WO2015041398A1 - Bone plate system - Google Patents

Abstract

The present invention relates to a bone plate system and, more particularly, to a bone plate system in which the angle of a locking screw can be adjusted. In addition, the present invention relates to a bone plate system capable of effectively maintaining a distance between a bone and a bone plate. The bone plate system according to the present invention comprises a plate and a locking screw for securing a bone. The plate comprises: an upper surface; a lower surface facing a bone; and a female screw formed in at least one hole which penetrates the upper surface and the lower surface. The locking screw has a screw, on the head thereof, for being coupled to the screw formed in the hole. The screw of the head is formed in a portion tapered in a truncated cone shape such that the diameter thereof decreases along the axial direction. Further, when the screw formed on the head and the screw formed in the hole of the plate are coupled, in order for the central axis of the locking screw to be inclined at a regular angle with respect to the central axis of the hole of the plate, the bone plate system has a gap between the screw of the head of the locking screw and the screw in the hole of the plate to be coupled. In addition, the locking screw, which is coupled to a locking hole, comprises: a head tapered such that the diameter thereof decreases along the central axis; a shaft extending from the head; a first male screw formed on the head so as to be coupled to a first female screw; and a second male screw formed on the shaft so as to be coupled to a bone. When the first male screw is coupled to the female screw, in order for the locking screw to be inclined with respect to the central axis of the locking hole, the depth of a groove having the largest external diameter among grooves of the first male screw is formed to be greater than the heights of threads of the female screw.

Description

Bone plate system

The present invention relates to a bone plate system, and more particularly to a bone plate system capable of adjusting the angle of the locking screw. The present invention also relates to a bone plate system capable of effectively maintaining a gap between bone and bone plate.

Bone plate systems for treating fractures are well known. The bone plate system squeezes broken bone fragments and pulls them together to facilitate treatment. The bone plate system includes a bone plate and a bone screw. The plate may include a hole in which an internal thread is formed and a hole in which the internal thread is not formed. The screw includes a locking screw in which an external thread is formed in the head and a non-locking screw in which the external thread is not formed in the head. Both the locking and non-locking screws have shafts with male threads formed to engage the bones.

The threaded shaft of the non-locking screw can be inserted into and coupled to the bone at various angles. However, since the non-locking screw is not screwed to the head and is not fixed to the bone plate, the angle between the bone plate and the screw may change during and / or after surgery. In addition, the screw may be loosened or loosened by the fractured bone and the dynamic load acting on the bone plate after surgery, resulting in insufficient fracture treatment.

The locking screw may be coupled to the female screw of the bone plate formed on the head to fix the angle at which the screw shaft is coupled to the bone. The central axis of the locking screw is coupled to be coaxial with the central axis of the internal thread. In addition, it is possible to prevent the screw coupled to the bone from loosening or loosening by the dynamic load acting on the bone fragments and the bone plate after surgery. However, the locking screw is limited in its ability to bind bone plates to compress bone fragments that affect fracture treatment.

That is, the locking screw can fix the joint angle of the bone pieces, but the insertion angle is limited, there is a disadvantage that the pressing ability is limited. Non-locking screws can be inserted into the bone at various angles and squeeze the bone fragments, but have the disadvantage of being loose.

U. S. Patent 6,669, 701 discloses a bone plate with at least one combination hole that can be used for both locking and non-locking screws. The combination hole includes a portion in which a circular thread is formed in the deche and a portion extending in the longitudinal direction and not formed in the thread. Non-locking screws are inserted at various angles in the unthreaded portions of the combination holes to be used to join the bone pieces and to provide a pressing force. The locking screw is inserted into the threaded portion of the combination hole to join the bone pieces and fix the engaged angle. However, there is a disadvantage in that it is limited to adjust the angle of locking the locking screw to the bone.

PCT International Publication No. WO 2009/023666 discloses a free versatile variable-angle bone plate system. The bone plate system disclosed in the above patent includes a locking screw, a non-locking screw, an adjustable angle locking screw and a bone plate having holes for using these screws together. The hole of the bone plate has a plurality of columns or threads of threads arranged around the circumference. The plurality of teeth or pillars are configured to engage with a male screw formed on the head of the locking screw and the locking screw which can be angled. The head of the locking screw which can adjust an angle is provided with the spherical part in which the thread is formed. However, the angle adjustable screw has a disadvantage that it is difficult to form a thread on the spherical portion. It is also difficult to process a plurality of discontinuous threaded pillars in the holes of the bone plate.

Various bone plate systems as described above have been disclosed, but there is still a need for a new bone plate system that is easy to produce and inexpensive, and which the surgeon can conveniently use for the purpose of treatment. In particular, there is a need for a bone plate system that is capable of angle adjustment and at the same time can selectively use locking screws and non-locking screws as needed. There is also a need for a bone plate system that can maintain a constant gap between the surface of the bone and the bone plate and at the same time maintain the bonding force in the treatment of fractures.

The present invention aims to provide a new bone plate system in which the locking screw and the non-locking screw can be selectively used as needed. It is also an object of the present invention to provide a new bone plate system capable of easily coupling the locking screw to a bone at a desired angle within a defined range. In addition, an object of the present invention is to provide a bone plate system configured in a shape that can be easily and inexpensively manufactured.

It is also an object of the present invention to provide a new bone plate system which can easily and accurately maintain the gap between bone and bone plate by fastening the locking screw. It is also an object of the present invention to provide a bone plate system capable of maintaining a bonding force between bones while maintaining a gap between bones and bone plates for bone regeneration and bonding.

