compliant balloon.
25. The device of claim 22, wherein the expandable member comprises a mesh material.
26. The device of claim 25, wherein the mesh material is coated with a non-porous material.
27. The device of claim 22, wherein the expandable member has a substantially H-shaped configuration.
28. The device of claim 22, wherein the expandable member comprises polyurethane.
29. The device of claim 22, further comprising at least one tab for anchoring the expandable member to the spinous processes.
30. The device of claim 29, further comprising a tether attached to the at least one tab.
31. The device of claim 22, further comprising at least one tether attached to the expandable member.
32. The device of claim 22, wherein the expandable member has a port for coupling to a source of an expansion medium.
33. The device of claim 22, wherein the port comprises a one-way valve mechanism.
34. The device of claim 22, wherein the expandable member is inflatable.
35. The device of claim 22, further comprising an expansion medium contained within the interior of the expandable member when in an expanded configuration.
36. The device of claim 22, further comprising at least one marker on a surface of the expandable member.
37. A system for stabilizing at least one spinal motion segment comprising:
- a first vertebra having a first spinous process and a second vertebra having a second spinous process, the system comprising: an expandable member having an unexpanded configuration and an expanded configuration, wherein the expandable member in an expanded configuration has a size and shape configured for positioning between and providing distraction of the first and second spinous processes, wherein the expandable member has a port; and an expansion medium fillable within the interior of the expandable member via the port.
38. The system of claim 37, further comprising at least one anchor for securing the expandable member to the spinal motion segment.
39. The system of claim 38, wherein the at least one anchor is a screw configured for securing the expandable member to a spinous process.
40. The system of claim 37, wherein the expansion medium comprises polyurethane.
41. A kit for stabilizing at least one spinal motion segment comprising:
- a first vertebra having a first spinous process and a second vertebra having a second spinous process wherein a spinous ligament extends between the first and second spinous processes, the kit comprising: at least one expandable member having an unexpanded configuration and an expanded configuration, wherein the at least one expandable member in an expanded configuration has a size and shape configured for positioning between and providing distraction of the first and second spinous processes; and a cannula configured for percutaneous delivery to a target site within the spinal motion segment wherein the expandable member is deliverable through the cannula when in an unexpanded configuration.
42. The kit of claim 41, further comprising instructions for implanting the expandable member between the first and second spinous processes.
43. A method for stabilizing at least one spinal motion segment comprising:
- a superior vertebra and an inferior vertebra, the method comprising: providing the device of claim 1; forming an opening in the spinous ligament; positioning the expandable member within the opening wherein the expandable member is in the unexpanded configuration; and expanding the expandable member to the expanded configuration wherein the first and second vertebrae are distracted a selected distance.
44. The method of claim 43, wherein the expanding comprises inflating the expandable member with air.
45. The method of claim 44, the expanding further comprises filling the expandable member with a flowable medium.
46. The method of claim 43, wherein the steps of forming, positioning and expanding are performed through a percutaneous penetration in the patient's skin.
47. The method of claim 46, wherein the steps of forming, positioning and expanding are performed through a cannula positioned within the percutaneous penetration.
48. The method of claim 43, further comprising anchoring the expandable member to one or both of the spinous processes.
49. The method of claim 43, wherein the expandable member has a volume in the expanded configuration, the method further comprising adjusting the volume of the expandable member.
50. The method of claim 49, further comprising reducing the volume of the expandable member and removing the expandable member subsequent to reducing the volume.
51. A method for stabilizing at least one spinal motion segment comprising:
- a superior vertebra and an inferior vertebra, the method comprising: forming an opening in the spinous ligament; positioning an expandable member within the opening wherein the expandable member is in an unexpanded configuration; and selectively expanding the expandable member to an expanded configuration wherein the first and second vertebrae are distracted a selected distance.
52. An interspinous device for stabilizing at least one spinal motion segment comprising:
- a first vertebra having a first spinous process and a second vertebra having a second spinous process, the device comprising: an expandable member having an unexpanded configuration and an expanded configuration, wherein the expandable member in the unexpanded configuration has a size configured for positioning between the first and second spinous process and in the expanded configuration provides distraction of the first and second spinous processes, wherein the expandable member is mechanically actuatable from the unexpanded configuration to the expanded configuration.
