Patent Application
20070233089
1. Field of the Invention
This application relates to apparatus and methods for providing support to one or more vertebrae that are adjacent to a surgical site, e.g., to reduce adjacent level disc disease.
2. Description of the Related Art
A common procedure for treating degenerative disc disease (DDD) is fusing or fixing together two or more vertebrae at the affected level or levels of the spine. However, many patients who have undergone a fusion or fixation procedure experience degeneration of the spinal segments (e.g., discs, vertebrae, and nerves) adjacent to the fusion or fixation site. This adjacent level degenerative disc disease can occur soon after surgery, e.g., within five years of the primary fusion or fixation procedure.
Adjacent level DDD is currently treated by performing a second fusion or fixation procedure at one or more levels adjacent to the primary fusion or fixation levels. The second procedure requires another operation on the patient and an extension of the fusion or fixation hardware to the affected level(s). In many cases, the second operation requires disassembly of some of the hardware from the site of the primary procedure. However, this hardware can be partially or completely encapsulated by bridging bone and/or scar tissue, which makes the second operation more difficult. Trauma caused by retraction of the musculature at the primary site can cause further damage to the tissue. The second operation causes significant trauma and discomfort to the patient.
Accordingly, there is a need for apparatus, systems, and methods that can eliminate, slow, or stop the progress of adjacent level DDD to reduce the patient's chances of requiring a second fusion, fixation or other operative procedure of the body adjacent to, and including, the spine.
In one embodiment for treating the spine, a crosslink spacer device can be implanted to support and stabilize adjacent levels to the primary fixation or fusion site. In one embodiment, the crosslink spacer device comprises a spacer rod, a crosslink spacer, and a connecting member to attach the device to the primary fusion or fixation hardware. In some embodiments, the crosslink spacer is positioned between the spinous processes of the primary and adjacent levels to limit the compression of the vertebrae.
In one embodiment, a device for supporting a spinal segment of a patient is provided that includes one or more spacer rods, one or more spacers configured to be coupled with the one or more spacer rods and configured to support and stabilize adjacent vertebrae. The device also includes one or more connecting members configured to couple the one or more spacer rods to the spine of the patient. The spacer is capable of being positioned between adjacent spinous processes of the spine of the patient.
In one another embodiment, a device is provided for supporting spinal anatomy adjacent to a spinal segment for which normal range of motion is compromised. The device comprises a spacer configured to be positioned between a spinal segment, e.g., a portion of a vertebra such as a spinous process or lamina, of one of a plurality of affected vertebrae and a spinal segment of another vertebra adjacent to the affected vertebrae. The device can be configured to extend between the spinal segment of one of a plurality of affected vertebrae and the spinal segment of the adjacent vertebra.
In another embodiment a method is provided for reducing, delaying, or eliminating adjacent level DDD. The method involves accessing a region of the spine where normal range of motion is compromised, e.g., as in a fusion procedure. A spacer is positioned between a vertebral portion of one of the vertebrae for which the normal range of motion is compromised and a corresponding vertebral portion of an adjacent vertebrae, e.g., between adjacent spinous processes or lamina. The spacer can be coupled with a fixation assembly, e.g., by a rigid member such as a rod. The spacer can be movably coupled using a device such as a ball joint to permit some motion of the spacer relative to the fused spinal segment or between the spacer and a fixation or motion limiting device coupled with the affected spinal segment.
In another embodiment a spinal stabilization apparatus comprises a primary stabilization device and a device configured to intermittently interact with an adjacent spinal level. The primary stabilization device comprises a first screw configured to be inserted into a first vertebra and a second screw configured to be inserted into a second vertebra. The primary stabilization device also comprises a first elongate member extendable between the first and second screws. The first elongate member is configured to reduce at least some of the range of motion of the first and second vertebrae. The device is configured to intermittently interact with an adjacent spinal level comprises a spacer and a second elongate member. The spacer is configured to be inserted between a spinous process of the first vertebra and a second vertebra adjacent to the first vertebra. The second elongate member is configured to interconnect the spacer and the primary stabilization device.
In another embodiment an apparatus is provided for reducing adjacent level disc disease. The apparatus comprises a fixation device and a device configured to reduce adjacent level disc disease. The fixation device comprises a first screw configured to be inserted into a first vertebra and a second screw configured to be inserted into a second vertebra. The device configured to reduce adjacent level disc disease comprises a spacer and an elongate member. The spacer is configured to be inserted between a spinous process of the second vertebra and a third vertebra adjacent to the second vertebra. The elongate member is configured to interconnect the spacer and the fixation device.
In another embodiment a spacer device is provided for use with a primary spinal fixation device. The spacer device comprises a compressible spacer, a transverse member, and a connecting member. The compressible spacer is sized to fit between the spinous processes of two lumbar vertebrae and is configured to reduce the range of motion of at least one vertebra. The transverse member is configured to extend from one side of the midline of the spine, extending through the interspinous process space. The transverse member is coupled with the spacer. The connecting member is attachable to the transverse member and to a primary spinal fixation device.
In another embodiment, a method is provided for reducing or delaying degenerative disc disease. The method involves accessing a region of the spine where normal range of motion is compromised. A spacer is placed between a vertebral portion of one of the vertebrae for which the normal range of motion is compromised and a corresponding vertebral portion of an adjacent vertebrae. The spacer is coupled with a fixation assembly by a rod.
In another embodiment, a method is provided for treating a spine of a patient. The method involves inserting an access device through a minimally invasive incision in the skin of the patient. The access device is advanced until a distal portion thereof is located adjacent the spine. The access device is expanded from a first configuration to a second configuration. The second configuration has an enlarged cross-sectional area at the distal portion thereof such that the distal portion extends across at least two of three adjacent vertebrae. A first device is delivered through the access device to a location between a first pair of adjacent vertebrae. The first device is configured to preserve motion between the first pair of adjacent vertebrae. A second device is delivered through the access device to a location between a second pair of adjacent vertebrae. The second device is configured to preserve motion between the second pair of adjacent vertebrae.
