Laminoplasty plate and laminoplasty implant device

Abstract

To stably hold a vertebral arch in accordance with the skeletal shape of a patient in laminoplasty.SOLUTION: Provided is a laminoplasty plate 1 for maintaining an interval between divided vertebral arches that includes: a plate-shaped main body portion having a longitudinal direction; and a spacer protrusion 30 protruding from the main body portion 10; wherein the main body portion 10 includes a substantially flat plate-shaped first fixing portion 11 provided on one end portion side in the longitudinal direction and fixed to one of the divided vertebral arches by a predetermined fixing tool 50, a substantially flat plate-shaped second fixing portion 12 provided on the other end portion side in the longitudinal direction and fixed to the other of the divided vertebral arches by a predetermined fixing tool 50, and a substantially plate-shaped connection plate portion 13 connecting the first fixing portion 11 and the second fixing portion 12, and the main body portion 10 has a configuration in which a thickness of a portion closer to the one end portion side in the longitudinal direction than a plate thickness changing position P1 located in the middle of the connection plate portion 13 is smaller than a thickness of a portion closer to the other end portion side in the longitudinal direction than the plate thickness changing position P2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to laminoplasty plates and laminoplasty implant devices for use in laminoplasty procedures to maintain spacing between vertebrae. [Background technology]

[0002] Laminoplasty is one of the treatments for spinal disorders. Various implant devices have been proposed for laminoplasty, which are inserted between the divided vertebrae and act as artificial bone.

[0003] For example, as one type of implant device for vertebral arch formation, a plate has been proposed which includes a spacer portion having a length equal to the gap between divided spinal lamina, a first end formed integrally with the spacer portion and having a first concave surface that can be abutted against one of the separated surfaces of the divided spinal lamina, and a second end formed integrally with the spacer portion and having a second concave surface that can be abutted against the other separated surface of the divided spinal lamina (Patent Document 1).

[0004] However, there are individual differences in the shape of the divided vertebral arch (skeletal shape) of patients undergoing laminoplasty, and it may be difficult to stably fix the implant device during laminoplasty. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-142657 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above-mentioned problems, an object of the present invention is to provide a laminoplasty plate and a laminoplasty implant device that enable stable retention of the vertebral arch in accordance with the skeletal shape of the patient during laminoplasty. [Means for solving the problem]

[0007] The present invention provides a laminoplasty plate and laminoplasty implant device, characterized in that the thickness of the portion of the main body portion that is located on one end of the connecting plate in the longitudinal direction and that is closer to one end of the longitudinal direction than the thickness change position is smaller than the thickness of the portion of the main body portion that is closer to the other end of the longitudinal direction than the thickness change position. [Effects of the Invention]

[0008] According to the present invention, during laminoplasty, it is possible to stably hold the vertebral arch in accordance with the skeletal shape of the patient. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of a laminoplasty implant device. [Figure 2] FIG. 1 is a schematic perspective view showing the configuration of a laminoplasty plate. [Figure 3] FIG. 10 is an explanatory diagram showing the fixed state of the laminoplasty implant device. [Figure 4] FIG. 2 is an enlarged side view showing the configuration of the main body of the laminoplasty plate. [Figure 5] FIG. 1 is an explanatory diagram showing the laminoplasty plate in use. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] Fig. 1 is a side view of laminoplasty implant device 100 (laminoplasty implant device including laminoplasty plate 1 and fixture 50). Fig. 2 is a schematic perspective view showing the configuration of laminoplasty plate 1. Fig. 3 is an explanatory diagram showing the fixed state of laminoplasty implant device 100.

[0012] Laminoplasty implant device 100 is used in laminoplasty. As shown in Figures 1 to 3, laminoplasty implant device 100 includes laminoplasty plates 1 that are fixed to each of a person's vertebral arches that have been divided by surgery or the like, and fixtures 50 for fixing laminoplasty plates 1 to each of the vertebral arches.

[0013] Both the laminoplasty plate 1 and the fixture 50 are made of titanium alloy Ti-6Al-4V ELI. However, the material of the laminoplasty plate 1 and the fixture 50 is not limited to titanium alloy Ti-6Al-4V ELI, and any suitable material compatible with the human body can be used.

[0014] 1 and 3, fixture 50 has a shaft portion 51 and a head portion 52 provided on the base end side of shaft portion 51. In this embodiment, fixture 50 is a so-called screw having a spiral groove along the surface of a cylinder or a cone, and head 52 of fixture 50 has a cross or hexagonal hole formed therein, and shaft portion 51 has a screw thread formed on the outer circumferential surface.

