A system for guiding an interbody spacer between vertebral bodies

Abstract

To provide a system that can easily and accurately place an interbody spacer at a predetermined position between vertebral bodies using the PLIF procedure even in a narrow surgical field. [Solution] An interbody spacer 10 is provided with a pair of contact surfaces that contact vertebral bodies, the pair of contact surfaces being connected at the ventral side, a ventral side surface that is a convex ventral side surface in plan view, a ventral groove is formed in the ventral side surface along the curved direction, and an interbody spacer engagement part is formed on a bottom surface of the ventral groove having a radius of curvature smaller than the radius of curvature of the ventral side surface. Also, a guide instrument 30 for guiding the interbody spacer to a predetermined position between the vertebral bodies is provided with a guide rail on a distal end side that fits with the ventral interbody spacer engagement part, and a handle part on a proximal end side that is held by the surgeon outside the patient's body, and the radius of curvature of the guide rail engagement part on the distal side of the guide rail in plan view is the same as the radius of curvature of the interbody spacer engagement part in plan view.

Description

[Technical field]

[0001] The present invention relates to a system for guiding an interbody spacer between vertebral bodies. [Background technology]

[0002] When inserting and setting an interbody spacer between vertebral bodies, the intervertebral disc 2 between the vertebral bodies 1 shown in FIG. The annulus fibrosus is opened to remove the nucleus pulposus inside, and an interbody spacer is inserted between the vertebrae after the removal. Since the spinal nerve system and blood vessels pass near the intervertebral disc 2, The technique requires careful attention.

[0003] The spine is responsible for supporting the body weight, so interbody spacers must have high rigidity and a wide space between the vertebrae. It is necessary to cover a large area, and the surgical field is narrow, with nerve systems and blood vessels nearby. In order to avoid these, it is necessary to place the interbody spacer in the appropriate position. Skills and surgical systems are required.

[0004] Interbody spacers are classified into box-type and boomerang-type interbody spacers. When comparing the bone fusion rate between the interbody spacer and the vertebral body, Run-type interbody spacers are superior to box-type interbody spacers.

[0005] FIG. 2(A) is a plan view of a lumbar vertebra. On the upper side of a vertebral body 1, there are a spinous process 3, There are transverse processes 4, vertebral arches 5, and facet joints 6, and the spinal nerves pass through the spinal canal 7. The surgical technique for placing an interbody spacer between vertebral bodies is mainly TLIF (transvertebral interbody fusion) shown in Figure 2(B). (Pinus approach lumbar interbody fusion) and (Posterior approach lumbar interbody fusion) shown in Figure 2(C). TLIF is a surgical procedure that involves resecting the facet joint6 of either the left or right vertebrae, and PLI F is a surgical procedure in which the spinous process 3 in the center of the vertebra is resected and invaded. The spacer is inserted in the direction of the arrow.

[0006] The system according to the invention described in Patent Document 1 is simple and easy to use even in a narrow surgical field. The boomerang-type interbody spacer can be easily and accurately placed at the desired position between the vertebral bodies. It is a system that [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6700511 Summary of the Invention [Problem to be solved by the invention]

[0008] Among spinal diseases such as lumbar spine, PLIF is mainly used for lumbar spinal canal stenosis, and The TLIF procedure is mainly used for lumbar foraminal stenosis. Most doctors who are familiar with spinal surgery are experts in PLIF surgery. These doctors tend to shy away from TLIF surgery.

[0009] The system described in Patent Document 1 is based on the TLIF procedure, so it is not suitable for PLIF. It is difficult to place the boomerang-type interbody spacer at a desired position between the vertebral bodies using the conventional method. Figure 13 shows the placement of a boomerang-shaped interbody spacer between the vertebral bodies during TLIF. The intervertebral spine engaged with the conventional guide rail engagement portion 47 of the conventional guide rail 46 is shown. The pacer 49 is conventionally pushed by a push rod 48. In this case, the vertebrae can be easily inserted into the desired position. An interbody spacer 49 can be placed. FIG. 14 shows a boomerang-type interbody spacer using the invention described in Patent Document 1 in a PLIF procedure. In the conventional method, the vertebral bodies are inserted along the guide rail engagement portion 47. As the interbody spacer 49 moves, the tip of the interbody spacer 49 comes into contact with the side wall between the vertebral bodies. As a result, it is not possible to place the interbody spacer 49 at a predetermined position within the interbody space.