According to one aspect of the invention there is provided a bone plate system capable of adjusting the locking angle. The present plate system includes a plate for locking the bone and a locking screw. The plate includes a top face, a bottom face facing the bone, and a screw formed in at least one hole passing through the top face and the bottom face. The locking screw is formed with a screw for fastening to the screw having a hole in the head. The locking screw also includes a shaft extending in the axial direction at the head and having a screwed shaft on the outer circumferential surface for coupling to the bone. In addition, the screw of the head is formed in the tapered portion in the shape of a truncated cone so that the diameter decreases along the axial direction. In addition, the screw head is fastened so that when the screw formed in the head and the screw formed in the hole of the plate are engaged, the center axis of the locking screw can be inclined at an angle with respect to the center axis of the plate hole. There is a play between the screw of the screw and the screw of the plate hole. The clearance between the screw of the screw head to be fastened and the screw of the plate hole is such that the depth of the valley having the largest diameter among the valleys of the screw formed in the tapered portion of the head is greater than the height of each of the peaks of the screw formed in the hole of the plate. It is.

The nose shape of the bite for forming the screw in the head portion of the screw and the bite for forming the screw in the hole of the plate may be different in order to form the clearance between the screws to be fastened as described above. That is, the head of the head is machined into a bite with a sharper nose end, so that the depth of the valley with the largest diameter of the valleys of the screw formed in the tapered portion of the head is greater than the height of each of the peaks of the screw formed in the hole of the plate. It can form large. When machining the screw of the screw head and plate hole, the ratio of the width of the end of the nose of the bite for machining the screw to the plate hole to the width of the end of the nose of the bite for machining the screw in the screw head is approximately 1.2. It is preferable to process the bytes in the range from 1.8 to 1.8.

Also in the bone plate system according to the present invention, the diameter of the valley of the screw formed in the hole of the plate is substantially equal to the diameter of the mountain having the maximum diameter among the threads of the screw formed in the tapered portion of the head of the locking screw. Preferably, the diameter of the thread of the screw formed in the plate hole is larger than the diameter of the acid having the smallest diameter among the acids formed in the tapered portion of the head.

In some embodiments, the tapered portion of the head is tapered in the form of a multistage truncated cone so that the diameter is reduced, and a screw may be formed in the tapered portion in the form of the multistage truncated cone. Further, the hole of the plate may include an upper portion tapered in a truncated conical shape and a lower portion not tapered, and the screw of the plate hole may be formed on the inner circumferential surface of the lower portion of the hole. In addition, the plate hole may further comprise a middle portion tapered and screwed in the form of a truncated cone between the upper portion and the lower portion. In addition, the lower surface of the plate may be configured in a concave curved shape. In addition, the screw formed in the head of the screw and the screw formed in the hole of the plate is preferably composed of double threads.

According to another aspect of the present invention, there is provided a bone plate system that can easily and accurately maintain the gap between bone and bone plate. The bone plate system according to the present invention includes a bone plate having a plurality of locking holes and a plurality of locking screws inserted into each of the locking holes and fastened to the bone. The locking holes are each formed with a first female thread. In addition, the locking screws are respectively coupled to the head tapered to reduce the diameter along the central axis, the shaft extending from the head, the first male screw formed on the head to be fastened to the first female screw, the bone The second male screw formed on the shaft is provided. The bone plate system according to the present invention is characterized in that, when the first male screw is fastened to the first female screw, the bone having the largest outer diameter of the bones of the first male screw is provided so that the locking screw can be fastened inclined with respect to the central axis of the locking hole. The depth is formed larger than the height of the mountains of the first female screw. Further, the pitch of the first male screw is smaller than the pitch of the second male screw so that the gap between the bone plate and the bone is maintained when the locking screw is fastened. The pitch of the first male screw can be configured to be 4/5, 3/4, 2/3 of the pitch of the second male screw, and preferably can be configured to be 1/2. In addition, the bone plate may have at least one pressing hole for fastening the non-locking screw. In addition, the lower surface of the bone plate may be formed in a concave curved shape for close contact with the bone.

In some embodiments, the head may be configured in the form of a multistage inverse truncated cone. In addition, the locking hole penetrates the upper and lower surfaces of the bone plate, the upper portion of the hole is tapered in the shape of a truncated cone, and the lower portion of the hole may be configured not to taper. In addition, the first female screw may be formed on the inner peripheral surface of the lower portion of the hole.

In some embodiments, the aperture further comprises an intermediate portion tapered in the form of a truncated cone between the upper portion and the lower portion, wherein a second female screw may be further formed in the intermediate portion.

In some embodiments, the valley diameter of the first female thread may be substantially equal to the maximum outer diameter of the first male thread, and the inner diameter of the first female thread may be larger than the minimum outer diameter of the first male thread.

According to the present invention, there is provided a bone plate system capable of selecting locking screws and non-locking screws as necessary and inserting them into the holes of the bone plate and fastening them to the bone, and at the same time adjusting the locking angle. In particular, the locking screw can be coupled to the bone at a desired angle in a defined range, allowing the surgeon to conveniently perform a fracture surgery using the bone plate system according to the present invention. That is, one locking screw to lock the plate in a predetermined direction or to be able to lock in various directions. In addition, the bone plate system of the locking angle adjustable according to the present invention, the head portion of the locking screw and the bone plate hole has a shape that can be easily screwed, it is possible to produce the bone plate system at a low cost.

In addition, according to the present invention, a bone plate system is provided that can easily and accurately maintain the gap between bone and bone plate. In particular, using the bone plate system according to the present invention, since the distance between the bone and the bone plate can be easily and accurately maintained by the fastening of the locking screw during the fracture procedure, the bone regeneration and bonding is excellent.

1 is a cross-sectional view of one embodiment of a plate according to the invention

FIG. 2 is a schematic diagram illustrating the steps of machining holes and screws in the plate of the embodiment shown in FIG.

3 is a schematic view showing a nose portion of a bite for machining a screw in the hole of the plate of the embodiment shown in FIG.

