CN116098665A - Interface screw - Google Patents

Abstract

The invention relates to an interface screw, which comprises a screw head, a screw rod and a screw tip which are sequentially connected along the axial direction, wherein a first thread section and a screw fixing structure are arranged on the screw rod, one end of the first thread section extends to the screw head, a spiral line of the screw fixing structure extends from the other end of the first thread section towards the screw tip along a spiral extension line of the first thread section, the screw fixing structure comprises a plurality of fixing parts, and the fixing parts are distributed at intervals along the spiral line of the screw fixing structure. According to the interface screw, when the interface screw is implanted into a bone tunnel, the fixed parts which are arranged at intervals can reduce the rotation friction on the ligament so as to reduce the damage to the ligament; after the bone marrow is implanted, the binding force between the fixing parts and the bone substance is uneven to the compression force generated by the ligament, so that the ligament is easier to be embedded into the bone substance in the bone tunnel, and the fixing effect on the ligament is improved.

Description

Interface screw

Technical Field

The invention relates to the field of orthopedic medical instruments, in particular to an interface screw.

Background

When anterior and posterior cruciate ligaments of a knee joint of a human body are damaged, reconstruction and fixation of the damaged ligaments are required, and at present, interfacial screws are commonly used by clinicians to fix the ligaments in bone tunnels by extrusion.

However, in order to improve the stability of ligament fixation, the conventional interface screw needs to be provided with a locking thread to squeeze and fix the ligament, and in the process of screwing in the bone tunnel, the thread of the conventional interface screw generates larger rotation friction and causes different degrees of damage to the ligament, and the larger the fastening force of the interface screw is, the larger the damage to the ligament is.

Disclosure of Invention

Based on this, an interface screw is provided to solve the problem of how to reduce damage to the ligament while ensuring effective fixation of the ligament.

The invention provides an interface screw which is used for fixing a ligament to a bone marrow canal, the interface screw comprises a screw head, a screw rod and a screw tip which are sequentially connected in the axial direction, the screw rod is provided with a first thread section and a screw fixing structure, one end of the first thread section extends to the screw head, a screw line of the screw fixing structure extends from the other end of the first thread section to the screw tip along a screw extension line of the first thread section, the screw fixing structure comprises a plurality of fixing parts, the fixing parts are arranged at intervals along the screw line of the screw fixing structure, and when the interface screw is implanted into the bone tunnel, the fixing parts are used for generating binding force with bone of the bone tunnel, so that the ligament is fixed to the bone marrow canal.

In one embodiment, the fixation portion includes a hole into which bone of the bone tunnel can be inserted when the interface screw is implanted into the bone tunnel such that the fixation portion engages the bone of the bone tunnel.

In one embodiment, the fixation portion includes protrusions, a plurality of the protrusions are embedded in bone such that the fixation portion engages bone of the bone tunnel when the interface screw is implanted in the bone tunnel, and at least a portion of the ligament is embedded between adjacent ones of the protrusions.

In one embodiment, the plurality of protrusions are formed by dividing the threads equal to the pitch and the thread lead angle of the first thread segment, and/or the plurality of protrusions are arranged at equal intervals, and the interval between adjacent protrusions is 0.5cm to 1.5cm.

In one embodiment, the thread height corresponding to the protrusion is greater than or equal to the thread height of the first thread segment.

In one embodiment, the part of the surface of the protrusion facing away from the screw is spherical, or the protrusion is spherical.

In one embodiment, the helix of the helical fixation structure extends to the screw tip.

In one embodiment, the threaded rod is provided with a second threaded section, and the helical fixation structure is located between the first threaded section and the second threaded section in the axial direction of the interface screw.

In one embodiment, the pitch of the first thread segments is equal to the pitch of the second thread segments, and/or the thread lead angle of the first thread segments is equal to the thread lead angle of the second thread segments.

In one embodiment, the shank is provided with a second thread section, the helix of the first thread section and its helical extension being spaced from the helix of the second thread section in the axial direction of the interface screw.

In one embodiment, the second thread segment extends from the screw head to the screw tip; or one end of the second thread section extends to the screw head, and the other end of the second thread section is also provided with the spiral fixing structure along the spiral extension line.

In one embodiment, the screw tip comprises a conical body and a through hole penetrating through the end face of the conical body, the interface screw is provided with a through hole, and the through hole penetrates through the end face of the screw head to the conical body along the axial direction of the interface screw and is communicated with the through hole, wherein the hole diameter of the through hole is larger than that of the through hole.