[0015] The axial length of the shaft portion 51 can be within a range of 4.0 mm to 10.0 mm, and preferably within a range of 5.00 mm to 7.00 mm. The outer diameter of the shaft portion 51 can be within a range of 2.6 mm to 3.0 mm. The axial length and outer diameter of the shaft portion 51 can be selected appropriately according to the skeletal shape of the patient.

[0016] 1 to 3, laminoplasty plate 1 is a member that is fixed to each of the two divided human vertebral arches with fixing devices 50, thereby being interposed between the two divided vertebral arches and maintaining the distance between the vertebral arches. In other words, laminoplasty plate 1 serves as an artificial bone.

[0017] The laminoplasty plate 1 has a plate-shaped main body 10 having a longitudinal direction and spacer projections 30 protruding from the main body 10. Furthermore, one of the main surfaces of the main body 10 becomes the surface facing (contacting) the vertebral arch when fixed to the vertebral arch (hereinafter sometimes referred to as the "rear surface"), and the surface facing the rear surface becomes the surface facing the outside of the vertebral arch (hereinafter sometimes referred to as the "front surface"). Furthermore, hereinafter, the longitudinal dimension of the main body 10 will be simply referred to as the "length," and the lateral dimension of the main body 10 will be simply referred to as the "width."

[0018] The main body portion 10 has a first fixing portion 11 which is approximately flat and is provided at one end side in the longitudinal direction and fixed to one of the divided vertebral arches, a second fixing portion 12 which is approximately flat and is provided at the other end side in the longitudinal direction and fixed to the other of the divided vertebral arches, a connecting plate portion 13 which is approximately flat and connects the first fixing portion 11 and the second fixing portion 12, a first curved plate portion 14 which is provided between the first fixing portion 11 and the connecting plate portion 13, and a second curved plate portion 15 which is provided between the second fixing portion 12 and the connecting plate portion 13. 1, the straight portion in side view at one end (left side in FIG. 1) is first fixing portion 11, the curved portion in side view continuing from the other end (right side in FIG. 1) of first fixing portion 11 is first curved plate portion 14, the straight portion in side view (the portion whose upper surface is straight in side view at least) continuing from the other end (right side in FIG. 1) of first curved plate portion 14 is connecting plate portion 13, the curved portion in side view continuing from the other end (right side in FIG. 1) of connecting plate portion 13 is second curved plate portion 15, and the straight portion in side view continuing from the other end (right side in FIG. 1) of second curved plate portion 15 is second fixing portion 12. Also, most of connecting plate portion 13 is thick connecting plate portion 13c, and thin connecting plate portion 13b is provided on one end (left side in FIG. 1), with inclined surface 13a provided therebetween.

[0019] The first curved plate portion 14 and the second curved plate portion 15 are each curved in the thickness direction of the main body portion 10, and are curved in opposite directions to each other. Specifically, the first curved plate portion 14 is curved toward the back surface of the main body portion 10 from the connecting plate portion 13 toward the first fixing portion 11 (a mountain fold when viewed from the front surface), whereas the second curved plate portion 15 is curved toward the front surface of the main body portion 10 from the connecting plate portion 13 toward the second fixing portion 12 (a valley fold when viewed from the front surface).

[0020] 2, at least one fixing hole 20 is formed in each of the first fixing portion 11 and the second fixing portion 12. In this embodiment, two fixing holes 20 are formed in each of the first fixing portion 11 and the second fixing portion 12. The fixing holes 20 are through holes for passing the shaft portion 51 of the fixing tool 50 therethrough.

[0021] Each fixing hole 20 is defined by a circular opening end 20a formed in each of the first fixing portion 11 and the second fixing portion 12. Each fixing hole 20 is a countersunk hole (countersink), and the front surface side of the opening end 20a is chamfered into a conical shape. That is, the front surface side portion of the opening end 20a has an inverted truncated cone shape with a diameter that decreases from the front surface to the back surface. Furthermore, because each fixing hole 20 is a countersunk hole, the fixing device 50 can be guided to an appropriate position and orientation, and the head 52 of the fixing device 50 can be prevented from protruding too far outward.

[0022] In this embodiment, the two fixing holes 20 formed in the first fixing portion 11 are arranged side by side in the longitudinal direction of the main body portion 10. The two fixing holes 20 formed in the second fixing portion 12 are arranged side by side in the short side direction (width direction) of the main body portion 10. In other words, the two fixing holes 20 on the first fixing portion 11 side and the two fixing holes 20 on the second fixing portion 12 side are arranged so that the lining directions differ by 90° in plan view.

