System for guiding interbody spacer between vertebral bodies

Abstract

To provide a system capable of easily and accurately installing an interbody spacer at a prescribed position between vertebral bodies by PLIF even in a narrow operation field.SOLUTION: A system comprise: an interbody spacer 10 including a pair of contact surfaces coming into contact with vertebral bodies, a ventral lateral face, the convex ventral-side lateral face in plan view, for connecting the pair of contact surfaces on the ventral side, a ventral groove formed on the ventral lateral face along the curved direction, and an interbody spacer engagement part formed on a bottom surface of the ventral groove and having a radius of curvature smaller than a radius of curvature of the ventral lateral face; and a guide instrument 30 for guiding the interbody spacer to a prescribed position between the vertebral bodies, the guide instrument including a guide rail on a distal end side, to be fitted with an abdominal interbody spacer engagement part, and a handle part on the proximal end side, to be gripped by an operator outside the patient's body, where a radius of curvature of the guide rail engagement part on the distal side of the guide rail in plan view is the same as a radius of curvature of the interbody spacer engagement portion in plan view.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] This invention relates to a system for guiding an intervertebral spacer between vertebrae.

Background Art

[0002] When inserting and installing an intervertebral spacer between vertebrae, the annulus fibrosus of the intervertebral disc 2 between the vertebrae 1 shown in FIG. 1 is windowed to remove the internal nucleus pulposus, and after this removal, an intervertebral spacer is inserted and installed between the vertebrae. Since the spinal nerve system and blood vessels pass near the intervertebral disc 2, extreme care is required for the surgery.

[0003] Since the spinal column plays a role in supporting body weight, the intervertebral spacer is required to have high rigidity and cover a wide area between the vertebrae. At the same time, the surgical field is narrow and the nerve system and blood vessels pass nearby, so skills and a surgical system for installing the intervertebral spacer at an appropriate position while avoiding these are required.

[0004] Intervertebral spacers can be roughly classified into two types morphologically: box-shaped intervertebral spacers and boomerang-shaped intervertebral spacers. Comparing the bone fusion rate between the intervertebral spacer and the vertebra, the boomerang-shaped intervertebral spacer is superior to the box-shaped intervertebral spacer. FIG. 2(A) is a plan view of the lumbar spine. Above the vertebra 1, there are the spinal canal 7, the spinous process 3,

[0005] the transverse process 4, the vertebral arch 5, and the zygapophyseal joint 6, and the spinal nerve passes through the spinal canal 7. The surgical procedures for installing an intervertebral spacer between vertebrae mainly include TLIF (transforaminal lumbar interbody fusion) shown in FIG. 2(B) and PLIF (posterior lumbar interbody fusion) shown in FIG. 2(C). There is. TLIF is a surgical procedure that invades by excising one of the left and right facet joints 6 of the vertebra, and PLI F is a surgical procedure that invades by excising the spinous process 3 in the central part of the vertebra. In each surgical procedure, the intervertebral spacer is inserted in the direction of the arrow.

[0006] The system according to the invention described in Patent Document 1 is simple even in a narrow surgical field and can accurately install the boomerang-shaped intervertebral spacer at a predetermined position between the vertebrae easily.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] Among spinal diseases such as lumbar vertebrae, the PLIF surgical procedure is mainly used for lumbar spinal stenosis, and the TLIF surgical procedure is mainly used for lumbar foraminal stenosis. Since lumbar spinal stenosis is frequently encountered in cases, most doctors who are familiar with spinal surgery are doctors who are good at the PLIF surgery and there are many of them. These doctors tend to avoid the TLIF surgery.