[0010] The purpose of this invention is to develop a simple system that can perform PLIF surgery even in a small surgical field. This system allows the interbody spacer to be easily and accurately placed at the desired position between the vertebral bodies. The aim of this project is to provide a [Means for solving the problem]

[0011] The present invention (1) is a system for treating a spinal disease, the system comprising: It is used by inserting it between the vertebral body and the , so that the ventral side is convex in plan view. bay A curved interbody spacer having a pair of abutment surfaces for abutting each of the vertebral bodies, the pair The contact surfaces are connected on the ventral side. ,stomach The ventral surface is a side surface of the Belly Gutters are formed The bottom surface of the ventral groove is provided with a vertebral body having a radius of curvature smaller than the radius of curvature of the ventral side surface. an intervertebral spacer having an interbody spacer engagement portion formed thereon; A guide device for guiding the vertebral spacer to a predetermined position between the vertebral bodies, the guide device having a distal end thereof engaging the interbody spacer. The handpiece has a guide rail that fits into the proximal end of the patient's hand. The guide rail engaging portion on the distal side of the guide rail has a radius of curvature in a plan view of A system having a guide instrument having a curvature radius equal to that of the intervertebral spacer engagement portion in a plan view. This is the system.

[0012] In the system of the present invention (1), the plan view of the guide rail engagement portion on the distal side of the guide rail The radius of curvature is the same as the radius of curvature of the interbody spacer engagement portion in a plan view, and the radius of curvature of the ventral surface is Since the radius of curvature is smaller than the planar radius, the interbody spacer can be moved with a small radius, and PLIF Even when using the above surgical procedure, the boomerang-type interbody spacer can be easily and precisely placed in the desired position between the vertebral bodies. It can be installed.

[0013] The present invention (2) is characterized in that the center of curvature of the intervertebral spacer engagement portion in a plan view is located on the flat surface of the ventral side. The interbody spacer is offset from the center of curvature in plan view toward the tip side when the interbody spacer is inserted between the vertebral bodies. This is the system of the present invention (1).

[0014] In the system of the present invention (2), the center of curvature of the interbody spacer engagement portion in a plan view is located on the ventral surface. When the interbody spacer is inserted between the vertebral bodies, it is eccentric to the tip side from the center of curvature in a plan view. This makes it easier to insert the boomerang-shaped interbody spacer into the desired position between the vertebral bodies during surgery. It can be installed.

[0015] The present invention (3) has a stopper portion on the guide rail of the guide instrument that hooks onto the intervertebral joint. The system of the present invention (1) or (2) is formed.

[0016] In the system of the present invention (3), a hook is attached to the guide rail of the guide instrument and to the intervertebral joint. The topper part is formed, so by hooking this stopper onto the intervertebral joint, The guide rail no longer protrudes from its designated position toward the ventral side, allowing for safer surgery. It is possible to do so.

[0017] The present invention (4) is A guide rail for guiding an interbody spacer for treating spinal disorders The guide has a guide rod at its distal end and a handle at its proximal end that is held by the surgeon outside the patient's body. The instrument is inserted between the vertebral bodies and is used with a convex ventral side in plan view. an interbody spacer curved to have a shape, the interbody spacer having a pair of abutting surfaces that abut against each of the vertebrae; a pair of abutment surfaces connected at a ventral side, a ventral side surface being a ventral side surface, A ventral groove is formed on the surface, and a curvature radius smaller than that of the ventral side surface is formed on the bottom surface of the ventral groove. An interbody spacer engagement portion is formed having a radius of curvature and adapted to engage with the guide rail, and the vertebral The center of curvature of the interbody spacer engagement portion in a plan view is closer to the center of curvature of the ventral side surface in a plan view. The interbody spacer is eccentric toward the tip when being inserted between the vertebral bodies. Interbody spacer .

