Bone fixation plate

Abstract

To provide a bone fixation plate capable of tightly attaching the bone fixation plate and a subcutaneous tissue in surgery.SOLUTION: A bone fixation plate 10 according to the present invention is a bone fixation plate fixed to a cranial bone by a fixture, and includes a mesh structure having an opening 13 to which the fixture is inserted and a plurality of connection pieces 14. At least one connection piece among the plurality of connection pieces is a curved projection 15 curved so as to project from one surface to the other surface of the bone fixation plate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to bone fixation plates for use in surgical procedures. [Background technology]

[0002] In the field of neurosurgery, craniotomy is performed to treat brain tumors, cerebral aneurysms, and the like.

[0003] In one example of craniotomy, first, the skin on the head is incised, and the subcutaneous tissue (fascia and aponeurosis) directly underneath is dissected away. Next, multiple holes (burr holes) are drilled in the skull using a medical drill or similar, and the skull is cut between the burr holes and a bone flap is removed. This creates a bone window in part of the skull. Next, the dura mater is incised through the bone window, and the lesion is treated. After treatment is complete, the dura mater is sutured, the removed bone flap is replaced in the bone window, and the skull and bone flap are fixed with a bone fixation plate. Finally, the skull, including the bone fixation plate, is covered with subcutaneous tissue, which is sutured, and then covered with skin, which is sutured (e.g., Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Daisuke Wakui et al.: "Three Cases of Scalp Disruption and Cosmetic Problems Caused by Skull Fixation Plates after Craniotomy," Jpn. J. Neurosurg, Vol. 21 (2012), pp. 138-142. [Non-patent document 2] Kimata Takahiro et al., "Reconstruction after resection of head and neck malignant tumors with consideration of QOL," Proceedings of the 7th Meeting of the Japanese Society of Cosmetic and Neurosurgery (2014), pp. 11-14. Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a bone fixation plate is used in craniotomy, chronic mechanical stimulation of the plate can damage the scalp, thinning the scalp and allowing the bone fixation plate to show through.Furthermore, scalp tears can occur at the weakened area after the skin incision.

[0006] Furthermore, if a gap (dead space) remains between the bone fixation plate and the subcutaneous tissue, subcutaneous retention occurs, leading to wound dehiscence, infection, and cerebrospinal fluid leakage (Non-Patent Documents 1 and 2). [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the bone fixation plate of the present invention is a bone fixation plate that is fixed to the skull by a fixing device, and has a mesh structure having an opening through which the fixing device is inserted and a plurality of connecting pieces, and at least one of the plurality of connecting pieces is a curved protrusion that is bent so as to protrude from one side of the bone fixation plate toward the other side.

[0008] Furthermore, the bone fixation plate according to the present invention is a bone fixation plate that is fixed to the skull by a fixing device, and comprises a plate body, an opening arranged on the periphery of the plate body and through which the fixing device is inserted, a plurality of slits formed in the plate body, and band-like structures arranged between the slits, and at least one of the band-like structures is a curved protrusion that is bent so as to protrude from one side of the bone fixation plate toward the other side.

[0009] In the bone fixation plate according to the present invention, the height of the apex of the curved protrusion may be 0.8 mm or more and 2.0 mm or less. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a bone fixation plate that can closely contact the bone fixation plate with subcutaneous tissue during surgical procedures. [Brief explanation of the drawings]

[0011] [Figure 1]FIG. 1 is a schematic top view showing the configuration of a bone fixation plate according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional side view showing the configuration of the curved protrusions in the bone fixing plate according to the first embodiment of the present invention. [Figure 3A] FIG. 3A is a view for explaining the effect of the bone fixing plate according to the first embodiment of the present invention. [Figure 3B] FIG. 3B is a view for explaining the effect of the bone fixing plate according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing clinical data for verifying the effect of the bone fixation plate according to the first embodiment of the present invention. [Figure 5] FIG. 5 is a diagram showing clinical data for verifying the effect of the bone fixation plate according to the first embodiment of the present invention. [Figure 6] FIG. 6 is a diagram showing clinical data for verifying the effect of the bone fixation plate according to the first embodiment of the present invention. [Figure 7] FIG. 7 is a diagram showing clinical data for verifying the effect of the bone fixation plate according to the first embodiment of the present invention. [Figure 8] FIG. 8 is a diagram showing clinical data for verifying the effect of the bone fixation plate according to the first embodiment of the present invention. [Figure 9] FIG. 9 is a schematic top view showing an example of the configuration of the bone fixing plate according to the first embodiment of the present invention. [Figure 10] FIG. 10 is a schematic top view showing the configuration of a bone fixation plate according to the second embodiment of the present invention. [Figure 11A] FIG. 11A is a schematic top view showing an example of the configuration of a bone fixing plate according to an embodiment of the present invention. [Figure 11B] FIG. 11B is a schematic top view showing an example of the configuration of a bone fixing plate according to an embodiment of the present invention. [Figure 12] FIG. 12 is a schematic diagram showing an application example of the bone fixation plate according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] First Embodiment A bone fixing plate according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3B.