[0009] In the system described in Patent Document 1, since the TLIF surgical procedure is the basis, it is difficult to install the boomerang-shaped intervertebral spacer at a predetermined position between the vertebrae by the PLIF surgical procedure. FIG. 13 shows the place where the boomerang-shaped intervertebral spacer is installed between the vertebrae by the TLIF surgical procedure. The intervertebral spacer engaged with the conventional guide rail engaging portion 47 of the conventional guide rail 46 in the past The pacer 49 is being pushed by the conventional push rod 48. In this case, the vertebral body spacer 49 can be easily installed at a predetermined position. Figure 14 shows the state of installing a boomerang-shaped intervertebral spacer between vertebrae using the invention described in Patent Document 1 in the PLIF surgical procedure. Since the intervertebral spacer 49 moves along the conventional guide rail engaging portion 47, the tip of the intervertebral spacer 49 hits the side wall between the vertebrae, and the intervertebral spacer 49 cannot be installed at a predetermined position within the intervertebral space.

[0010] An object of the present invention is to provide a simple system that can accurately install an intervertebral spacer at a predetermined position between vertebrae in the PLIF surgical procedure even in a narrow surgical field.

Means for Solving the Problems

[0011] The present invention (1) is a system for treating spinal diseases, and the system is an intervertebral spacer that is horizontally curved and used by being inserted between vertebrae between the vertebrae, and has a pair of abutting surfaces that abut against each of the vertebrae, and the pair of abutting surfaces are connected on the ventral side to form a ventral side that is a convex side surface in plan view. A ventral groove is formed along the curved direction on the ventral side surface, and an intervertebral spacer engaging portion having a radius of curvature smaller than the radius of curvature of the ventral side surface is formed on the bottom surface of the ventral groove. And a guide device for guiding the intervertebral spacer to a predetermined position between the vertebrae, which has a guide rail that is fitted with the ventral intervertebral spacer engaging portion on the distal end side, and a handle portion that an operator grips outside the patient's body on the proximal end side. The curvature of the guide rail engaging portion on the distal side of the guide rail in plan view a guide instrument having a radius that is the same as the radius of curvature in plan view of the intervertebral spacer engaging portion It is a system having the same.

[0012] In the system of the present invention (1), the radius of curvature in plan view of the guide rail engaging portion on the distal side of the guide rail is the same as the radius of curvature in plan view of the intervertebral spacer engaging portion, and is smaller than the radius of curvature in plan view of the ventral surface. Therefore, the intervertebral spacer can rotate smoothly, and even when using the surgical method of PLIF the boomerang-shaped intervertebral spacer can be easily and accurately installed at a predetermined position between the vertebrae. installed.

[0013] In the present invention (2), the center of curvature in plan view of the intervertebral spacer engaging portion is eccentric toward the distal end side when inserting the intervertebral spacer between the vertebrae with respect to the center of curvature in plan view of the ventral surface This is the system of the present invention (1).

[0014] In the system of the present invention (2), the center of curvature in plan view of the intervertebral spacer engaging portion is eccentric toward the distal end side when inserting the intervertebral spacer between the vertebrae with respect to the center of curvature in plan view of the ventral surface Therefore, in the operation, the boomerang-shaped intervertebral spacer can be more easily installed at a predetermined position between the vertebrae installed.

[0015] The present invention (3) is the system of the present invention (1) or (2) in which a stopper portion that catches on the facet joint is formed on the guide rail of the guide instrument

[0016] In the system of the present invention (3), since a stopper portion that catches on the facet joint is formed on the guide rail of the guide instrument, by catching this stopper on the facet joint the guide rail will not protrude ventrally beyond a predetermined position, and a safer operation can be performed ​​​​​ It is possible to do so.

[0017] The present invention (4) is an intervertebral spacer of either the present invention (1) or (2). By using such an intervertebral spacer, even in a narrow surgical field using the PLIF surgical procedure, it is possible to accurately install the boomerang-shaped intervertebral spacer at a predetermined position between the vertebrae. It can be done.

[0018] The present invention (5) and the present invention (6) are respectively guide instruments of the present invention (1) and the present invention (3). By using such a guide instrument, even in a narrow surgical field using the PLIF surgical procedure, it is possible to accurately install the boomerang-shaped intervertebral spacer at a predetermined position between the vertebrae. It can be done.