These and other features, embodiments, and advantages of the present invention will now be described in connection with preferred embodiments of the invention, in reference to the accompanying drawings. The illustrated embodiments, however, are merely examples and are not intended to limit the invention.
Throughout the figures, the same reference numerals and characters, unless otherwise stated, are used to denote like features, elements, components or portions of the illustrated embodiments. Moreover, while the subject invention will now be described in detail with reference to the figures, it is done so in connection with the illustrative embodiments. It is intended that changes and modifications can be made to the described embodiments without departing from the true scope and spirit of the subject invention as defined by the appended claims.
As should be understood in view of the following detailed description, this application is primarily directed to apparatuses and methods for treating the spine of a patient. The apparatuses described below can be configured to provide a variety of treatments to reduce or delay degenerative disc disease (DDD) in or near the spine of a patient. In particular, various embodiments described herein below can include devices for fusion, fixation, limiting motion, or providing dynamic support of one or more levels of the spine and structures adjacent to or near the spine. Various methods are disclosed for working with these apparatuses. The apparatuses and methods described enable a surgeon to perform a wide variety of methods of treatment for reducing or delaying adjacent level DDD of a patient as described herein. Such apparatuses can be deployed through an access device that at least partially defines an access path through otherwise naturally continuous tissue from outside the patient to the spine. Such an access device preferably would provide minimally invasive access, but the apparatuses and methods described herein are applicable to open surgery as well.
A. Apparatuses for Treating and Reducing Adjacent Level Degenerative Disc Disease
The degeneration of spinal segments, such as vertebral levels, vertebrae, discs, and nerves, adjacent to a spinal segment where a primary fusion, stabilization or fixation procedure has been performed can be caused by one or more of a concentration of force and certain types of movement of the adjacent level(s) as a result of the restriction of movement of the fused or fixated level or levels. This application discusses devices that can reduce at least one of the concentration of force on and particular types of movement of adjacent level spinal segments. Adjacent and primary sites can include joints between any of the cervical, thoracic, lumbar, and sacral vertebrae, as well as the joint between the skull and the first cervical vertebra (skull-C1). Such devices can slow down or substantially prevent the degeneration known as adjacent level DDD. For example, an adjacent level device can be configured to restrict the compression, flexion, or torsion of the spinal segments, e.g., vertebral levels adjacent to the primary treatment (e.g., fixation) site and to provide additional dynamic support to the adjacent levels. Implanting the adjacent level device during the initial fusion or fixation procedure can beneficially delay or substantially prevent the onset of adjacent level DDD. Implanting the adjacent level device during the initial fusion, fixation, or other adjacent procedure can advantageously eliminate or reduce the need for a second operation to treat adjacent spinal segments, e.g., to fuse or fix adjacent levels that have collapsed or degenerated. Further, embodiments of the device that are sized and shaped so as to be capable of being implanted during a minimally invasive surgical procedure will beneficially reduce operative and post-operative trauma to the patient.
Accordingly, one embodiment of an adjacent level device 5 which comprises a spacer device 50 is implantable in the patient. The adjacent level device 5 can be configured to connect with or be coupled with a stabilization device 10. In some embodiments, the stabilization device 10, which can include pedicle screws and fixation rod(s), as discussed below, can form a part of a device counteracting adjacent level DDD.
In one embodiment a stabilization device 10 is adapted to be secured to vertebrae V1 and V2. In various embodiments, the stabilization device 10 is a fixation device, a fusion device, or a dynamic stabilization device. As shown in
The elongate element 12 can take any suitable form, for example, being stiff enough to assure that there is no motion between the vertebrae V1, V2 or to be flexible to permit some motion, e.g., in providing dynamic stabilization with at least a fraction of the normal range of motion. This fixation procedure can be accompanied by a procedure in which a fusion device is inserted between the vertebrae V1, V2. In other embodiments, different or multiple stabilization devices 10 can be used, and the stabilization device 10 can comprise additional or different components, e.g., more screws and longer rods for multi-level fixation or other hardware discussed below.
The spacer device 5 can be installed in patients where degeneration of adjacent spinal segments, (e.g., a vertebral level including vertebra V3) could occur. The spacer device 50 can be configured to reduce motion or force, particularly the concentration of force due the presence of a fixation or other stabilization device, on the adjacent spinal segment.
In one embodiment, the spacer device 50 comprises a spacer 60 and a spacer rod 70 configured to position the spacer 60 between spinous processes S2 and S3 of the vertebrae V2 and V3, respectively. In one embodiment, the spacer device 50 is a crosslink spacer assembly or a crosslink spacer device. The spacer device 50 can be moveably or fixedly coupled to one or more stabilization devices 10 in one, two, or any number of places. For example, the spacer device 50 can be moveably or fixedly attached to a stabilization device 10 on one side of a spinous process with a single spacer rod 70. In some embodiments the spacer device 50 is configured to be attached to the spine with its own fasteners, such as a screw or a connecting member with a screw and housing. Such an arrangement can still include an elongate member similar to the spacer rod 70 that interconnects the spacer 60 with the screw or other implant to be coupled with the spine.
In some embodiments, the spacer rod 70 can be any form of elongate element that holds a spacer 60 in a desired orientation within an intervertebral region, such as in I2 or such as between two spinous processes, e.g., between a spinous process associated with a vertebra that has been fixed or fused and a spinous process above or below the fixed or fused vertebra. In some embodiments the spacer rod 70 is configured, e.g., is sized or rigid enough, to hold the spacer 60 in an interspinous process space, such as ISPS-2. The spacer 60 can be positioned between adjacent spinous processes and, at various times depending on the flexion or position of the spine of the patient, the spacer 60 can touch one, both, or neither of the adjacent spinous processes.