4 is a front view of one embodiment of a locking screw according to the present invention;

5 is a schematic diagram illustrating the step of machining the locking screw of the embodiment shown in FIG.

6 is a schematic view showing the nose portion of a bite for machining a screw in the head of the locking screw of the embodiment shown in FIG.

7 is an explanatory view showing a state in which a screw formed in the hole of the plate shown in FIG. 1 and a screw formed in the head of the locking screw shown in FIG. 4 are fastened in a concentric axis;

FIG. 8 is an explanatory view showing a state where the screw formed in the hole of the plate shown in FIG. 1 and the screw formed in the head of the locking screw shown in FIG.

9 is a perspective view of another embodiment of a plate according to the invention

10 is an explanatory view showing a state where the screw formed in the hole of the plate shown in FIG. 9 and the screw formed in the head of the locking screw shown in FIG. 4 are fastened in the forward direction;

FIG. 11 is an explanatory view showing a state where the screw formed in the hole of the plate shown in FIG. 9 and the screw formed in the head of the locking screw shown in FIG. 4 are fastened in the inclined cup direction;

12 is a schematic view showing a state in which a non-locking screw is inserted into a screwed hole of the plate shown in FIG.

13 is a cross-sectional view showing a configuration in which the locking screw is concentrically fastened to the locking hole of the bone plate in the bone plate system according to the present invention.

14 is a cross-sectional view showing a configuration in which the locking screw shown in FIG. 13 is inclinedly fastened to the locking hole.

15 is a perspective view showing an example of a bone plate in the bone plate system according to the present invention.

16 is a cross-sectional view showing the configuration of the bone plate in the bone plate system according to the present invention.

FIG. 17 is a schematic view showing a step of processing the locking hole shown in FIG. 16. FIG.

FIG. 18 is a view partially showing the nose portion of the bite for machining the locking hole shown in FIG.

19 is a front view showing the configuration of the locking screw in the bone plate system according to the present invention.

20 is a schematic view showing a step of processing the locking screw shown in FIG. 19.

FIG. 21 is a view partially showing the nose portion of the bite for machining the locking screw shown in FIG.

22 is a cross-sectional view showing a configuration in which the locking screw is concentrically fastened to the locking hole of the bone plate in another embodiment of the bone plate system according to the present invention.

FIG. 23 is a cross-sectional view showing a configuration in which the locking screw shown in FIG. 22 is inclinedly fastened to the locking hole of the bone plate.

24 is a perspective view showing an example of a bone plate in another embodiment of the bone plate system according to the present invention.

25 is a cross-sectional view showing a configuration in which the non-locking screw is concentrically fastened to the locking hole of the bone plate in another embodiment of the bone plate system according to the present invention.

Other objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments associated with the accompanying drawings.

Generally, the present plate system includes a plate and a screw. The plate has a screwed hole and a screwed hole. Locking screws are screws with threaded heads, typically used in threaded holes. Locking screws are engaged with threaded holes to provide high resistance to shear stress and torsion, and the screws and plates are combined to ensure stability. Non-locking screws are typically used in unthreaded holes and can be inserted at any angle. Non-locking screws provide optimal compression to fractured ends.

Hereinafter, a preferred embodiment of the bone plate system capable of adjusting the locking angle provided according to one aspect of the present invention will be described. The bone plate system according to the present invention, unlike the conventional bone plate system known, the locking screw can be fastened to the threaded hole of the plate at any angle.

1 is a cross-sectional view of one embodiment of a plate 10 for use in the bone plate system according to the present invention. The plate 10 has a plurality of holes formed therein, and there are holes formed with screws and those without screws. 1 is a cross-sectional view of a portion where the hole of the plate 10 is formed. The plate 10 has an upper surface 11 and a lower surface 12 disposed to face the bone, and a hole 13 penetrating the upper surface 11 and the lower surface 12 is formed. The plate 10 preferably uses a biocompatible material such as titanium, but is not limited thereto. A screw 14 is formed on the inner circumferential surface of the hole 13, and the screw 14 includes a valley 14a, a peak 14c, and a flank 14b connecting the valley and the peak. The screw 14 of the present embodiment may use a double thread or a single thread.

With reference to FIG. 2, the hole 13 and the screw 14 of the plate 10 shown in FIG. 1 are demonstrated in more detail. FIG. 2 (a) shows the hole processing state before the step of forming a screw in the hole 13 in the plate 10. The hole 13 before machining the thread has a tapered upper portion 16 and a tapered intermediate portion extending at different angles from the upper portion 16 so that the inner circumferential surface is inclined at an angle with respect to the central axis X. 13b) and a lower portion 13a which extends from the middle portion to be perpendicular to the upper surface 11 and the lower surface 12. Referring to FIG. 2 (b), the screw is not machined in the upper portion 16, but the screw 14 is machined in the lower portion 13a and the middle portion 13b. The diameter (d2) of the valleys of the screws (14) formed in the middle portion (13b) and the lower portion (13a) is the same, and the diameter of the threads of the threads formed in the middle portion (13b) tapered with respect to the upper surface is equal to the upper surface. It is larger than the diameter d1 of the thread of the screw formed in the vertical lower part. In some embodiments, the middle portion 13b may be omitted. 3 (c) shows the state in which the plate 10 is bent in order to bring the lower surface 12 closer to the bone. The plate 110 of the embodiment shown in FIG. 3 (c) will be described later.

3 shows the nose of a hole threading bite 19 for forming a screw 14 in a hole 13 of the plate 10. The threaded bite 19 nose end 19a has a constant width w1. When the width of the nose end 19a is narrow with respect to the angle A of the same thread, a deep valley (high peak) is formed, and a wide valley produces a shallow valley (low peak). In this embodiment, the thread 24 of the screw 20 head 21 was machined using a nose angle A of the hole threading bite 19 of 60 ° and a width w1 of 0.16 mm. .