According to the interface screw, the plurality of fixing parts of the spiral fixing structure are arranged at intervals, so that when the interface screw is implanted into a bone tunnel, the rotation friction on a ligament is reduced, and the damage to the ligament is reduced; meanwhile, the fixing parts can generate binding force with the bone of the bone tunnel, and based on the arrangement mode of the fixing parts at intervals, the binding force between the fixing parts and the bone is presented as a plurality of intermittent binding force points on a spiral line along the spiral fixing structure, and then the compression force generated on the ligament is uneven, so that the ligament is easier to be embedded into the bone inside the bone tunnel, and the fixing effect on the ligament is improved.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other embodiments of the drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of the structure of an interface screw of the present invention;

FIG. 2 is a schematic view of another embodiment of an interface screw of the present invention;

FIG. 3 is a schematic view of a further embodiment of an interface screw of the present invention;

FIG. 4 is a schematic view of the interface screw removal screw fixation structure shown in FIG. 3;

FIG. 5 is a schematic view of an interface screw according to another embodiment of the present invention;

FIG. 6 is a schematic view of an interface screw according to yet another embodiment of the present invention;

FIG. 7 is a schematic view of an interface screw according to yet another embodiment of the present invention;

fig. 8 is an axial cross-sectional view of an interface screw of an embodiment.

Reference numerals: 10. a screw head; 10a, a driving hole; 20. a screw; 20a, holes; 21. a first thread segment; 22. a spiral fixing structure; 22a, protrusions; 22b, convex ball; 22c, holes; 23. a second thread segment; 30. a screw tip; 30a, perforating; 30b, a conical body.

Detailed Description

In order that the invention may be readily understood, a more complete description of the invention will be rendered by reference to the appended drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Referring to fig. 1, an interface screw for fixing a ligament to a bone marrow canal according to an embodiment of the present invention includes a screw head 10, a screw shaft 20, and a screw tip 30 sequentially connected in an axial direction, the screw head 10 being provided with a driving hole 10a, the driving hole 10a being shaped like a line, a cross, a regular polygon, or a quincuncial shape to facilitate cooperation with an operation instrument for implanting the interface screw into the bone marrow canal, and to provide a rotational torque to the interface screw. The screw 20 is provided with a first thread section 21 and a screw fixing structure 22, one end of the first thread section 21 extends to the screw head 10, a spiral line of the screw fixing structure 22 extends from the other end of the first thread section 21 towards the screw tip 30 along a spiral extension line of the first thread section 21, the screw fixing structure 22 comprises a plurality of fixing parts, the fixing parts are distributed at intervals along the spiral line of the screw fixing structure 22, and when the interface screw is implanted into a bone tunnel, the fixing parts are used for generating binding force with bones of the bone tunnel, so that the ligament is fixed in the bone marrow tunnel. It is understood that the whole structure of the spiral fixing structure 22 extends in a spiral manner similar to that of a screw thread, and accordingly, the spiral line of the spiral fixing structure 22 refers to a path in which a plurality of fixing portions of the spiral fixing structure 22 are arranged in a spiral manner, that is, the plurality of fixing portions are arranged in a spiral manner to form the spiral fixing structure 22.

Because the plurality of fixing portions of the screw fixing structure 22 are spaced apart from each other, rotational friction to the ligament can be reduced to reduce damage to the ligament when the interface screw is implanted in the bone tunnel; meanwhile, the fixing part can generate binding force with the bone of the bone tunnel. Based on the arrangement mode of the fixing parts at intervals, the binding force between the fixing parts and the bone is presented as a plurality of intermittent binding force points on the spiral line along the spiral fixing structure 22, and then the compression force generated on the ligament is uneven, so that the ligament is easier to be embedded into the bone in the bone tunnel, and the fixing effect on the ligament is improved.

With continued reference to fig. 1, in some embodiments, the fixation portion includes protrusions 22a, where the plurality of protrusions 22a extend toward the screw tip 30 along the helical extension of the first thread segment 21. Based on the fact that the inside of the human bone is cancellous bone and the surface of the bone is cortical bone, the cortical bone can provide a greater back pressure, so that the first thread segment 21 is located at the end of the interface screw near the screw head 10, which can provide a more stable fixation effect. The plurality of spaced apart bosses 22a are positioned at an end adjacent the screw tip 30 such that when the interface screw is implanted into the bone tunnel, the plurality of bosses 22a are embedded in bone, thereby creating a bond with the bone of the bone tunnel and at least a portion of the ligament is embedded between adjacent bosses 22a. The ligament pressed by the protrusions 22a is stably embedded into the bone, and the portion of the ligament between the protrusions 22a is less in pressing force, so that the plurality of protrusions 22a generate uneven pressing force on the ligament, and finally the ligament is embedded into the bone in the bone tunnel, so that the purpose of fixing the bone more effectively is achieved.