[0013] <Bone fixation plate configuration> 1, the bone fixation plate 10 according to this embodiment has a mesh plate portion 11 and a burr hole plate portion 12 connected to an end of the mesh plate portion 11. Hereinafter, in the bone fixation plate of the present invention, the surface that faces or contacts the skull when fixing a bone flap in craniotomy will be referred to as the "back surface," and the opposite surface (the surface that faces or contacts the subcutaneous tissue) will be referred to as the "front surface."

[0014] When fixing the bone flap in craniotomy, the mesh plate portion 11 is placed mainly at the boundary (craniotomy line) between the skull body and the bone flap.

[0015] The mesh plate portion 11 has openings 13 with edges that define fixing holes into which fasteners such as screws and bolts are inserted to fix the bone fixation plate 10 to the skull, and connecting pieces 14 that connect the openings 13. The mesh plate portion 11 is formed by connecting basic triangular components made up of the openings 13 and the connecting pieces 14, and has the openings 13 on its periphery.

[0016] The size of the bone fixation plate 10 is approximately 80 mm x 30 mm. The bone fixation plate 10 is made of titanium and has a thickness of 0.3 mm.

[0017] The length of the connecting piece 14 is about 3.8 mm, and the width is about 0.8 mm.

[0018] The burr hole plate portion 12 is disposed so as to mainly cover the burr hole when fixing a bone flap during craniotomy.

[0019] Openings 13 are located around the periphery of burr hole plate portion 12. Burr hole plate portion 12 also includes openings 16 with edges defining holes through which no fasteners are inserted, and slits 17. This allows the plate to be easily bent to fit the shape of the skull surface.

[0020] In the mesh plate portion 11, some of the connecting pieces 15 of the multiple connecting pieces 14 are curved toward the surface side from the reference plane of the bone fixation plate 10 (the shaded areas in FIG. 1). These curved connecting pieces, i.e., curved strip-like structures, are hereinafter referred to as "curved protrusions" 15. The curved protrusions 15 are not limited to curved shapes and may also have a bent shape, as long as they are bent so as to protrude from one surface (rear surface) toward the other surface (surface surface). A curved shape of the curved protrusions 15 is preferable because it reduces irritation to the subcutaneous tissue.

[0021] 2 shows a schematic cross-sectional view of the curved protrusion 15. As shown in Fig. 2, when the bone fixation plate 10 (plate thickness: t) is placed on the surface of the skull 1, a gap is created between the surface of the skull 1 (or the reference surface of the bone fixation plate 10) and the curved protrusion 15. A suture is inserted into this gap to tightly attach the bone fixation plate 10 to the subcutaneous tissue (described later).

[0022] The height h of the apex of the curved portion of the curved projection 15 is about 1.1 mm, and the height s of the gap is 0.8 mm.

[0023] The bone fixation plate 10 is configured to have a curved shape so as to fit the curved shape of the skull or the like.

[0024] The bone fixation plate 10 is manufactured, for example, as follows.

[0025] First, for example, a metal (titanium) plate is punched into the shape of the bone fixation plate, and then the plate is formed into a predetermined curved shape. Other processing methods such as laser processing and etching may also be used.

[0026] Next, in the formed bone fixation plate, some of the connecting pieces are bent into a predetermined curved shape, thereby forming the curved protrusions. The curved protrusions may be formed by press working.

[0027] <Function of bone fixation plate> An example of craniotomy using the bone fixing plate 10 according to this embodiment will be described.

[0028] First, the skin on the head is incised and the subcutaneous tissue (fascia and aponeurosis) immediately below is peeled away.

[0029] Next, a portion of the skull is cut using a drill or the like, and the bone flap is removed, thereby forming a bone window in the portion of the skull.

[0030] Next, the dura mater is incised through the bone window and the lesion is treated.