53. The device of claim 52, wherein the expandable member comprises a plurality of parallel struts.
54. The device of claim 53, wherein the plurality of struts are affixed between two opposing hubs.
55. The device of claim 52, wherein the expandable member comprises a coiled band.
56. The device of claim 55, wherein the coiled band comprises inner and outer ends which are connectable to each other.
57. The device of claim 52, wherein the expandable member comprises a plurality of nested portions.
58. The device of claim 52, wherein the expandable member has a spherical configuration.
59. The device of claim 52, wherein the expandable member has an elliptical configuration.
60. The device of claim 52, wherein the expandable member has a disk configuration.
61. The device of claim 52, wherein the expandable member is self-expanding.
62. A system for stabilizing at least one spinal motion segment comprising:
- a first vertebra having a first spinous process and a second vertebra having a second spinous process, the system comprising: an expandable member having an unexpanded configuration and an expanded configuration, wherein the expandable member in the unexpanded configuration has a size configured for positioning between the first and second spinous process and in the expanded configuration provides distraction of the first and second spinous processes, wherein the expandable member is mechanically actuatable from the unexpanded configuration to the expanded configuration; and means for mechanically actuating the expandable member.
63. The system of claim 62, wherein said mechanical actuation means is a guide wire.
64. A method for stabilizing a vertebrae relative to another vertebrae, the method comprising:
- introducing an expandable interspinous device to laterally of an interspinous space of the vertebrae;
- expanding the interspinous device; and
- inserting the interspinous device within the interspinous space.
65. The method of claim 64, further comprising: distracting the interspinous space prior to inserting the interspinous device.
66. The method of claim 65, wherein the distracting comprises introducing a device within the interspinous space and expanding the distracting device.
67. The method of claim 66, wherein the distracting device is a balloon.
68. The method of claim 66, wherein the distracting device is a mechanical device.
69. The method of claim 67, wherein the distracting device is introduced on one side of the interspinous space and the expandable interspinous device is introduced on the opposite side of the interspinous space.
70. The method of claim 67, wherein the distracting device and the expandable interspinous device are introduced on the same side of the interspinous space.
71. A kit for stabilizing at least one spinal motion segment comprising:
- a first vertebra having a first spinous process and a second vertebra having a second spinous process, the kit comprising: the interspinous device of claim 52; and a cannula configured for percutaneous delivery to a target site within the spinal motion segment wherein the expandable member is deliverable through the cannula when in an unexpanded configuration.
72. The kit of claim 71, further comprising instructions for implanting the expandable member between the first and second spinous processes.
73. A method for stabilizing at least one spinal motion segment comprising a superior vertebra and an inferior vertebra, the method comprising:
- providing the device of claim 52;
- forming an opening in the spinous ligament;
- positioning the expandable member within the opening wherein the expandable member is in the unexpanded configuration; and
- expanding the expandable member to the expanded configuration wherein the first and second vertebrae are distracted a selected distance.
74. The method of claim 73, wherein the expanding comprises mechanical actuation.
75. The method of claim 73, wherein the steps of forming, positioning and expanding are performed through a percutaneous penetration in the patient's skin.
76. The method of claim 75, wherein the steps of forming, positioning and expanding are performed through a cannula positioned within the percutaneous penetration.
77. The method of claim 73, further comprising anchoring the expandable member to one or both of the spinous processes.
78. An interspinous device for stabilizing at least one spinal motion segment comprising:
- a first vertebra having a first spinous process and a second vertebra having a second spinous process, the device comprising: an axial dimension and a radial dimension substantially transverse to the axial dimension, wherein the axial dimension is greater when the device is in an undeployed configuration and the radially dimension is greater when the device is in a deployed configuration.
79. The interspinous device of claim 78, wherein the axial dimension is defined by a central member and the radial dimension is defined at least in part by a plurality of radially expandable members.
80. The interspinous device of claim 79, comprising a first strap extending between a first pair of the radially expandable members and a second strap extending between a second pair of the radially expandable members.
81. The interspinous device of claim 79, wherein the radially expandable members comprise linkages.
82. The interspinous device of claim 79, wherein the radially expandable members comprise deformable struts.
83. The interspinous device of claim 79, wherein the radially expandable members comprise a compressible material.
84. A system for stabilizing at least one spinal motion segment comprising:
- a first vertebra having a first spinous process and a second vertebra having a second spinous process and an interspinous space defined between the first and second spinous processes, the system comprising: the interspinous device of claim 78; and a device for delivering the interspinous device in the undeployed state within the interspinous processes and for axially reducing and radially expanding the device from the undeployed state to the deployed state.
85. The system of claim 84, wherein the interspinous device is configured for delivery by the delivery device through a midline incision.