The spacer 60 can be moveably or fixedly coupled to the spacer rod 70. In certain embodiments, the spacer rod 70 is welded, bonded or adhered to the spacer 60. In other embodiments, the spacer rod 70 can be secured to the spacer 60 by one or more connectors such as, for example, screws or rivets. In other embodiments, the spacer rod 70 is inserted into or through a passageway that extends within or entirely through the spacer 60. In other embodiments the spacer rod 70 has a texture or surface treatment that increases the friction between the rod 70 and the spacer 60, e.g., to hold the spacer 60 in a particular location along the rod 70. In other embodiments, the stabilization elongate element 12 can be welded, bonded or adhered to the spacer 60. In other embodiments where the stabilization elongate element 12 is contiguous with or forms a part of the spacer rod 70, the stabilization elongate element 12 can be secured to the spacer 60 by one or more connectors such as, for example, screws or rivets. In other embodiments, the stabilization elongate element 12 is inserted through a passageway within the spacer 60.
As shown in
The configuration, e.g., the size, shape, and material properties of the spacer 60, are selected to provide a suitable amount of support for the adjacent spinal segment(s) to reduce the concentration of force on these segments due to the primary stabilization, fusion, or fixation. In some embodiments, the spacer 60 can be hollow. In some embodiments the spacer 60 can be made of a combination of materials. In some embodiments, the spacer 60 can be a spring, a resilient member, or a compressible member, e.g. one that will compress under normal loading conditions of the spine. In some embodiments, the spacer 60 can be a resilient member that can be compressed up to about 25% of its unloaded shape or size (e.g., transverse size) when subject to normal loading, such as in walking twisting, jumping, running, or other typical activities. In some cases, the spacer 60 is a resilient member that can be compressed up to about 50% under such normal conditions. In some cases, the spacer 60 is a resilient member that can be compressed by 50% or more than 50% under such normal conditions. In other embodiments the spacer can not significantly deflect or compress under normal spinal loading. In
In some embodiments the spacer rod 70 and 70A-70H can be elastic, axially elongatable, or compressible. In some embodiments the spacer rod 70 and 70A-70H comprises biocompatible flexible fibers such as, for example, natural or artificial ligaments. In some embodiments, the spacer 60 and 60A-60H can be a spring configured to interact with one or two spinous processes, where the spring can be shaped in a manner similar to spacer 60A in
The spacer 60 can comprise either a rigid or an elastic material depending on the amount of movement reduction desired for the adjacent levels. In certain embodiments the spacer 60 can comprise a biocompatible metal such as, for example, titanium, or the spacer 60 can comprise a biocompatible polymer (such as PEEK) or an elastomeric material. In some embodiments, the spacer 60 is configured so that minimal bone growth will occur between the spacer and adjacent bony segments, such as the spinous processes S2, S3.
In some embodiments, the spacer device 50 is sized and shaped to be implanted during a minimally invasive surgical procedure. It is preferable, although not necessary, for the spacer device 50 to be implanted during a fusion or fixation procedure that is performed at the same time (sometimes referred to herein as the “primary” fixation or fusion) so as to minimize trauma and to eliminate or slow the onset of adjacent level DDD. However, the spacer device 50 can also be implanted during a later surgical procedure. Although
The embodiment illustrated in
The connecting member 30 can be configured to provide a desired range of motion for the spacer device 52. For example, in one embodiment the ball 32 can be adapted to fit snugly within the socket 31 such that frictional engagement between the ball 32 and the socket 31 provides a suitable range of motion. For example, such friction can limit the range of motion of the ball 32 and/or the socket 31 or can absorb some of the energy that would otherwise be transferred to the spine or the spacer 60 coupled therewith. In other embodiments, the ball and socket joint can be clamped or otherwise configured to limit or restrict the range of motion.
In one embodiment, the spacer rod 70 and/or the elongate element 12 can be secured by a clamping screw 110 that is configured to clamp directly on the spacer rod 70 and/or the elongate element 12 in a passageway 120 or 121, or in a separate, open- or close-ended channel (not illustrated). Other embodiments can utilize additional screws or clamps to position and secure the spacer rod 70 and/or the elongate element 12.
In certain embodiments, the spacer rod 70 (not illustrated) is secured to the connecting member 200 by a flexible wing portion, passageway, groove, and set screw that are substantially similar to those shown in
The spacer device 55 comprises a spacer 60G (see
Other embodiments of the connecting member can include a snap fit configured to work with a spacer rod 70E as shown in
The connecting member 600 can include one or more devices, e.g., screws such as a clamping screw or other threaded members, adapted to engage and secure one or more spacer rods 70 and/or one or more elongate elements 12. The clamping screws can be oriented in any direction. During implantation, the spacer rod 70 and/or the elongate element 12 can be slid through passageways in the connecting member 600 to adjust and position the spacer device relative to the stabilization device or relative to the spine of the patient. When the spacer device is in a suitable location, the clamping screw (and/or other threaded member or device) is secured to clamp the spacer device into position. The connecting member 600 can comprise any suitable substantially rigid material. For example, the connecting member 600 can comprise a metal such as titanium and its alloys, Nitinol, or a polymeric compound, including PEEK.
As illustrated in
As illustrated in
In various embodiments, a passageway in the housing 650 is adapted to receive or to engage or to house at least one of the spacer rod 70 and an elongate element 12. In one embodiment, the passageway in the housing 650 is adapted to receive or to engage or to house a spacer rod 70 with a first end portion 71. The first end portion 71 can be slid through the passageway in the housing 650 and clamped into place by one or more clamping members, such as a clamping screw 670.