[0031] After the treatment is completed, the dura mater is sutured, the removed bone flap is returned to the bone window, and the skull and bone flap are fixed with the bone fixation plate 10. At this time, the bone fixation plate 10 is positioned so that the surface (surface) of the protruding side of the curved projection 15 faces or contacts the subcutaneous tissue.

[0032] Next, the skull fixed with the bone fixing plate is covered with subcutaneous tissue, and at this time, the curved protrusion 15 of the bone fixing plate 10 is bound to the subcutaneous tissue with a suture.

[0033] Specifically, a suture needle with a suture attached is inserted into the gap directly below one curved protrusion 15, and the suture needle is inserted into the subcutaneous tissue and pulled out, passing the suture through the subcutaneous tissue. The suture is then tied (tied). This allows the area around the curved protrusion 15 of the bone fixation plate 10 to adhere tightly to the subcutaneous tissue. Similar suturing and tying processes are then repeated for the other curved protrusions 15. This allows the entire bone fixation plate 10 to adhere tightly to the subcutaneous tissue.

[0034] Finally, the subcutaneous tissue is sutured, and the wound is covered with skin, which is then sutured.

[0035] <Effects> The effects of the bone fixation plate 10 according to this embodiment will be described with reference to Figures 3A and 3B. Figure 3A shows a case where the bone fixation plate 10 according to this embodiment is used. For comparison, Figure 3B shows a case where a conventional bone fixation plate 101 is used.

[0036] Conventionally, in the fixation of a bone fixation plate, after fixing the skull 1 with the bone fixation plate 101, the bone fixation plate 101 is covered with subcutaneous tissue 2, and the outside of the edge of the bone fixation plate is sutured (suture point 3). In this case, a gap (dead space) 5 is formed between the subcutaneous tissue 2 and the bone fixation plate 101, causing subcutaneous accumulation (Fig. 3B). Subcutaneous accumulation generates tension, which can lead to wound dehiscence, infection, and cerebrospinal fluid leakage. Currently, subcutaneous CSF leakage occurs in approximately 30% of craniotomy procedures. (G. Hutter et al.: “Risk factors for postoperative CSF leakage after elective craniotomy and the efficacy of fleece-bound tissue sealing against dural suturing alone: ​​a randomized controlled trial”, J. Neurosurgery, Vol. 121, Issue 3 (2014), pp. 735-744, https: / / doi.org / 10.3171 / 2014.6.JNS131917. A. Kumar et al.: “Evaluation of the use of BioGlue in neurosurgical procedures”, J. Clinical Neuroscience, Vol. 10, Issue 6 (2003), pp. 661-664, https: / / doi.org / 10.1016 / S0967-5868(03)00163-2.)

[0037] According to the bone fixation plate of this embodiment, a suture can be inserted into the gap formed between the curved projection 15 and the skull 1, and the subcutaneous tissue 2 can be firmly and easily tied to the curved projection 15, thereby closely fixing the subcutaneous tissue 2 and the bone fixation plate 10 (FIG. 3A). This reduces the gap (dead space) between the subcutaneous tissue 2 and the bone fixation plate 10. Subcutaneous retention can be reduced to about 10%, and even to several percent (including almost 0%).

[0038] Below, clinical data will be presented to verify the effect of closely contacting the bone fixation plate with the subcutaneous tissue at the surgical site, assuming the bone fixation plate according to this embodiment.

[0039] In the clinical data, the amount of subcutaneous fluid at the surgical site was quantitatively measured using postoperative head MRI images in cases where treatment to reduce dead space was administered (“treatment administered”) and where it was not (“no treatment administered”).

[0040] In the following cases, commercially available bone fixation plates were used.

[0041] The treatment to reduce the dead space (Cases 1 to 3) was performed assuming that the bone fixation plate of the present invention would be used to bring the bone fixation plate into close contact with the surgical site. Specifically, when performing the treatment to reduce the dead space, a suture was threaded through the small gap between the bone fixation plate (commercially available) and the surface of the surgical site (e.g., the surface of the skull) to bring the bone fixation plate into close contact with the surgical site, thereby fixing the bone fixation plate to the surgical site.

[0042] In cases where no treatment to reduce dead space was performed (Cases 4 to 6), the bone fixation plate (commercially available) was fixed in the conventional manner without contacting the surface of the surgical site.

[0043] 4 to 6 show CT or MRI images of cases 4 to 6 without treatment, respectively.

