Systems for guiding intervertebral spacers between vertebrae

Abstract

A simple system is provided that can easily and accurately set an intervertebral spacer at a predetermined position between vertebrae even in a narrow surgical area. The system is a system for treating spinal diseases, and comprises: an intervertebral spacer that is inserted between vertebrae and is curved in a horizontal direction, the intervertebral spacer having: a convex ventral side surface having a pair of abutment surfaces that abut against each vertebrae, the abutment surfaces being connected on the ventral side; and a concave dorsal side surface that is connected on the dorsal side, a snap-fitting portion along the curved direction on the ventral side surface and / or the dorsal side surface, and a guide tool that guides the intervertebral spacer to a predetermined position between vertebrae, and a guide rail portion that is engaged with the snap-fitting portion of either the ventral side surface or the dorsal side surface on the distal end, the curvature radius of the guide rail portion when viewed from above being substantially the same as the curvature radius of the ventral side surface or the dorsal side surface when viewed from above.

Description

Technical Field

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

[0002] For example, in order to obtain bone healing based on PLIF (posterior path lumbar interbody fixation surgery), the use of intervertebral spacers is indispensable. By inserting a spacer as large as possible that is suitable for the shape between the vertebrae, the intervertebral space can be stabilized and a more secure fixation can be obtained. In addition, a large spacer is expected to be able to fill more transplanted bone, etc., which is believed to contribute to future intervertebral bone healing.

[0003] In the conventional unilateral intervertebral spacer insertion using a box-type intervertebral spacer by unilateral approach and unilateral intervertebral joint resection, there is a concern that intervertebral instability on the opposite side may remain, which may be detrimental to bone healing. In addition, in the bilateral box-type intervertebral spacer insertion by bilateral approach and bilateral intervertebral joint resection, intervertebral instability may be caused. In contrast, the insertion of the intervertebral spacer to the opposite side by unilateral approach and unilateral intervertebral joint resection, or the conventional dart-type intervertebral spacer insertion, is a reasonable method because it can support the opposite side while maintaining the intervertebral joint on the opposite side.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application No. 2012-532693

[0007] Patent Document 2: Japanese Patent Application No. 2016-512107

[0008] Patent Document 3: Japanese Patent Application No. 2019-517891 Summary of the invention

[0009] Problems to be solved by the invention

[0010] When inserting an intervertebral spacer between vertebrae, Figure 1 The fiber ring of the intervertebral plate 2 between the vertebral bodies 1 shown is opened to remove the nucleus pulposus inside, and an intervertebral spacer is inserted between the removed vertebral bodies. Since the spinal nerve system and blood vessels pass near the intervertebral plate 2, careful attention is required during the operation.

[0011] The spine is responsible for supporting the body weight, so the intervertebral spacer is required to cover a large area between the vertebrae with high rigidity. In addition, the surgical field is narrow, with the nervous system and blood vessels passing nearby, so it is necessary to install the intervertebral spacer at an appropriate position while avoiding them and requiring a surgical system.

[0012] As described above, the conventional insertion of a dart-type intervertebral spacer is a method of supporting the intervertebral joint on the opposite side while maintaining the intervertebral joint on the opposite side. However, when inserting the intervertebral spacer to the opposite side, it is necessary to use a fluoroscopic device during surgery or to have a high level of technology.

[0013] In addition, the size of the intervertebral spacer that can be inserted through a narrow insertion port is limited in the conventional intervertebral spacer. Therefore, flexible intervertebral spacers and insertion devices that change direction inside the intervertebral body have been developed, but many systems are structurally complex or have the associated fragility, and few systems can be put into practical use.

[0014] In the system described in Patent Document 1, intervertebral spacers are connected to each other by a flexible bridge. The intervertebral spacer is placed in an insertion tube and inserted through the insertion tube to be arranged between vertebrae. The structure of the intervertebral spacer is complicated, and the rigidity of the intervertebral spacer is reduced. In addition, in the disclosed embodiment, the insertion instrument has a guide rail for guiding the bottom surface of the intervertebral spacer and a guide rail for guiding the bottom surface, upper surface and side surface, so there is a problem in guiding the intervertebral spacer in a narrow surgical area.

