JP2017012354A - Living matter implant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a living matter implant capable of preventing postoperative infection.SOLUTION: Provided is a living matter implant comprising: a pin 2 located in a tip part 1a; a stopper 3 continuous to the pin 2; and a first coating layer 5 laminated on the stopper 3 and made of calcium phosphate-based material. The living matter implant further includes: a second coating layer 6 laminated on a part 22 including a tip part 21 located on the side of the stopper 3 in the pin 2 and made of a calcium phosphate base material; a columnar shaft 4 continuous to the stopper 3; and a third coating layer 7 laminated on a part 42 including a tip part 41 located on the side of the stopper 3 in the shaft 4 and made of a calcium phosphate base material. It is preferable that the first coating layer 5 being a silver hydroxyapatite sprayed coating for the incorporation of antibacterial components.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a biological implant.

  As biological implants, external fixation pins and bone screws used for the treatment of fractures and the like are known. Since the external fixation pin is embedded in the living body with a part thereof protruding from the skin, the postoperative infection rate is relatively high. Various investigations have been made to prevent postoperative infection by applying a predetermined coating on the surface of a biological implant having a high postoperative infection rate such as an external fixation pin (see, for example, Patent Document 1). ). Patent Document 1 discloses a biological implant coated with a low crystalline apatite layer containing fibroblast growth factor (FGF-2).

Further, for example, in Patent Document 2, as a bioimplant having antibacterial properties for reducing the risk of postoperative infection, a sprayed coating made of a calcium phosphate-based material is formed on at least a part of a substrate. A biological implant characterized in that the silver concentration in it is 0.02% to 3.00% by weight is shown. As an example of the biological implant, an artificial joint having a stem and a neck portion for fixing a head ball formed on the upper end of the stem is mentioned, but there is no description regarding an external fixation pin.
It is desirable that the risk of postoperative infection can be further reduced not only in the external fixation pin but also in the bone screw.

JP 2009-18086 A JP 2012-40194 A

  The subject of this invention is providing the biological implant which can prevent a postoperative infection.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a solution means having the following constitution and have completed the present invention.
(1) A biological implant comprising a pin located at a distal end, a stopper continuous with the pin, and a first coating layer made of a calcium phosphate material laminated on the stopper.
(2) The living body implant according to (1), wherein the pin includes a screw-shaped part.
(3) The living body implant according to (1) or (2), wherein the first coating layer is a silver hydroxyapatite sprayed coating.
(4) In any one of the above (1) to (3), further comprising a second coating layer made of a calcium phosphate-based material and laminated on a portion including an end portion located on the stopper side of the pin. The biological implant as described.
(5) When viewed from a direction perpendicular to the rotation axis, the stopper has a substantially trapezoidal shape with a long side on the pin side, and the diameter of at least the long side is larger than the diameter of the pin (1 The biological implant according to any one of (4) to (4).
(6) The biological implant according to any one of (1) to (5), wherein the stopper is formed integrally with the pin.
(7) A columnar shaft continuous to the stopper, and a third coating layer made of a calcium phosphate-based material and laminated on a portion including an end portion of the shaft located on the stopper side. The biological implant according to any one of (1) to (6).
(8) The living body implant according to (7), wherein, when implanted in a living body, an end portion of the third coating layer located on a side farther from the stopper is located above the skin.
(9) The biological implant according to any one of (1) to (8), wherein the implant is implanted in a living body and removed from the living body after healing.
(10) The biological implant according to any one of (1) to (9), which is an external fixation pin.

  ADVANTAGE OF THE INVENTION According to this invention, the effect that postoperative infection can be prevented and a patient's burden can be reduced is acquired.

