JP2009531155A - Dynamic motion spine stabilization system - Google Patents

Abstract

  A system and medical implant for joining two vertebrae are provided. The implant features a dynamic member 102 having two ends, the dynamic member substantially constraining the relative movement of the first end relative to the second end to a three-dimensional curved surface, the first The first end includes means for coupling the first alignment member 118 and the second end includes means for coupling the second alignment member 120 so that the second end is in the second position. It can rotate about the longitudinal axis of the mating member. The first and second alignment members may be coupled to the first and second bone anchoring means 110, 112 at the first and second ends, respectively, and the first and second ends are It may be rotatable with respect to the longitudinal axes 128, 130 of the first and second alignment members, respectively.

Description

PRIORITY CLAIM This application is incorporated by reference herein in its entirety, US Provisional Application No. 60 / 786,898, filed March 29, 2006, and filed April 21, 2006 US Provisional Patent Application No. 60 / 793,829.

  The present disclosure relates to skeletal stabilization, more specifically to systems and methods for stabilizing the human spine, and more specifically to dynamic stabilization techniques.

  The human spine is a complex structure designed to accomplish a myriad of tasks, most of which have complex kinematic properties. The vertebrae allow the spine to bend in three directions of motion with respect to the portion of the spine that is moving. These axes include a horizontal axis (bend either anterior / ventral or posterior / dorsal), a roll axis (bend either left or right), and a vertical axis (twist the shoulder against the pelvis). Including.

  When bending to bend (bend forward, ventral) and extend (bend backward, dorsal) about the horizontal axis, the vertebrae of the spine must rotate about the horizontal axis at various rotational angles. I must. The sum of all such movements about the horizontal axis causes the entire spine to bend or extend. For example, the vertebrae that make up the lumbar portion of the human spine move in an arc of about 15 ° relative to the adjacent or adjacent vertebrae. The vertebrae of other parts of the human spine (eg, thorax and neck) have different ranges of motion. Thus, when looking at the dorsal edge of a healthy vertebra, the edge is a few degrees arc centered around the center of rotation (eg, about 15 ° for flexion at the waist, and for extension) It moves in the range of about 5 °. During such rotation, the ventral (anterior) edges of adjacent vertebrae move closer together, the dorsal edges move away, and the ventral side of the spine is compressed. Similarly, during extension, the dorsal edges of adjacent vertebrae move closer together and the ventral edges move away, thereby compressing the dorsal side of the spine. During flexion and extension, the vertebrae move in a horizontal relationship with each other, resulting in a translation of no more than 2-3 mm.

  In normal vertebrae, vertebrae can also bend laterally. Thus, right flexion indicates that the spine can bend to the right by compressing the right portion of the spine and reducing the spacing between the right edges of the associated vertebrae. Similarly, left flexion indicates that the spine can bend to the left by compressing the left portion of the spine and reducing the spacing between the left edges of the associated vertebrae. The side of the spine opposite to the compressed portion is expanded, increasing the spacing between the edges of the vertebrae that include that portion of the spine. For example, the vertebrae that make up the lumbar region of the human spine rotate about the roll axis and move in an arc of about 10 ° relative to the adjacent vertebra during lateral bending.

  Relative rotational movement about the vertical axis is also natural in a healthy spine. For example, rotational movement can be described as a clockwise or counterclockwise twist of a vertebra during a golf swing.

  In a healthy spine, the intervertebral spacing between adjacent vertebrae is maintained by a compressible and somewhat elastic disc. The disc serves to allow the spine to move about various axes of rotation and in various arcs and ranges of motion necessary for normal mobility. The elasticity of the disc maintains the spacing between vertebrae during flexion and lateral flexion of the spine, thereby allowing room for spaces or gaps in which adjacent vertebrae are compressed. In addition, the disc allows the adjacent vertebrae to rotate relative to each other about the vertical axis, allowing the shoulder to twist relative to the waist and pelvis. A healthy disc also maintains a gap between adjacent vertebrae so that nerves from the notochord can extend out of the spine between adjacent vertebrae without being crushed or hit by the vertebrae. It becomes possible.

  In situations where the disc is not functioning properly, the intervertebral disc tends to be compressed, thereby reducing the intervertebral spacing and putting pressure on the nerves extending from the spinal cord. For example, an outgoing nerve root is compressed in a nerve hole, a passing nerve root is compressed, and an energized ring (a nerve cracked / damaged ring Various other types of problems with nerves can occur in the spine, such as growing in and causing pain each time the disc / ring is compressed. Many medical procedures have been devised to alleviate such nerve compression and pain due to nerve pressure. Many of these procedures focus on attempts to prevent the vertebrae from getting too close to each other to maintain space for the nerves to exit without hitting the nerves as the spine moves.

  In one such procedure, screws are implanted in adjacent vertebrae pedicles and then a rigid rod or plate is secured between the screws. In such a situation, the pedicle screw presses a stiff spacer that serves to distract the altered intervertebral space, thereby maintaining proper separation between adjacent vertebrae and the vertebrae compressing the nerves To prevent. The above procedure prevents nerve pressure due to spinal extension, but when the patient subsequently tries to flex forward (bend the spine), the dorsal portions of at least two vertebrae are effectively held together. Furthermore, the strong connection of the spacers greatly reduces the lateral bending or rotational movement between the diseased vertebrae. As more vertebrae are distracted by such stiff spacers, movement of the entire spine is reduced. This type of spacer not only limits patient movement, but often places additional stresses on other parts of the spine, such as adjacent vertebrae without spacers, which later lead to further complications.