[0018] The present invention (4) By using the interbody spacer, the PLIF procedure can be used in narrow surgical areas. Boomerang-type interbody spacers can be easily and accurately placed at the desired position between the vertebrae, even in the field. It is possible. Effect of the Invention

[0019] The system of this invention is simple, so even in a narrow surgical field, PL The boomerang-type interbody spacer can be easily and accurately placed at the desired position between the vertebral bodies using the IF procedure. It is possible. [Brief description of the drawings]

[0020] [Figure 1] A lateral view of the spine (lumbar vertebrae) is shown. [Diagram 2] (A) shows a plan view of the spine (lumbar vertebrae), (B) shows the approach direction of the TLIF procedure, and (C) shows the approach direction of the PLIF procedure. [Diagram 3] FIG. 13 is a schematic diagram showing a state in which an interbody spacer is attached to a guide instrument and is being operated. [Figure 4] 1 shows an enlarged view of the guide device with an interbody spacer attached. [Diagram 5]1 shows a perspective view of an interbody spacer according to the present invention. [Figure 6] 1A shows a front view, FIG. 1B shows a plan view, and FIG. 1C shows a horizontal cross-sectional view of an interbody spacer according to the present invention. [Figure 7] FIG. 1 shows a schematic diagram illustrating a comparison between a system according to a first embodiment of the present invention (upper part) and a conventional interbody spacer described in Patent Document 1 (lower part). [Figure 8] FIG. 2 is a schematic diagram showing a comparison between a system according to a first embodiment (upper part) and a system according to a second embodiment (lower part) of the present invention. [Figure 9] FIG. 2 is a schematic diagram showing the state in which a first interbody spacer is inserted in the system according to the present invention. [Figure 10] FIG. 2 is a schematic diagram showing the system of the present invention being inserted with a second interbody spacer. [Figure 11] 13 is a schematic diagram showing a system according to a third embodiment of the present invention, in which a stopper is attached to a guide instrument. [Figure 12] 10A and 10B are schematic diagrams illustrating a specific example of an engagement state between an interbody spacer of the system according to the present invention and a guide rail engagement portion of a guide instrument. [Figure 13] 1 shows a schematic diagram of an interbody spacer being inserted between vertebral bodies using the TLIF procedure in the system described in Patent Document 1. [Figure 14] 1 shows a schematic diagram of an interbody spacer being inserted between vertebral bodies using the PLIF procedure in the system described in Patent Document 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The embodiment of the present invention will be described below with reference to the drawings. The "upper and lower" in this figure are for convenience only, and when installing the product, It can also be reversed or horizontal.

[0022] FIG. 3 shows a state in which an interbody spacer is attached to the guide instrument according to the present invention and is being operated. FIG. 1A is a schematic diagram showing a state in which an interbody spacer 10 is attached to a guide device 30. FIG. 1B shows the intervertebral spacer 10 inserted about halfway toward the predetermined position between the vertebral bodies. FIG. 1C shows the state in which the interbody spacer 10 is placed at a predetermined position between the vertebral bodies, and FIG. 3 shows the state of removal from the device 30.

[0023] In FIG. 3A, the head 32 of the push rod 31 is raised upward. 3 protrudes upward from the upper end of the handle portion 34. The release button 35 is in the protruding state and locks the push rod 31 so that it cannot move downward. The interbody spacer 10 is attached to the lower end of the push rod tip 37 and is held in place. The release button 36 is pushed down, and the gripping rod ( The tip of the intervertebral spacer 10 is gripped by the intervertebral spacer 10.

[0024] Thereafter, the intervertebral spacer 10 is inserted between the vertebrae while being grasped as shown in FIG. 3(A), and then released. When the button 36 is pulled up, the gripping rod (without a number) is removed from the interbody spacer 10. The grip is released. Then, push the push rod release button 35 and push the head 32 downward. The rod tip 37 also moves down and pushes the upper end of the interbody spacer 10. 10 is guided by a guide rail 38 (not shown in FIG. 3) and reaches the state shown in FIG. 3(B).

[0025] FIG. 3C shows the head 32 being pushed up to the upper surface of the handle 34 to form the interbody spacer 10. The figure shows a state in which the handle is moved along the guide rail engagement portion 39. When the portion 34 is lifted upward, the interbody spacer 10 engages with the guide rail engaging portion 39. Since the handle 34 is removed, only the handle portion 34 is taken out of the body and the interbody spacer 10 is inserted into the vertebrae. It is now placed at a designated position between the bodies.

[0026] FIG. 4 shows an enlarged view of the interbody spacer 10 attached to the guide instrument 30. This shows stage 3(B). A guide rail 38 having a push rod tip 37 and a guide rail engagement portion 39 at its tip The push rod tip 37 is provided with a gripping rod (not shown) for inserting the vertebral body into the vertebral body. The spacer 10 is gripped.