4 is a front view of one embodiment of a locking screw 20 used in the bone plate system according to the present invention. The locking screw 20 of this embodiment includes a head 21 and a shaft 26 extending in the axial direction from the head. Screw 20 is preferably manufactured using a biocompatible material, for example, titanium, but is not limited thereto. The head 21 is provided with a screw 24 for fastening with the screw 14 formed in the hole of the plate 10. The screw 24 includes a flank 24b and a flank 24b which connects the valley 24c with the valley 24c. The screw 24 of the present embodiment is formed with two rows of screws to be engaged with the screw 14 formed in the hole 13 of the plate 10. In addition, a shaft 27 is formed on the shaft 26 to be coupled to the bone, and a flute 28 is formed at the end to allow self-tapping or self-drilling. It is.

The locking screw 20 shown in FIG. 4 will be described in more detail with reference to FIG. 5. 5 (a) shows the state before the screw is machined into the locking screw 20. On the outer circumferential surface of the head 23 of the locking screw 20, a threaded portion 23 tapered at an angle with respect to the central axis Y is formed. The threaded portion 23 is in the form of a tapered truncated cone so that the diameter decreases along the central axis Y. The threaded portion 23 may include an upper threaded portion 23a and a lowered threaded portion 23b extending from the upper threaded portion 23a and tapered to reduce its diameter. In some embodiments, the lower threaded portion 23b may be omitted. 5 (b) shows a state in which a screw 27 for joining to a bone is processed on the shaft 26 of the screw 20. Referring to FIG. 5B, the upper threaded portion 23a has a maximum diameter D1 and a minimum diameter D2. 5C shows a state in which the screw 24 is processed in the screw processing portion 23 of the head 21. The maximum diameter of the peak of the screw 24 processed in the head 21 is equal to the maximum diameter D1 of the threaded portion 23a. 5 (d) shows a state in which the flute 28 is processed at the end of the shaft 26. Fig. 5 (e) is a cross sectional view showing a recess 22a (recess) for accommodating a tool for screwing a screw into a bone or fastening it to a hole in a plate in the upper face 22 of the head.

6 shows the nose of a threading bite 29 for forming a screw 24 in the head 21 of the screw 20. The threaded bite 29 nose end 29a has a constant width w2. If the width w2 of the nose end 29a is narrow with respect to the angle A of the same thread, a deep valley is formed, and if the width w2 is wide, a shallow valley is formed. In this embodiment, the screw 24 of the screw 20 head 21 was processed using a nose angle A of the threading bite 29 of 60 ° and a width w2 of 0.1 mm.

7 is an explanatory view showing a state in which a screw formed in the hole of the plate shown in FIG. 1 and a screw formed in the head of the locking screw shown in FIG. 4 are fastened in the forward direction. As described above, the width w1 of the nose end of the hole threading bite 19 in which the screw 14 of the plate 10 hole 13 of the present embodiment is machined is the screw of the head of the screw 20. It is larger than the width w2 of the nose end of the threading bite 29 which processed (24). Therefore, the height h1 of the thread of the head 21 of the screw 20 is higher than the height h2 of the thread of the hole 13 of the plate 10. Thus, when the screw 24 of the head 21 of the screw 20 and the screw 14 of the hole 13 of the plate 10 are fastened in the concentric axis, between the screw 24 and the screw 14 There is play. When the center axis X of the plate 10 hole 13 and the center axis Y of the screw 20 are arranged concentrically and rotated so that the screw 20 is engaged, the head 21 screw 24 The flanks and the flanks of the screw 14 of the hole 13 are in contact, and the clearances C1 and C2 are formed between the valleys of the screw 24 of the head 21 screw and the mountains of the screw 14 formed in the hole 13. Is formed. In addition, since the head 21 has a tapered truncated truncated cone shape, the closer to the shaft 26, the larger the size (volume) of the clearance (C2> C1). When the locking screw 20 is coaxially fastened, the first peak 24c-1 of the locking screw 20 comes into contact with the middle portion 13b of the hole of the plate 10.

FIG. 8 is an explanatory view showing a state where the screw formed in the hole of the plate shown in FIG. 1 and the screw formed in the head of the locking screw shown in FIG. 4 are fastened in an inclined direction. Referring to FIG. 8, the locking screw 20 of the present embodiment has a central axis Y of the screw 20 with respect to the center axis X of the hole 13 of the plate 10 within a range of an angle θ. It can be fastened at any angle. Referring to FIG. 8, the screw 24 is formed in the truncated head of the locking screw 20, so that the diameter of the thread decreases as it approaches the shaft direction, so that the closer to the shaft 26, the hole is formed in the plate 10. The play with the screw 14 is increased. Accordingly, the plate 10 may be inclined and fastened with the screw 14 formed in the lower portion 13a of the hole 13 vertically penetrated to the upper surface 11 and the lower surface 12. The maximum value of the angle θ that can be tightened to be inclined is limited by the sizes of the clearances C1 and C2, and the sizes of the clearances C1 and C2 are the width of the nose end of the hole threading bite and the head threading bite It is defined by the width of the nose end. In addition, the magnitude | size of a clearance is limited by the inclination degree of the taper of the threaded part in which the screw of a head is formed. In some embodiments, the ratio of the width of the end of the nose of the bite to thread the plate hole to the width of the end of the nose of the bite to thread the locking screw head is in the range of approximately 1.2 to 1.8. Can be. When the locking screw 20 is fastened to be inclined as shown in FIG. 8, a part of the first peak 24c-1 of the screw 24 of the locking screw 20 is screwed into the hole of the plate 10. It is inserted into the first valley 14a-1 of (14), and a part of the first hill 24c-1 comes into contact with the middle portion 13b of the hole 13 of the plate 10. If the locking screw 20 can be fastened inclined, it is possible to avoid interference between the locking screws during the procedure, and to fix the fractured bone in a direction effective for bone bonding.