Additional features of a device similar to the connecting member 600 are also described in U.S. patent application Ser. No. 10/075,668, filed Feb. 13, 2002, published as U.S. Application Publication No. 2003/0153911A1 on Aug. 14, 2003 and issued as U.S. Pat. No. 7,066,937 on Jun. 27, 2006, and application Ser. No. 10/087,489, filed Mar. 1, 2002, published as U.S. Application Publication No. 2003/0167058A1 on Sep. 4, 2003 and issued as U.S. Pat. No. 6,837,889 on Jan. 4, 2005, and U.S. patent application Ser. No. 10/483,605, filed Jan. 13, 2004, published as U.S. Application Publication No. US 2004-0176766 on Sep. 4, 2003 and issued as U.S. Pat. No. 7,144,396 on Dec. 5, 2006, which are incorporated by reference in their entireties herein.
Although many of the embodiments described thus far have been illustrated with stabilization devices 10 that in certain cases relate to a fixation device with fastening assemblies attachable to the vertebral body or pedicles, other embodiments of a stabilization device 10 include facet joint fixation devices such as facet screws using a transfacet or translaminal approach or angle for insertion of the facet screws into vertebrae. In one embodiment, an adjacent level device 5 comprises at least one transfacet screw and any of the spacer device 58 described herein. The facet screw can be configured for a transfacet or translaminal approach and can be inserted through a hole or slot in a spacer rod of a spacer device. In another embodiment, a spacer device can comprise a connecting member (similar to connecting member 30, 100, 200, 300, 400, 500 or 600) that is configured to be coupled with a facet screw in a transfacet or translaminal approach to the spine.
B. Methods for Treating Adjacent Level Disc Disease
The adjacent level devices described above can be implanted during a surgical procedure, which advantageously can be a minimally invasive surgical procedure. In some embodiments, at least a portion of the adjacent level device 5 can be inserted through a cannula or access device. In other embodiments, at least a portion of the adjacent level device 5 is implanted through a minimally invasive access device, such as one that can be expanded at least at the distal end. Additional details on some minimally invasive apparatuses and methods suitable for use with the adjacent level device 5 are disclosed in U.S. patent application Ser. No. 10/693,250, filed Oct. 24, 2003, entitled “Methods and Apparatuses for Treating the Spine Through an Access Device,” and in U.S. application Ser. No. 11/241,811, filed Sep. 30, 2005, and in U.S. application Ser. No. 10/972,987, filed Oct. 25, 2004, which are hereby incorporated by reference herein in their entireties and made part of this specification.
The adjacent level device 5 and similar structures can also be applied to a patient using open surgical and mini-open surgical techniques. For example, in certain embodiments the adjacent level device 5 is implanted through a generally open surgery. With open surgery, the device 5 can be installed by attaching a stabilization device to a portion of the spine, cutting, piercing, or otherwise providing a passage through the interspinous ligament, inserting a spacer device, such as any of the spacer devices described herein between the spinous processes of an adjacent level (e.g., immediately above or below the spinous process of one of the fixed vertebrae), and attaching the spacer device to the stabilization device 10.
Visualization of the surgical site can be achieved in any suitable manner, e.g., by direct visualization, or by use of a viewing element, such as an endoscope, a camera, loupes, a microscope, or any other suitable viewing element, or a combination of the foregoing. The term “viewing element” is used in its ordinary sense to mean a device useful for viewing and is a broad term and it also includes elements that enhance viewing, such as, for example, a light source or lighting element. In one embodiment, the viewing element provides a video signal representing images, such as images of the surgical site, to a monitor. The viewing element can be an endoscope and camera that captures images to be displayed on the monitor whereby the physician is able to view the surgical site as the procedure is being performed.
The systems are described herein in connection with minimally invasive postero-lateral and posterior spinal surgery. One such procedure is a two level postero-lateral fixation and fusion of the spine involving the L4, L5, and S1 vertebrae. In the drawings, such as
It is believed that embodiments of the invention are also particularly useful where any body structures must be accessed beneath the skin and muscle tissue of the patient, and/or where it is desirable to provide sufficient space and visibility in order to manipulate surgical instruments and treat the underlying body structures. For example, certain features or instrumentation described herein are particularly useful for minimally invasive procedures, e.g., arthroscopic procedures. As discussed more fully below, one embodiment of an apparatus described herein provides an access device that is expandable, e.g., including an expandable distal portion. In addition to providing greater access to a surgical site than would be provided with a device having a constant cross-section from proximal to distal, the expandable distal portion prevents or substantially prevents the access device, or instruments extended therethrough to the surgical site, from dislodging or popping out of the operative site.
C. Systems and Devices for Establishing Access
In certain embodiments, retractors can be used to create an open space for accessing the spine. In one embodiment, the system includes an access device that provides an internal passage for surgical instruments to be inserted through the skin and muscle tissue of a patient to the surgical site. This access device can be a cannula or a series of cannulae. The access device can have a uniform cross section. The access device preferably has a wall portion defining a reduced profile, or low-profile, configuration for initial percutaneous insertion into the patient. This wall portion can have any suitable arrangement. In one embodiment, the wall portion has a generally tubular configuration that can be passed over a dilator that has been inserted into the patient to atraumatically enlarge an opening sufficiently large to receive the access device therein.