[0027] 5 shows a perspective view of an interbody spacer 10 according to the present invention. The ventral groove 15 is formed, and a bottom surface 23 is formed at the bottom of the ventral groove 15. The interbody spacer 15 is formed along the bottom surface 23. The side that engages with the guide instrument 30 is the rear end surface 12 side, The tip surface 11 is formed on the opposite side. The surface that comes into contact with the cranial vertebrae between the vertebrae is the upper surface 13, and the The surface that comes into contact with the interbody caudal vertebra is the lower surface 14 (see FIG. 6). The spacer 10 has many deep grooves to accommodate the bone graft. A bone graft area 19 is opened for inserting hydroxyapatite or the like.

[0028] FIG. 6 shows a front view (A), a plan view (B) and a horizontal cross-sectional view of an intervertebral spacer according to the present invention. Fig. 5(C) is a horizontal cross-sectional view of the gripping mechanism. Hole 18 is a hole for engaging with the tip of a grasping rod (not numbered) of guide instrument 30. .

[0029] FIG. 7 shows the system of Example 1 (upper part) and the conventional intervertebral spacer system described in Patent Document 1. FIG. 1 is a schematic diagram showing a comparison between the intervertebral spacer 10 and the guide rail 11. FIG. At (B), the guide rail 38 starts to move, and at (C), the guide rail 38 engages with the guide rail engaging portion 39. (C) shows the interbody spacer in place. The radius of curvature of the laser engaging portion 20 is R 1 It is. (D) The conventional interbody spacer 24 starts to move along the conventional guide rail 46. FIG. 1(E) shows the conventional interbody spacer 24 engaged with the conventional guide rail engagement portion 47. (F) shows the completed placement in the desired position between the vertebral bodies. The rate radius is R C It is. The system of Example 1 of the present invention shown in the upper row is compared with the conventional interbody spacer system shown in the lower row. The width from the guide rail is l 1 , l 2 , l 3 and L 1 , L 2 , L 3 With For comparison, 1 <L 1 ,l 2 <L 2 ,l 3 <L 3 Using the system of the first embodiment of the present invention, This makes it easy to insert the boomerang-shaped interbody spacer into the desired position between the vertebrae even during PLIF. It can be inserted accurately.

[0030] FIG. 8 shows a system according to the first embodiment of the present invention (upper part) and a system according to the second embodiment (lower part). The schematic diagrams for comparison are (A), (B), and (C) in the upper row, which correspond to (A) and (B) in the upper row of Fig. 7. ,(C). The center of curvature O of the upper engagement part 1The vertical position of the ventral surface 15 center of curvature O 2 The vertical position of the arrows is the same as that of the arrows in the vertical direction. In the system of Example 2 shown in the lower part, the center of curvature O of the interbody spacer engagement portion 20 is 1 and ventral surface 16 centers of curvature O 2 It is not the same core, 1 The position of is shifted by d toward the tip side. The width from the rail is l 1 '=l 1 ,l 2 ' <l 2 ,l 3 ' <l 3 Therefore, The system of Example 2 has a boomerang-shaped vertebra in the PLIF procedure compared to the system of Example 1. The interbody spacer can be more easily inserted into position between the vertebral bodies.

[0031] FIG. 9 shows the insertion of the first interbody spacer 10 using the system of the present invention. The schematic diagrams are shown in the order of (A) to (B), (B) to (C), and (C) to (D). Interbody spacer 10 is inserted between the vertebral bodies and allowed to set in place.

[0032] FIG. 10 shows the state in which the second interbody spacer 10 is being sequentially placed, following FIG. As can be seen from this figure, the first and second interbody spacers 10 are used for the PLIF procedure. It can be seen that the device can be easily and accurately placed at the desired position between the vertebral bodies using the formula.

[0033] FIG. 11 shows a system according to a third embodiment of the present invention, in which a stopper 41 is provided on a guide device 40. The attached system is shown diagrammatically. (A) shows the first interbody spacer 10 inserted. FIG. 1(B) shows a state in which the second interbody spacer 10 is being inserted. do. In (A), the interbody spacer 10 is engaged with the tip of the guide rail 40, and the push rod The rod tip 37 presses against the rear end surface 12 of the interbody spacer 10. A stopper 41 is formed at a predetermined position, and the stopper 41 is hooked on the upper surface of the intervertebral joint 6. The stopper 41 prevents the guide rail 40 from protruding beyond the vertebral body 1. This can be prevented. (B) shows the state in which the second interbody spacer 10 is being inserted. The guide rail 40 has been replaced with a guide rail 42. The stopper 43 is formed, but is formed closer to the tip side than the stopper 41. This is to prevent the first interbody spacer 10 from being pressed by mistake.