In some embodiments, the diameter (d1) of the peak of the plate hole and the diameter (d2) of the valley and the maximum diameter (D1) of the peak of the screw head (D1) and the minimum diameter (D2) of the peak may be configured such that the table below has dimensions. Can be. As shown in the table below, it is preferable to equalize the diameter of the valley of the screw formed in the hole of the plate and the maximum diameter of the peak of the screw formed in the taper of the head of the locking screw. In embodiments having the dimensions as shown in the table below, the nose angle A of the threading bites 19, 29 is 60 °, the nose end width w1 of the hole threading bite 19 is 0.16, The width w2 of the nose end of the threading bite 19 processed the thread using the thing of 0.1 mm, respectively. When a screw was formed in the hole of the plate having the dimensions as shown in the table below and the locking screw head, the maximum value of the angle that can be inclined was approximately 10 °. Plate thicknesses range from approximately 1.6-2.0 mm.

Table 1

9 is another embodiment of a plate 110 according to the present invention. The plate 110 is formed with a plurality of holes 113 and 150. Among the holes are holes 113 with screws 114 and holes 150 without screws. The locking screw 20 or the non-locking screw is inserted into the hole 113 formed with the screw 114, and the non-locking screw is inserted into the hole 150 without the screw forming. The shape and action of the unthreaded holes are widely used in known bone plate systems, and detailed descriptions thereof are omitted. The plate 110 of the present embodiment is bent so that the lower surface is concavely curved with respect to the longitudinal axis to be in close contact with the bone during the procedure. In addition, the upper surface of the plate 110 is convexly curved by bending. In addition, the central axes of the holes 113 and 150 that were parallel before bending are offset from each other by bending. Referring to FIG. 9, the edge of the plate 110 is curved to form a thinner thickness toward the edge to reduce foreign body feeling at the surgical site and prevent secondary damage such as inflammation after the procedure.

FIG. 10 shows a state in which the locking screw 20 is coaxially fastened to the plate 110 of the embodiment shown in FIG. 9. As shown in FIG. 2C, when the plate 110 is bent, the diameter d3 of the peak of the screw 14 and the diameter d4 of the valley are changed. When the plate 110 is bent, the clearances C1 and C2 are not to be removed between the screw 24 of the locking screw 20 and the screw 114 of the plate 110. If the bending is excessively excessive, the diameters of the valleys and the peaks of the screws 14 are changed so that the locking screws cannot be tightened, or the locking screws cannot be tightened obliquely.

FIG. 11 illustrates a state in which the locking screw 20 is inclined at an angle θ to the bent plate 110 of the embodiment illustrated in FIG. 9. A part of the first peak 24c-1 of the screw 24 of the locking screw 20 is inserted into the first valley 114a-1 of the screw 114 of the hole 113 of the plate 110, and the first peak 24c. A part of -1 comes into contact with the middle portion 113b of the hole 113 of the plate 110.

FIG. 12 shows a state in which the non-locking screw 50 is inserted into the hole 113 in which the screw 114 of the plate 110 is formed. The non-locking screw is not threaded in the head 51, and the inclined surface 52 of the screw head 51 has a hole in the plate 110 when the shaft of the non-locking screw 50 is inserted into and coupled to the bone. In contact with the middle portion 113b of the 113 to maintain the inserted direction. That is, by forming the intermediate portion 113b in the hole 113 of the plate 110 and machining the screw, the locking screw and the non-locking screw can be selectively used as necessary.

In the following, a preferred embodiment of the bone plate system, which is provided according to another aspect of the present invention, which can easily and accurately maintain the gap between the bone and the bone plate, is described.

First, referring to FIGS. 13 to 16, the bone plate system 100 according to the present invention includes a bone plate 110. The bone plate 110 is a material having not only excellent mechanical properties but also biocompatibility and biofuntionability to maintain a stable function in vivo for the treatment of fractures, for example, titanium. It is preferably prepared as, but is not limited thereto. In addition, as exemplarily illustrated in FIG. 15, the bone plate 110 may be manufactured in various shapes and structures to be suitable for treating fractures.

The bone plate 110 has an upper surface 112, a lower surface 114 disposed toward the bone 10, and a plurality of locking holes 120. The locking holes 120 are a hole 122 penetrating the upper surface 112 and the lower surface 114, and a female screw formed on the inner circumferential surface of the hole 122 to the first female screw 130 and the second female screw 140. Consists of. The first female screw 130 includes a plurality of flanks connecting the plurality of valleys 132; (Flank: 136) and a first pitch (P ₁ P). The first female screw 130 of the present embodiment is composed of two threads, but may be composed of a single thread. As shown in FIG. 3B, at least one compression hole 150 is formed in the bone plate 110. The compression hole 150 is a hole in which no female thread is formed, and a non-locking screw is inserted into and fixed to the bone.

A hole and a female screw in the locking hole will be described with reference to FIG. 17. As shown in FIG. 17 (a), the hole 122 before the first female screw 130 is formed has an upper portion 124, an intermediate portion 126, and a lower portion 128. The upper portion 124 is formed as a taper bore inclined at an angle with respect to the center axis line CA ₁ . The intermediate portion 126 is formed as a tapered bore that is inclined at a different angle from the upper portion 124. The lower portion 128 is formed to extend from the middle portion 126 so as to be perpendicular to the upper surface 112 and the lower surface 114.

As shown in FIG. 17B, the female thread is not machined in the upper portion 124. The first female screw 130 is formed in the lower portion 128. The second female thread 140 is formed in the middle portion 126. The second female screw 140 has the same pitch as the first pitch P ₁ of the first female screw 130. The inner diameter of the second female thread 140 is greater than the inner diameter d ₁ of the first female thread 130.