  In other procedures, dynamic fixation devices are used. However, the conventional dynamic fixing device does not facilitate the lateral bending and rotational movement with respect to the fixed disk. This can create additional pressure on adjacent disks during these types of movements, which can cause additional problems in adjacent disks over time.

  Therefore, there is a need for a dynamic system that allows and allows for a greater range of motion and stabilizes the spine.

  In one embodiment, a dynamic member having a first end and a second end, the dynamic member substantially constraining the relative movement of the first end relative to the second end to a three-dimensional curved surface, The first end comprises means for coupling to the first alignment member so that the first end can be rotated relative to the longitudinal axis of the first alignment member and the second end Two parts of the spine, characterized in that the part comprises means for coupling to the second alignment member, whereby the second end can be rotated relative to the longitudinal axis of the second alignment member There are medical implants that connect the vertebrae.

  The medical implant is further characterized in that the dynamic member comprises a first coupling member, a second coupling member, and means for rotationally coupling the first coupling member to the second coupling member. be able to.

  The medical implant may be further characterized in that the means for rotationally coupling includes a pin joint.

  The medical implant can be further characterized in that the longitudinal axes of the first alignment member, the second alignment member, and the pin joint intersect about the center of rotation.

  The medical implant can be further characterized in that the dynamic member comprises a first coupling member that is slidably coupled to the second coupling member.

  The medical implant may be further characterized in that the connecting member is a non-linear member.

  The medical implant may be further characterized in that the means for coupling includes an aperture formed in each end.

  The medical implant can be further characterized in that the aperture is rotationally coupled to a bushing adapted to mate with the aperture.

  The medical implant can be further characterized in that the bushing is adapted to engage one of the alignment members by screwing.

  The medical implant can be further characterized in that the alignment member includes means for engaging the bone engaging member.

  Furthermore, the first bone anchoring means, the second bone anchoring means, the first alignment means coupled to the first bone anchoring means, the first alignment means and the second alignment means. A second alignment means coupled to the second bone anchoring means, the first end and the second end, such that the longitudinal axis can be aligned to intersect at the center of rotation; Means for allowing relative movement between the first end and the second end, the first end being coupled to the first alignment means Including a means for allowing the first end to rotate relative to the longitudinal axis of the first alignment means and the second end to couple to the second alignment member; The second end can be rotated relative to the longitudinal axis of the second alignment means. To medical system that joins two vertebrae of the spine are also disclosed.

  The medical system can be further characterized in that the dynamic member limits relative movement to a three-dimensional curved surface.

  The medical system is further characterized in that the dynamic member comprises a first coupling member, a second coupling member, and means for rotationally coupling the first coupling member to the second coupling member. Can do.

  The medical system can be further characterized in that the means for rotationally coupling includes a pin joint.

  The medical system can be further characterized in that the longitudinal axes of the first alignment member, the second alignment member, and the pin joint intersect about a center of rotation.

  The medical system can be further characterized in that the dynamic member comprises a first coupling member that is slidably coupled to the second coupling member.

  The medical system can be further characterized in that the connecting member is a non-linear member.

  The medical system can be further characterized in that the means for coupling includes an aperture formed in each end.

  The medical system can be further characterized in that the aperture is rotationally coupled to a bushing adapted to mate with the aperture.

  The medical system can be further characterized in that the bushing is adapted to engage one of the alignment members by screwing.

  The medical system can be further characterized in that the alignment member includes means for engaging the bone engaging member.

  For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following examples, taken in conjunction with the accompanying drawings.

  It should be understood that the following disclosure provides a number of different embodiments or examples for implementing various features of the present disclosure. In order to simplify the present disclosure, specific examples of components and arrangements are described below. Of course, these are only examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and / or reference characters in various embodiments. This repetition is for simplicity and clarity and as such does not affect the relationship between the various embodiments and / or configurations considered.

  Certain aspects of the present disclosure stabilize the spine by maintaining a spacing between consecutive vertebrae while allowing the vertebrae to move relative to each other in at least two, preferably three axes of rotation. A dynamic stabilization system, dynamic stabilization device, and / or method are provided. Adjacent vertebrae may be immediately adjacent to each other or may be spaced apart from each other by one or more intervening vertebrae.

  Matching the dynamic stabilization system to the specific patient anatomy and ensuring the minimum range of motion that can be used for dynamic implants is such as pedicle distance variations in the lumbar spine. It may be difficult depending on factors. In general, the dynamic stabilization system is implanted in a neutral position that allows minimal usable range of motion, and the system is positioned with a center of rotation at, for example, the 60-70% AP marker of the vertebral body. It may be desirable to align.

  For example, if a sliding dynamic stabilization system has to be extended to reach a well-spaced pedicle, there may not be enough engagement left for the system to flex ( That is, the system may reach the limit of sliding motion before sufficient bending is achieved). It may be desirable to always have the same relative starting engagement (e.g., neutral) because it has a consistent and predictable range of motion. It may also be desirable to ensure that the damping forces are consistent at both extremes of relative motion.

  One possible solution to address the adaptation of the dynamic stabilization system to anatomical variations is to design multiple sizes. For example, such a dynamic stabilization system may have a fixed relative starting engagement so that sufficient range of motion is available. However, it may be necessary to shift the position of the center of rotation forward or backward in the AP direction in order to fit the dynamic stabilization system (in its neutral engagement state) within the anatomy. Sensitivity studies show that small changes in the distance between pedicles (eg 1 mm) can shift the center of rotation from 65% AP mark to 70% AP mark (ie 5% change). I know. If the distance between the pedicles changes by another 1 mm, the center of rotation may be placed at the 75% AP mark, which may be unacceptable. Therefore, it can adapt to all anatomical variations, align the center of rotation with the 60-70% AP mark, and align the dynamic stabilization system pair (ie left and right) with each other. In order to do so, a plurality of sizes having overlapping ranges must be designed.