It is a side view which shows the biological implant which concerns on one Embodiment of this invention. It is a figure which shows the biological implant shown in FIG. 1, (a) is a side view which shows the state in which the 1st-3rd coating layer is not laminated | stacked, (b) is a partial expanded side view which shows the stopper vicinity of (a). (C) is the A arrow enlarged view (enlarged front end view) of (a). It is a schematic explanatory drawing which shows the implantation state of the biological implant shown in FIG. It is a figure which shows the biological implant which concerns on other embodiment of this invention, (a) is a side view, (b) is a side view which shows the state in which the 1st and 2nd coating layer is not laminated | stacked. It is a figure which shows the biological implant which concerns on other embodiment of this invention, (a)-(d) is the stopper vicinity of the state by which the 1st-3rd coating layer corresponding to FIG.2 (b) is not laminated | stacked FIG. It is a figure which shows the biological implant which concerns on other embodiment of this invention, (a)-(d) is an enlarged front end view equivalent to FIG.2 (c).

  Hereinafter, a biological implant according to an embodiment of the present invention will be described in detail with reference to FIGS.

  As shown in FIG. 1, the biological implant of this embodiment is an external fixation pin 1. The external fixation pin 1 of this embodiment is used for external fixation, and penetrates the skin 101 and is embedded in the living body 100 in the order of the soft tissue 102 and the bone 103 as shown in FIG. It is inserted and removed from the living body 100 after healing of the bone 103.

  As shown in FIGS. 1 and 2 (a), the external fixation pin 1 of the present embodiment includes a pin 2, a stopper 3, and a shaft 4 in order from the distal end portion 1a side.

(pin)
The pin 2 is a part located at the distal end portion 1 a of the external fixation pin 1. Further, as shown in FIG. 3, the pin 2 is a part located on the bone 103 when the external fixation pin 1 is embedded in the living body 100.

  The pin 2 may include a screw-shaped part. The pin 2 of the present embodiment is entirely screw-shaped. According to such a configuration, the external fixation pin 1 can be rotated about the rotation axis S so that the pin 2 can be screwed into the bone 103, and as a result, the external fixation pin 1 can be inserted into the living body 100. Can be firmly fixed. The pin 2 is not limited to a configuration in which the entirety is a screw shape, and may be configured to include a screw-shaped portion in a part thereof, or a configuration not including a screw-shaped portion. It may be.

  In the present embodiment, the length L 2 of the pin 2 in the direction parallel to the rotation axis S is the same as the thickness T of the bone 103. According to such a configuration, the pin 2 can be sufficiently implanted in the bone 103, and the external fixation pin 1 can be firmly fixed in the living body 100. Note that the length L2 of the pin 2 being the same as the thickness T of the bone 103 means that the thickness of both is substantially the same, and there is a slight difference between the thicknesses of the two. Shall. Further, the length L2 of the pin 2 is not limited to the same configuration as the thickness T of the bone 103, and may be larger or smaller than the thickness T of the bone 103, for example.

  Examples of the constituent material of the pin 2 include pure titanium, titanium alloy, cobalt-chromium alloy, stainless steel (SUS) for biomaterials, and examples of SUS for biomaterials include SUS316L. However, it is not limited to these.

(stopper)
As shown in FIG. 2A, the stopper 3 is a portion that is continuous with the pin 2 described above. If demonstrating it more concretely, the stopper 3 is a site | part which is following the edge part 21 located in the stopper 3 side among the pins 2. FIG. In addition, as shown in FIG. 3, the stopper 3 is positioned near the boundary 104 with the bone 103 in the soft tissue 102 when the external fixation pin 1 is embedded in the living body 100, and is more wound than the stopper 3. A portion on the rear end portion 1 b side of the external fixing pin 1 functions as a portion that suppresses being embedded in the bone 103.

  The stopper 3 has a portion where the diameter D3 is larger than the diameter D2 of the pin 2 as shown in FIG. In this embodiment, when the external fixation pin 1 is viewed from a direction perpendicular to the rotation axis S, the stopper 3 has a substantially trapezoidal shape with the long side 31 on the pin 2 side. The diameter D3 at least on the long side 31 is larger than the diameter D2 of the pin 2. According to these configurations, it is possible to suppress the site on the rear end portion 1 b side from the long side 31 from being embedded in the bone 103. Moreover, since the diameter D3 of the stopper 3 decreases as the distance from the pin 2 increases, the removal property when the external fixation pin 1 is removed from the living body 100 can be improved.

  The stopper 3 of this embodiment is formed integrally with the pin 2. According to such a configuration, the connection strength between the pin 2 and the stopper 3 can be improved. Note that the stopper 3 can be formed of a member separate from the pin 2 as necessary.