Further, the surface of the portion of the protrusion 22a facing away from the screw 20 is, rather, spherical, or the protrusion 22a is spherical. For example, as shown in fig. 2, the fixing portion includes a convex ball 22b, so that the contact surface between the screw fixing structure 22 of the interface screw and the ligament is smooth, and no edge angle is generated, so as to reduce the probability of damage to the ligament.

In some embodiments, the plurality of protrusions 22a are formed by dividing the threads with the pitch and the thread lead angle equal to those of the first thread segment 21, in this way, the plurality of protrusions 22a extend along the spiral extension line of the first thread segment 21, so that the interface screw is implanted into the bone marrow canal, and meanwhile, the protrusions 22a are formed by adopting the thread division mode, so that the manufacturing difficulty is low, and the processing cost is effectively reduced.

The plurality of protrusions 22a may be equally spaced apart, with a spacing between adjacent protrusions 22a of 0.5cm to 1.5cm, such as 0.5cm, 0.7cm, 0.9cm, 1.1cm, 1.3cm, or 1.5cm. The protrusions 22a are suitably spaced to facilitate securing the helical fixation structure 22 to the bone tunnel while providing sufficient clearance to avoid the ligament, thereby reducing the chance of damage to the ligament.

The thread height corresponding to the protrusions 22a is greater than or equal to the thread height of the first thread section 21, so that in the process of implanting the interface screw into the bone marrow canal, the plurality of protrusions 22a can firstly spirally enter the bone marrow canal to form corresponding internal threads on the side wall of the bone marrow canal, and the first thread section 21 can be smoothly screwed into the bone marrow canal. Because the plurality of protrusions 22a are arranged at intervals, gaps among the protrusions 22a accumulate bone fragments, the bone fragments and bones of the bone tunnels are easy to heal, and then the fixing parts and bones of the bone tunnels generate binding force so as to limit the rotation, the forward and backward movement and the sliding of the interface screw and improve the fixing effect on the ligaments.

As shown in fig. 1 and 2, the helix of the helical fixation structure 22 extends to the screw tip 30 so that the ligament can be pressed as deep as possible into the bone tunnel to be fixed with the bone inside the bone tunnel.

In some embodiments, as shown in connection with fig. 3, the fixation portion includes a hole 22c, and when the interface screw is implanted into the bone tunnel, bone of the bone tunnel can be inserted into the hole 22c to create a coupling force of the fixation portion with bone of the bone tunnel.

In order to improve the binding force between the interface screw and the bone tunnel, the screw 20 may further include other thread segments besides the first thread segment 21, and the number of thread segments may be 2 or more, and the structure of the interface screw will be further described below by taking the case that 2 thread segments are provided on the screw 20, specifically, the screw 20 is provided with the second thread segment 23.

In the axial direction of the interface screw, a screw fixation structure 22 is located between the first thread segment 21 and the second thread segment 23. In this embodiment, the screw fixation structure 22 extends from the first thread segment 21 to the second thread segment 23, and extends to the screw head 10 based on one end of the first thread segment 21, so that the second thread segment 23 is closer to the screw tip 30 than the screw fixation structure 22, so that during implantation of the interface screw into the bone tunnel, the second thread segment 23 is first screwed into the bone marrow canal to guide the screw fixation structure 22 into the bone marrow canal, making the implantation of the interface screw into the bone marrow canal easier.

Further, the pitch of the first thread segment 21 is equal to the pitch of the second thread segment 23, so that the interface screw structure is simplified, and the processing is convenient.

In some embodiments, the lead angle of the first thread segment 21 and the lead angle of the second thread segment 23 are equal, thereby facilitating threading of the interface screw into the bone marrow canal, leaving threads of the second thread segment 23 on the side wall of the bone marrow canal that facilitate threading of the first thread segment 21 into the bone marrow canal.

The second thread segment 23 on the screw 20 may not be disposed along the spiral extension line of the first thread segment 21. For example, in some embodiments, in conjunction with the illustration of fig. 4, the interface screw illustrated in fig. 4 has the screw fixation structure 22 removed to facilitate distinguishing between the first thread segments 21 and the second thread segments 23. In this embodiment, along the axial direction of the interface screw, the spiral line of the first thread section 21 and the spiral extension line thereof are spaced from the spiral line of the second thread section 23, so that the first thread section 21 and the second thread section 23 form a double-line thread structure on the interface screw, thereby improving the lead and facilitating rapid guiding of the implantation of the interface screw into the bone marrow canal.