[0023] The outer contours of first fixing portion 11 and second fixing portion 12 are shaped as if two connected (joined) ring-shaped portions around fixing hole 20. Therefore, the outer contours of first fixing portion 11 and second fixing portion 12 are configured to be compact, with no portions protruding more than necessary.

[0024] 3, each of the first fixing portion 11 and the second fixing portion 12 is fixed to each vertebral arch by a fixing device 50. Here, the user (practitioner) of the laminoplasty implant device 100 can select one or more appropriate fixing holes 20 from the two fixing holes 20 based on the shape of the patient's vertebral arch, and then pass the fixing device 50 through the selected fixing holes 20 to fix them. For example, the fixing device 50 can be passed through both of the two fixing holes 20 to fix the laminoplasty plate 1 to each vertebral arch at a total of four locations.

[0025] 1 and 3, the spacer protrusion 30 is a protrusion that protrudes from one of the main surfaces (the back surface in this embodiment) of the main body 10. The spacer protrusion 30 is provided to abut against each of the two halves of a divided human vertebral arch, thereby maintaining the positional relationship between the laminoplasty plate 1 as an artificial bone and each vertebral arch.

[0026] The spacer protrusion 30 of this embodiment has two spacer protrusions 30a and 30b arranged at a predetermined distance from each other. Each of the spacer protrusions 30a and 30b is provided on the back surface of the connecting plate portion 13. That is, the spacer protrusions 30a and 30b are provided between the first curved plate portion 14 and the second curved plate portion 15.

[0027] One spacer protrusion 30a is arranged at one end side of the longitudinal direction of the connecting thick plate portion 13c of the connecting plate portion 13, and the other spacer protrusion 30b is arranged at the other end side of the longitudinal direction of the connecting plate portion 13 (near the second curved plate portion 15).

[0028] The spacer protrusions 30a are formed to extend substantially perpendicular to the rear surface of the connecting plate portion 13. The tip of the spacer protrusions 30a is tapered. The tapered portion of the spacer protrusions 30a can be approximately one-half to one-third of the protruding height when viewed from the tip side of the spacer protrusions 30a, and the tip is curved so that the thinnest part is approximately one-third to one-half of the thickest part. The spacer protrusions 30a are formed so that the protruding height is greater than the thickness and width. Specifically, the length of the spacer protrusions 30a is formed to be 1.5 times or more, or two times or more, the thickness and width.

[0029] The spacer protrusion 30b is formed to extend substantially perpendicular to the second fixed portion 12. The side surface on the other end side of the spacer protrusion 30b is curved so as to be continuous with the rear surface of the second fixed portion 12 at the base end of the spacer protrusion 30b.

[0030] As shown in Figure 3, when the laminoplasty plate 1 and each vertebral arch are fixed, the spacer protrusions 30a and 30b abut against each vertebral arch, thereby maintaining the positional relationship between the laminoplasty plate 1 and each vertebral arch. In other words, the relative positions of each vertebral arch can be maintained. In this way, the relative positions of each vertebral arch are fixed by the spacer protrusions 30a and 30b, so the positions of each vertebral arch can be stabilized.

[0031] Fig. 4 is an enlarged view showing the configuration of the main body 10 of the laminoplasty plate 1. Fig. 5 is an explanatory view showing the laminoplasty plate 1 in use (in use during laminoplasty).

[0032] As shown in Figures 1 and 4, the thickness T1 of the portion (thin plate portion) 10a of the main body 10 on one end side in the longitudinal direction of the plate thickness change position P1 located halfway along the connecting plate portion 13 is smaller than the thickness T2 of the portion (thick plate portion) 10b on the other end side in the longitudinal direction of the plate thickness change position P1.

[0033] With this configuration, as shown in FIG. 5, one end of the laminoplasty plate 1 can be deformed (bended) using Kocher forceps or the like while the other end of the laminoplasty plate 1 is fixed with a fixture 50 so that the laminoplasty plate 1 fits the vertebral arch. Therefore, the angle of the laminoplasty plate 1 (first fixing portion 11) can be adjusted to an appropriate angle to match the patient's skeletal shape. Thus, the present invention can accommodate individual differences in the skeletal shapes of patients undergoing laminoplasty and stably fix the implant device during laminoplasty. In other words, the laminoplasty plate 1 of the present invention can stably hold the vertebral arch in accordance with the patient's skeletal shape.