As shown in FIG. 17 (a), the inner diameter d ₁ of the first female screw 130 is the diameter d of the lower portion 128. Major diameter of first internal thread d ₂ of the first female screw 130 is the same. In some embodiments, the middle portion 126 may be deleted. FIG. 5C shows the bone plate 210 of the bone plate system 200 of another embodiment shown in FIGS. 22-25. The bone plate 210 of another embodiment is bent (Banding) so that the lower surface 112 is in close contact with the bone. The bone plate 210 of another embodiment will be described in more detail below.

18 shows a bite used to machine a female thread according to the invention. Referring to FIG. 18, the female thread machining bite 150 has a nose 152 for machining the female thread. The nose end 154 has a constant width w ₁ . The angle of the thread (Angle of thread) is determined by the angle θ ₂ of the nose 152. If the width w ₁ of the nose end 154 is narrow with respect to the angle θ ₂ of the same nose 152, a deep-threaded female screw is formed. On the other hand, if the width w ₁ of the nose end 154 is high, a female screw having a shallow valley is formed. In the present embodiment, the angle θ ₂ of the nose 152 is 60 °, and the first female thread 130 is formed by the female thread-processing bite 150 having a width w ₁ of the nose end 154. Was processed.

13, 14, and 19, the locking screw 300 includes a head 302 and a shaft 304 extending along the axial direction from the head 302. The locking screw 300 may be made of titanium in the same manner as the bone plates 110 and 210. The upper surface 306 of the head 302 is composed of a round head formed in a round.

A first male screw 310 is formed in the head 302 to be fastened to the first female screw 130. The first male thread 310 includes a plurality of valleys 312, a plurality of hills 316, and a plurality of flanks 316 connecting the valleys 312 and the hills 316 adjacent to each other. . The first male screw 310 has a second pitch P ₁ for fastening with the first female screw 130. In the present embodiment, the first male screw 310 is formed of two rows of screws for fastening with the first female screw 130.

The second male screw 320 is formed along the outer circumferential surface of the shaft 304 to be coupled to the bone 10. The second male screw 320 has a third pitch P ₃ . The second pitch P ₂ of the first male screw 310 is configured to be smaller than the third pitch P ₃ of the second male screw 320. The second pitch P ₂ is configured to be 1/2 smaller than the third pitch P ₃ . When the locking screw 300 is rotated once, the second male thread 320 is fastened to the bone 10 by one pitch, and the first male thread 310 is half the pitch to the first and second female threads 130 and 160. Is fastened. That is, when the locking screw 300 rotates once, the second male screw 320 is fastened to the bone 10 by twice as much as the first male screw 310. By the locking of the locking screw 300, the gap G ₁ is maintained between the lower surface 116 and the bone 10 for regeneration and growth of the bone 10. A flute 322 is formed at the tip of the shaft 304 to allow self-tapping or self-drilling.

With reference to Figure 20 looks at in more detail with respect to the locking screw. The locking screw 300 shown in FIG. 20A is a state before the first male thread 310 and the second male thread 320 are processed. The head 302 of the locking screw 300 is formed on the outer circumferential surface thereof with a threaded portion 330 tapered at an angle with respect to the central axis CA ₂ . The thread processing unit 330 is in the form of a reverse circular cone frustum tapered to reduce the diameter along the central axis CA ₂ . The thread machining portion 330 is composed of an upper thread machining portion 332 and a lower thread machining portion 334 extending from the upper thread machining portion 332 and tapered to reduce the diameter. In some embodiments, the lower threaded portion 334 may be deleted.

20 (b) shows a state in which the second male screw 320 is processed in the shaft 304 of the locking screw 300. The upper threaded portion 332 has a maximum diameter D ₁ and a minimum diameter D ₂ . 20C shows a state in which the first male screw 310 is processed in the screw machining portion 330 of the head 302. The maximum major diameter first external thread D _{3 of} the first male thread 310 is the same as the maximum diameter D ₁ of the threaded part 330. The minimum major diameter first external thread D _{4 of} the first male thread 310 is equal to the minimum diameter D ₂ of the threaded portion 330.

FIG. 20 (d) shows a state in which the flute 322 is processed at the distal end of the shaft 304. FIG. 20E shows a tool, for example a driver, for driving the locking screw 300 into the bone 10 or fastening the first female screw 130 to the upper surface 110 of the head 302. It shows a state in which a recess 308 is formed.

Figure 21 shows the bite used to machine the first male thread of the locking screw according to the invention. Referring to FIG. 21, the male thread machining bite 340 has a nose 342 for processing a first male thread. The nose end 344 has a constant width w ₂ . The angle of the thread is determined by the angle θ ₃ of the nose 342. If the width w ₂ of the nose end 344 is narrow with respect to the angle (theta) ₃ of the same nose 342, a deep-threaded male thread is formed. On the other hand, if the width w ₂ of the nose end 342 is wide, a male screw having a shallow valley is formed. The width w ₁ of the nose end 164 of the female threaded bite 160 is greater than the width w ₂ of the nose end 344 of the male threaded bite 340. In the present embodiment, the angle θ ₃ of the nose 342 is 60 °, and the first male thread 310 is provided by the male thread cutting bite 340 having a width w ₂ of the nose end 344 of 0.1 mm. Was processed.

13 shows a state in which the locking screw is fastened to the female screw of the bone plate in the forward direction in the bone plate system according to the present invention. As described above, the width w ₁ of the nose end 164 of the female thread machining bite 160 is larger than the width w ₂ of the nose end 344 of the male thread machining bite 340. Therefore, the height of the thread (h ₁ ) of the first male thread 310 is higher than the thread height (h ₂ ) of the first female thread (130). That is, the bone depth DP ₁ of the bone having the largest outer diameter among the valleys 312 of the first male thread 310 is greater than the thread height h ₂ of the peaks 164 of the first female thread 130. It is formed larger than the bone depth DP ₂ of the valleys 162. The thread height h ₁ of the first male thread 310 is substantially equal to the bone depth DP ₁ , and the thread height h ₂ of the first female thread 130 is substantially equal to the bone depth DP ₂ . Do.