Further, as shown in connection with fig. 5, the second thread segments 23 extend from the screw head 10 to the screw tip 30, so that the second thread segments 23 may form double-thread with other thread segments on the screw shaft 20 in the axial direction of the whole interface screw, to have the effect of increasing the lead. As shown in fig. 5, when the plurality of fixing portions of the screw fixing structure 22 are protrusions 22a on the spiral extension line of the first screw thread segment 21, the spiral line where the plurality of protrusions 22a are located and the spiral line of the second screw thread segment 23 are also kept at intervals. It will be appreciated that the spacing between the helix at which the plurality of protrusions 22a are located and the helix of the second thread segments 23 is equal to the spacing between the helix of the first thread segments 21 and the helix of the second thread segments 23.

Preferably, as shown in fig. 6, the fixing portion may be a convex ball 22b, so that the contact surface between the screw fixing structure 22 of the interface screw and the ligament is smooth, and no corner angle is generated, so as to reduce the probability of damage to the ligament.

Of the plurality of fixing portions of the screw fixing structure 22, only some of the fixing portions are holes 22c, and the other fixing portions are protrusions 22a. The binding force between the fixing part and the bone of the bone tunnel can be generated only when the interface screw is implanted into the bone tunnel.

Taking the example of the screw 20 being provided with a first thread segment 21 and a second thread segment 23, in embodiments where the spiral of the first thread segment 21 and the spiral of the second thread segment 23 are spaced apart from each other, the second thread segment 23 may not extend to the screw tip 30. In some embodiments, the second thread segment 23 extends at one end to the screw head 10 and at the other end along its helical extension is also provided with a helical fixation structure 22. Specifically, as shown in fig. 7, a plurality of fixing portions provided on the spiral extension of the first screw thread segment 21 are protrusions 22a. A plurality of holes 22c and a plurality of balls 22b are provided in this order on the spiral extension of the second thread segment 23. Under the structure, the interface screw structurally forms a double-spiral structure and has a large lead, so that the interface screw can be quickly implanted into a bone marrow canal, the operation time is shortened, and the pain of a patient is shortened; in addition, the plurality of holes 22c and the plurality of convex balls 22b on the spiral extension line of the second thread segment 23 can also play a role in reducing damage to bones or ligaments, and the plurality of holes 22c and the plurality of convex balls 22b are used for generating binding force with bones of bone tunnels, so that the fixation stability of the ligaments in bone marrow tunnels is improved.

The plurality of holes 22c and the plurality of balls 22b provided on the spiral extension line of the second thread section 23 may be alternately provided, or may be provided in different sections of the screw 20. For example, as shown in fig. 7, a plurality of holes 22c are provided at intervals between the second screw thread section 23 and the knob 22b closest to the screw head 10, and at this time, the plurality of knobs 22b are then provided at intervals along the spiral extension line of the second screw thread section 23 next to the furthest hole 22c from the screw head 10. In this way, the plurality of balls 22b are closer to the screw tip 30, so that when the interface screw is implanted into the bone tunnel, the plurality of balls 22b engage the side walls of the bone tunnel, allowing the interface screw to easily and stably enter the bone tunnel.

In some embodiments, the first thread segments 21 are provided only on the portion of the screw 20 proximate to the screw head 10, and the screw fixation structure 22 is provided on the other portion of the screw 20.

Referring to fig. 8, for convenience of understanding, the interface screw is divided into a thread head section a, a thread middle section B and a thread tail section C along the axial direction thereof, the screw head 10 and the first thread section 21 are both located in the thread head section a, the screw tip 30 is located in the thread tail section C, and the screw fixing structure 22 is disposed in the thread middle section B and the thread tail section C.

With this arrangement, the first thread segment 21 or the double-thread structure (i.e., the axially corresponding portions of the first thread segment 21 and the second thread segment 23 of the interface screw) located in the thread head segment a more easily forms a larger compression force with the harder cortical bone of the human bone surface, so that the screw head 10 more easily clamps the ligament. The multiple fixing parts positioned on the thread middle section B and the thread tail section C can provide rotary guiding for the screwing of the interface screw on one hand, and on the other hand, when the fixing parts are the bulges 22a, the surface bulges 22a can generate larger stress, so that softer cancellous bones are easier to embed, the fixing strength is improved, bone fragments can be accumulated in gaps between the intermittent bulges 22a, the bone fragments are easier to heal with bones of the bone tunnel, and then the fixing parts and the bones of the bone tunnel generate binding force so as to limit the rotation, the forward and backward movement and the sliding of the interface screw, and the fixing effect on ligaments is improved. Accordingly, when the fixing portion is the hole 22c, damage to the ligament in the process of implanting the interface screw into the bone tunnel can be reduced, and growth of soft tissues is facilitated, so that the bone of the bone tunnel is finally embedded into the hole 22c to generate binding force, rotation, forward and backward movement and sliding of the interface screw are limited, and the fixing effect on the ligament is improved.