[0034] Returning to FIG. 4, the plate thickness changing position P1 is located closer to one end than the center in the longitudinal direction of the connecting plate portion 13. Therefore, at least the second fixing portion 12 and the second curved plate portion 15 become thick plate portions 10b. Furthermore, more than half of the longitudinal direction of the connecting plate portion 13 becomes thick plate portions 10b, and less than half of the longitudinal direction becomes thin plate portions 10a. In this way, because more than half of the longitudinal direction of the laminoplasty plate 1 becomes thick plate portions 10b, it is possible to ensure the strength, rigidity, durability, etc. of the second fixing portion 12, the second curved plate portion 15, and the connecting plate portion 13 (the other end side of the plate thickness changing position P1 in the main body portion 10).

[0035] In this embodiment, when the overall longitudinal length of the connecting plate portion 13 is taken as 1, the plate thickness change position P1 (i.e., the length of the thin connecting plate portion 13b in the connecting plate portion 13) can be located within a range of 1 / 3 of the length from one end of the connecting plate portion 13, and is preferably located within a range of 1 / 4 of the length from one end of the connecting plate portion 13. In this case, the proportion of the thick plate portion 10b in the connecting plate portion 13 becomes greater than half (2 / 3 or 3 / 4), so that the strength, rigidity, durability, etc. of the connecting plate portion 13 can be ensured at a higher level.

[0036] Furthermore, in this embodiment, the plate thickness changing position P1 is located closer to one end than the spacer protrusion 30. That is, the spacer protrusion 30 is disposed in the thick plate portion 10b of the main body portion 10. This ensures the strength, rigidity, durability, etc. of the base end of the spacer protrusion 30, and allows the laminoplasty plate 1 to be reliably fixed to each vertebral arch.

[0037] The upper limit of the thickness T1 of the portion (thin portion) 10a of the main body 10 located on one longitudinal end side of the thickness change position P1 can be 2 / 3 or less, preferably 3 / 5 or less, and can also be 1 / 2 or less, of the thickness T2 of the portion (thick portion) 10b located on the other longitudinal end side of the thickness change position P1. Furthermore, the lower limit of the thickness T1 of the thin portion 10a can be 2 / 5 or more, and can also be 1 / 2 or more, of the thickness T2 of the thick portion 10b. This facilitates deformation of the one end side (thin portion) of the laminoplasty plate 1, and ensures the necessary strength, rigidity, durability, etc., of the thin portion after fixation of each vertebral arch.

[0038] Furthermore, in the portion (thick plate portion) 10b of the main body 10 that is closer to one end in the longitudinal direction than the plate thickness change position P1, the thickness T1b of the first curved plate portion 14 is smaller than the thickness T1a of the first fixing portion. For example, the thickness T1b of the first curved plate portion 14 and the thin connecting plate portion 13b of the connecting plate portion 13 is within a range of 85% to 99% of the thickness T1a of the first fixing portion. This makes it easier to deform the one end side (thin portion) of the laminoplasty plate 1, centered around the area between the first curved plate portion 14 and the thin connecting plate portion 13b of the connecting plate portion 13, thereby improving the workability during laminoplasty. Furthermore, the degree of freedom (flexibility) of the laminoplasty plate 1 during deformation is increased, making it easier to accommodate individual differences in patient skeletal shape. In particular, when laminoplasty plate 1 is deformed to fit the skeletal shape of a patient undergoing laminoplasty, the deformed portion can be limited to the range between thin connecting plate portion 13b of connecting plate portion 13 and first curved plate portion 14, so that connecting plate portion 13 and second fixing portion 12, which will be the long portion after the procedure, are stably fixed without deformation, and first fixing portion 11 can deform freely near first fixing portion 11 without deformation. Therefore, after the first step of fixing second fixing portion 12 with fixing device 50, the second step of fixing first fixing portion 11 with fixing device 50 can be easily and stably achieved regardless of the skeletal shape or size of the patient.

[0039] Furthermore, an inclined surface 13a is formed on the back surface of connecting plate 13, which is inclined toward the front surface as it moves from thickness changing position P1 toward one end. This inclined surface 13a causes the thickness of connecting plate 13 (main body 10) to gradually decrease as it moves from thickness changing position P1 toward one end. This prevents stress from concentrating in one area when the angle of laminoplasty plate 1 (first fixing portion 11) is changed, and prevents a decrease in the strength, rigidity, durability, etc. of laminoplasty plate 1.