[0044] Figure 4 shows a horizontal CT image of a head after removal of a meningioma in the petrous clivus (Case 4). In the image, the black area within the area surrounded by the white dashed line indicates subcutaneous fluid. This indicates that the amount of subcutaneous fluid was 81 ml.

[0045] Figure 5 shows a horizontal MRI image of a patient after surgery for acute subdural hematoma in the posterior fossa (Case 5). The white area within the dashed white line in the image represents the subcutaneous fluid. This indicates that the amount of subcutaneous fluid was 73.5 ml.

[0046] Figure 6 shows a head MRI image after removal of a foramen magnum meningioma (Case 6). The left image is a horizontal section, and the right image is a sagittal section. In the image, the white area within the area surrounded by the white dashed line indicates subcutaneous fluid. This indicates that the amount of subcutaneous fluid was 110 ml.

[0047] Figure 7 shows a horizontal MRI image of a head after treatment for hemifacial spasm (MVD) (Case 1). In the image, the white area within the dashed white line indicates subcutaneous fluid. This indicates that the amount of subcutaneous fluid was 1.5 ml.

[0048] Figure 8 shows the subcutaneous fluid accumulation obtained by quantitative measurement from postoperative head CT images or head MRI images for cases with and without treatment (cases 1 to 6). It also shows the postoperative course, including the occurrence of cerebrospinal fluid leakage and infection (meningitis). Cases 2 and 3 were performed using suboccipital craniotomy.

[0049] When no treatment to reduce the dead space was performed ("no treatment", cases 4 to 6), the subcutaneous fluid accumulation was approximately 81 to 110 ml. Furthermore, in case 1, cerebrospinal fluid leakage and infection (meningitis) occurred after surgery.

[0050] If the amount of subcutaneous fluid retention is large, stress (pressure) is applied to the wound, causing it to dehiscence, resulting in a CSF leak and subsequent infections such as meningitis. Even if the amount of subcutaneous fluid retention is large, CSF leakage and infection may not occur if the wound is tightly adhered and does not dehiscence (Cases 2 and 3 without treatment).

[0051] On the other hand, when treatment to reduce the dead space was performed ("with treatment", cases 1-8), the subcutaneous fluid accumulation was approximately 1.5-5 ml, which was significantly reduced compared to when no treatment was performed. Furthermore, there was no postoperative cerebrospinal fluid leakage or infection (meningitis), and the patient's progress was favorable.

[0052] In this way, it was found that by performing treatment to reduce dead space, subcutaneous fluid accumulation can be reduced and the occurrence of postoperative cerebrospinal fluid leakage and infection can be suppressed.

[0053] From the above, it was found that use of the bone fixation plate according to the present invention can be expected to reduce subcutaneous fluid accumulation and suppress the occurrence of postoperative cerebrospinal fluid leakage and infections.

[0054] Furthermore, when using commercially available bone fixation plates to reduce dead space, as in this experiment, it is necessary to thread sutures through the small gap between the bone fixation plate and the surface of the surgical site to tightly attach the bone fixation plate to the surgical site. While this procedure is possible for experienced physicians, it is difficult and risky for inexperienced physicians to perform it.

[0055] The bone fixation plate of the present invention has a curved protrusion for passing a suture between the bone fixation plate and the surface of the surgical site, so that even an inexperienced doctor can easily and safely pass a suture through the curved protrusion, thereby enabling the bone fixation plate to be tightly attached to the surgical site.

[0056] Therefore, subcutaneous accumulation can be reduced or suppressed, and wound dehiscence, infection, and cerebrospinal fluid leakage can be reduced or suppressed.

[0057] In recent years, bone fixation plates have been around 0.5 mm thick, but in order to reduce irritation to the scalp and prevent surface exposure, the plate thickness has been reduced to around 0.3 mm (thinner plate thickness) (NS03 / ST03 Plate System catalog (Bear Medic Co., Ltd., published May 2018, http: / / www.bearmedic.co.jp / library / 55066c20daa60f3c4a000e39 / 5ecdcad18edade3f3a32a467.pdf)).

[0058] On the other hand, the embodiment of the present invention is based on the finding that in order to reduce irritation of the bone fixation plate to the scalp, it is more effective to improve the adhesion between the plate and the subcutaneous tissue than to reduce the thickness of the plate. Therefore, according to the embodiment of the present invention, even when a bone fixation plate with a plate thickness of 0.4 mm to 0.6 mm is used, irritation of the bone fixation plate to the scalp can be reduced, and wound dehiscence, infection, and cerebrospinal fluid leakage can be reduced or prevented.