The wall portion of the access device preferably can be subsequently expanded to an enlarged configuration, by moving against the surrounding muscle tissue to at least partially define an enlarged surgical space in which the surgical procedures will be performed. In a sense, it acts as its own dilator. The access device can also be thought of as a retractor, and can be referred to herein as such. Both the distal and proximal portion can be expanded, as discussed further below. However, the distal portion preferably expands to a greater extent than the proximal portion, because the surgical procedures are to be performed at the surgical site, which is adjacent the distal portion when the access device is inserted into the patient. The surgical space provides a large working area for the surgeon inside the body within the confines of the cannula. Furthermore, the enlarged configuration provides a working area that is only as large as needed. As a result, the simultaneous use of a number of endoscopic surgical instruments, including but not limited to steerable instruments, shavers, dissectors, scissors, forceps, retractors, dilators, and video cameras, is made possible by the expandable access device.
While in the reduced profile configuration, the access device preferably defines a first unexpanded configuration. Thereafter, the access device can enlarge the surgical space defined thereby by engaging the tissue surrounding the access device and displacing the tissue outwardly as the access device expands. The access device preferably is sufficiently rigid to displace such tissue during the expansion thereof. The access device can be resiliently biased to expand from the reduced profile configuration to the enlarged configuration. In addition, the access device can also be manually expanded by an expander device with or without one or more surgical instruments inserted therein, as will be described below. The surgical site preferably is at least partially defined by the expanded access device itself. During expansion, the access device can move from a first overlapping configuration to a second overlapping configuration in some embodiments.
In some embodiments, the proximal and distal portions are separate components that can be coupled together in a suitable fashion. For example, the distal end portion of the access device can be configured for relative movement with respect to the proximal end portion in order to allow the physician to position the distal end portion at a desired location. This relative movement also provides the advantage that the proximal portion of the access device nearest the physician can remain substantially stable during such distal movement. In one embodiment, the distal portion is a separate component that is pivotally or movably coupled to the proximal portion. In another embodiment, the distal portion is flexible or resilient in order to permit such relative movement.
With reference to
Preferably, the proximal portion 1100 is sized to provide sufficient space for inserting multiple surgical instruments through the elongate body 1020 to the surgical location. The distal portion 1120 preferably is expandable and comprises first and second overlapping skirt members 1140, 1160. The degree of expansion of the distal portion 1120 is determined by an amount of overlap between the first skirt member 1140 and the second skirt member 1160 in one embodiment. The elongate body 1020 of the access device 1000 has a first location 1180 distal of a second location 1200. The elongate body 1020 preferably is capable of having a configuration when inserted within the patient wherein the cross-sectional area of the passage 1040 at the first location 1180 is greater than the cross-sectional area of the passage 1040 at the second location 1200.
The proximal portion 1100 is coupled with the distal portion 1120, e.g., with one or more couplers 1050. The proximal and distal portions 1100, 1120 are coupled on a first lateral side 1062 and on a second lateral side 1064 with the couplers 1050 in one embodiment. When applied to a patient in a postero-lateral procedure, either of the first or second lateral sides 1062, 1064 can be a medial side of the access device 1000, i.e., can be the side nearest to the patient's spine. The couplers 1050 can be any suitable coupling devices, such as, for example, rivet attachments. In one embodiment, the couplers 1050 are located on a central transverse plane of the access device 1000. The couplers 1050 preferably allow for at least one of rotation and pivotal movement of the proximal portion 1100 relative the distal portion 1120. The proximal portion 1100 is seen at an angle alpha α of about 20 degrees with respect to a transverse plane extending vertically through the couplers. One skilled in the art will appreciate that rotating or pivoting the proximal portion 1100 to the angle alpha α permits enhanced visualization of and access to a different portion of the spinal location accessible through the access device 1000 than would be visualized and accessible at a different angle. Depending on the size of the distal portion 1120, the angle alpha α can be greater than, or less than, 20 degrees. Preferably, the angle alpha α is between about 10 and about 40 degrees. The pivotable proximal portion 1100 allows for better access to the surgical location and increased control of surgical instruments.
In one embodiment, the access device has a uniform, generally oblong shaped cross section and is sized or configured to approach, dock on, or provide access to, anatomical structures. The access device preferably is configured to approach the spine from a posterior position or from a postero-lateral position. A distal portion of the access device can be configured to dock on, or provide access to, posterior portions of the spine for performing spinal procedures, such as, for example, fixation, fusion, or any other suitable procedure. In one embodiment, the distal portion of the access device has a uniform, generally oblong shaped cross section and is configured to dock on, or provide access to, generally posterior spinal structures. Generally posterior spinal structures can include, for example, one or more of the transverse process, the superior articular process, the inferior articular process, and the spinous process. In some embodiments, the access device can have a contoured distal end to facilitate docking on one or more of the posterior spinal structures. Accordingly, in one embodiment, the access device has a uniform, generally oblong shaped cross section with a distal end sized, configured, or contoured to approach, dock on, or provide access to, spinal structures from a posterior or postero-lateral position.
Further details and features pertaining to access devices and systems are described in U.S. Pat. No. 6,800,084, issued Oct. 5, 2004, U.S. Pat. No. 6,652,553, issued Nov. 25, 2003, application Ser. No. 10/678,744 filed Oct. 2, 2003, published as Publication No. 2005/0075540 on Apr. 7, 2005, which are incorporated by reference in their entireties herein.
D. Methods for Implanting an Apparatus to treat Adjacent Level Disc Disease
A type of procedure that can be performed by way of the systems and apparatuses described herein involves the placement of a device that treats, e.g., by reducing the likelihood of adjacent level degenerative disc disease while preserving or restoring a degree of normal motion after recovery. Such a procedure can be applied to a patient suffering degenerative disc disease or otherwise suffering from disc degeneration. A variety of adjacent level spinal implants that can be applied are described below. The access devices and systems described herein enable these devices and methods associated therewith to be practiced minimally invasively. A doctor can create one or more incisions through the skin of the back of a patient in order to insert an access device through the skin and tissue between the skin and the spine, providing a closed channel for delivering and affixing a device or implant to the spine.