  Thus, the following disclosure provides for adjustable stabilization of the intervertebral space, while still providing sufficient 2D and / or 3D range of motion for the patient. A dynamic stabilization system, device, and method are described. Such a dynamic stabilization system can allow the vertebra to which it is attached to move within a natural arc that may resemble a virtual three-dimensional surface, such as a spherical or elliptical surface. Thus, such a system can help to allow sufficient range of motion in flexion, extension, rotation, back and forth translation, and / or other desired types of natural spinal motion.

  Referring to FIG. 1, one embodiment of a spinal stabilization system 100 is shown. The spinal stabilization system 100 may include a dynamic stabilization device 102 that includes two members 104 and 106 joined by a pin 108. The pin 108 may allow the two members 104 and 106 to move relative to each other, as will be described in more detail below.

  Members 104 and 106 may be secured to portions of the spine, such as the pedicle (not shown), by respective fastening elements, such as bone anchors (eg, pedicle screws) 110 and 112, respectively. Bone anchors 110 and 112 may include or be attached to multiaxial heads 114 and 116, respectively. The member 104 may be coupled to the multiaxial head 114 of its respective bone anchor 110 using, for example, a bearing post 118 (eg, a set screw) and a locking nut 122. Similarly, the member 106 may be coupled to the multiaxial head 116 of its respective bone anchor 112 using, for example, a bearing post 120 (eg, a set screw) and a locking nut 124.

  As shown, the pin 108 may be aligned with the first axis 126. The bearing posts 118 and 120 may be aligned with the second axis 128 and the second axis 130, respectively. Axes 126, 128, and 130 may intersect area 132 (eg, a rotational zone). In some embodiments, axes 126, 128, and 130 may intersect at point 134 (eg, center of rotation) within area 132. Point 134 may be stationary or may move within area 132 in response to the movement of a vertebra (not shown) to which spinal stabilization device 102 is coupled. It should be understood that the areas 132 and points 134 are merely exemplary and are not limited to the shape or size shown. For example, the area 132 is shown as a spherical surface, but the area may be an ellipsoid or other shape. Further, although axes 126, 128, and 130 are shown intersecting each other at point 134, they may not actually intersect each other, but instead may pass within a certain distance from each other. I want you to understand. Further, point 134 need not be a stationary point and may follow a path on or through area 132. For example, point 134 may move along the surface of area 132 such that area 132 defines a shell shape and movement of point 134 is constrained to the outer surface of the shell by device 102. For convenience, the term center of rotation may be used herein to refer to a specific point and / or a three-dimensional surface.

  Referring to FIG. 2, one embodiment of the dynamic stabilization device 102 is shown. As described with respect to FIG. 1, the dynamic stabilization device 102 may include two members 104 and 106 joined by a pin 108. In this example, member 104 may include a joining end 202 and a fastening end 204, and member 106 may include a joining end 206 and a fastening end 208. The joining end 202 of the member 104 may include one or more apertures 210 and the fastening end 204 of the member 104 may include an aperture 212. Similarly, the joining end 206 of the member 106 may include an aperture 214 (shown in FIG. 6) and the fastening end 208 of the member 106 may include an aperture 216. Pin 108 may couple members 104 and 106 by insertion into apertures 210 and 214, respectively. Bearing posts 118 and 120 (FIG. 1) are inserted into apertures 212 and 216, respectively, to couple members 104 and 106 to the pedicle or other bone (not shown).

  In this example, one or more of apertures 210, 212, 214, and 216 may include a bushing or other insertion member. For example, as shown, the aperture 212 may include a bushing 218 and the aperture 216 may include a bushing 220. Bushings 218 and 220 may help secure dynamic stabilization device 102 to bearing posts 118 and 120 (FIG. 1). One or both of the bushings 218 and 220 may be internally threaded to engage the bearing posts 118 and 120, respectively. In some embodiments, the outer surfaces of the bushings 218 and 220 may be relatively smooth to facilitate rotation of the respective members 104 and 106 around the bushing.

  As shown, the apertures 210 and 214 may be aligned with the first axis 126. Apertures 212 and 216 may be aligned with second axis 128 and third axis 130, respectively. Since the apertures 210, 212, 214, and 216 may be aligned with their respective axes, the pin 108 and the bearing posts 118 and 120 are aligned with the axis due to their insertion into their respective apertures. It should be understood that they may be aligned. Alternatively, the pins 108 and bearing posts 118 and 120 may be aligned with their respective axes, and as a result of their alignment, may be aligned with their respective apertures.

  Referring to FIG. 3, the spinal stabilization device 102 of FIG. 2 is shown in a fully extended or extended position (eg, during flexion). In this embodiment, apertures 210, 212, and 216 are aligned with axes 126, 128, and 130, respectively, when in the fully extended position. Accordingly, the axes 126, 128, and 130 may move along a surface that intersects the point 134 and / or is defined by the region of rotation 132 as described above.

  With further reference to FIG. 4, a cross-sectional view of one embodiment of the spinal stabilization device 102 of FIG. 3 is shown. As described above, members 104 and 106 may be joined by pins 108. As shown, bushings 218 and 220 are located within apertures 212 and 216, respectively. In this embodiment, the bushing cap 402 may abut the bushing 218 and the bushing cap 404 may abut the bushing 220. A bushing 406 in the aperture 214 and an abutting bushing cap 408 are also shown. In contrast to the illustrated bushings 218 and 220, the bushing 406 may have a smooth bore (eg, not threaded) to facilitate rotation with the pin 108.