86. A method for stabilizing a vertebrae relative to another vertebrae wherein the vertebrae define an interspinous space, the method comprising:
- introducing the interspinous device of claim 78 within the interspinous space when in the undeployed state; and
- radially expanding and axially shortening the device to engage with the spinous processes.
87. The method of claim 86, further comprising forming an incision along the midline above the interspinous space, wherein the introducing the interspinous device comprises inserting the device within the midline incision.
88. An interspinous device for stabilizing at least one spinal motion segment comprising:
- a first vertebra having a first spinous process and a second vertebra having a second spinous process, the device comprising: a tubular member having a length and a diameter and being deployable from a first configuration to a second configuration, wherein one of the length and the diameter of the tubular member in the first configuration is changed when the tubular member is in the second configuration.
89. The device of claim 88 wherein the length of the tubular member in the first configuration is greater than the length of the tubular member in the second configuration.
90. The device of claim 88 wherein the diameter of the tubular member in the second configuration is greater than the diameter of the tubular member in the first configuration.
91. The device of claim 88 further comprising a retaining member circumferentially positioned about a portion of the length of the tubular member, wherein the diameter of the retained portion of the tubular member is less than the diameter of the unretained portion of the tubular member when the tubular member is in the second configuration.
92. The device of claim 91 wherein the diameter of the retained portion of the tubular member in the second configuration is sufficient to distract the first and second vertebrae relative to each other when the device is operably implanted between the first and second spinous processes.
93. The device of claim 91, wherein the retaining member is positioned about a central portion of the tubular member.
94. The device of claim 88, further comprising a core member positionable within the tubular member; and first and second hubs configured for coupling with a first end of the core member and a second end of the core member, respectively.
95. The device of claim 94, wherein the at least one of the hubs is configured to translate axially over the core member.
96. The device of claim 94, wherein the core member comprises segments of length which are removable from the core member.
97. The device of claim 88, wherein the tubular member comprises a polymer material.
98. The device of claim 88, wherein the retaining member comprises a braided or mesh material.
99. The device of claim 88, wherein a luminal surface of the tubular member is contoured.
100. A system for stabilizing at least one spinal motion segment comprising:
- a first vertebra having a first spinous process and a second vertebra having a second spinous process, the system comprising: the interspinous device of claim 88; and a device for delivering the interspinous device when in the first configuration between the first and second spinous process and for deploying the interspinous device in the second configuration.
101. The system of claim 98 wherein the delivery device comprises:
- an elongated shaft having a detachable distal end configured for insertion into the tubular member of the interspinous device; and
- a handle mechanism for moving the elongated shaft wherein the movement causes the tubular member to be deployed from the first configuration to the second configuration.
102. A method for stabilizing a vertebrae relative to another vertebrae wherein the vertebrae define an interspinous space, the method comprising:
- introducing the interspinous device of claim 88 within the interspinous space when in the first configuration; and
- deploying the interspinous device to the second configuration.
103. A device for stabilizing at least one spinal motion segment comprising a first vertebra having a first spinous process and a second vertebra having a second spinous process, the device comprising:
- an undeployed configuration having an axial dimension and a radial dimension substantially transverse to the axial dimension; and a deployed configuration having an axial dimension and a radial dimension substantially transverse to the axial dimension;
- wherein the radial dimension of the undeployed configuration is less than the radial dimension in the deployed configuration.
104. The device of claim 103, wherein the axial dimension of the undeployed configuration is greater than the axial dimension in the deployed configuration.
105. The interspinous device of claim 103, wherein the radial dimension is defined at least in part by a plurality of radially expanding members.
106. The device of claim 105, wherein the radially expanding members comprise deformable struts.
107. The device of claim 105, wherein the radially expanding members comprise linkages.
108. The device of claim 105, comprising a first bracket extending between a first pair of the radially expandable members and a second bracket extending between a second pair of the radially expandable members.
109. The device of claim 107, wherein the brackets each comprise a substantially rigid central portion and two substantially flexible lateral portions.
110. The device of claim 103, wherein the device in the undeployed has a cylindrical shape.
111. The device of claim 103, wherein the device in the deployed has a “X” shape.
112. A system for stabilizing at least one spinal motion segment comprising:
- a first vertebra having a first spinous process and a second vertebra having a second spinous process and an interspinous space defined between the first and second spinous processes, the system comprising: the device of claim 103; and a device for delivering the device in the undeployed configuration within the interspinous processes and for radially expanding the device from the undeployed configuration to the deployed configuration.
113. The system of claim 112, wherein the device is configured for delivery by the delivery device through a midline incision.
