Interference Screw with Soft Tissue Compression Function

Abstract

The present invention provides an interface screw with a soft tissue squeezing function, which includes a nail body and a plug. The nail body has a tail and a head, and a thread is formed on the outer surface of the nail body. The nail body also forms a through hole extending axially from the tail to the head along the nail body, and the through hole penetrates at least part of the teeth of the thread during the extension process. The plug is provided with a cover and a plug rod extending from the cover, and the plug rod is matched with the through hole so that the plug rod can be inserted into the through hole, thereby squeezing the soft tissue squeezed between the teeth of the thread. According to the present invention, the holding force of the interface screw for fixing soft tissue can be improved, and the non-loosening of the soft tissue and the bone can be ensured.

Description

Technical Field

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

[0002] Interface screws are used to solve problems such as complex fracture repair, joint reconstruction, and soft tissue fixation. During surgery, the interface screw is screwed into a pre-drilled hole in 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 interface screw, so as to achieve the purpose of fixing the bone and the soft tissue. The interface screws of the prior art have the problem that the holding force for fixing the soft tissue is insufficient, resulting in the loosening of the soft tissue from the bone. Summary of the Invention

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

[0004] Specifically, the present invention is implemented through the following technical solutions:

[0005] An embodiment of the present invention provides an interface screw with a soft tissue squeezing function, including a nail body and a plug. The nail body has a tail and a head, and a thread is formed on the outer part of the nail body. The nail body also forms a through hole extending axially along the nail body from the tail to the head, and the through hole penetrates at least part of the teeth of the thread during the extension process. The plug is provided with a cover and a plug rod extending from the cover. The plug rod is matched with the through hole so that the plug rod can be inserted into the through hole to squeeze the soft tissue squeezed between the teeth of the thread.

[0006] In some embodiments, the end of the plug rod is spherical.

[0007] In some embodiments, a conical boss is provided on the side of the cover facing the plug rod, and a conical concave is formed at the tail of the nail body. The conical boss is matched with the conical concave.

[0008] In some embodiments, a first limiting strip extending axially along the nail body is provided on the side of the conical boss facing the plug rod, and a first limiting groove is formed at the tail of the nail body. The first limiting strip is matched with the first limiting groove and is located in the outer peripheral area of the circular cross-section of the nail body.

[0009] In some embodiments, both the first limiting strip and the first limiting groove are straight line segments and arc segments that are sequentially connected along the radial direction of the nail body.

[0010] In some embodiments, the arc segment is tapered axially from the tail of the nail body towards the head.

[0011] In some embodiments, a central boss extending axially along the nail body is provided on the side of the conical boss facing the plug rod, and a central concave is formed at the tail of the nail body. The central boss is matched with the central concave and is located in the central area of the circular cross-section of the nail body.

[0012] In some embodiments, the conical boss is provided with a second limiting strip extending along the axial direction of the nail body toward the side of the plug rod. A second limiting groove is formed at the tail of the nail body. The second limiting strip is matched with the second limiting groove. The second limiting strip extends between the central boss and the plug rod, and the second limiting groove extends between the central concave platform and the through hole.

[0013] In some embodiments, the top of the tooth 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.

[0014] In some embodiments, the nail body is made of a degradable polymer material, and the plug is made of a degradable metal material; or, both the nail body and the plug are made of a degradable metal material.

[0015] According to the embodiments of the present invention, when the external thread of the nail body squeezes the soft tissue tightly, the plug is inserted into the through hole, so that the plug rod performs secondary extrusion on the soft tissue caught between the teeth of the thread, and the soft tissue is further squeezed tightly from the gap between the teeth of the thread toward the inner wall of the preset hole, thereby improving the holding force for fixing the soft tissue and ensuring that the soft tissue and the bone do not become loose.

[0016] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with this application, and are used together with the specification to explain the principles of this application.

[0018] Figure 1 is a first perspective schematic view of the split state of an interface screw with a soft tissue squeezing function in an embodiment of the present invention;

[0019] Figure 2 is Figure 1 a partial enlarged view of A in

[0020] Figure 3 is a second perspective schematic view of the split state of an interface screw with a soft tissue squeezing function in an embodiment of the present invention;

[0021] Figure 4 is Figure 3 a partial enlarged view of B in

[0022] Figure 5 is a top view of the plug and the nail body in an embodiment of the present invention;

[0023] Figure 6 is a cross-sectional view of the assembled state of an interface screw with a soft tissue squeezing function in an embodiment of the present invention;

[0024] Figure 7It is a third - perspective schematic diagram of the disassembled state of an interface screw with a soft - tissue squeezing function in an embodiment of the present invention.

