CN209847354U - Medical implanted lag screw, intramedullary nail and fixing system - Google Patents

Abstract

The utility model discloses a medical implantation lag screw, intramedullary nail and fixing system. The medical implantation lag screw comprises a screw body, a first fixing piece and a second fixing piece, wherein the screw body is provided with a first head part and a first tail part; the outer wall surface of the first head is provided with a first thread, the first thread is provided with a plurality of reverse threads, and the distances from the top ends of the reverse threads to the outer wall surface of the first head are sequentially reduced in the direction from the first head to the first tail. By arranging the reverse screw teeth, the holding force can be increased, the Z effect can be reduced, and the treatment effect can be improved.

Description

Medical implanted lag screw, intramedullary nail and fixing system

Technical Field

The utility model relates to the field of medical equipment, especially, relate to a medical lag screw, intramedullary nail and fixing system of implanting.

Background

Proximal femoral fractures are clinically common fractures, and the incidence rate of the fractures is continuously increased, especially for the elderly. The fracture of the proximal femur part is easy to cause complications such as fracture nonunion due to the special fracture part, and the treatment difficulty is large.

In the treatment of proximal femoral fractures, conventional internal treatment and traction treatment have problems of long operation time, poor treatment effect and the like. If an intramedullary nail fixing system treatment method is adopted, although the internal fixation treatment effect can be improved to a certain extent, the traditional intramedullary nail has the Z effects of withdrawing of a lag screw, cutting of a femoral neck by the lag screw and the like after operation, so certain potential safety hazards exist, and the clinical treatment is not facilitated.

Therefore, a novel medical implantation lag screw, an intramedullary nail and a fixing system are provided.

Disclosure of Invention

In order to solve the above technical problems, an object of the present invention is to provide a medical implant lag screw, an intramedullary nail and a fixation system.

The utility model discloses a following technical scheme realizes:

in a first aspect, there is provided a medical implant lag screw, comprising:

a screw body having a first head and a first tail;

the first head part is provided with a first thread for implantation, the first thread is provided with a plurality of reverse threads, and the distances from the top ends of the reverse threads to the outer wall surface of the first head part are sequentially reduced in the direction from the first head part to the first tail part.

In the embodiment of the utility model provides an in, the longitudinal section of first head is trapezoidal, and each the line on the top of reverse screw tooth with the axis of first head parallels.

In the embodiment of the utility model, at least one implant injection hole is arranged between the adjacent reverse screw teeth on the first head part;

and a plurality of first cutting grooves matched with the threads of the pressurizing screws are formed in the first tail part.

In a second aspect, an intramedullary nail is provided, comprising a lag screw having integrally connected proximal, intermediate and distal portions, a main nail having a proximal portion, an intermediate portion and a distal portion, a cross locking nail traversing the proximal portion through a first bore, and a compression screw for compressing the lag screw traversing the distal portion through a second bore.

In the embodiment of the utility model, the first tail part of the lag screw is provided with a plurality of first cutting grooves matched with the thread of the compression screw;

the intramedullary nail further comprises a fixing component, the fixing component is accommodated in the cavity of the proximal end portion of the main nail, and a second cutting groove matched with the fixing component is formed in the first tail portion of the lag screw.

In the embodiment of the present invention, the fixing assembly includes a locking member and a fixing member connected to the locking member, the locking member is fixedly connected to the inner wall of the main nail, the fixing member includes a tip portion, and the tip portion can be inserted into the second slot to limit the relative rotation between the tension screw and the main nail;

still be equipped with first step on the mounting, be equipped with on the inner wall of proximal end portion with first step matches the second step, in order to restrict the mounting is in following the axis direction motion of main nail.

In the embodiment of the present invention, the pressurizing screw is provided with a second thread matching with the first thread, and the span of the second thread is larger than that of the first thread and can match with the first notch;

the intramedullary nail further comprises a tail nail, and the tail nail is accommodated in the proximal end portion.