In one embodiment an adjacent level device 5 is an implant comprising a stabilization device 10 (among various embodiments described herein) and a spacer device 50 (among various embodiments described herein). By way of illustration, embodiments of the stabilization device 10 can be used to treat, fix or assist in fusion of a first vertebra V1 and a second vertebra V2. The spacer device 50 can be used at one or more adjacent levels, such as between second vertebra V2 and a third vertebra V3 or between first vertebra V1 and a “zero” vertebra V0. Alternatively, the spacer device 50 can be used at a separate level that is not immediately adjacent to the primary treatment site with the stabilization device 10, such as a location that is two, three, or more vertebrae away from the primary treatment site. In some embodiments, the stabilization assembly 10 can be implanted in one procedure while the spacer device 50 can be implanted before, at the same time as, or in a subsequent procedure from the stabilization device 10. In some embodiments the spacer device 50 is advantageously installed in the same procedure as a stabilization device 10. In other embodiments, the spacer device 50 can be installed with, e.g., attached to, a pre-placed fixation assembly using a connecting member. For the purposes of illustrating the steps in a method of implanting an adjacent level device 5 comprising a stabilization device 10 and a spacer device 50, the following description will list steps in placing both types of devices in the body of the patient during one minimally invasive surgical procedure. The method is not limited to the order of steps set forth below, nor does it always require all steps or exclude other steps.
In one embodiment of a method for implanting the adjacent level device 5, after the doctor has created an incision through the skin and placed an access device through the skin to access the spine of the patient, a fastener assembly 14 including pedicle screws is implanted into each of the vertebrae V1 and V2. In some embodiments, the stabilization device 10 is mounted to bone by the screws in an early stage of a procedure, while in others the stabilization device is mounted in a later step. In some embodiments, a second set of screws and a second stabilization device 10 is mounted on another part of vertebrae V1 and V2. A spacer rod 70 is advanced through the spinous process ligament. For example, a surgical instrument can be used to form a passage through the ligament or other tissue located between adjacent spinous processes. In another embodiment, a portion of the device 5 can be configured to form such a passage. For example, as discussed above, the spacer rod 70 can have a sharp end to pierce the ligament. A spacer 60 can be inserted over the spacer rod 70. In certain embodiments, the elongate element 12 of the stabilization device 10 can be inserted into the patient. The spacer rod 70 can be coupled to the elongate element 12 by, for example, a ball and socket joint 30 (
Referring to
The elongate body 1508 has a length between the proximal end 1512 and the distal end 1516 that is selected such that when the access device 1504 is applied to a patient during a surgical procedure, the distal end 1516 can be positioned inside the patient adjacent a spinal location, and, when so applied, the proximal end 1512 preferably is located outside the patient at a suitable height. As discussed below, various methods can be performed through the access device 1504 by way of a variety of anatomical approaches, e.g., anterior, lateral, transforaminal, postero-lateral, and posterior approaches. The access device 1504 can be used for any of these approaches and can be particularly configured for any one of or for more than one of these approaches.
The access device 1504 can be configured to be coupled with a viewing element (not illustrated in
Various methods can be performed through the access device 1504 by way of a variety of anatomical approaches, e.g., anterior, lateral, transforaminal, postero-lateral, and posterior approaches, and the dashed-line outlines of various access devices, such as access device 1504, in
In some methods of applying an adjacent level device 5 (not shown here), a second access device, such as an expandable conduit or other suitable access device, can be inserted into the patient. For example, a second access device could be inserted through a postero-lateral approach on the opposite side of the spine, as indicated by an arrow 1554, to provide access to at least a portion of an intervertebral region, e.g., the intervertebral region I. In another embodiment, a second access device could be inserted through a posterior approach on the opposite side of the spine, as indicated by an arrow 1556 to provide access to at least a portion of an intervertebral region, e.g., the intervertebral region I. This second access device can provide access to the intervertebral region I1 at about the same time as the first access device 1504 or during a later or earlier portion of a procedure. In one method, an implant is inserted from both sides of the spine using first and second access devices. Likewise, a second access device can be inserted as described herein to provide access to at least a portion of two intervertebral regions, e.g., the intervertebral regions I1 and I2.
In various applications, one or more adjacent level devices can be delivered through one or more access devices, such as the access device 1504, from different directions. For example, a first adjacent level device could be delivered through a first access device from the approach indicated by the arrow 1544, and a second adjacent level device could be delivered through a second access device from the approach indicated by the arrow 1554. In another method, a first portion of a first adjacent level device, e.g., a portion to be coupled with the superior vertebra defining the intervertebral region I, could be delivered through a first access device from the approach indicated by the arrow 1544, and a second portion of the first adjacent level device, e.g., a portion to be coupled with the inferior vertebra defining the intervertebral region I, could be delivered through a second access device from the approach indicated by the arrow 1556. Thus, any combination of single, multiple implants, or implant sub-components can be delivered through one or more access devices from any combination of one or more approaches, such as the approaches indicated by the arrows 1540A, 1540P, 1544, 1546, 1550A, 1550P, 1554, 1556, or any other suitable approach to either intervertebral region I1 or intervertebral region I2, or both intervertebral regions I1 and I2.
As discussed above, in some methods, suitable procedures can be performed to prepare the spine to receive an implant, e.g., the adjacent level device. For example, the surfaces of the vertebrae V1, V2 and V3 or any surface in the intervertebral region I1 or I2 can be prepared as needed, e.g., the surfaces can be scraped or scored, and/or holes can be formed in the vertebrae to receive one or more features formed on a surface of the adjacent level device. Also, in some procedures, degraded natural disc material can be removed in a suitable manner, e.g., a discectomy can be performed.