[0015] In the system described in Patent Document 2, the intervertebral spacer has an expandable function. It is a system in which the intervertebral spacer is set between the vertebrae using an instrument in a non-expanded state, and then the intervertebral spacer is expanded between the vertebrae. The intervertebral spacer has a large number of parts connected by pins, etc., and the structure is complex and the rigidity is reduced. In addition, after the intervertebral spacer is set between the vertebrae in a non-expanded state, the intervertebral spacer must be expanded, so the system is complex and requires high skills of the doctor during the operation.

[0016] In the system described in Patent Document 3, the intervertebral spacer is a one-piece rigid body. The instrument for installing the intervertebral spacer has a gripping portion for gripping a pin provided in the intervertebral spacer, and the surgeon must install the intervertebral spacer while adjusting the orientation of the intervertebral spacer in a narrow surgical area, which makes surgery difficult.

[0017] An object of the present invention is to provide a simple system that can easily and accurately place an intervertebral spacer at a predetermined position between vertebral bodies even in a narrow surgical area.

[0018] Means of solving problems

[0019] The system of the present invention (1) is a system for treating spinal diseases, characterized in that the system includes: an intervertebral spacer that is inserted between vertebrae and is curved in a horizontal direction, the intervertebral spacer having: a ventral side surface, which has a pair of abutment surfaces that abut against each of the vertebrae, the ventral side surface being connected to the pair of abutment surfaces on the ventral side and being a convex ventral side surface when viewed from above; and a dorsal side surface, which is connected to the pair of abutment surfaces on the dorsal side and is a concave dorsal side surface when viewed from above, the ventral side surface and / or the dorsal side surface having an engaging portion along the direction of the curvature, and a guiding device that guides the intervertebral spacer to a specified position between the vertebrae, the distal end having a guide rail portion that is engaged with the engaging portion of either the ventral side surface or the dorsal side surface, the curvature radius of the guide rail portion when viewed from above being substantially the same as the curvature radius of the ventral side surface or the dorsal side surface when viewed from above,

[0020] One of the cross sections of the engagement portion and the rail portion is a concave shape, and the other is a convex shape corresponding to the concave shape, wherein the concave shape has a portion with a maximum width wider than an opening width of the concave shape facing the convex shape.

[0021] In the system of the present invention (1), the ventral side and / or dorsal side of the intervertebral spacer are provided with a snap-fitting portion along the direction of the curvature. The distal end of the guide device is provided with a guide rail portion that engages with the snap-fitting portion of either the ventral side or the dorsal side. The radius of curvature of the guide rail portion when viewed from above is substantially the same as the radius of curvature of the ventral side or the dorsal side when viewed from above, so that the intervertebral spacer can be moved along the guide rail portion. As long as the guide device is set at a specified position, the intervertebral spacer can be accurately and easily guided to a specified appropriate position between the vertebrae.

[0022] If the present system is used, for example, in the case of insertion from the TLIF (transforaminal lumbar interbody fixation) method, the dura mater is turned approximately in the center and inserted from the outer edge of the intervertebral spacer in a manner that it is connected to the front edge and the outer edge of the opposite side. By inserting the intervertebral spacer along the guide rail portion of the guide tool pre-set between the vertebrae, the intervertebral spacer can be safely, more accurately and easily inserted to the optimal position on the opposite side.

[0023] The present invention (2) is the system of the present invention (1), characterized in that the lateral width of the guide rail portion is less than the height of the ventral side surface and / or the dorsal side surface of the intervertebral spacer. Thus, by making the lateral width of the guide rail portion less than the height of the ventral side surface and / or the dorsal side surface of the intervertebral spacer, the intervertebral spacer can be smoothly placed at a predetermined position between vertebrae even in a narrow surgical area.

[0024] The present invention (3) is the system of the present invention (1) or (2), characterized in that the cross-section of the engaging portion is a T-shaped concave shape, and the cross-section of the guide rail portion is a T-shaped convex shape.

[0025] In the present invention (3), the cross section of the engaging portion on the intervertebral spacer side is a T-shaped concave shape, and the cross section of the guide rail portion is a T-shaped convex shape, so the intervertebral spacer can be guided along the convex track of the guide rail portion and easily set at a specified position between vertebrae.

[0026] The present invention (4) is the system of the present invention (1) or (2), characterized in that the cross-section of the engaging portion is a convex T-shaped shape, and the cross-section of the guide rail portion is a concave T-shaped shape.