  As a constituent material of the stopper 3, for example, the same material as exemplified in the pin 2 described above can be used.

(shaft)
As shown in FIG. 2A, the shaft 4 is a portion that is continuous with the stopper 3 described above. If demonstrating it more concretely, the shaft 4 is a site | part which is following the stopper 3 in the edge part 41 located in the stopper 3 side among the shafts 4. FIG. As shown in FIG. 3, the shaft 4 has such a length that a part on the rear end 1 b side protrudes from the skin 101 when the external fixation pin 1 is embedded in the living body 100. An external fixator (not shown) is attached to a portion of the shaft 4 protruding from the skin 101.

  The shaft 4 is columnar. The shaft 4 of this embodiment is substantially cylindrical. Note that the shape of the shaft 4 is not limited to a substantially cylindrical shape, and may be other shapes such as a polygonal column shape.

  The shaft 4 of this embodiment is formed integrally with the stopper 3. According to such a configuration, the connection strength between the stopper 3 and the shaft 4 can be improved. In addition, the shaft 4 can also be comprised with the stopper 3 and another member as needed.

  As a constituent material of the shaft 4, for example, the same material as exemplified in the pin 2 described above can be used.

(Coating layer)
On the other hand, the external fixation pin 1 of the present embodiment further includes a coating layer. The coating layer of this embodiment is made of a calcium phosphate material. Examples of the calcium phosphate material include calcium phosphate ceramics including hydroxyapatite (HA), tertiary calcium phosphate (TCP), and fourth calcium phosphate (TeCP), calcium phosphate glass, calcium phosphate glass ceramic, and the like. Or you may use it, mixing 2 or more types.

  Moreover, the coating layer of this embodiment has disappearance in the living body 100. Therefore, for example, when the coating layer of this embodiment contains (supports) an antibacterial agent or an antibiotic (antibacterial agent), the antibacterial agent and the like are gradually released into the living body 100 using the disappearance of the coating layer. be able to. The disappearance rate and disappearance period of the coating layer can be adjusted by, for example, the composition of the calcium phosphate material, the crystallinity, the thickness of the coating layer, and the like.

  The crystallinity of the calcium phosphate material is preferably 90% or less, and more preferably 10 to 90%. This ensures that the coating layer has disappearance in the living body 100. The crystallinity is a value measured by an X-ray diffraction method.

  The thickness of the coating layer is preferably 5 to 100 μm, but is not limited thereto. The coating layer may be a single layer or a plurality of layers.

  Examples of the antibacterial agent to be included in the coating layer include a natural antibacterial agent, an organic antibacterial agent, and an inorganic antibacterial agent. Examples of natural antibacterial agents include hinokitiol. Examples of the organic antibacterial agent include benzalkonium. Examples of the inorganic antibacterial agent include metals such as silver, copper, and zinc. The inorganic antibacterial agent of this embodiment utilizes the antibacterial action of metal ions such as silver ions, copper ions, and zinc ions. As the inorganic antibacterial agent, silver is preferable among the exemplified metals.

  Examples of antibiotics to be included in the coating layer include vancomycin. The above-mentioned antibacterial agents and antibiotics can be used as a mixture. In addition, as a method of making an antibacterial agent or an antibiotic agent contain in a coating layer, a well-known method is employable and it does not specifically limit.

  Examples of the method for laminating the coating layer include a thermal spraying method, a vapor deposition method, and a wet coating method. Examples of the thermal spraying method include flame spraying, high-speed flame spraying, and plasma spraying. Examples of the vapor deposition method include physical vapor deposition methods such as sputtering, ion plating, ion beam vapor deposition, and ion mixing. Examples of the wet coating method include a sol-gel method.

As a preferable structure of the coating layer described above, for example, a silver hydroxyapatite sprayed coating in which a hydroxyapatite containing silver is laminated by a spraying method may be used. According to such a configuration, since the coating layer functions as an antibacterial coating layer, the external fixation pin 1 can function as an antibacterial biological implant.
A more detailed description of the coating layer is described in, for example, Japanese Patent No. 5069888.