Advantages of the Invention

[0019] According to the system of this invention, since the system is simple, even in a narrow surgical field, it is possible to easily and accurately install the boomerang-shaped intervertebral spacer at a predetermined position between the vertebrae using the PLIF surgical procedure. It can be done.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Mode for Carrying Out the Invention

[0021] Embodiments of the present invention will be described with reference to the following drawings. In the following description, up and down refer to the up and down in the figure. This "up and down" is for convenience, and during installation, the up and down may be reversed or horizontal.

[0022] FIG. 3 is a schematic diagram showing a state in which an intervertebral spacer is attached to and operated on a guide device according to the present invention, and (A) shows a state in which the intervertebral spacer 10 is attached to the guide device 30. shown, and (A) shows a state in which the intervertebral spacer 10 is attached to the guide device 30. is shown, and (B) shows a state where the intervertebral spacer 10 is inserted about halfway toward a predetermined position between the vertebrae. is shown, and (C) shows a state where the intervertebral spacer 10 is removed from the guide instrument 30 after being installed at a predetermined position between the vertebrae.

[0023] In FIG. 3(A), the head 32 of the push rod 31 is raised upward, and the rod portion 3 3 protrudes partially upward from the upper end of the handle portion 34. At this time, the push rod release button 35 is in a protruding state, and the push rod 31 is locked so as not to move downward. The intervertebral spacer 10 is applied to the lower end of the tip portion 37 of the push rod, and the grasp release button 36 is lowered, and the tip of the grasping rod ( not numbered) charged inside the guide instrument 30 grasps the intervertebral spacer 10.

[0024] Thereafter, in the state of FIG. 3(A) where the intervertebral spacer 10 is grasped, it is inserted between the vertebrae, and when the grasp release button 36 is pulled upward, the grasping rod (not numbered) is pulled out from the intervertebral spacer 10 and the grasp is released. Thereafter, when the push rod release button 35 is pushed in and the head 32 is pushed downward, the tip of the push rod 37 also descends and the upper end of the intervertebral spacer 10 is pushed, and the intervertebral spacer 10 is guided by a guide rail 38 not shown in FIG. 3 and reaches the state of FIG. 3(B).

[0025] FIG. 3(C) shows a state where the head 32 is pushed into the upper surface of the handle portion 34 and the intervertebral spacer 10 is moved along the guide rail engaging portion 39. In this state, when the handle portion 34 is lifted upward, the intervertebral spacer 10 disengages from the engagement with the guide rail engaging portion 39 Since it has come off, only the handle portion 34 is taken out of the body, and the intervertebral spacer 10 is placed at a predetermined position between the vertebrae. It is in a state where it is installed at a predetermined position between the vertebrae.

[0026] FIG. 4 shows an enlarged view of the state where the intervertebral spacer 10 is attached to the guide device 30, and shows the stage of FIG. 3(B). There is a guide rail 38 having a push rod tip portion 37 and a guide rail engaging portion 39 at the tip, and the intervertebral spacer 10 is held by a holding rod (not numbered) provided inside the push rod tip portion 37.

[0027] FIG. 5 shows a perspective view of the intervertebral spacer 10 according to the present invention. A ventral groove 15 is formed on the ventral surface 16, a bottom surface 23 is formed at the bottom of the ventral groove 15, and an intervertebral spacer engaging portion 20 is formed along the bottom surface 23. The side that engages with the guide device 30 is the rear end surface 12 side, and the front end surface 11 is formed on the opposite side. The surface that contacts the cephalad vertebra between the vertebrae is the upper surface 13, and the surface that contacts the caudal vertebra between the vertebrae is the lower surface 14 (see FIG. 6). Many deep grooves are engraved on these contact surfaces so that bone fusion is good. In the center of the intervertebral spacer 10, a bone graft portion 19 for inserting bone grafts, hydroxyapatite, etc. is opened.

[0028] FIG. 6 shows a front view (A), a plan view (B), and a horizontal cross-sectional view (C) of the intervertebral spacer according to the present invention. The parts overlapping with FIG. 5 are omitted from the description. (C) is a horizontal cross-sectional view, and the gripping hole 18 is a hole for engaging with the tip of the gripping rod (not numbered) of the guide device 30.