[0059] The height of the gap directly below the curved protrusion is preferably 0.5 mm or more, taking into consideration the insertion of sutures. Furthermore, the height of the curved protrusion is preferably 2 mm or less, taking into consideration the irritation to the scalp and visibility of the bone fixation plate. Therefore, for bone fixation plates with a plate thickness of 0.4 mm to 0.6 mm, the height of the curved protrusion is preferably 0.9 mm to 2.0 mm, and the height of the gap directly below the curved protrusion is preferably 0.5 mm to 1.6 mm.

[0060] Furthermore, thin bone fixation plates with a plate thickness of approximately 0.3 mm can further reduce irritation to the scalp, reducing or preventing wound dehiscence, infection, and cerebrospinal fluid leakage.

[0061] Furthermore, when the curved protrusions in this embodiment are provided on a thin bone fixation plate with a plate thickness of approximately 0.3 mm (0.3 mm or more and less than 0.4 mm), if the height of the curved protrusions is large, the curved protrusions may be damaged. Also, if the height of the curved protrusions is large, the curved protrusions of the bone fixation plate are likely to be exposed on the surface. Therefore, it is desirable that the height of the curved protrusions is small.

[0062] Therefore, in this embodiment, it is desirable that the height of the curved protrusions is about 0.8 to 2.0 mm, and the height of the gaps directly below the curved protrusions is 0.5 to 1.7 mm.More preferably, the height of the curved protrusions is about 1.1 mm, and the height of the gaps is about 0.8 mm.

[0063] In the present embodiment, an example has been shown in which connecting pieces 14 connect openings 13 having edges that define fastening holes into which fasteners are inserted in a mesh plate, but this is not limiting. As shown in Fig. 9, in the mesh plate, the connecting pieces are not limited to connecting pieces that connect openings 13 (e.g., 14a in the figure), but the connecting pieces may also be connecting pieces that connect openings 16 that define holes into which fasteners are not inserted (e.g., 14b in the figure) or connecting pieces that connect connecting pieces together (e.g., 14c in the figure). Any of these connecting pieces may be curved protrusions 15.

[0064] As described above, in the bone fixation plate according to this embodiment, in the mesh structure formed by a plurality of connecting pieces, any of the connecting pieces may be a curved protrusion.

[0065] In this embodiment, an example has been shown in which the bone fixation plate includes a mesh plate portion and a burr hole plate portion, but this is not limiting, and the bone fixation plate may be configured to include only the mesh plate portion.

[0066] <Second embodiment> A bone fixation plate according to a second embodiment of the present invention will be described with reference to FIG.

[0067] <Bone fixation plate configuration> As shown in FIG. 10, the bone fixing plate 20 according to this embodiment is a burr hole plate, and has a plurality of openings 22 on the periphery, with notches 23 formed between each opening 22.

[0068] Two slits 24 are formed in the main body 21 of the bone fixation plate 20, and the strip-shaped portion between the two slits is curved so as to protrude from one surface (back surface) of the bone fixation plate 20 toward the other surface (front surface), forming a curved protrusion 25 (hatched portion in Figure 10) as in the first embodiment.

[0069] When the bone fixation plate 20 is placed on the skull surface, a gap is created between the skull surface (or the reference surface of the bone fixation plate 20) and the curved protrusion 25. A suture is inserted into this gap to tightly attach the bone fixation plate 20 to the subcutaneous tissue. The height of the apex of the curved part of the curved protrusion 25 is about 1.1 mm, and the height of the gap is 0.8 mm.

[0070] According to the bone fixation plate of this embodiment, as in the first embodiment, a suture can be inserted into the gap formed between the curved protrusion and the skull, firmly and easily tying the subcutaneous tissue to the curved protrusion, thereby tightly and easily fixing the subcutaneous tissue and the bone fixation plate, thereby reducing subcutaneous accumulation.

[0071] In this embodiment, an example is shown in which the bone fixation plate has one band-shaped structure between two slits, but this is not limited to this, and it may have multiple band-shaped structures between multiple slits, and at least one band-shaped structure may be a curved protrusion.