  Here, the external fixation pin 1 of this embodiment includes the above-described coating layers as a first coating layer 5, a second coating layer 6, and a third coating layer 7, as shown in FIG. And in this embodiment, the 1st coating layer 5 is laminated | stacked on the stopper 3 mentioned above. Moreover, the 2nd coating layer 6 is laminated | stacked on the site | part 22 containing the edge part 21 located in the stopper 3 side among the pins 2. FIG. The 3rd coating layer 7 is laminated | stacked on the site | part 42 containing the edge part 41 located in the stopper 3 side among the shafts 4. FIG. According to these configurations, the following effects can be obtained.

  That is, the coating layer of this embodiment which comprises the 1st-3rd coating layers 5-7 consists of a calcium phosphate type material as above-mentioned. It is known that apatite, which is calcium phosphate, has a high affinity for skin 101 and soft tissue 102 and has an effect of preventing gap infection (for example, Itsuo Ito, “By bioactive molecule fixation using apatite crystallization”). Creation of regenerative medical materials ”, [online], [Search April 17, 2015], Internet <URL: https://www.jstage.jst.go.jp/article/scej/2009f/0/2009f_0_441/ _pdf>). As shown in FIG. 3, the external fixation pin 1 of the present embodiment has the first coating layer 5 and the third coating layer 7 laminated on the portion that comes into contact with the skin 101 and the soft tissue 102. And the third coating layer 7, and the soft tissue 102, the first coating layer 5, and the third coating layer 7 can suppress the invasion of bacteria into the living body 100, resulting in postoperative infection. Can be prevented. Further, the second coating layer 6 laminated on the pin 2 can prevent bacteria from entering the bone 103 and prevent osteomyelitis.

  In particular, when the first to third coating layers 5 to 7 are the above-described silver hydroxyapatite sprayed coatings, the first to third coating layers 5 to 7 contain an antibacterial component. Even if the contact portion with the skin 101 is broken by excessive movement and bacteria enter the living body 100, the invading bacteria can be sterilized on the spot, and the bacteria enter the deep tissue (inside the bone). Can be suppressed. That is, when the first to third coating layers 5 to 7 are silver hydroxyapatite sprayed coatings, a double defense against infection, that is, a tissue adhesion effect by a calcium phosphate material and a bactericidal effect by an antibacterial component, should be realized. Can do. The same applies to the case where the first to third coating layers 5 to 7 contain an antibacterial agent or antibiotic other than silver.

  In the present embodiment, the end portion 61 located on the side farther from the stopper 3 in the second coating layer 6 is located in the vicinity of the stopper 3. According to such a configuration, the second coating layer 6 is suppressed while the second coating layer 6 and the bone 103 are fixed and the removal property when the external fixation pin 1 is removed from the living body 100 is reduced. The effect which suppresses the penetration | invasion of the bacterium into the bone 103 by can be acquired. In obtaining this effect, the length L6 of the second coating layer 6 in the direction parallel to the rotation axis S is preferably 0.1 to 5 mm, more preferably 0.5 to 4 mm. Although it is more preferable that it is 1-3 mm, it is not limited to these.

  In the present embodiment, when the external fixation pin 1 is implanted in the living body 100, the end portion 71 located on the side farther from the stopper 3 in the third coating layer 7 is located above the skin 101. . According to such a configuration, the skin 101 and the third coating layer 7 can be brought into close contact with each other, and bacteria can be prevented from entering the living body 100.

  In the present embodiment, each of the first to third coating layers 5 to 7 described above is continuous with each other. Moreover, each structure of the 1st-3rd coating layers 5-7 is substantially the same. According to these structures, workability | operativity when each of the 1st-3rd coating layers 5-7 is laminated | stacked on the specific site | part of the external fixation pin 1 can be improved. In addition, each structure of the 1st-3rd coating layers 5-7 can also be varied as needed.

  As mentioned above, although preferred embodiment which concerns on this invention was illustrated, this invention is not limited to embodiment mentioned above, It cannot be overemphasized that it can be made arbitrary, unless it deviates from the summary of this invention.