[0029] FIG. 7 shows the system of Example 1 (upper row) and the conventional intervertebral spacer system described in Patent Document 1. ​​​​​​​​​​It is a schematic diagram showing a comparison with the tem (lower part). (A) shows the point where the intervertebral spacer 10 starts to move along the guide rule 38. It engages with the guide rail engaging portion 39 and rotates as shown in (B), and (C) shows the point where the placement at a predetermined position between the vertebrae is completed. The radius of curvature of the intervertebral spacer engaging portion 20 is R1. (D) shows the point where the conventional intervertebral spacer 24 starts to move along the conventional guide rail 46. It engages with the conventional intervertebral spacer engaging portion 47 and rotates as shown in (E), and (F) shows the point where the placement at a predetermined position between the vertebrae is completed. The radius of curvature of the engaging portion is R C The system of Example 1 of the present invention in the upper part turns more easily than the conventional intervertebral spacer system in the lower part. Therefore, the comparison of the widths l1, l2, l3 and L1, L2, L3 from the guide rail shows l1 < L1, l2 < L2, l3 < L3. When using the system of Example 1 of the present invention even in the PLIF surgical procedure, the boomerang-shaped intervertebral spacer can be easily and accurately inserted into a predetermined position between the vertebrae.

[0030] Figure 8 is a schematic diagram showing a comparison between the system of Example 1 (upper part) and the system of Example 2 (lower part) according to the present invention. (A), (B), and (C) in the upper part are the same figures as (A), (B), and (C) in the upper part of Figure 7. The vertical position of the center of curvature O1 of the engaging portion in the upper part is the same as the vertical position of the center of curvature O2 of the ventral surface 15. In the system of Example 2 in the lower part, the center of curvature O1 of the intervertebral spacer engaging portion 20 and the center of curvature O2 of the ventral surface 16 are not concentric, and the position of O1 is shifted d towards the tip side. Since the width from the guide rail is l1' = l1, l2' < l2, l3' < l3, the implementation ​​​​​​​​​​​Compared with the system of Example 1, the system of Example 2 can more easily insert the boomerang-shaped intervertebral spacer at a predetermined position between the vertebrae in the PLIF surgical procedure.

[0031] FIG. 9 is a schematic diagram showing the position where the first intervertebral spacer 10 is inserted by the system according to the present invention. In the order from (A) to (B), from (B) to (C), and from (C) to (D), the intervertebral spacer 10 is inserted between the vertebrae and installed at a predetermined position.

[0032] FIG. 10 shows the state where the second intervertebral spacer 10 is successively installed following FIG. 9. From this figure, it can be seen that the first and second intervertebral spacers 10 are easily and accurately installed at a predetermined position between the vertebrae using the PLIF surgical procedure.

[0033] FIG. 11 schematically shows a system in which a stopper 41 is attached to a guide instrument 40 in the system of Example 3 according to the present invention. (A) shows the state where the first intervertebral spacer 10 is inserted, and (B) shows the state where the second intervertebral spacer 10 is inserted. In (A), the intervertebral spacer 10 is locked to the tip of the guide rail 40, and the push rod tip portion 37 is pressing the rear end surface 12 of the intervertebral spacer 10. A stopper 41 is formed at a predetermined position of the guide rail 40, and the stopper 41 is hooked on the upper surface of the intervertebral joint 6. This stopper 41 can prevent the guide rail 40 from protruding beyond the vertebra 1. (B) shows the state where the second intervertebral spacer 10 is inserted. The guide rail 40 used in (A) is replaced with a guide rail 42. A stopper 41 is also formed at a predetermined position of the guide rail 42. The stopper 43 is formed, but it is formed on the tip side rather than the stopper 41. This is to prevent accidentally pressing the first intervertebral spacer 10.