[0025] Reference numerals:

[0026] 10: Nail body; 11: Thread; 12: Through - hole; 131: Conical concave; 132: First limiting groove; 133: Central concave; 134: Second limiting groove;

[0027] 20: Plug; 21: Plug rod; 22: Cover; 221: Conical boss; 222: First limiting strip; 223: Central boss; 224: Second limiting strip. Detailed implementation manners

[0028] Now, the present invention will be described with reference to several embodiments. It should be understood that these embodiments are described only to enable those of ordinary skill in the art to better understand and thus implement the present invention, rather than implying any limitation on the scope of the present invention.

[0029] As used herein, the term "including" and its variants are to be construed as open - ended terms meaning "including but not limited to"; the terms "embodiment" and "an embodiment" are to be construed as "at least one embodiment"; the term "another embodiment" is to be construed as "at least one other embodiment"; the terms "first", "second", etc. may refer to different or the same objects; the term "arranged" is not limited to direct connection or indirect connection, nor to a specific connection manner. There may be other explicit and implicit definitions hereinafter.

[0030] 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 may be conducive to 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 otherwise.

[0031] As described above, the interface screws in the prior art have the problem that the fixation of soft tissues has insufficient holding force, resulting in the loosening of soft tissues from bones. The interface screw with a soft - tissue squeezing function proposed by the embodiments of the present invention at least partially solves the above - mentioned problem. The following will refer to Figures 1 to 7 to describe the structure and working principle of the interface screw with a soft - tissue squeezing function according to the exemplary embodiments of the present invention. As Figure 1 and Figure 3As shown, the interference screw with soft tissue squeezing function according to the embodiment of the present invention generally includes a nail body 10 and a plug-in member 20. Threads 11 are formed on the outside of the nail body 10 for screwing the nail body 10 into a pre-drilled hole. A cavity is formed inside the nail body 10, and the cavity has a special-shaped hole to facilitate the operation of screwing the nail body 10 with a tool. The plug-in member 20 is provided with a cover 22 and a plug rod 21. One end of the plug rod 21 is connected to the cover 22 and extends from the cover 22 towards the other end. Among them, the cover 22 plugs the cavity of the nail body 10 at the tail of the nail body 10 to prevent body fluid from entering the inner cavity of the nail rod and delay 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 far from the bone is defined as the "tail".

[0032] When the nail body 10 is screwed into the pre-drilled hole in the bone and the soft tissue is squeezed against the inner wall of the pre-drilled hole by using the threads 11, only the contact position between the top of the thread teeth of the threads 11 and the inner wall of the pre-drilled hole can exert a squeezing force on the soft tissue, while the gap between the thread teeth of the threads 11 will be filled by the soft tissue getting into it, and the soft tissue in the gap area is not subjected to the squeezing force, which to a certain extent results in insufficient holding force of the interference screw for fixing the soft tissue. To solve this problem, a through hole 12 is formed in the nail body 10 in the embodiment of the present invention. The extending direction of the through hole 12 is consistent with the axial direction of the nail body 10, and the position of the through hole 12 on the cross-section of the nail body 10 is at least partially coincident with the area of the thread teeth of the threads 11, as Figure 6 shown, so that the structure of the plug rod 21 can occupy at least part of the gap between the thread teeth of the threads 11, thereby squeezing the soft tissue getting into the thread teeth gap of the threads 11 towards the inner wall direction of the pre-drilled hole, so that the soft tissue in the gap is squeezed tightly by the inner wall of the pre-drilled hole, the plug rod 21 and the thread teeth of the threads 11 together, forming a secondary squeezing effect of the cross-section screw on the soft tissue.

[0033] In one embodiment, the length of the through hole 12 can completely penetrate between the head and the tail of the nail body 10, or can only extend 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 through at least part of the thread teeth of the threads 11, that is to say, as long as the through hole 12 can allow the plug rod 21 to occupy part of the gap between the thread teeth of the threads 11. Exemplarily, as Figure 6 shown, the penetration of the through hole 12 terminates at the position of the second-to-last thread tooth of the threads 11 outside the nail body 10; in another example, it is appropriate that the through hole 12 penetrates 3 / 4 of the length of the nail body 10.

