Interface screw with soft tissue squeezing function

Abstract

The interface screw with the soft tissue squeezing function comprises a screw body and an inserting piece, the screw body is provided with a tail portion and a head portion, threads are formed outside the screw body, a through hole extending in the axial direction of the screw body from the tail portion to the head portion is further formed in the screw body, and the through hole penetrates through at least part of teeth of the threads in the extending process. The inserting piece is provided with a sealing cover and an inserting rod extending out of the sealing cover, and the inserting rod is matched with the through hole so that the inserting rod can be inserted into the through hole, and therefore the soft tissue between the teeth squeezed into the threads can be tightly squeezed. According to the invention, the holding force of the interface screw for fixing the soft tissue can be improved, and the soft tissue and the skeleton are not loosened.

Description

Technical Field

[0001] The invention relates to the field of orthopedic medical devices, and in particular to an interface screw with a soft tissue squeezing function. Background Art

[0002] Interference screws are used to solve complex fracture repair, joint reconstruction and soft tissue fixation problems. During surgery, the interference screw is screwed into the pre-drilled hole of the bone, and the soft tissue (tendon or ligament) is squeezed between the inner wall of the pre-drilled hole and the thread by the interference screw, thereby achieving the purpose of fixing the bone and soft tissue. The existing interface screws have the problem of insufficient holding force for fixing soft tissue, resulting in loosening of soft tissue and bone. Summary of the invention

[0003] The invention provides an interface screw with a soft tissue squeezing function.

[0004] Specifically, the present invention is achieved through the following technical solutions: An embodiment of the present invention provides an interface screw with a soft tissue tightening function, comprising a nail body and an insert, the nail body having a tail and a head, a thread formed on the outside of the nail body, and a through hole extending from the tail to the head along the axial direction of the nail body. The through hole penetrates at least part of the teeth of the thread during the extension process. The insert is provided with a cover and an insertion rod extending from the cover, the insertion rod matches the through hole so that the insertion rod can be inserted into the through hole, thereby squeezing the soft tissue squeezed between the teeth of the thread.

[0005] In some embodiments, the end of the plunger is spherical.

[0006] In some embodiments, a conical boss is provided on the side of the cover facing the insertion rod, a conical recess is formed on the tail of the nail body, and the conical boss matches the conical recess.

[0007] In some embodiments, a first limiting strip extending axially along the nail body is provided on the conical boss side facing the insertion rod, a first limiting groove is formed at the tail of the nail body, the first limiting strip matches the first limiting groove and is located in the peripheral area of ​​the circular cross-section of the nail body.

[0008] In some embodiments, the first limiting strip and the first limiting groove are both straight line segments and arc segments connected in sequence along the radial direction of the nail body.

[0009] In some embodiments, the arc segment is tapered along the axial direction of the nail body from the tail of the nail body toward the head.

[0010] In some embodiments, a central boss extending axially along the nail body is provided on the side of the conical boss facing the insertion rod, and a central concave platform is formed at the tail of the nail body. The central boss matches the central concave platform and is located in the central area of ​​the circular cross-section of the nail body.

[0011] In some embodiments, a second limiting strip extending along the axial direction of the nail body is provided on the conical boss side toward the insertion rod, a second limiting groove is formed at the tail of the nail body, the second limiting strip matches the second limiting groove, the second limiting strip extends between the center boss and the insertion rod, and the second limiting groove extends between the center recess and the through hole.

[0012] In some embodiments, the top of the thread of the nail body is tapered from the tail of the nail body toward the head along the axial direction of the nail body.

[0013] In some embodiments, the nail body is made of a degradable polymer material, and the insert is made of a degradable metal material; or, both the nail body and the insert are made of a degradable metal material.

[0014] According to an embodiment of the present invention, when the external thread of the nail body squeezes the soft tissue, the plug-in is inserted into the through hole, so that the insertion rod performs a second squeezing on the soft tissue trapped between the teeth of the thread, and further squeezes the soft tissue from the gap between the teeth of the thread toward the inner wall of the preset hole, thereby improving the holding force of fixing the soft tissue and ensuring that the soft tissue and the bone are not loose.

[0015] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. Figure 1 is a schematic diagram from a first perspective of a disassembled state of an interface screw with a soft tissue tightening function in one embodiment of the present invention; Figure 2 yes Figure 1 A partial enlarged view of the middle A; Figure 3 is a schematic diagram from a second viewing angle of the disassembled state of the interface screw with soft tissue tightening function in one embodiment of the present invention; Figure 4 yes Figure 3 A partial enlarged view of point B in the middle; Figure 5 is a top view of an insert and a nail body in one embodiment of the present invention; Figure 6 is a cross-sectional view of an assembled state of an interface screw with a soft tissue tightening function in one embodiment of the present invention; Figure 7 3. It is a schematic diagram of the disassembled state of the interface screw with soft tissue tightening function in one embodiment of the present invention from a third viewing angle.