  Pins 108 may couple members 104 and 106, respectively, by insertion into apertures 210 and 214. Bearing struts 118 and 120 may couple members 104 and 106 to pedicles or other bone (not shown) by apertures 212 and 216, respectively.

  Referring to FIG. 5, one embodiment of the member 104 of FIG. 1 is shown in more detail. As described above, the member 104 may include one or more apertures 210 at the joining end 202 and an aperture 212 at the fastening end 204. In this embodiment, member 104 defines a “Y” shape, or yoke, formed by branches 506 and 508. The branches 506 and 508 may be spaced to provide a gap for the end 206 of the member 106. As shown, the inner portion of the member 104 (eg, the portion that forms the bottom of the yoke) may be thicker than the fastening end 204 and the branches 506 and 508 that form the joining end 202.

  In this example, the upper surface 502 and the lower surface 504 of the member 104 may be curved to align the apertures 210 and 212 with the axes 126 and 128 (FIG. 2), respectively, to accommodate the natural movement of the spine. . It should be understood that the curves may be defined differently depending on factors such as the length of the member 104, the location of the apertures 210 and / or 212, and the desired center of rotation of the dynamic stabilization device 102.

  Inner wall 510 of aperture 210 may be relatively smooth to facilitate rotation of member 104 relative to pin 108. In some embodiments, a bushing (FIG. 4) may be provided to improve rotation of the pin 108 within the aperture 210. The inner wall 512 of the aperture 212 may include ridges, grooves, threads, or other means for engaging the bushing 218 (FIG. 2). Member 104 may also include one or more beveled or otherwise shaped surfaces 514.

  Referring to FIG. 6, one embodiment of member 106 of FIG. 1 is shown in more detail. As described above, the member 106 may include an aperture 214 at the joining end 206 and an aperture 216 at the fastening end 208. In this embodiment, the joining end 206 may be sized to fit within the yoke (FIG. 5) of the member 104.

  In this example, the upper surface 602 and lower surface 604 of member 102 may be curved to align the apertures 214 and 216 with the axes 126 and 130 (FIG. 2), respectively, to accommodate the natural movement of the spine. . It should be understood that the curves may be defined differently depending on factors such as the length of the member 106, the location of the apertures 214 and / or 216, and the desired center of rotation of the dynamic stabilization device 102.

  Inner wall 606 of aperture 214 may be relatively smooth to facilitate rotation of member 106 relative to pin 108. In some embodiments, a bushing (FIG. 4) may be provided to improve rotation of the pin 108 within the aperture 214. The inner wall 608 of the aperture 216 may include ridges, grooves, threads, or other means for engaging the bushing 220 (FIG. 2). Member 106 may also include one or more beveled or otherwise shaped surfaces 610.

  Referring to FIG. 7, a side view of one embodiment of the dynamic stabilization device 102 of FIG. 2 is shown. As described above, members 104 and 106 may be designed and arranged to align with axes 126, 128, and 130.

  Referring to FIG. 8, a side view of the dynamic stabilization system 100 of FIG. 1 is shown. As described above, the pin 108 may be aligned with the axis 126 and the bearing posts 118 and 120 may be aligned with the axes 128 and 130, respectively. In this example, bone anchors 110 and 112 may be oriented along other axes, but using multiaxial heads 114 and 116 may direct spinal stabilization device 102 to area 132. It becomes possible. This flexibility allows the surgeon to insert the bone anchors 110 and 112 as desired while maintaining movement of the spinal stabilization device 102 relative to the area 132 and / or point 134.

  With further reference to FIGS. 9 and 10, enlarged views of a portion of the spinal stabilization device 102 of FIG. 8 are shown in side perspective and cross-sectional views, respectively. As shown, the bearing post 118 may extend through the aperture 212 and into the multi-axis head 114. Bushing 218 and bushing cap 402 may be held within aperture 212. The locking cap 122 may be used to secure the member 104 to the bearing post 118 at a particular position to allow adjustment of the vertical height of the member 104 relative to the multi-axis head 114. In this example, the distal portion of the bearing post 118 may be clamped relative to the bone anchor 110 within the multiaxial head to lock the bone anchor in a desired position relative to the multiaxial head 114. . Prior to tightening the bearing post 118, the bone anchor 110 may move relatively freely within the multiaxial head 114. Accordingly, the dynamic stabilization device 102 may be aligned and then the bearing post 118 may be tightened to lock the position of the dynamic stabilization device relative to the multiaxial head 114 and the bone anchor 110. .

  Referring to FIGS. 11A and 11B, there is shown a sagittal cross-sectional view showing the range of motion and center of rotation between two adjacent vertebrae 1100 and 1102 connected by the spinal stabilization system 100 of FIG. FIG. 11A shows the spinal stabilization system 100 when two adjacent vertebrae 1100 and 1102 are in a neutral position. FIG. 11B shows the spinal stabilization system 100 when two adjacent vertebrae 1100 and 1102 are flexed (eg, when the patient is flexed forward). As shown in FIGS. 11A and 11B, the spinal stabilization system 100 maintains alignment with the section 132 (eg, with the center of rotation or rotation) regardless of the position of the two vertebrae 1100 and 1102.