[0027] In the present invention (4), in contrast to the present invention (3), the cross-section of the engaging portion on the intervertebral spacer side is a convex T-shaped shape, and the cross-section of the guide rail portion is a concave T-shaped shape, so that the intervertebral spacer can be guided along the concave track of the guide rail portion and easily set at a specified position between the vertebrae.

[0028] The present invention (5) is an intervertebral spacer, characterized in that it is the intervertebral spacer according to any one of the present inventions (1) to (4). By using such an intervertebral spacer, the intervertebral spacer can be accurately and easily installed at a predetermined position between vertebral bodies.

[0029] The present invention (6) is a guide tool, characterized in that it is the guide tool according to any one of the present inventions (1) to (4). By using such a guide tool, an intervertebral spacer can be accurately and easily installed at a predetermined position between vertebral bodies.

[0030] Effects of the Invention

[0031] According to the system of the present invention, the system is simple, and therefore the intervertebral spacer can be easily and accurately placed at a predetermined position between vertebral bodies even in a narrow surgical area. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a side view showing the spine (lumbar vertebrae).

[0033] Figure 2 This is a three-dimensional diagram showing that a guide tool is installed between vertebral bodies.

[0034] Figure 3 It is a perspective view showing Example 1 of the intervertebral spacer of the present invention.

[0035] Figure 4 1 and 2 are a plan view, a medial side view, a lateral side view, and a ventral side view showing a first embodiment of the intervertebral spacer of the present invention.

[0036] Figure 5 It is a perspective view showing a second embodiment of the guide tool of the present invention.

[0037] Figure 6 It is a top view showing Example 2 of the guide tool of the present invention.

[0038] Figure 7 It is a perspective view showing a third embodiment of the guide tool of the present invention.

[0039] Figure 8 It is a top view showing Example 3 of the guide tool of the present invention.

[0040] Fig. 9 The figure schematically shows a state where the intervertebral spacer of the present invention is engaged with the inner periphery of the guide rail portion of the guide tool of Example 2 and the ventral side surface of the intervertebral spacer, and two intervertebral spacers are symmetrically arranged between vertebral bodies.

[0041] Fig.10 The figure schematically shows a state where the intervertebral spacer of the present invention is engaged with the inner periphery of the guide rail portion of the guide tool of Example 3 and the dorsal surface of the intervertebral spacer, and two intervertebral spacers are symmetrically arranged between vertebral bodies.

[0042] Fig.11 This is a specific example schematically showing the engagement state of the intervertebral spacer and the guide rail portion of the guide tool in the system of the present invention. DETAILED DESCRIPTION

[0043] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, up and down refer to the up and down of the drawings. The "up and down" is a name for convenience, and when set, sometimes the up and down are reversed or horizontal.

[0044] Figure 2 The schematic diagram shows a state where the guide rail portion 31 provided with the guide tool 30 is inserted between the vertebral bodies between the head side vertebral body 1A and the caudal side vertebral body 1B as viewed from the ventral side. The operator grasps and inserts the gripping portion 32. In fact, since the vertebral bodies between the head side vertebral body 1A and the caudal side vertebral body 1B are surrounded by a tissue called annulus fibrosus, it cannot be observed from the ventral side, but in order to understand the setting state, the annulus fibrosus is omitted for illustration.

[0045] Figure 3The present invention is a stereoscopic view of the embodiment 1 of the intervertebral spacer as viewed from the ventral side. The upper surface 13 abuts against the caudal side of the cranial vertebra 1A, and the lower surface 14 abuts against the cranial side of the caudal vertebra 1B. The lateral surface 11 and the medial surface 12 are located at both ends along the central axis CL. The overall shape is a convex shape that is curved ventrally. The ventral side surface is the ventral side surface 17, and the concave side surface is the dorsal side surface 18. Grooves are engraved on the upper surface 13 and the lower surface 14 for firmly connecting the cranial vertebra 1A and the caudal vertebra 1B, respectively, but in the embodiment of the present invention, the ... arranged on the upper surface 13 and the lower surface 14. Figure 3 In the diagram, these slots are omitted.