[0016] Reference numerals: 10: nail body; 11: thread; 12: through hole; 131: conical concave platform; 132: first limiting groove; 133: central concave platform; 134: second limiting groove; 20: plug-in; 21: plug-in rod; 22: cover; 221: conical boss; 222: first limiting strip; 223: center boss; 224: second limiting strip. DETAILED DESCRIPTION

[0017] The present invention will now be discussed with reference to several embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present invention, rather than implying any limitation on the scope of the present invention.

[0018] As used herein, the term "including" and its variants are to be interpreted as open-ended terms meaning "including but not limited to"; the terms "embodiment" and "one embodiment" are to be interpreted as "at least one embodiment"; the term "another embodiment" is to be interpreted as "at least one other embodiment"; the terms "first", "second", etc. may refer to different or the same objects; the term "setting" is not limited to direct connection or indirect connection, nor is it limited to a specific connection method. Other explicit and implicit definitions may also be included below.

[0019] In the following description, some specific numerical values ​​or numerical ranges may be involved. It should be understood that these numerical values ​​and numerical ranges are merely exemplary, and they may be helpful in putting the idea of ​​the present invention into practice. However, the description of these examples is not intended to limit the scope of the present invention in any way. According to specific application scenarios and requirements, these numerical values ​​or numerical ranges can be set separately.

[0020] As mentioned above, the prior art interface screw has the problem of insufficient soft tissue holding force, which leads to loosening of soft tissue and bone. The interface screw with soft tissue tightening function proposed in the embodiment of the present invention at least partially solves the above problem. Figures 1 to 7 The structure and working principle of the interference screw with soft tissue tightening function according to the exemplary embodiment of the present invention are described below. Figure 1 and Figure 3As shown, the interface screw with soft tissue tightening function of the embodiment of the present invention generally includes a nail body 10 and an insert 20. The nail body 10 is formed with a thread 11 on the outside, which is used to enable the nail body 10 to be screwed into the pre-drilled hole. The nail body 10 is formed with a cavity inside, and the cavity has a special-shaped hole, which is convenient for using tools to operate the nail body 10 to screw. The insert 20 is provided with a cover 22 and an insertion rod 21. One end of the insertion rod 21 is connected to the cover 22 and extends from the cover 22 toward the other end, wherein the cover 22 blocks the cavity of the nail body 10 at the tail of the nail body 10, prevents body fluids from entering the inner cavity of the nail rod, and slows down the degradation rate of the nail rod. For clear description, the end of the nail body 10 close to the bone when screwed into the bone is defined as the "head", and the end away from the bone is defined as the "tail".

[0021] When the nail body 10 is screwed into the pre-drilled hole of the bone and the soft tissue is squeezed against the inner wall of the pre-drilled hole by the thread 11, only the contact position between the top of the thread 11 and the inner wall of the pre-drilled hole can exert a squeezing force on the soft tissue, and the gaps between the threads of the thread 11 will be filled by the soft tissue. The soft tissue in the gap area is not subjected to the squeezing force, which to a certain extent leads to insufficient holding force of the interface screw to fix the soft tissue. To solve this problem, the embodiment of the present invention forms a through hole 12 in the nail body 10, and the extension direction of the through hole 12 is consistent with the axial direction of the nail body 10. The position of the through hole 12 on the cross section of the nail body 10 is located at a position that overlaps with at least part of the area of ​​the thread 11. Figure 6 As shown, the structure of the insertion rod 21 can occupy at least part of the gap between the teeth of the thread 11, thereby squeezing the soft tissue trapped in the gap between the teeth of the thread 11 toward the inner wall of the pre-drilled hole, so that the soft tissue in the gap is squeezed to a certain extent by the inner wall of the pre-drilled hole, the insertion rod 21 and the teeth of the thread 11, forming a secondary squeezing effect of the cross-sectional screw on the soft tissue.

[0022] In one embodiment, the length of the through hole 12 can be completely through the head and tail of the nail body 10, or can be extended from the tail of the nail body 10 to a certain position in the middle of the nail body 10, as long as the through hole 12 can penetrate a part of the teeth of the thread 11, that is, as long as the through hole 12 can allow the insertion rod 21 to occupy a part of the gap between the teeth of the thread 11. For example, Figure 6 As shown, the penetration of the through hole 12 ends at the position of the second to last thread 11 on the outside of the nail body 10; in another example, it is appropriate for the through hole 12 to penetrate 3 / 4 of the length of the nail body 10.