[0072] The shape and dimensions of the curved protrusions in this embodiment are the same as those in the first embodiment. The curved protrusions may have a bent shape, as long as they are bent so as to protrude from one surface (rear surface) to the other surface (front surface). In addition, the height of the curved protrusions is preferably 0.8 mm to 2 mm when the plate thickness is 0.3 mm to 0.6 mm.

[0073] In the embodiments of the present invention, examples have been shown in which curved protrusions are provided on a mesh-like structure and a burr hole plate, but this is not limiting. The bone fixation plate may have the structure of bone fixation plate 30 shown in Fig. 11A or bone fixation plate 40 shown in Fig. 11B, or may have other structures.

[0074] 12 shows an example of fixing a bone flap (autogenous bone) 6 to the skull using a bone fixation plate according to an embodiment of the present invention. Bone fixation plates 10, 30 are placed and fixed so as to cover the craniotomy line 7. While an example using bone fixation plates 10, 30 is shown here, bone fixation plates of other shapes may also be used.

[0075] In the embodiment of the present invention, the bone fixation plate is made of titanium, but it is not limited to this, and may be made of metal such as titanium alloy, biocompatible resin, ceramic, etc. When the bone fixation plate is made of resin, it may be manufactured by injection molding.

[0076] In the embodiments of the present invention, examples of the structure, dimensions, materials, etc. of each component in the configuration and manufacturing method of the bone fixation plate are shown, but the present invention is not limited to these examples. Anything that can demonstrate the function and effect of the bone fixation plate may be used.

[0077] A part or all of the above-described embodiment or an example thereof can be described as, but is not limited to, the following supplementary notes.

[0078] (Appendix 1) A bone fixation plate that is fixed to the skull by a fixation device, the bone fixation plate having a mesh structure with an opening through which the fixation device is inserted and a plurality of connecting pieces, at least one of the plurality of connecting pieces being a curved protrusion that is bent so as to protrude from one side of the bone fixation plate toward the other side.

[0079] (Appendix 2) A bone fixation plate that is fixed to the skull by a fixing device, comprising: a plate body; an opening disposed on the periphery of the plate body and through which the fixing device is inserted; a plurality of slits formed in the plate body; and band-like structures disposed between the slits, wherein at least one of the band-like structures is a curved protrusion bent so as to protrude from one side of the bone fixation plate toward the other side.

[0080] (Appendix 3) The bone fixation plate according to appendix 1 or 2, wherein the height of the apex of the curved protrusion is 0.8 to 2.0 mm.

[0081] (Appendix 4) A bone fixation plate described in any one of Appendices 1 to 3, which is placed between the skull and subcutaneous tissue and fixed to the skull by a fixing device, wherein a suture is inserted into the gap created between the curved protrusion and the skull, the suture is inserted into the subcutaneous tissue, and the suture is tied to adhere the bone fixation plate to the subcutaneous tissue.

[0082] (Appendix 5) A bone fixation plate according to any one of Appendices 1 to 4, wherein the thickness of the bone fixation plate is 0.4 mm or more and 0.6 mm or less.

[0083] (Appendix 6) A bone fixation plate according to any one of Appendices 1 to 4, wherein the thickness of the bone fixation plate is 0.3 mm or more and less than 0.4 mm. [Industrial Applicability]

[0084] The present invention relates to a bone fixation plate, which can be applied as a medical device to surgical operations, particularly craniotomy in neurosurgery. [Explanation of symbols]

[0085] 10, 20, 30, 40 bone fixation plates 11 Mesh plate part 12 Burr hole plate section 13, 22 Opening 14 Connecting piece 15, 25 Curved protrusions (connecting pieces, strip-like structures) 21 Bone fixation plate body 23 Cutout 24 Slit

Claims

1. A bone fixation plate that is fixed to the skull by a fixator, a mesh structure having an opening through which the fastener is inserted and a plurality of connecting pieces; A bone fixation plate, wherein at least one of the plurality of connecting pieces is a curved protrusion bent so as to protrude from one surface of the bone fixation plate toward the other surface.

2. A bone fixation plate that is fixed to the skull by a fixator, The plate body, an opening disposed on a periphery of the plate body and through which the fastener is inserted; A plurality of slits formed in the plate body; a band-shaped structure disposed between the slits; Equipped with A bone fixation plate, wherein at least one of the band-like structures is a curved protrusion that is bent so as to protrude from one surface of the bone fixation plate to the other surface.

3. 3. The bone fixation plate according to claim 1, wherein the height of the apex of the curved protrusion is 0.8 to 2.0 mm.

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