[0034] FIG. 12 illustrates a specific example of an engagement state between the interbody spacer 10 and the guide rail engagement portion 39. In FIG. 12(A-1), the cross section of the guide rail engagement portion 39 is T The cross section of the interbody spacer engagement portion is a T-shaped convex shape, while the cross section of the interbody spacer engagement portion is a T-shaped concave shape. In (A-2), the opposite is true.

[0035] In (B-1) and (B-2) of FIG. 12, the engagement structure is a dovetail groove, and in (C-1) of FIG. The engagement structure of (C-1) and (C-2) is a ball and socket structure. Each has its own characteristics, and it is certain that the T-shape and dovetail groove shapes are advantageous in terms of processing costs. It has the characteristic of being able to hold the device securely, and the ball-and-socket shape allows for good sliding properties.

[0036] FIG. 12D shows a modification of FIG. 12A-1, in which the height of the guide rail engagement portion 39 is , the height of the ventral surface of the interbody spacer is extremely small compared to the height of the ventral surface of the interbody spacer, In the above-mentioned area, the interbody spacer 10 can be more easily and accurately placed in a desired position. can. [Industrial Applicability]

[0037] The system of this invention is a simple system, and even in a small surgical field, PL The IF procedure allows the interbody spacer to be easily and accurately placed at the desired position between the vertebral bodies. do. [Explanation of symbols]

[0038] 1: Vertebral body 2: Intervertebral disc 3: spinous process 4: Transverse process 5:Lateral arch 6: Facet joint 7: Spinal canal 10: Interbody spacer 11: Tip surface 12: Rear end surface 13:Top surface 14: Bottom surface 15:Ventral groove 16: Ventral aspect 17: Dorsal side 18:Gripping hole 19: Bone graft section 20: Interbody spacer engagement part 23: Bottom 24: Conventional interbody spacer 30: Guide equipment 31: Push rod 32:Head 33: Rod section 34: Handle section 35: Push rod release button 36: Release button 37: Push rod tip 38, 40, 42: Guide rail 39: Guide rail engagement part 41,43: Stopper 46: Conventional guide rail 47: Conventional guide rail engagement part 48: Conventional push rod O 1 : Center of curvature of interbody spacer engagement part O 2 :Ventral center of curvature R 1 : Interbody spacer engagement part curvature radius R 2 :Ventral radius of curvature R c : Conventional guide rail engagement part curvature radius

Claims

1. 1. A system for treating a spinal disorder, the system comprising: It is inserted between the vertebral bodies and is used so that the ventral side has a convex shape when viewed from above. A curved interbody spacer as described above, A pair of abutment surfaces that abut against each of the vertebrae are provided, the pair of abutment surfaces being connected on the ventral side, and the ventral It has a ventral surface, which is the side surface, A ventral groove is formed on the ventral side surface, and a bottom surface of the ventral groove has a radius of curvature smaller than that of the ventral side surface. and an intervertebral spacer having an intervertebral spacer engagement portion formed with a smallest radius of curvature. 、 A guide instrument for guiding the interbody spacer to a predetermined position between the vertebral bodies, A guide rail is provided on the distal end side to be fitted with the intervertebral spacer engagement portion, and a proximal end A handle portion is provided on the distal side of the guide rail, which is held by the surgeon outside the patient's body. The radius of curvature of the rail engagement portion in a plan view is the same as the radius of curvature of the interbody spacer engagement portion in a plan view. and a guide instrument, the guide instruments being identical.

2. The center of curvature of the intervertebral spacer engagement portion in a plan view is larger than the center of curvature of the ventral surface in a plan view.

2. The interbody spacer according to claim 1, wherein the interbody spacer is offset toward the distal end when the interbody spacer is inserted between the vertebral bodies. system.

3. The guide rail of the guide device is formed with a stopper portion that is hooked onto the intervertebral joint.

3. The system according to claim 1 or 2.

4. An interbody spacer as described in claim 2.

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