[0034] 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, in the embodiment of the present invention, the cross-sectional shapes, numbers, and positions of the insertion rod 21 and the through hole 12 are all matched. Exemplarily, the through hole 12 is provided with a circular cross-section, and a pair of through holes 12 are arranged in a relative position on the cross-section of the nail body 10. Correspondingly, the insertion rod 21 is also provided with a circular cross-section and a diameter slightly smaller than that of 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 insertion rods 21 can be one or a pair. When the number of insertion rods 21 is a pair, the pair of insertion rods 21 should also be arranged in a relative position. In addition, corresponding to the through hole 12 with a circular cross-section, the cross-sectional shape of the insertion rod 21 can be any other shape, as long as the contour size allows the insertion rod 21 to be inserted into the through hole 12. In another example, the numbers of the through holes 12 and the insertion rods 21 are respectively set to four. 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 holes 12 can also provide sufficient limiting effect.

[0035] In one embodiment, the end of the insertion rod 21 is provided as a spherical shape. 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 to guiding the soft tissue to the side of the insertion rod 21 close to the inner wall of the pre-drilled hole, and ensuring that the insertion rod 21 can smoothly achieve secondary squeezing of the soft tissue.

[0036] To enable the insertion rod 21 to occupy as many tooth gaps of the thread 11 as possible, the insertion rod 21 needs to be set to have a longer dimension. However, this will bring the following problems: Since the insertion rod 21 is also subject to the reaction force of the soft tissue in the tooth gap area of the thread 11, the deformation or position offset of the insertion rod 21 will cause the position of the cap 22 to change. In particular, the cap 22 will have a position offset in the radial and circumferential directions of the nail body 10. This situation directly affects the sealing performance between the cap 22 and the tail of the nail body 10, and the cavity of the nail body 10 cannot be well sealed. To solve this problem, in the embodiment of the present invention, multiple groups of limiting and matching structures are provided between the cap 22 and the tail of the nail body 10, and these limiting and matching structures provide radial and circumferential limiting effects between the cap 22 and the tail of the nail body 10. In fact, any one of the multiple groups of limiting and matching structures can provide the limiting effect alone.

[0037] In one embodiment, as Figure 2 、 Figure 4 and Figure 5 shown, the cap 22 is provided with a conical boss 221 on the side facing the insertion rod 21, and a conical concave 131 is formed at the tail of the nail body 10. The conical boss 221 is matched with the conical concave 131, so as to provide radial limitation between the cap 22 and the tail of the nail body 10.

[0038] In one embodiment, a first limiting strip 222 extending along the axial direction of the nail body 10 is provided on the side of the conical boss 221 facing the insertion rod 21. A first limiting groove 132 is formed at the tail of the nail body 10. The first limiting strip 222 is matched with the first limiting groove 132 and is located in the outer peripheral area of the circular cross-section of the nail body 10, so as to provide radial limitation and circumferential limitation 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. Correspondingly, the first limiting grooves 132 are also arranged at this position.

[0039] In another embodiment, the first limiting strip 222 and the first limiting groove 132 are both straight line segments and arc segments that are sequentially connected along the radial direction of the nail body 10. The straight line segments improve the strength of radial limitation and circumferential limitation, and the arc segments reduce the stress concentration problem caused by processing.

[0040] In another embodiment, as Figure 7 shown, the arc segment is tapered from the tail of the nail body 10 towards the head along the axial direction of the nail body 10. Correspondingly, the corresponding surface of the first limiting groove 132 is also set to be tapered. Such a setting is beneficial to the first limiting strip 222 being smoothly guided and inserted into the first limiting groove 132. Exemplarily, the tapered angle b of the arc segment is ~ 。

[0041] In one embodiment, a central boss 223 extending along the axial direction of the nail body 10 is provided on the side of the conical boss 221 facing the insertion rod 21. A central concave groove 133 is formed at the tail of the nail body 10. The central boss 223 is matched with the central concave groove 133 and is located in the central area of the circular cross-section of the nail body 10, so as to provide radial limitation between the cover 22 and the tail of the nail body 10.

[0042] In one embodiment, a second limiting strip 224 extending along the axial direction of the nail body 10 is provided on the side of the conical boss 221 facing the insertion rod 21. A second limiting groove 134 is formed at the tail of the nail body 10. The second limiting strip 224 is matched with the second limiting groove 134. The second limiting strip 224 extends between the central boss 223 and the insertion rod 21, and the second limiting groove 134 extends between the central concave groove 133 and the through hole 12, so as to provide circumferential limitation between the cover 22 and the tail of the nail body 10.