When the first male screw 310 is fastened, a gap exists between the first male screw 310 and the first female screw 130. Flank of the locking hole 130, the central axis (CA ₁₎ and the locking if the central axis (CA ₂₎ of the screw 300, rotating the locking screw 300 is in a state arranged on the same axis, a first female screw 130 of the ( 166 and the flanks 316 of the first male thread 310 are in contact with each other. Spaces G ₂ and G ₃ are formed between the valleys 162 of the first female thread 130 and the peaks 316 of the first male thread 310. Since the head 302 has an inverted truncated cone shape, the closer the shaft 304 is, the larger the size (volume) of the gap is (G ₃ > G ₂ ). When the locking screw 300 is coaxially fastened, the first of the peaks 316-1 of the first male thread 310 comes into contact with the middle portion 136 of the hole 132.

Figure 14 shows a state in which the locking screw is fastened in the oblique direction to the female screw of the bone plate in the bone plate system according to the present invention. Referring to FIG. 13, the locking screw 300 has its center axis CA ₂ fastened at an arbitrary angle within a range of a constant angle θ ₁ with respect to the center axis CA ₁ of the locking hole 130. Can be. Since the first male thread 310 is formed in the head 302 having an inverted truncated cone shape and the outer diameter decreases as it approaches the shaft 304, the distance from the first female thread 130 becomes closer as the shaft 304 approaches. It becomes bigger. Accordingly, the first male screw 310 is inclinedly fastened with the first female screw 130 formed in the lower portion 128 vertically penetrating the upper and lower surfaces 110 and 112 of the bone plates 110 and 210, respectively. Can be.

The maximum value of the angle θ ₁ through which the first female screw 130 and the first male screw 310 may be inclined may be defined by the sizes of the gaps G ₂ and G ₃ . Gap (G _2, G ₃₎ of the size is defined by the width (w ₂₎ of the female screw processing byte 160, the width (w ₁₎ and externally threaded processing byte 340. In addition, the size of the gaps G ₂ , G ₃ is defined by the degree of inclination of the taper of the thread processing portion 330. In some embodiments, the ratio of the width w ₁ of the female threaded bite 160 to the width w ₂ of the male threaded bite 340 may range from approximately 1.2 to 1.8.

When the locking screw 300 is fastened to be inclined, a part of the first peak 316-1 of the first male thread 310 of the locking screw 300 is the first valley 132-1 of the first female screw 130. It comes into contact with the middle portion 136 while being inserted. As such, the locking screw 300 is obliquely fastened to prevent interference between the locking screws 300 fastened to the bone 10 during surgery, and to fix the bone fragments in a direction effective for bone bonding. have.

On the other hand, in the bone plate system according to the present invention, the inner diameter (d ₁ ), the rib diameter (d ₂ ) of the first female screw 130 and the maximum outer diameter (D ₃ ), the minimum outer diameter of the first male thread (310). (D ₄ ) may be configured in the dimensions of Table 2 below. It is preferable to make the rib diameter (d ₂ ) and the maximum outer diameter (D ₃ ) the same. As described above, each of the first female thread 130 and the first male thread 310 is processed by the female thread and the male thread machining bite 340. The nose angles 162 and 342 at the angles θ ₂ and θ _{3 of the} female thread and the male thread machining bite 160 and 340 are 60 °. The width w ₁ of the nose end 164 of the female threaded bite 160 is 0.16 mm, and the width w ₂ of the nose end 344 of the male threaded bite 340 is 0.1 mm. When the first female screw 130 and the first male screw 310 having the dimensions shown in [Table 2] were formed, the maximum value of the angle at which the locking screw 300 can be fastened inclined was approximately 10 °. The thickness of the bone plates 110 and 210 was about 1.6-2.0 mm.

TABLE 2

22-25, another embodiment of the bone plate system according to the present invention is shown. Referring to FIGS. 14C, 22, and 23, the bone plate 210 is bent such that the lower surface 116 is concavely curved with respect to the longitudinal axis to be in close contact with the bone 10. In addition, the upper surface 112 of the bone plate 210 is convexly curved by bending. The locking axes 120 and the central axes of the compression holes 150, which were parallel before bending, are offset from each other by bending. The edge of the plate 210 is formed in a curved shape whose thickness gradually becomes thin so as to reduce foreign body feeling at the surgical site and prevent secondary damage such as inflammation after the procedure. 12, the plate 210 is illustrated as being configured in a straight line.

22 and 23, when the bone plate 210 is bent, the gaps G ₂ and G ₃ between the first female screw 130 and the first male screw 310 should not be lost. When the bone plate 310 is excessively bent, the diameters of the valleys 132 and the peaks 134 of the first female screw 130 are changed so that the locking screw 300 cannot be fastened or cannot be fastened inclinedly. .

FIG. 24 shows a state where the locking screw 300 is inclinedly fastened at a predetermined angle θ ₄ to the locking hole 130 of the bone plate 310. A portion of the first peak 416-1 of the first male thread 310 is inserted into the first valley 162-1 of the first female screw 130. At this time, a portion of the first peak 416-1 comes into contact with the middle portion 136 of the locking hole 130.

FIG. 25 shows a state in which the non-locking screw 400 is inserted into the locking hole 130 of the bone plate 310. The non-locking screw 400 is not threaded in the head 402. When the shaft 404 of the non-locking screw 400 is coupled to the bone, the inclined surface 404 of the head 402 is in contact with the middle portion 136 of the locking hole 130 to maintain the inserted direction. That is, when the intermediate portion 136 is formed in the locking hole 130 of the bone plate 310 and the second female thread 140 is processed, the locking screw 300 and the non-locking screw 400 may be selectively selected as necessary. Can be used.