114. A method for stabilizing a vertebra relative to another vertebra wherein the vertebrae define an interspinous space therebetween, the method comprising:
- introducing the device of claim 103 within the interspinous space when in the undeployed configuration; and
- radially expanding the device to selectively distract the spinous processes.
115. The method of claim 114, further comprising forming an incision along the midline above the interspinous space, wherein the introducing the interspinous device comprises inserting the device within the midline incision.
116. A posterior element distraction system for implantation at a spinal motion segment comprising a superior vertebra, an inferior vertebra, each vertebra comprising a posterior element comprising a spinous process, laminal portions and a set of facet joints, and further comprising an interspinous space between the spinous processes, the system comprising:
- at least one lateral member for positioning on a side of the spinal motion segment and outside the interspinous space, wherein the at least one lateral member has an unexpanded configuration and an expanded configuration; and
- first and second transverse members extending transversely from the at least one lateral member, wherein when the system is operatively implanted at a spinal motion segment and the at least one lateral member is in an expanded configuration, the transverse members are caused to contact a portion of either the superior or inferior posterior elements thereby providing distraction between the superior and inferior posterior elements.
117. The system of claim 116, wherein the system comprises two lateral members for positioning on opposite sides of spinal motion segment.
118. The system of claim 117, wherein each transverse member is a strap extending between the two lateral members.
119. The system of claim 117, further comprising a meshing about the two lateral members.
120. The system of claim 116, wherein the system comprises only one lateral member.
121. The system of claim 116, wherein the at least one lateral member comprises a balloon configuration.
122. The system of claim 117, wherein the at least one lateral member comprises a strut configuration.
123. The system of claim 118, wherein the at least one lateral member comprises a balloon and a strut.
124. The system of claim 116, wherein the transverse members have a pre-formed configuration.
125. The system of claim 116, wherein the transverse members have a flexible configuration.
126. A system for implanting the system of claim 116, the implantation system comprising:
- a temporary distraction device having an expanded configuration and an unexpanded configuration and further configured for insertion within the interspinous space, wherein upon expansion of the device, the superior and inferior vertebrae are distracted from each other.
127. The system of claim 126, further comprising:
- a working channel for delivering the temporary distraction device and the posterior distraction system, wherein the temporary distraction device is deliverable in an unexpanded configuration.
128. The system of claim 127, wherein the temporary distraction device and the posterior distraction system are deliverable simultaneously to the spinal motion segment.
129. The system of claim 126, wherein the temporary distraction device comprises a balloon.
130. A method for distracting at least a portion of a spinal motion segment comprising:
- a superior vertebra, an inferior vertebra, each vertebra comprising a posterior element comprising a spinous process, laminal portions and a set of facet joints, and further comprising an interspinous space between the spinous processes, the method comprising: inserting an expandable member laterally of the spinal motion segment; and expanding the expandable member thereby distracting the superior vertebra and the inferior vertebra relative to each other.
131. The method of claim 130, further comprising:
- inserting two transverse members within the interspinous space.
132. The method of claim 130, wherein the distraction between the vertebrae is along the longitudinal axis of the spine.
133. The method of claim 130, wherein the distraction between the vertebrae is rotational.
134. A method for distracting at least a portion of a spinal motion segment comprising:
- a superior vertebra, an inferior vertebra, each vertebra comprising: a posterior element comprising a spinous process, laminal portions and a set of facet joints, and further comprising an interspinous space between the spinous processes, the method comprising: distracting the superior vertebra and the inferior vertebra relative to each other until a desired amount of distraction is achieved; inserting an implantable expandable member within the interspinous space; and expanding the implantable expandable member to contact the spinous processes thereby maintaining the distraction achieved.
135. The method of claim 134, wherein the distracting comprises using another expandable member positionable within the interspinous space; and wherein the other expandable member is removed subsequent to the expanding of the implantable expandable.
Type: Application
Filed: Apr 19, 2007
Publication Date: Apr 10, 2008
Applicant: St. Francis Medical Technologies, Inc. (Concord, CA)
Inventors: James Zucherman (San Francisco, CA), Ken Hsu (San Francisco, CA), Charles Winslow (Walnut Creek, CA), Henry Klyce (Piedmont, CA), Scott Yerby (Montara, CA), John Flynn (West Milford, NJ), Steven Mitchell (Pleasant Hill, CA), John Markwart (Castro Valley, CA)
Application Number: 11/788,763
International Classification: A61F 2/44 (20060101); A61B 17/58 (20060101);