[0034] Fig. 12 schematically shows a specific example of the engagement state between the intervertebral spacer 10 and the guide rail engaging portion 39. In (A-1) of Fig. 12, the cross-section of the guide rail engaging portion 39 has a T-shaped convex shape, and the cross-section of the corresponding intervertebral spacer engaging portion has a T-shaped concave shape. In (A-2), it is the opposite. (A-2) shows the reverse.

[0035] In (B-1) and (B-2) of Fig. 12, the engagement structure is a groove, and in (C-1) and (C-2) of Fig. 12, the engagement structure is a ball-and-socket relationship. These engagements each have their respective characteristics. The T-shaped and grooved shapes have the characteristics of being advantageous in processing cost and enabling reliable retention, and the ball-socket shape has good slidability. In the ball-socket shape, the slidability is improved.

[0036] Fig. 12 (D) is a modification of Fig. 12 (A-1), and the height of the guide rail engaging portion 39 is extremely small compared to the height of the ventral surface of the intervertebral spacer, and even in a narrow region between vertebrae, the intervertebral spacer 10 can be more easily and accurately installed at a predetermined position.

Industrial Applicability

[0037] The system according to this invention is a simple system, and even in a narrow surgical field, the intervertebral spacer can be easily and accurately installed at a predetermined position between vertebrae by a PLIF surgical procedure.

Explanation of Reference Numerals

[0038] 1: Vertebra​​​ 2: Intervertebral disc 3: Spinous process 4: Transverse process 5: Vertebral arch 6: Zygapophysis 7: Spinal canal 10: Intervertebral spacer 11: Front end face 12: Rear end face 13: Upper face 14: Lower face 15: Ventral groove 16: Ventral surface 17: Dorsal surface 18: Holding hole 19: Bone grafting part 20: Intervertebral spacer engaging part 23: Bottom face 24: Conventional intervertebral spacer 30: Guide instrument 31: Push rod 32: Head part 33: Rod part 34: Handle part 35: Push rod release button 36: Holding release button 37: Push rod tip part 38,40,42: Guide rail 39; Guide rail engaging part 41,43: Stopper 46: Conventional guide rail 47: Conventional guide rail engaging part 48: Conventional push rod O1: Center of curvature of intervertebral spacer engaging part O2: Center of curvature of ventral surface R1: Radius of curvature of intervertebral spacer engaging part R2: Radius of curvature of ventral surface R c : Radius of curvature of conventional guide rail engaging part

Claims

1. A system for treating spinal diseases, the system comprising: An intervertebral spacer that is horizontally curved and is used by being inserted between vertebrae between adjacent vertebrae, wherein: It includes a pair of abutting surfaces that abut against each of the said vertebrae, and connects the pair of abutting surfaces ventrally, and has a ventral surface that is a convex ventral side surface in plan view, wherein a ventral groove is formed in the ventral surface along the curved direction, and on the bottom surface of the ventral groove, an intervertebral spacer engaging portion having a radius of curvature smaller than the radius of curvature of the ventral surface of the intervertebral spacer is formed, and an intervertebral spacer; A guide device for guiding the intervertebral spacer to a predetermined position between the vertebrae, having a guide rail that is fitted with the intervertebral spacer engaging portion on the distal end side, and having a handle portion that an operator grips outside the patient's body on the proximal end side, and the radius of curvature in plan view of the guide rail engaging portion on the distal side of the guide rail is the same as the radius of curvature in plan view of the intervertebral spacer engaging portion, and a guide device. A system having the same.

2. The system according to claim 1, wherein the center of curvature in plan view of the intervertebral spacer engaging portion is eccentric toward the distal end side when the intervertebral spacer is inserted between the vertebrae, relative to the center of curvature in plan view of the ventral surface.

3. The system according to claim 1 or 2, wherein a stopper portion that catches on the facet joint is formed on the guide rail of the guide device.

4. The intervertebral spacer according to any one of claims 1 or 2.

5. The guide device according to claim 1.

6. The guide device according to claim 3. ​ ​ ​ ​ ​

Images