  Referring to FIGS. 12A-12E, posterior views showing the range of motion and center of rotation between two adjacent vertebrae 1200 and 1202 connected by spinal stabilization systems 100a and 100b are shown. Although not described in detail herein, spinal stabilization system 100a may include members 104a and 106a (which may be similar to or identical to members 104 and 106 of FIG. 1) Stabilization system 100b may include members 104b and 106b (which may be similar to or the same as members 104 and 106 of FIG. 1). FIG. 12A shows spinal stabilization systems 100a and 100b when two adjacent vertebrae 1200 and 1202 are in a neutral position. FIG. 12B shows spinal stabilization systems 100a and 100b when two adjacent vertebrae 1200 and 1202 are bent (eg, when the patient is bent forward). FIG. 12C shows spinal stabilization systems 100a and 100b when two adjacent vertebrae 1200 and 1202 are rotating (eg, when the patient is facing right or left). FIG. 12D shows spinal stabilization systems 100a and 100b when two adjacent vertebrae 1200 and 1202 are in a lateral bending position (eg, when the patient is bending right or left). FIG. 12E shows spinal stabilization systems 100a and 100b when two adjacent vertebrae 1200 and 1202 are extended (eg, when the patient is bent back). As shown in FIGS. 12A-12E, spinal stabilization systems 100a and 100b maintain alignment with area 132 (eg, with a center of rotation or range of rotation) regardless of the position of the two vertebrae 1200 and 1202. To do.

  Referring to FIG. 13, a spinal stabilization system 1300 in another example is shown. In the illustrated example, spinal stabilization system 1300 includes a plurality of bone anchors 1302a and 1302b that may be secured to a patient's vertebrae or other bone structure. Bone anchors 1302a and 1302b may be pedicle screws or other suitable bone anchoring devices known to those skilled in the art. A dynamic stabilization device 1304 is coupled between bone anchors 1302a and 1302b. The dynamic stabilization device 1304 may be coupled to the bone anchor by threaded fastener systems 1306a and 1306b, which allows adjustment of the dynamic stabilization device 1304 relative to the bone anchors 1302a and 1302b. Also good. In certain embodiments, the dynamic stabilization device 1304 may be a spherical surface or other cubic that has a center of rotation in which the relative movement between the outer ends of the dynamic stabilization device approximates the natural center of rotation of the spine. You may adjust so that the surface of original shape (for example, elliptical surface) may be followed.

  For example, portions of threaded fastener systems 1306a and 1306b may be aligned with axes 1322 and 1324, respectively. Axes 1322 and 1324 may intersect an area 1326 (eg, a rotational range). In some examples, axes 1322 and 1324 may intersect at point 1328 (eg, center of rotation) within area 1326. Point 1328 may be stationary or may move within area 1326 in response to movement of a vertebra (not shown) to which spinal stabilization device 1304 is coupled. It should be understood that the areas 1326 and points 1328 are merely exemplary and are not limited to the shape or size shown. For example, the area 1326 is shown as a spherical surface, but the area may be an ellipsoid or other shape. Further, although axes 1322 and 1324 are shown intersecting each other at point 1328, it is understood that they may not actually intersect each other and instead may pass within a certain distance of each other. I want. Further, point 1328 need not be a stationary point and may follow a path on or through area 1326. For example, point 1328 may move along the surface of area 1326 such that area 1326 defines a shell shape and movement of point 1328 is constrained to the outer surface of the shell by device 1304. For convenience, the term center of rotation may be used herein to refer to a specific point and / or a three-dimensional surface.

  Threaded fastener systems 1306a and 1306b include bearing struts (eg, set screws) 1308a and 1308b received within multiaxial heads 1310a and 1310b, which may be coupled to the proximal ends of bone anchors 1302a and 1302b, respectively. But you can. The fastener systems 1306a and 1306b may further include fasteners 1312a and 1312b that secure the dynamic stabilization device 1304 to the bearing posts 1308a and 1308b. Fasteners 1312a and 1312b may be locking caps, nuts, or other similar threaded fasteners known to those skilled in the art. In some embodiments, the dynamic stabilization device 1304 may rotate around one or both of the bearing posts 1308a and 1308b, and in other embodiments, the dynamic stabilization device may not move. It may be fastened to the column.

  The dynamic stabilization device 1304 may include a male member 1314 and a female member 1316 each having an outer end and an inner end. Male member 1314 and female member 1316 may be coupled together at their inner ends so that they can slide and rotate relative to the roll axis and horizontal axis within a defined range of motion. The range of motion may be designed to allow the desired amount of lateral bending and twisting of the upper and lower vertebrae relative to each other while maintaining the desired separation between the vertebrae. In certain embodiments, male member 1314 and female member 1316 may be coupled by a curved shaft 1318 of male member 1314 that is received in a channel of extension 1320 of female member 1316. In some embodiments, the curved shaft 1318 may be sized to slidably move and / or rotate within the channel of the extension 1320 about both the horizontal and vertical axes.

  Still referring to FIG. 14A, one embodiment of a dynamic stabilization device 1304 is shown. In this example, the male member 1314 may include an aperture 1400 configured to receive the bearing post 1308a (FIG. 13) of the threaded fastener system 1306a. A threaded bushing 1402, which may be similar to or identical to the threaded bushing discussed with respect to the above-described embodiments, may be positioned within the aperture 1400. Bushing 1402 may be secured within aperture 1400 using a bushing cap (not shown) secured to the bushing (eg, welded). In some embodiments, the outer surface of the bushing 1402 may be relatively smooth to facilitate the male member 1314 to rotate about the bushing. The bearing post 1308a may be fixed to the bushing 1402 by a fastener 1312a.

  The female member 1316 may include an aperture 1404 configured to receive the bearing post 1308b (FIG. 13) of the threaded fastener system 1306b. A threaded bushing 1406, which may be similar to or the same as the threaded bushing discussed with respect to the above embodiments, may be positioned within the aperture 1404. The bushing 1406 may be secured within the aperture 1404 using a bushing cap (not shown) secured to the bushing (eg, welded). In some embodiments, the outer surface of the bushing 1406 may be relatively smooth to facilitate the female member 1316 rotating about the bushing. The bearing post 1308b may be fixed to the bushing 1406 by a fastener 1312b.