[0046] The intervertebral spacer 10 of Example 1 is provided with two holes penetrating the upper surface 13 and the lower surface 14, and the two holes are separated by the middle part 15. These holes are called bone graft parts 16, which are used to fill the patient's autologous bone, artificial bone or other materials with high bone affinity. Figure 3 The ventral side surface 17 is formed with an engaging portion 20 for engaging with a guide tool described later. The number of these holes is not limited to two, and in the present invention, these holes are not essential, and the intervertebral spacer may be without holes.

[0047] Figure 4 A plan view, a medial side view, a lateral side view, and a ventral side view of Example 1 of the intervertebral spacer 10 are shown. Figure 4 (A) is the top view, Figure 4 (B) is the medial side view. Figure 4 (C) is the lateral view. Figure 4 (D) is a ventral side view. In the figure, H1 is the height of the ventral side 17, and H2 is the height of the dorsal side 18.

[0048] Figure 5 A perspective view showing a guide tool 30 according to Embodiment 2, Figure 6 FIG. 2 is a top view of a guide tool 30 according to Example 2. The guide tool 30 includes a rail portion 31 that engages with the engagement portion 20 of the intervertebral spacer 10 and a grip portion 32 that is gripped by the operator. Figure 6 , a state in which the engaging portion 20 formed on the ventral side surface 17 of the intervertebral spacer 10 is engaged with the guide rail portion 31 is shown. Figure 5 W in ? is the lateral width of the guide rail portion 31 .

[0049] Figure 7 A perspective view showing a guide tool 30 according to Embodiment 3, Figure 8 FIG. 2 is a top view of a guide tool 30 according to Example 3. The guide tool 30 includes a rail portion 31 that engages with the engagement portion 20 of the intervertebral spacer 10 and a grip portion 32 that is gripped by the operator. Figure 8 , a state in which the engaging portion 20 formed on the dorsal surface 18 of the intervertebral spacer 10 is engaged with the guide rail portion 31 is shown. Figure 7W in ? is the lateral width of the guide rail portion 31 .

[0050] Fig. 9 The following schematically shows the steps of installing two intervertebral spacers 10 between vertebral bodies using the guide tool 30 of the second embodiment. Fig. 9 In (A), the guide tool 30 is set at a predetermined position, avoiding the nerve 3. Fig. 9 In (B), the engaging portion 20 of the ventral side surface 17 on the lateral side 11 of the intervertebral spacer 10 is engaged with the guide rail portion 31. Fig. 9 In (C), the inner side 12 is pressed with a push rod (not shown) and the intervertebral spacer 10 is inserted along the guide rail 31. Fig. 9 In (D), the first intervertebral spacer 10 is installed at a predetermined position.

[0051] Afterwards, in Fig. 9 In (E), the guide tool 30 is pulled out, and a new guide tool 30 having a shorter guide rail portion 31 is set at a predetermined position between the vertebral bodies. Fig. 9 In (F), the engaging portion 20 of the ventral side surface 17 on the inner side surface 12 of the intervertebral spacer 10 is engaged with the guide rail portion 31. Fig. 9 In (G), the outer side 11 is pressed with a push rod (not shown) and the intervertebral spacer 10 is inserted along the guide rail 31. Fig. 9 In (H), the second intervertebral spacer 10 is set at a predetermined position, and the guide tool 30 is pulled out.

[0052] The guide rail portion 31 of the second embodiment is provided in contact with the annulus fibrosus of the intervertebral disc located on the ventral side between the vertebral bodies, thereby forming a ventral wall, and preventing the intervertebral spacer from penetrating the annulus fibrosus and falling out from the vertebral bodies to the ventral side.

[0053] Fig.10 The procedure of installing two intervertebral spacers 10 between vertebral bodies using the guide tool 30 of Example 3 is schematically shown. The guide tool 30 of Example 3 is different from the guide tool 30 of Example 2 in that it engages with the engaging portion 20 formed on the dorsal side surface 18 of the intervertebral spacer 10. Thus, the nerve 3 is protected by the guide tool 30.

[0054] Fig.11 1 is a diagram schematically showing a specific example of the engagement state between the intervertebral spacer 10 and the guide rail portion 31 of the guide tool 30. Fig.11 In (A-1), the cross section of the guide rail portion 31 is a convex T-shaped shape, and the cross section of the engaging portion 20 of the intervertebral spacer 10 facing it is a concave T-shaped shape. Fig.11 In (A-2), it is the opposite.