[0040] Furthermore, one end of the inclined surface 13a is spaced apart from the connection position between the first curved plate portion 14 and the connecting plate portion 13. The distance L between one end of the inclined surface 13a and the connection position between the first curved plate portion 14 and the connecting plate portion 13 (i.e., the longitudinal length of the connecting thin plate portion 13b of the connecting plate portion 13) is a distance (length) that is at least equal to or greater than the thickness T1b of the first curved plate portion 14 or the thickness T1a of the first fixing portion.

[0041] The laminoplasty plate of this invention corresponds to laminoplasty plate 1 of the above embodiment, and similarly, the main body corresponds to main body 10, the spacer protrusions correspond to spacer protrusions 30, the first fixing portion corresponds to first fixing portion 11, the second fixing portion corresponds to second fixing portion 12, the connecting plate portion corresponds to connecting plate portion 13, the plate thickness changing position corresponds to plate thickness changing position P1, the curved plate portion corresponds to first curved plate portion 14, and the fixing device corresponds to fixing device 50. However, this invention is not limited to this embodiment and can be embodied in various other ways. Furthermore, the specific configurations and the like given in the above embodiment are merely examples and can be modified as appropriate depending on the actual product. [Industrial Applicability]

[0042] INDUSTRIAL APPLICABILITY The present invention can be applied to the industries of laminoplasty plates and laminoplasty implant devices that are fixed to one side and the other side of divided vertebral arches to maintain the spacing between the divided vertebral arches. [Explanation of symbols]

[0043] 100...Implant device 1...Laminoplasty plate 11...First fixed part 12…Second fixed part 13...Connection plate 14...First curved plate section 15...Second curved plate section 20…Fixing hole 20a...Open end 50…Fixing tool

Claims

1. A laminoplasty plate for maintaining a distance between the divided vertebral arches by being fixed to each of the divided vertebral arches, a plate-shaped main body portion having a longitudinal direction; a spacer protrusion protruding from the main body portion, The main body portion is a first fixing portion having a substantially flat plate shape, which is provided on one end side in the longitudinal direction and is fixed to one of the divided vertebral arches by a predetermined fixing device; a second fixing portion having a substantially flat plate shape, which is provided on the other end side in the longitudinal direction and is fixed to the other of the divided vertebral arches by a predetermined fixing device; a substantially plate-shaped connecting plate portion that connects the first fixing portion and the second fixing portion, The main body portion is The thickness of a portion of the connecting plate portion on one end side in the longitudinal direction from the plate thickness change position located in the middle of the connecting plate portion is smaller than the thickness of a portion of the connecting plate portion on the other end side in the longitudinal direction from the plate thickness change position. Laminoplasty plate.

2. The thickness change position is located closer to one end than the center in the longitudinal direction of the connecting plate portion. The laminoplasty plate of claim 1.

3. The thickness of the portion from the thickness change position to one end side is set to a range of 2 / 3 or less of the thickness of the portion from the thickness change position to the other end side and 2 / 5 or more of the thickness of the portion from the thickness change position to the other end side. The laminoplasty plate of claim 2.

4. the main body further includes a curved plate portion provided between the first fixing portion and the connecting plate portion, The thickness of the curved plate portion is smaller than the thickness of the first fixing portion. The laminoplasty plate of claim 3.

5. The thickness change position is located closer to one end than the spacer protrusion.

5. The laminoplasty plate of claim 4.

6. laminoplasty plates fixed to one and the other of the divided vertebral arches to maintain the spacing between the divided vertebral arches; two or more fasteners for fastening the laminoplasty plate to one side and the other side of the vertebral arch, respectively; The laminoplasty plate comprises: a plate-shaped main body portion having a longitudinal direction; a spacer protrusion protruding from the main body portion, The main body portion is a first fixing portion having a substantially flat plate shape, which is provided on one end side in the longitudinal direction and is fixed to one of the divided vertebral arches by a predetermined fixing device; a second fixing portion having a substantially flat plate shape, which is provided on the other end side in the longitudinal direction and is fixed to the other of the divided vertebral arches by a predetermined fixing device; a substantially plate-shaped connecting plate portion that connects the first fixing portion and the second fixing portion, The main body portion is The thickness of a portion of the connecting plate portion on one end side in the longitudinal direction from the plate thickness change position located in the middle of the connecting plate portion is smaller than the thickness of a portion of the connecting plate portion on the other end side in the longitudinal direction from the plate thickness change position. Laminoplasty implant device.

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