  Referring to FIG. 14B, a side view of the dynamic stabilization device 1304 of FIG. 14A shows a male-female coupling relationship between a male member 1314 and a female member 1316. As described above, the extension 1320 of the female member 1316 may include a channel that receives the curved shaft 1318 of the male member 1314 therein. For example, the curved shaft 1318 may have a curved surface that slidably engages one or more inner curved surfaces of the channel of the extension 1320. This slidable engagement of the respective curved surfaces allows the male member 1314 and female member 1316 to move relative to each other while maintaining alignment with the rotational zone 1326 and / or center point 1328. Good. This may maintain alignment of the dynamic stabilization device 1304 with the natural center of rotation of the spine, and thereby allow the upper and lower vertebrae to be more natural while maintaining the degree of separation. It may be possible to move on.

  In other embodiments, the curved shaft 1318 and the extension 1320 may include a horizontal curved surface that allows the slidable movement horizontally relative to the center of rotation. The male member 1314 may move spherically relative to the female member 1316 if the vertical and horizontal curve radii of each surface have approximately similar or identical centers of rotation. In other words, the movement of the male member 1314 and the female member 1316 may follow a path constrained by a spherical surface (for example, the rotation region 1326). It should be understood that other curves may be used so that male member 1314 and / or female member 1316 create a non-spherical (eg, elliptical) travel path.

  Referring to FIG. 15, a perspective view of one embodiment of the female member 1316 of FIG. 13 is shown. In this example, a channel 1500 within extension 1320 is shown. As described above, the channel 1500 may be configured to receive the extension 1318 of the male member 1314. Channel 1500 may be curvilinear or straight, and may have any desired cross-sectional characteristics. For example, although the illustrated channel 1500 is substantially square in cross section, it should be understood that the cross section of the channel may be circular, rectangular, or any other desired shape. A flange 1502 may be formed around the extension 1320 to engage or abut the complementary flange of the male member 1314.

  Referring to FIG. 16, a perspective view of one embodiment of the male member 1314 of FIG. 13 is shown. As described above, the curved shaft 1318 may be configured to enter the channel 1500 (FIG. 15) of the female member 1316. It should be understood that although shaft 1318 is curved in this embodiment, in some embodiments the shaft may be straight and may have any desired cross-sectional characteristics. For example, although the illustrated curved shaft 1318 is substantially square in cross section, it should be understood that the cross section of the shaft may be circular, rectangular, or any other desired shape. In some examples, the distal portion of the curved shaft 1318 may include an inclined surface 1600. Such a surface 1600 may assist in the movement of the curved shaft 1318 within the channel 1500, for example. A flange 1602 may be formed around the curved shaft 1318 to engage or abut the complementary flange of the female member 1316.

  Referring to FIGS. 17A-17C, in one example, a side view shows the stabilization system 1300 of FIG. 13 coupled to an upper vertebra 1700 and a lower vertebra 1702. FIGS. 17A-17C also illustrate exemplary ranges of motion and center points 1328 for the upper vertebra 1700 and the lower vertebra 1702 about which the spinal stabilization system 1300 may rotate. FIG. 17A shows the spinal stabilization system 1300 when two adjacent vertebrae 1700 and 1702 are in a neutral position. FIG. 17B shows the spinal stabilization system 1300 when two adjacent vertebrae 1700 and 1702 are in a fully extended position (eg, when the patient is bent back). FIG. 17C shows a spinal stabilization system 1300 when two adjacent vertebrae 1700 and 1702 are in a flexed position (eg, when the patient is flexing forward).

  Referring to FIGS. 18A-18F, in one example, the posterior view shows two spine stabilization systems 1300a and 1300b coupled to an upper vertebra 1800 and a lower vertebra 1802. FIG. 18A shows spinal stabilization systems 1300a and 1300b when two adjacent vertebrae 1800 and 1802 are in a neutral position. FIG. 18B shows spinal stabilization systems 1300a and 1300b when two adjacent vertebrae 1800 and 1802 are in the extended position (eg, when the patient is bent back). FIG. 18C shows spinal stabilization systems 1300a and 1300b when two adjacent vertebrae 1800 and 1802 are in a flexed position (eg, when the patient is flexing forward). FIG. 18D shows spinal stabilization systems 1300a and 1300b when two adjacent vertebrae 1800 and 1802 are in a lateral bending position (eg, when the patient is bending right or left). FIG. 18E shows spinal stabilization systems 1300a and 1300b when two adjacent vertebrae 1800 and 1802 are in the lateral extension position (eg, when the patient is twisted and bent back). FIG. 18F shows spinal stabilization systems 1300a and 1300b when two adjacent vertebrae 1800 and 1802 are in a roll-bend position (eg, when the patient is twisted and bent forward).

  Referring to FIG. 19, in another example, a posterior view of spinal stabilization systems 1300a and 1300b when two adjacent vertebrae 1900 and 1902 are in a neutral position is shown. In this example, spinal stabilization systems 1300a and 1300b incorporate control members 1904a and 1904b that control relative movement between male members 1314a and 1314b and respective female members 1316a and 1316b. In some embodiments, the control members 1904a and 1904b may be coil springs. The spring may increase the resistance when the male members 1314a and 1314b and the outer ends of the female members 1316a and 1316b slide toward each other, such as when fully extended. In some embodiments, control members 1904a and 1904b may be coupled to both male members 1314a and 1314b and female members 1316a and 1316b. In such embodiments, control members 1904a and 1904b also increase resistance as the distance between the outer ends of male members 1314a and 1314b and female members 1316a and 1316b increases, such as when fully bent. May be.