[0055] Fig.11 (B-1) and Fig.11 The engagement structure of (B-2) is a dovetail groove. Fig.11 (C-1) and Fig.11 The engagement structure (C-2) is the relationship between the ball and the socket. The engagement has its own characteristics. The T-shaped and dovetail groove shapes have the characteristics of being cost-effective and reliably maintained, and the ball-socket shape has good sliding properties.

[0056] Fig.11 (D) Yes Fig.11 In the modification (A-1), the lateral width of the guide rail portion 31 is extremely smaller than the height of the ventral and / or dorsal surfaces of the intervertebral spacer, and the intervertebral spacer 10 can be easily and accurately set at a predetermined position even in a narrow area between vertebrae.

[0057] This international application claims the benefit of priority based on Japanese Patent Application No. 2019-157595, filed on August 30, 2019, the entire contents of which are hereby incorporated by reference.

[0058] Industrial Applicability

[0059] The system of the present invention is a simple system, and by using the system, an intervertebral spacer can be easily and accurately placed at a predetermined position between vertebral bodies even in a narrow surgical area.

[0060] Explanation of symbols

[0061] 1: Vertebrae

[0062] 1A: Cephalad vertebra

[0063] 1B: Caudal vertebra

[0064] 2: Intervertebral disc

[0065] 3. Nerve

[0066] 10: Intervertebral spacer

[0067] 11: Outer side

[0068] 12: Inner side

[0069] 13: Upper surface

[0070] 14: Lower surface

[0071] 15: Middle

[0072] 16: Bone transplantation department

[0073] 17: Ventral side

[0074] 18: back side

[0075] 20: snap-fit ​​part

[0076] 30: Guidance Device

[0077] 31: Guide rail

[0078] 32:Handling part

Claims

1. A system for treating spinal diseases, characterized in that: The system includes: An intervertebral spacer that is inserted between vertebral bodies and is curved in a horizontal direction, the intervertebral spacer comprising: a ventral side surface having a pair of abutting surfaces that abut against each of the vertebral bodies, the ventral side surface being connected to the pair of abutting surfaces on the ventral side and being a convex ventral side surface when viewed from above; and a dorsal side surface that is connected to the pair of abutting surfaces on the dorsal side and is a concave dorsal side surface when viewed from above, the ventral side surface and / or the dorsal side surface having an engaging portion along the curved direction, and A guide device guides the intervertebral spacer to a predetermined position between the vertebral bodies, and has a guide rail portion at the distal end thereof that engages with the engaging portion of either the ventral side or the dorsal side, wherein the curvature radius of the guide rail portion when viewed from above is substantially the same as the curvature radius of the ventral side or the dorsal side when viewed from above, One of the cross sections of the engagement portion and the rail portion is a concave shape, and the other is a convex shape corresponding to the concave shape, wherein the concave shape has a portion with a maximum width wider than an opening width of the concave shape facing the convex shape.

2. The system according to claim 1, characterized in that The lateral width of the guide rail portion is less than the height of the ventral surface and / or the dorsal surface of the intervertebral spacer.

3. The system according to claim 1 or 2, characterized in that: The cross section of the engaging portion is a concave T-shaped shape, and the cross section of the rail portion is a convex T-shaped shape.

4. The system according to claim 1 or 2, characterized in that: The cross section of the engaging portion is a convex T-shaped shape, and the cross section of the rail portion is a concave T-shaped shape.

5. An intervertebral spacer, which is inserted between vertebral bodies and bent in the horizontal direction, characterized in that: The intervertebral spacer comprises: A pair of abutment surfaces abutting against each of the vertebral bodies; a ventral side surface that connects the pair of abutting surfaces on the ventral side and is a convex ventral side surface in a plan view; and The dorsal side surface is a dorsal side surface that connects the pair of abutting surfaces on the dorsal side and is concave in a plan view, and has an engaging portion along the curved direction on the ventral side surface and / or the dorsal side surface.

6. A guiding tool for guiding the intervertebral spacer according to claim 5 to a predetermined position between vertebral bodies, characterized in that: The guide tool has a rail portion at the distal end thereof that engages with an engaging portion of either the ventral side or the dorsal side of the intervertebral spacer, and a curvature radius of the rail portion in a plan view is substantially the same as a curvature radius of the ventral side or the dorsal side in a plan view.

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