[0023] In order to ensure that the insertion rod 21 can be inserted into the through hole 12 and smoothly occupy the gap between the teeth of the thread 11, the embodiment of the present invention makes the cross-sectional shape, number and position of the insertion rod 21 match those of the through hole 12. Exemplarily, the through hole 12 is set to a circular cross-section, and a pair of through holes 12 are arranged in relative positions on the cross section of the nail body 10. Correspondingly, the insertion rod 21 is also set to a circular cross-section and has a diameter slightly smaller than the through hole 12, so as to ensure that the insertion rod 21 can be smoothly inserted into the through hole 12. Those skilled in the art can understand that, corresponding to the number of a pair of through holes 12, the number of the insertion rod 21 can be one or a pair. When the number of the insertion rod 21 is a pair, the pair of insertion rods 21 should also be arranged in relative positions. In addition, corresponding to the circular cross-sectional through hole 12, the cross-sectional shape of the insertion rod 21 can be any other shape, as long as the outline size allows the insertion rod 21 to be inserted into the through hole 12. In another example, the number of through holes 12 and the number of insertion rods 21 are set to four respectively. In this case, although there is not enough space to set the limiting structure, the alignment design of the four insertion rods 21 and the through hole 12 can also provide sufficient limiting effect.

[0024] In one embodiment, the end of the insertion rod 21 is configured to be spherical. When the end of the insertion rod 21 touches the gap between the teeth of the thread 11, the spherical end can prevent the insertion rod 21 from hooking the soft tissue, which is beneficial for guiding the soft tissue to the side of the insertion rod 21 close to the inner wall of the pre-drilled hole, ensuring that the insertion rod 21 can smoothly achieve secondary tightening of the soft tissue.

[0025] In order to make the insertion rod 21 occupy as much of the tooth gap of the thread 11 as possible, the insertion rod 21 needs to be set to have a longer size, but this will bring the following problems: since the insertion rod 21 is also subjected to the reaction force of the soft tissue in the tooth gap area of ​​the thread 11, the deformation or positional displacement of the insertion rod 21 will cause the position of the cover 22 to change, especially the cover 22 will be offset along the radial and circumferential directions of the nail body 10, which directly affects the sealing performance between the cover 22 and the tail of the nail body 10, so that the cavity of the nail body 10 cannot be well sealed. To solve this problem, the embodiment of the present invention sets a plurality of sets of limiting matching structures between the cover 22 and the tail of the nail body 10, and these limiting matching structures provide radial and circumferential limiting effects between the cover 22 and the tail of the nail body 10. In fact, any one of the plurality of sets of limiting matching structures can provide a limiting effect alone.

[0026] In one embodiment, Figure 2 , Figure 4 and Figure 5 As shown, the cover 22 is provided with a conical boss 221 facing the insertion rod 21 , and the tail of the nail body 10 is formed with a conical recess 131 , and the conical boss 221 matches with the conical recess 131 , thereby providing radial limitation between the cover 22 and the tail of the nail body 10 .

[0027] In one embodiment, the conical boss 221 is provided with a first limiting strip 222 extending axially along the nail body 10 toward the insertion rod 21, and a first limiting groove 132 is formed at the tail of the nail body 10. The first limiting strip 222 matches the first limiting groove 132 and is located at the outer peripheral area of ​​the circular cross section of the nail body 10, thereby providing radial and circumferential limiting between the cover 22 and the tail of the nail body 10. Exemplarily, the number of the first limiting strips 222 is a pair, and the pair of first limiting strips 222 and the pair of insertion rods 21 are evenly distributed in the cross section, and correspondingly, the first limiting grooves 132 are also arranged in this position.

[0028] In another embodiment, the first limiting strip 222 and the first limiting groove 132 are both straight segments and arc segments connected in sequence along the radial direction of the nail body 10. The straight segments improve the radial limiting and circumferential limiting strengths, and the arc segments reduce the stress concentration problem caused by processing.

[0029] In another embodiment, if Figure 7 As shown, the arc segment is tapered from the tail of the nail body 10 toward the head along the axial direction of the nail body 10. Accordingly, the corresponding surface of the first limiting groove 132 is also configured to be tapered. Such a configuration is conducive to the first limiting strip 222 being smoothly guided and inserted into the first limiting groove 132. For example, the tapered angle b of the arc segment is ~ .

[0030] In one embodiment, the conical boss 221 is provided with a center boss 223 extending axially along the nail body 10 toward the insertion rod 21 side, and a center recess 133 is formed at the tail of the nail body 10. The center boss 223 matches the center recess 133 and is located in the central area of ​​the circular cross-section of the nail body 10, thereby providing radial limitation between the cover 22 and the tail of the nail body 10.