  Referring to FIG. 20, in another embodiment, the posterior view shows two adjacent vertebrae 2000 and 2002 coupled to spinal stabilization systems 1300a and 1300b. In this example, spinal stabilization systems 1300a and 1300b incorporate control members 2004a and 2004b that control relative movement between respective male members 1314a and 1314b and female members 1316a and 1316b. In this embodiment, the control members 2004a and 2004b may be elastomer sleeves. Control members 2004a and 2004b may increase resistance when the outer ends of male members 1314a and 1314b and female members 1316a and 1316b slide closer together, such as when fully extended. In some embodiments, control members 2004a and 2004b may be coupled to both male members 1314a and 1314b and female members 1316a and 1316b. In such embodiments, control members 2004a and 2004b also increase resistance as the distance between the outer ends of male members 1314a and 1314b and female members 1316a and 1316b increases, such as when fully bent. May be. Furthermore, the sleeve may prevent surrounding meat and tissue from entering the components of the respective spinal stabilization system.

  Referring to FIG. 21, in yet another embodiment, a sleeve 2100 is shown that may be used with the spinal stabilization system embodiment described above. In this embodiment, the sleeve 2100 may include a helical shape used in conjunction with a spring member (not shown). In such an embodiment, the spring may provide or control resistance to each movement and the sleeve may prevent surrounding tissue from entering the spinal stabilization system. In yet other embodiments, the sleeve may be made from a surgical mesh.

  Referring to FIG. 22, in another embodiment, method 2200 is used to insert a dynamic stabilization system, such as dynamic stabilization system 100 of FIG. 1 or dynamic stabilization system 1300 of FIG. Also good. In step 2202, a center of rotation may be identified between the first vertebra and the second vertebra. In step 2204, the first member of the dynamic stabilization device may be coupled to the first multi-axis head, and in step 2206, the second member of the dynamic stabilization device is coupled to the second multi-axis head. May be combined. In steps 2208 and 2210, the axis of each of the first and second multi-axis heads may be directed to the center of rotation. In step 2212, the first and second members may be secured to the first and second multi-axis heads, respectively, so as to maintain the orientation of the first and second axes relative to the center of rotation.

  In another embodiment, a dynamic stabilization device may be inserted. As shown in the above examples, the dynamic stabilization device may be designed to be coupled to a bone anchor inserted into an adjacent vertebra. For example, the dynamic stabilization device includes a bottom member and a top member that may be coupled together at their proximal ends so that they can rotate relative to each other within at least a roll axis and a horizontal axis within a movable range. However, the movable range allows the upper vertebra and lower vertebra to bend and twist with respect to each other while maintaining separation between the vertebrae. The distal end of the bottom member may be coupled to the lower bone anchor and the distal end of the top member may be coupled to the upper bone anchor. The upper and lower connecting members may be coupled to the bone anchor via threaded fasteners and bushings. The threaded fastener may comprise a bearing post that is secured by a locking cap or other similar threaded fastener, and a locking mechanism known to those skilled in the art. Both the upper member and the lower member are adjusted vertically along the threaded fastener during adjustment of the dynamic stabilization device, after which the device is approximately aligned with the natural center of rotation of the spine. It may be locked in a permanent position.

  Once the bone anchor and dynamic stabilization device are implanted, and before the implantation procedure is complete, the device may be aligned with the natural center of rotation of the spine. This includes the use of an aligning cross-connector, the use of a removable alignment tool coupled to the bone anchor, and the removable device coupled to the dynamic stabilization device between the bone anchors. This is accomplished by several methods, such as but not limited to the use of alignment tools, or various other alignment methods known to those skilled in the art. In general, the alignment tool may be coupled to the dynamic stabilization device, and then the alignment rod may be attached thereto. The alignment rod may be rotated to adjust the various components of the dynamic stabilization device such that the components of the dynamic stabilization device are aligned with the natural center of rotation of the spine. Alternatively, an alignment tool coupled to the bone anchor may be used to align the bone anchor before any other component of the dynamic stabilization device is implanted.

  Although only a few exemplary embodiments of the present disclosure have been described in detail above, those skilled in the art will understand that the exemplary embodiments can be made without substantially departing from the novel teachings and advantages of the present disclosure. It will be readily understood that various modifications can be made. Also, the features illustrated and discussed above for some embodiments can be combined with the features illustrated and discussed above for other embodiments. Accordingly, all such modifications are intended to be included within the scope of this disclosure.