In one procedure, a gripping apparatus 1580, is coupled with one or more portions and/or surfaces of the adjacent level device to facilitate insertion of the adjacent level device. In one embodiment, the gripping apparatus 1580 has an elongate body 1584 that extends between a proximal end (not shown) and a distal end 1588. The length of the elongate body 1584 is selected such that when the gripping apparatus 1580 is inserted through the access device 1504 to the surgical location, the proximal end extends proximally of the proximal end 1512 of the access device 1504. This arrangement permits the surgeon to manipulate the gripping apparatus 1580 proximally of the access device 1504. The gripping apparatus 1580 has a grip portion 1592 that is configured to engage the adjacent level device. In one embodiment, the grip portion 1592 comprises a clamping portion configured to firmly grasp opposing sides of the implant. The clamping portion can further comprise a release mechanism, which can be disposed at the proximal end of the gripping apparatus 1580, to loosen the clamping portion so that the adjacent level device can be released once delivered to the surgical location of the spine. In another embodiment, the grip portion 1592 comprises a jaw portion with protrusions disposed thereon, such that a portion of the adjacent level device fits within the jaw portion and engages the protrusions. In another embodiment, the grip portion 1592 comprises a malleable material that can conform to the shape of the adjacent level device and thereby engage it. Other means of coupling the gripping apparatus 1580 to the adjacent level device known to those of skill in the art could also be used, if configured to be inserted through the access device 1504. In one method of delivering the adjacent level device to the surgical location, the gripping apparatus 1580 is coupled with the adjacent level device, as described above. The gripping apparatus 1580 and the adjacent level device are advanced into the proximal end 1512 of the access device 1504, to the surgical space 1542, and further into the surgical space 1542.
In one embodiment an adjacent level device can be delivered to a surgical site in separate parts. In one embodiment, a stabilization device 50, which can be a fixation, fusion, stabilization or dynamic stabilization assembly, is implanted first. One procedure performable through the access device 1504, described in greater detail below, is a two-level spinal fixation using a stabilization device 50. Surgical instruments inserted into the expandable access device 1504 can be used for debridement and decortication. In particular, the soft tissue, such as fat and muscle, covering the vertebrae can be removed in order to allow the physician to visually identify the various “landmarks,” or vertebral structures, which enable the physician to locate the location for attaching a fastener, such a fastener assembly 14, discussed herein, or other procedures, as will be described herein. Allowing visual identification of the vertebral structures enables the physician to perform the procedure while viewing the surgical area through the endoscope, microscope, loupes, etc., or in a conventional, open manner. As illustrated, the end of an endoscope 1502 can be used to visualize the procedure within the access device 1504.
Tissue debridement and decortication of bone are completed using one or more debrider blades, bipolar sheath, high speed burr, and additional conventional manual instruments. The debrider blades are used to excise, remove and aspirate the soft tissue. The bipolar sheath is used to achieve hemostasis through spot and bulk tissue coagulation. The debrider blades and bipolar sheath are described in greater detail in U.S. Pat. No. 6,193,715, assigned to Medical Scientific, Inc., which is hereby incorporated by reference in its entirety herein. The high speed burr and conventional manual instruments are also used to continue to expose the structure of the vertebrae.
A subsequent stage is the attachment of fasteners to the vertebrae V. Prior to attachment of the fasteners, the location of the fastener attachment is confirmed. In the exemplary embodiment, the pedicle entry point of the L5 vertebrae is located using visual landmarks as well as lateral and A/P fluoroscopy, as is known in the art. With reference to
After a hole in the pedicle is provided at the entry point at a hole 1792 (or at any point during the procedure), an optional step is to adjust the location of the distal portion of the access device 1504. This can be performed by inserting an expander apparatus (not shown) into the access device 1504, expanding the distal portions 1524, and contacting the inner wall of the skirt portion 1525 to move the skirt portion 1525, to the desired location. This step can be performed while the endoscope is positioned within the access device 1504, and without substantially disturbing the location of the proximal portion of the access device 1504 to which an endoscope mount platform can be attached.
In one embodiment, a fastener assembly 14 can be inserted which is particularly applicable in a procedures involving fixation. A fastener assembly 14 is described in greater detail in U.S. patent application Ser. No. 10/075,668, filed Feb. 13, 2002 and application Ser. No. 10/087,489, filed Mar. 1, 2002, which are hereby incorporated by reference in their entirety. Fastener assembly 14 can include a screw, a screw portion, a housing, a spacer member, a biasing member, or a clamping member, such as a cap screw. The screw portion has a distal threaded portion and a proximal, substantially spherical joint portion. The threaded portion is inserted into the hole 1792 in the vertebrae, as will be described below. The substantially spherical joint portion is received in a substantially annular, part spherical recess in the housing in a ball and socket joint relationship. The fastener assembly 14 can be attached to the spine and to an elongated member 12 (or a fixation plate, fusion-assisting device, or stabilization rod) using any variety of tools appropriate for actuating or connecting the fastener assembly 14, such as a screwdriver or other tool. In certain embodiments, the fastener assembly 14 can be attached to a spacer device 50 or to a type of connecting member 30, 100, 200, 300, 400, 500 or 600 to connect the spacer device 50 to bone or some other component or device placed in the body.
For a two-level fixation, it can be necessary to prepare several holes and attach several fastener assemblies 14 on one or both sides of a spinous process. Typically, the access device 1504 will be sized in order to provide simultaneous access to all vertebrae in which the surgical procedure is being performed. In some cases, however, additional enlargement or repositioning of the distal portion of the expandable conduit can be required in order to have sufficient access to the outer vertebrae, e.g., the L4 and S1 vertebrae. The expander apparatus can be repeatedly inserted into the access device 1504 and expanded in order to further open or position the skirt portion 1525. In one procedure, additional fasteners are inserted in the L4 and S1 vertebrae in a similar fashion as the fastener assembly 14 is inserted in to the L5 vertebra as described above., (When discussed individually or collectively, a fastener assembly and/or its individual components will be referred to by the reference number, e.g., fastener assembly 14, where the fastener assembly 14 can have a housing or other attachment structure attached.)