[0043] In one embodiment, as Figure 7 shown, the top of the tooth of the thread 11 of the nail body 10 is tapered from the tail of the nail body 10 towards 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. Exemplarily, the tapered included angle a of the top of the tooth of the thread 11 is ~ 。

[0044] In one embodiment, the nail body 10 is made of a biodegradable polymer material, while the insert 20 is made of a biodegradable metal material. With this arrangement, the degradation products of the metal material are alkaline, and the degradation products of the polymer material are acidic. The acid-base neutralization avoids erosion of soft tissues and bones, ensuring that the holding force for fixing soft tissues is sufficient. In another embodiment, both the nail body and the insert are made of a biodegradable metal material, such as a biodegradable magnesium alloy material, so that the structural strength of the nail body is greater.

[0045] When using the interface screw of the present invention for soft tissue fixation, first screw the nail body 10 into the pre-drilled hole so that the external thread 11 of the nail body 10 squeezes the soft tissue against the inner wall of the pre-drilled hole. Then insert the insert 20 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 at the tail of the cavity of the nail body 10, thereby using the gap between the insertion rod 21 and the teeth of the thread 11 to secondarily squeeze the soft tissue, and at the same time the cover 22 prevents body fluid from entering the cavity of the nail body 10.

[0046] Any reference to directions and orientations in the description of the embodiments herein is for the convenience of description only and should not be construed as any limitation on the protection scope of the present invention. The description of the preferred embodiments involves combinations of features that may exist independently or in combination. The present invention is not particularly limited to the preferred embodiments. The scope of the present invention is defined by the claims.

[0047] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An interface screw with a soft tissue squeezing function, characterized in that, It includes a nail body and a plug-in. The nail body has a tail and a head. Threads are formed on the outer part of the nail body. A through hole extending axially along the nail body from the tail to the head is also formed in the nail body. During the extension, the through hole penetrates at least part of the teeth of the threads. The position of the through hole in the cross-section of the nail body is located where it partially coincides with the area of the teeth of the threads, so that the top of the thread teeth will not be penetrated by the through hole. The plug-in is provided with a cover and a plug rod extending from the cover. The plug rod is matched with the through hole so that the plug rod can be inserted into the through hole to squeeze the soft tissue squeezed into the space between the teeth of the threads tightly.

2. The interference screw with soft tissue squeezing function according to claim 1, wherein The end of the plug rod is spherical.

3. The interference screw with soft tissue squeezing function according to claim 1, characterized in that, A conical boss is provided on the side of the cover facing the plug rod. A conical recess is formed at the tail of the nail body. The conical boss is matched with the conical recess.

4. The interference screw with soft tissue squeezing function according to claim 3, wherein, A first limiting strip extending axially along the nail body is provided on the side of the conical boss facing the plug rod. A first limiting groove is formed at the tail of the nail body. The first limiting strip is matched with the first limiting groove and is located in the outer peripheral area of the circular cross-section of the nail body.

5. The interfacial screw with a soft tissue squeezing function according to claim 4, wherein, Both the first limiting strip and the first limiting groove are in the form of sequentially connected straight line segments and arc segments along the radial direction of the nail body.

6. The interfacial screw with a soft tissue squeezing function according to claim 5, wherein, The arc segment is tapered axially along the nail body from the tail to the head of the nail body.

7. The interference screw with soft tissue squeezing function according to claim 1, wherein, A central boss extending axially along the nail body is provided on the side of the conical boss facing the plug rod. A central recess is formed at the tail of the nail body. The central boss is matched with the central recess and is located in the central area of the circular cross-section of the nail body.

8. The interfacial screw placement device with a soft tissue squeezing function according to claim 7, characterized in that, A second limiting strip extending axially along the nail body is provided on the side of the conical boss facing the plug rod. A second limiting groove is formed at the tail of the nail body. The second limiting strip is matched with the second limiting groove. The second limiting strip extends between the central boss and the plug rod, and the second limiting groove extends between the central recess and the through hole.

9. The interference screw with soft tissue squeezing function according to claim 1, wherein The top of the teeth of the threads of the nail body is tapered axially along the nail body from the tail to the head of the nail body.

10. The interference screw with soft tissue squeezing 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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