The embodiments described above are merely illustrative of the preferred embodiments of the present invention, the scope of the present invention is not limited to the described embodiments, those skilled in the art within the spirit and claims of the present invention It will be understood that various changes, modifications, or substitutions may be made thereto, and such embodiments are to be understood as being within the scope of the invention.

Claims (18)

1. A bone plate system comprising a locking screw and a plate for fixing a bone,

   The plate includes a top surface, a bottom surface facing the bone, and screws formed in at least one hole passing through the top surface and the bottom surface,

   The locking screw includes a head and a shaft extending along the axial direction in the head and a screwed shaft for engaging the bone on the outer circumferential surface, wherein the head is formed in the tapered portion in the shape of a truncated cone to reduce the diameter along the axial direction. Including screws,

   The valleys of the screw formed in the tapered portion of the head so that when the screw formed in the head and the screw formed in the hole of the plate are fastened, the center axis of the locking screw can be inclined at an angle with respect to the center axis of the plate hole. The bone plate system which can adjust the locking angle formed larger than the height of each of the mountains of the screw formed in the hole of the plate.
2. The method of claim 1,

   The tapered portion of the head is a bone plate system capable of adjusting the tapered locking angle in the form of a multistage truncated cone to reduce the diameter.
3. The method of claim 1,

   The hole of the plate includes an upper portion tapered in the shape of a truncated cone and a lower portion not tapered, and the screw of the plate hole is formed on the inner circumferential surface of the lower portion of the hole.
4. The method of claim 3,

   And the plate hole further comprises a middle portion tapered and screwed in the form of a truncated cone between the upper portion and the lower portion.
5. The method according to any one of claims 1 to 4,

   The diameter of the valley of the screw formed in the hole of the plate is substantially the same as the diameter of the mountain having the largest diameter among the mountains of the screw formed in the tapered portion of the head of the locking screw,

   A bone plate system capable of adjusting a locking angle formed with a diameter of a thread of a screw formed in the plate hole is larger than a diameter of a mountain having a minimum diameter among the mountains formed in the tapered portion of the head.
6. The method of claim 4, wherein

   The lower surface of the plate is a bone plate system capable of adjusting the locking angle of the concave curved shape.
7. The method of claim 4, wherein

   And a screw formed in the head of the screw and a screw formed in the hole of the plate are two rows of screws.
8. A bone plate system comprising a locking screw and a plate for fixing a bone,

   The plate includes a top surface, a bottom surface facing the bone, and screws formed in at least one hole passing through the top surface and the bottom surface,

   The locking screw includes a head and a shaft extending along the axial direction in the head and a screwed shaft for engaging the bone on the outer circumferential surface, wherein the head is formed in the tapered portion in the shape of a truncated cone to reduce the diameter along the axial direction. Including screws,

   To the tapered portion of the head of the screw so that when the screw formed in the head and the screw formed in the hole of the plate are engaged, the center axis of the locking screw can be inclined at an angle with respect to the center axis of the plate hole. And the formed screw is sharper than the end of the nose of the threaded bite which has machined the screw formed in the hole of the plate.
9. The method of claim 7, wherein

   Adjusting the locking angle with the bite in the ratio of the width of the end of the nose of the bite to the plate hole to the width of the end of the nose of the bite for threading the screw head is in the range of approximately 1.2 to 1.8. This possible bone plate system.
10. The method according to claim 7 or 8,

    The diameter of the valley of the screw formed in the hole of the plate is substantially the same as the diameter of the mountain having the largest diameter among the mountains of the screw formed in the tapered portion of the head of the locking screw,

    A bone plate system capable of adjusting a locking angle formed with a diameter of a thread of a screw formed in the plate hole is larger than a diameter of a mountain having a minimum diameter among the mountains formed in the tapered portion of the head.
11. A bone plate having at least one locking hole in which a first female thread is formed;

    A head tapered to reduce the diameter along a central axis by being fastened to the at least one locking hole, a shaft extending from the head, and a first male screw formed on the head to be fastened to the first female screw; And a locking screw having a second male thread formed on the shaft to be coupled to the bone,

    When the first male thread is fastened to the first female thread, the depth of the bone having the largest outer diameter of the bones of the first male thread is such that the locking screw can be fastened inclined with respect to the central axis of the one or more locking holes. It is formed larger than the height of the mountains of the first female thread,

    And a pitch of the first male screw is smaller than a pitch of the second male screw so that a gap is maintained between the bone plate and the bone when the locking screw is fastened.
12. The method of claim 1,

    The head is tapered in the form of a multistage inverse truncated cone.
13. The method of claim 1,

    The at least one locking hole has a hole penetrating the upper surface and the lower surface of the bone plate, the hole has a tapered upper portion and a non-tapered lower portion, the first female screw is the lower portion Bone plate system formed on the inner peripheral surface of the part.
14. The method of claim 3,

    And the hole further comprises an intermediate portion tapered in the form of a truncated cone between the upper portion and the lower portion, wherein the second female thread is further formed in the intermediate portion.
15. The method according to any one of claims 1 to 4,

    And a bone diameter of the first female thread is substantially equal to a maximum outer diameter of the first male thread, and an inner diameter of the first female thread is larger than a minimum outer diameter of the first male thread.
16. The method of claim 5,

    The bottom surface of the bone plate is formed in a concave curved shape for close contact with the bone.
17. The method according to any one of claims 1 to 4,

    The pitch of the said 1st male thread is a bone plate system comprised by 1/2 of the pitch of the said 2nd male thread.
18. The method according to any one of claims 1 to 4,

    The bone plate has at least one pressing hole is formed for the fastening of the non-locking screw.

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