[0031] In one embodiment, a second limiting strip 224 extending axially along the nail body 10 is provided on the conical boss 221 toward the insertion rod 21 side, and a second limiting groove 134 is formed at the tail of the nail body 10. The second limiting strip 224 matches the second limiting groove 134. The second limiting strip 224 extends between the center boss 223 and the insertion rod 21, and the second limiting groove 134 extends between the center recess 133 and the through hole 12, thereby providing circumferential limitation between the cover 22 and the tail of the nail body 10.

[0032] In one embodiment, Figure 7 As shown, the top of the thread 11 of the nail body 10 is tapered from the tail of the nail body 10 to the head along the axial direction of the nail body 10, ensuring that the nail body 10 is smoothly screwed into the pre-drilled hole. ~ .

[0033] In one embodiment, the nail body 10 is made of a degradable polymer material, and the plug-in 20 is made of a degradable metal material. In this configuration, the degradation product of the metal material is alkaline, and the degradation product of the polymer material is acidic. The acid-base neutralization avoids erosion of soft tissue and bone, ensuring sufficient holding force for fixing soft tissue. In another embodiment, the nail body and the plug-in are both made of a degradable metal material, such as a degradable magnesium alloy, so that the nail body structure is stronger.

[0034] When the interface screw of the present invention is used for soft tissue fixation, the nail body 10 is first screwed into the pre-drilled hole so that the threads 11 on the outside of the nail body 10 squeeze the soft tissue against the inner wall of the pre-drilled hole, and then the plug-in 20 is inserted from the tail of the nail body 10 so that the insertion rod 21 is inserted into the through hole 12 until the cover 22 blocks the opening of the cavity of the nail body 10 at the tail, thereby utilizing the gap between the teeth of the insertion rod 21 on the thread 11 to squeeze the soft tissue for a second time, and at the same time, the cover 22 prevents body fluids from entering the cavity of the nail body 10.

[0035] The description of the embodiments herein and any reference to directions and orientations are only for the convenience of description and are not to be construed as any limitation on the scope of protection of the present invention. The description of the preferred embodiments may involve combinations of features, which may exist independently or in combination, and the present invention is not particularly limited to the preferred embodiments. The scope of the present invention is defined by the claims.

[0036] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An interface screw with soft tissue tightening function, characterized in that: The invention comprises a nail body and an insert, wherein the nail body has a tail and a head, a thread is formed on the outside of the nail body, and the nail body is also formed with a through hole extending from the tail to the head along the axial direction of the nail body, wherein the through hole penetrates at least part of the teeth of the thread during the extension process, and the insert is provided with a cover and an insertion rod extending from the cover, wherein the insertion rod matches the through hole so as to be suitable for the insertion rod to be inserted into the through hole, thereby squeezing the soft tissue squeezed between the teeth of the thread.

2. The interface screw with soft tissue tightening function according to claim 1, characterized in that: The end of the insertion rod is spherical.

3. The interface screw with soft tissue tightening function according to claim 1, characterized in that: A conical boss is arranged on the side of the sealing cover facing the insertion rod, and a conical concave boss is formed on the tail of the nail body, and the conical boss matches the conical concave boss.

4. The interface screw with soft tissue tightening function according to claim 3, characterized in that: A first limiting strip extending along the axial direction of the nail body is arranged on the conical boss toward the insertion rod side, a first limiting groove is formed at the tail of the nail body, the first limiting strip matches the first limiting groove and is located at the peripheral area of ​​the circular cross section of the nail body.

5. The interference screw with soft tissue tightening function according to claim 4, characterized in that: The first limiting strip and the first limiting groove are both in the form of straight line segments and circular arc segments connected in sequence along the radial direction of the nail body.

6. The interference screw with soft tissue tightening function according to claim 5, characterized in that: The arc segment is tapered along the axial direction of the nail body from the tail of the nail body toward the head.

7. The interference screw with soft tissue tightening function according to claim 1, characterized in that: The conical boss is provided with a central boss extending along the axial direction of the nail body toward the insertion rod side, and a central concave platform is formed at the tail of the nail body. The central boss matches the central concave platform and is located in the central area of ​​the circular cross section of the nail body.

8. The interference screw device with soft tissue tightening function according to claim 7, characterized in that: A second limiting strip extending along the axial direction of the nail body is arranged on the conical boss toward the insertion rod side, and a second limiting groove is formed at the tail of the nail body. The second limiting strip matches the second limiting groove. The second limiting strip extends between the center boss and the insertion rod, and the second limiting groove extends between the center recess and the through hole.

9. The interference screw with soft tissue tightening function according to claim 1, characterized in that: The top of the thread of the nail body is tapered along the axial direction of the nail body from the tail of the nail body toward the head.

10. The interference screw with soft tissue tightening function according to claim 1, characterized in that: The nail body is made of a degradable polymer material, and the plug-in is made of a degradable metal material; or, both the nail body and the plug-in are made of a degradable metal material.

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