  For example, in the above-described embodiment, the case where the living body implant is the external fixation pin 1 has been described as an example. However, the living body implant according to the present embodiment is embedded in the bone 103 and also contacts the soft tissue 102. It can be applied to a living implant that is not permanently implanted but is supposed to be removed from the living body 100 after healing.

  If a specific example is given, the biological implant shown in FIG. 4 will be mentioned. The biological implant shown in FIG. 4 is a bone screw 10 for internal fixation. The bone screw 10 includes a screw-shaped pin 12 and a substantially disk-shaped stopper 13 in order from the distal end portion 10a side. Similar to the external fixation pin 1, the first coating layer 5 and the second coating layer are provided. Layer 6 is provided.

Moreover, the bone screw 10 is further provided with the recessed part 14 located in the upper surface 131 of the stopper 13, as shown in FIG.4 (b). The recess 14 functions as a part into which a jig (not shown) that rotates the bone screw 10 is inserted.
Other configurations are the same as those of the external fixation pin 1 according to the above-described embodiment, and thus description thereof is omitted.

  In addition to the external fixation pin 1 and the bone screw 10 described above, the living body implant of the present embodiment includes, for example, a spinal rod, a pedicle screw, and a set screw. The present invention can also be applied to a spinal correction device provided.

  Further, in the above-described embodiment, as shown in FIG. 2B, when the external fixation pin 1 is viewed from the direction perpendicular to the rotation axis S, the stopper 3 is a substantial base having the long side 31 on the pin 2 side. However, instead of this, the shape of the stopper 3 may be a shape such as the stoppers 3A1 to 3D1 shown in FIGS. The shape of the stopper 3 is not limited to the shapes of the stoppers 3A1 to 3D1.

  In the above-described embodiment, as shown in FIG. 2C, when the external fixation pin 1 is viewed from the distal end portion 1a side, the stopper 3 is substantially ring-shaped, but instead of this, the stopper 3 For example, the shapes of the stoppers 3A2 to 3D2 shown in FIGS. The shape of the stopper 3 is not limited to the shapes of the stoppers 3A2 to 3D2.

DESCRIPTION OF SYMBOLS 1 External fixed pin 1a Tip part 1b Rear end part 2 Pin 21 End part 22 Part D2 Diameter L2 Length 3 Stopper 31 Long side D3 Diameter 4 Shaft 41 End part 42 Part 5 1st coating layer 6 2nd coating layer 61 End Part L6 Length 7 Third coating layer 71 End 10 Bone screw 10a Tip 12 Pin 13 Stopper 131 Upper surface 14 Recess 3A1, 3B1, 3C1, 3D1 Stopper 3A2, 3B2, 3C2, 3D2 Stopper 100 Living body 101 Skin 102 Soft tissue 103 Bone 104 Boundary part T Thickness S Rotation axis

Claims (10)

A pin located at the tip,
A stopper continuous with the pin;
And a first coating layer made of a calcium phosphate material and laminated on the stopper.   The living body implant according to claim 1, wherein the pin includes a screw-shaped part.   The living body implant according to claim 1 or 2, wherein the first coating layer is a silver hydroxyapatite sprayed coating.   The living body implant according to any one of claims 1 to 3, further comprising a second coating layer that is laminated on a portion including an end portion that is located on the stopper side of the pin and made of a calcium phosphate material.   The stopper according to claim 1, wherein when viewed from a direction perpendicular to the rotation axis, the stopper has a substantially trapezoidal shape with a long side on the pin side, and at least a diameter of the long side is larger than a diameter of the pin. The biological implant in any one.   The living body implant according to any one of claims 1 to 5, wherein the stopper is formed integrally with the pin. A columnar shaft continuous with the stopper;
The biological implant according to any one of claims 1 to 6, further comprising a third coating layer made of a calcium phosphate-based material and laminated on a portion of the shaft including an end portion located on the stopper side. .   The living body implant according to claim 7, wherein when implanted in a living body, an end portion of the third coating layer located on a side farther from the stopper is located above the skin.   The living body implant according to any one of claims 1 to 8, which is implanted in a living body and removed from the living body after healing.   The biological implant according to any one of claims 1 to 9, which is an external fixation pin.

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