As illustrated in
In some embodiments the cut-out portions 1526 and 1527 of the skirt portion 1525 also provide access within the skirt portion 1525 to an interspinous process space, such as ISPS-2, through which a spacer rod 70 or a spacer device 50 is inserted for placement of the spacer 60. In other embodiments, no cut-out portions are needed as the interspinous process space, such as ISPS-2, can be accessed through the open distal end of the skirt portion 1525 of the access device 1504.
In one embodiment, a tool such as a gripper, pliers, or a grasping apparatus 1704 can be inserted into the working space of the access device 1504 to bend or configure implants to conform to the boney geography of the patient in a manner appropriate for treatment of the spine. As illustrated in the embodiment depicted in
In several embodiments of an adjacent level device, the device comprises a stabilization device, such as stabilization device 10, a spacer device, such as spacer device 50, and a connecting member to connect the stabilization device 10 to the spacer device 50. Any variation of connecting member 30, 100, 200, 300, 400, 500 or 600 discussed herein can be installed, including connecting members with a hole, slot, or screw which can be used with a screw housing or in conjunction with a fastener assembly 14 as described above. As illustrated in
Placement of the spacer 60 in an intervertebral region I2 can be accomplished in a number of methods. The spacer 60 can be placed in an interspinous process space ISPS-2. In one embodiment, the spacer 60 can be placed in a facet joint. Each of these locations has a ligament or disk-type structure which would need to be pierced or severed to make room for the spacer.
In open procedures, the spacer 60 can be placed in a channel of a ligament created by any tool. The ligament can have a hole pierced or drilled in it, or the ligament can be cut open for placement of the spacer 60. In less invasive procedures, including minimally invasive procedures using an access device, cannula, or expandable access device as described above, the spacer 60 or the spacer rod 70 can be threaded through a ligament using the blunt or sharpened leading end of the spacer 60 or spacer rod 70 to pierce or tear through the ligament. (See embodiments of spacer rod 70A in
The order of the steps as described above can be transposed or accomplished in alternative sequences. For instance, a spacer device 50 can be inserted in an interspinous ligament prior to the installation of an elongate element 12, or vice versa. Several combinations of steps are possible.
Although many of the embodiments of methods of installing an adjacent level device described thus far have been illustrated with stabilization devices 10 that in certain cases relate to a fixation device with fastening assemblies attachable to the vertebral body or pedicles, other embodiments of a stabilization device 10 include facet joint fixation devices such as facet screws using a transfacet or translaminal approach or angle for insertion of the facet screws into bone. In one embodiment, an adjacent level device comprises a spacer device 58 (not illustrated) which comprises a spacer 60 and a spacer rod 70 which can be a spacer elongate element or a spacer plate that is configured to be attached to one or more facet screws. The spacer elongate element or spacer plate can have a hole or slot through which the facet screw can be inserted into bone. The facet screw can be configured for a transfacet or translaminal approach and is placed through a hole or slot in a spacer rod 70 of a spacer device 50 (or any embodiment of the spacer devices disclosed herein). The spacer rod 70 and spacer 60 can be inserted through a ligament in ISPS-2 in a manner as described above, after which one or more facet screws can be inserted through the spacer rod 70 and into the facet joint through either a transfacet or translaminal approach. In another embodiment, a spacer device 50 can comprise a connecting member (similar to connecting member 30, 100, 200, 300, 400, 500 or 600) which is configured to be attached to a facet screw in a transfacet or translaminal approach to the spine. In steps in inserting a spacer device 50 with a connecting member can use the steps described above for inserting and positioning a spacer 60 or spacer rod 70 first, inserting the spacer rod 70 into a connecting member, then inserting the facet screws through a hole or slot in the connecting member in a transfacet or translaminal approach to the spine. In another embodiment, the connecting member is attached to bone near the facet joints by the insertion of the facet screws prior to the placement of a spacer rod 70 or spacer 60 into the ligament or the ISPS-2 as discussed in any of the variety of steps disclosed above, with the spacer rod 70 and connecting member being attached in a subsequent step.
Another procedure that can be performed through the access device 1504 involves treatment or replacement of one or more joints. Some patients who are suffering from degenerative disc disease can also suffer from degenerative facet joint disease. While treatment or replacement of both a disc and a facet joint in such a patient is possible during the same operation using other methods, such an operation would be very complicated because it would likely require that the spine be approached both anteriorly and posteriorly. In contrast, in some approaches described hereinabove, the access device 1504 would provide sufficient access to spine to facilitate treatment of a part of the spine with the adjacent level device, including to one or more disc or facet joints to facilitate treatment or replacement of one or more facet joints. For example, the postero-lateral approaches indicated by the arrows 1544, 1554 in
E. Methods for Removing an Apparatus to treat Adjacent Level Disc Disease
Referring back to
The foregoing methods and apparatuses advantageously provide minimally invasive treatment of spine conditions in a manner that preserves some degree of motion between the vertebrae on either side of the replaced disc. Accordingly, trauma to the patient can be reduced, thereby shortening recovery time. Many of the implants provide a more normal post-recovery range of motion of the spine, which can reduce the need for additional procedures.
It will be understood that the foregoing is only illustrative of the principles of the invention, and that various modifications, alterations, and combinations can be made by those skilled in the art without departing from the scope and spirit of the invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims.
This application claims the benefit of priority from U.S. Provisional No. 60/774,320, filed Feb. 17, 2006, which is incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 60774320 | Feb 2006 | US |