The screw tip 30 includes a tapered body 30b and a penetration hole 30a penetrating an end surface of the tapered body 30b, so that the screw tip 30 can conveniently enter the bone marrow canal, facilitating the implantation of the guide interface screw.

With continued reference to fig. 8, the interface screw is provided with a through hole 20a, and the through hole 20a penetrates from the end surface of the screw head 10 to the conical body 30b along the axial direction of the interface screw and is communicated with the through hole 30a, so that when the interface screw is implanted into the bone marrow canal, bone fragments can enter the through hole 20a through the through hole 30a, thereby reducing the amount of bone fragments between the interface screw and the inner wall of the bone marrow canal and reducing the extrusion of the bone marrow canal during the implantation of the interface screw. The hole diameter of the through hole 20a is larger than that of the penetration hole 30a to secure structural strength of the tapered body of the screw tip 30.

The screw head 10 is flat, round or countersunk. In some embodiments, a through hole 20a penetrates an end surface of the screw head 10 to form a driving hole 10a.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The foregoing examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims (12)

1. An interface screw for be fixed in bone marrow way with the ligament, its characterized in that, interface screw includes along axial connect gradually screw head, screw rod and screw point, be equipped with first screw thread section and spiral fixed knot structure on the screw rod, the one end of first screw thread section extends to the screw head, spiral line of spiral fixed knot structure follows the spiral extension line of first screw thread section by the other end of first screw thread section extends towards the screw point, spiral fixed knot structure includes a plurality of fixed parts, a plurality of fixed part is followed spiral line interval arrangement of spiral fixed knot structure, and when interface screw implants the bone tunnel, a plurality of fixed part be used for with the bone of bone tunnel produces the cohesion, makes the ligament is fixed in the bone marrow way.

2. The interface screw of claim 1, wherein the fixation portion includes a hole into which bone of the bone tunnel can be inserted when the interface screw is implanted into the bone tunnel to create a coupling force with bone of the bone tunnel.

3. The interface screw of claim 1 or 2, wherein the fixation portion comprises protrusions, a plurality of the protrusions being embedded in bone such that the fixation portion engages bone of the bone tunnel when the interface screw is implanted in the bone tunnel, and at least a portion of the ligament is embedded between adjacent ones of the protrusions.

4. An interface screw according to claim 3, wherein a plurality of said protrusions are segmented by threads equal to both the pitch and the thread lead angle of said first thread segments and/or wherein a plurality of said protrusions are equally spaced apart, with a spacing between adjacent protrusions of 0.5cm to 1.5cm.

5. The interface screw of claim 4, wherein the protrusion corresponds to a thread height that is greater than or equal to a thread height of the first thread segment.

6. The interface screw of claim 3, wherein a portion of the surface of the boss facing away from the shank is spherical or the boss is spherical.

7. The interface screw of claim 1, wherein a helix of the helical fixation structure extends to the screw tip.

8. The interface screw of claim 1, wherein the shank is provided with a second threaded section, the helical fixation structure being located between the first threaded section and the second threaded section along an axial direction of the interface screw.

9. The interface screw of claim 8, wherein the pitch of the first thread segment is equal to the pitch of the second thread segment and/or the thread lead angle of the first thread segment is equal to the thread lead angle of the second thread segment.

10. Interface screw according to claim 1, characterized in that the shank is provided with a second thread section, the helix of the first thread section and its helical extension being spaced from the helix of the second thread section in the axial direction of the interface screw.

11. The interface screw of claim 10, wherein the second threaded section extends from the screw head to the screw tip; or one end of the second thread section extends to the screw head, and the other end of the second thread section is also provided with the spiral fixing structure along the spiral extension line.

12. The interface screw of claim 1, wherein the screw tip comprises a tapered body and a bore extending through an end face of the tapered body, the interface screw being provided with a through bore extending from the end face of the screw head to the tapered body in an axial direction of the interface screw and communicating with the bore, wherein a bore diameter of the through bore is larger than a bore diameter of the bore.

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