1 is a perspective view of one embodiment of a dynamic stabilization system. FIG. 2 is a perspective view of one embodiment of a dynamic stabilization device that may be used in the dynamic stabilization system of FIG. 1. FIG. 3 is a diagram of the dynamic stabilization device shown in FIG. 2 in the extended position. FIG. 4 is a cross-sectional view of the dynamic stabilization device of FIG. 3. FIG. 3 is a perspective view of one embodiment of a member of the dynamic stabilization device of FIG. 2. FIG. 3 is a perspective view of one embodiment of a member of the dynamic stabilization device of FIG. 2. FIG. 3 is a side view of one embodiment of the dynamic stabilization device of FIG. 2. FIG. 2 is a side view of one embodiment of the dynamic stabilization system of FIG. 1. FIG. 9 is an enlarged view of a portion of the dynamic stabilization system of FIG. FIG. 10 is a cross-sectional view of a portion of the dynamic stabilization system of FIG. FIG. 2 is a sagittal cross-sectional perspective view of the dynamic stabilization system shown in FIG. 1 in a neutral position. FIG. 2 is a sagittal cross-sectional perspective view of the dynamic stabilization system shown in FIG. 1 in a bent position. FIG. 2 is a rear perspective view of the dynamic stabilization system shown in FIG. 1 in a neutral position. FIG. 2 is a rear perspective view of the dynamic stabilization system shown in FIG. 1 in a bent position. 2 is a rear perspective view of the dynamic stabilization system shown in FIG. 1 in a rotational position. FIG. 2 is a rear perspective view of the dynamic stabilization system shown in FIG. 1 in a side-bent position. FIG. FIG. 2 is a rear perspective view of the dynamic stabilization system shown in FIG. 1 in the extended position. FIG. 6 is a side view of another embodiment of a dynamic stabilization system. FIG. 14 is a perspective view of one embodiment of a dynamic stabilization device that may be used in the dynamic stabilization system of FIG. 13. FIG. 14B is a side view of the dynamic stabilization device of FIG. 14A. FIG. 14B is a perspective view of one embodiment of members of the dynamic stabilization device of FIG. 14A. FIG. 14B is a perspective view of one embodiment of members of the dynamic stabilization device of FIG. 14A. FIG. 14 is a side view of the dynamic stabilization system of FIG. 13 in a neutral position. FIG. 14 is a side view of the dynamic stabilization system of FIG. 13 in the extended position. FIG. 14 is a side view of the dynamic stabilization system of FIG. 13 in a bent position. FIG. 14 is a rear perspective view of the dynamic stabilization system of FIG. 13 in a neutral position. FIG. 14 is a rear perspective view of the dynamic stabilization system of FIG. 13 in the extended position. FIG. 14 is a rear perspective view of the dynamic stabilization system of FIG. 13 in a bent position. FIG. 14 is a rear perspective view of the dynamic stabilization system of FIG. 13 in a side-bent position. FIG. 14 is a rear perspective view of the dynamic stabilization system of FIG. 13 in a rotational extended position. FIG. 14 is a rear perspective view of the dynamic stabilization system of FIG. 13 in a rotational bending position. FIG. 6 is a rear perspective view of an alternative embodiment of a dynamic stabilization system in a neutral position. FIG. 6 is a rear perspective view of another embodiment of a dynamic stabilization system in a neutral position. FIG. 14 is a perspective view of one possible component that may be used with some embodiments of the dynamic stabilization system shown in FIGS. 2 is a flowchart of one embodiment of a method of using a dynamic stabilization system.

Claims (21)

A dynamic member having a first end and a second end, the dynamic member substantially constraining a relative movement of the first end with respect to the second end to a three-dimensional curved surface;
The first end comprises means for coupling to a first alignment member, whereby the first end can be rotated relative to the longitudinal axis of the first alignment member;
The second end comprises means for coupling to a second alignment member, whereby the second end can be rotated relative to the longitudinal axis of the second alignment member. A medical implant that joins the two vertebrae of the spine.   The dynamic member comprises a first connecting member, a second connecting member, and means for rotationally coupling the first connecting member to the second connecting member. A medical implant as described in 1.   The medical implant according to claim 2, characterized in that the rotational coupling means comprises a pin joint.   The medical implant of claim 3, wherein longitudinal axes of the first alignment member, the second alignment member, and the pin joint intersect about a center of rotation.   The medical implant of claim 1, wherein the dynamic member comprises a first coupling member slidably coupled to a second coupling member.   The medical implant according to claim 2, wherein the connecting member is a nonlinear member.   7. A medical implant according to claims 1 to 6, characterized in that the means for joining includes an aperture formed in each of the ends.   The medical implant according to claim 7, wherein the aperture is rotationally coupled to a bushing adapted to mate with the aperture.   The medical implant according to claim 8, wherein the bushing is adapted to engage one of the alignment members by screwing.   The medical implant of claim 9, wherein the alignment member includes means for engaging a bone engaging member. First bone anchoring means;
A second bone anchoring means;
First alignment means coupled to the first bone anchoring means;
A second coupled to the second bone anchoring means such that the longitudinal axes of the first and second alignment means can be aligned to intersect at the center of rotation. Alignment means;
A dynamic member having a first end and a second end and allowing relative movement between the first end and the second end;
The first end includes means for coupling to the first alignment means, whereby the first end can be rotated relative to a longitudinal axis of the first alignment means; The second end includes means for coupling to a second alignment member, whereby the second end can be rotated relative to the longitudinal axis of the second alignment means. A medical system that joins two vertebrae of the spine.   The medical system according to claim 11, wherein the dynamic member limits relative movement to a three-dimensional curved surface.   12. The dynamic member comprises a first connecting member, a second connecting member, and means for rotationally coupling the first connecting member to the second connecting member. Medical system as described in.   14. The medical system according to claim 13, wherein the rotational coupling means comprises a pin joint.   15. The medical system of claim 14, wherein longitudinal axes of the first alignment member, the second alignment member, and the pin joint intersect about a center of rotation.   13. The medical system according to claim 11 and 12, wherein the dynamic member comprises a first connecting member that is slidably coupled to a second connecting member.   The medical system according to claim 13, wherein the connecting member is a nonlinear member.   18. A medical system according to claims 11 to 17, characterized in that the means for coupling includes an aperture formed in each of the ends.   The medical system according to claim 18, wherein the aperture is rotationally coupled to a bushing adapted to mate with the aperture.   The medical system according to claim 19, wherein the bushing is adapted to engage one of the alignment members by screwing.   21. The medical system according to claim 20, wherein the alignment member includes means for engaging a bone engaging member.

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