The embodiment of the utility model provides an in, the cross sectional shape of nearly end face direction is circular for the little formula of diameter gradual change on the proximal end portion, is close to the at least partial outer wall of the proximal end portion of intermediate part has the curved surface of indent, the intermediate part is equipped with the recess that sets up along the axis direction, the distal end portion is equipped with a plurality of bifurcation groove.

In the embodiment of the present invention, the first hole is a hole similar to a "8" -shaped hole, the lag screw and the compression screw both cross the first hole, and the first hole is provided with an orifice platform for reducing stress concentration;

an inner hole platform is further arranged at the first hole channel, and a pressurizing platform matched with the inner hole platform is arranged on the pressurizing screw to limit the pressurizing screw to advance.

In a third aspect, a medical implant fixation system is provided, comprising an intramedullary nail as described in any one of the above.

The patent name of the utility model has the following beneficial effects:

1) by arranging the reverse threads, the holding force can be increased, and the Z effect is reduced. In addition, through setting up the reverse thread that the size diminishes gradually, so when guaranteeing good fastening effect, can avoid lag screw to implant the back and cause too much injury to patient's bone.

2) The second slot and the tip on the fixing component are arranged and matched with each other to limit the relative rotation of the tension screw and the main nail.

3) By providing a main nail with a rounded end, the size of the required bore hole can be reduced, thereby reducing the risk of injury to the patient's bone.

4) Through the gradual change type circular design of the end part, the strength of the hole wall position of the near end can be ensured, the end part is gradually reduced, more sclerotin can be obtained, and the stability of internal fixation can be better enhanced.

5) At least part of the outer wall surface of the main nail is provided with a concave curved surface and a concave groove. This reduces the stress on the outer wall after implantation and after operation of the intramedullary nail.

6) The wall surface of the distal part of the main nail is provided with a plurality of forked grooves, so that the distal part has certain elasticity and can be bent, the stress on the distal part of the main nail is further reduced, and stress fracture caused by stimulation to the bone wall is avoided.

7) The first pore canal is arranged to be a similar 8-shaped pore canal, and an orifice platform is further arranged at the first pore canal. Therefore, stress concentration can be reduced, and the main nail is prevented from being broken in the first pore channel.

8) The first pore passage is also provided with an inner hole platform, and the pressurizing screw is provided with a pressurizing platform matched with the inner hole platform. Therefore, in the process of implanting the compression screw, the compression platform is in contact with the platform in the hole in the lag screw, so that the relative displacement between the compression screw and the main screw is convenient to limit, the acting force of the compression screw is converted into the relative motion for driving the lag screw by the compression screw, and the compression is further realized.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural view of the intramedullary nail of the present invention.

Fig. 2 is a sectional view of a partial structure of the intramedullary nail of the present invention.

Fig. 3-5 are schematic structural views of the lag screw of the present invention.

Fig. 6 is a schematic structural view of the compression screw of the present invention.

Fig. 7-8 are schematic structural views of the main nail of the present invention.

Fig. 9 is a cross-sectional view taken at a-a in fig. 7.

Fig. 10 is an exploded view of the securing assembly of the present invention.

Fig. 11 is a schematic structural view of the locking member in fig. 10.

Fig. 12 is a schematic view of the structure of the fixing member of fig. 10.

Reference numbers in the figures:

100-lag screw, 110-first head, 120-first tail, 130-first thread, 140-first undercut, 150-implant injection hole, 160-first tool recess, 170-second undercut;

200-main nail, 210-proximal end, 211-curved surface, 212-groove, 213-first tunnel, 214-orifice platform, 215-in-orifice platform, 216-second step, 217-second tunnel, 220-middle, 230-distal end, 231-diverging slot;

300-compression screw, 310-second head, 311-second thread, 312-self-tapping groove, 320-second tail, 330-compression platform;

400-transverse locking nails;

500-fixing component, 510-locking element, 511-ring groove, 520-fixing element, 521-open groove, 522-tip, 523-first step, 530-gasket;

600-tail nail.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

Referring to the description and to fig. 1 and 2, an intramedullary nail includes a medical implant lag screw 100, a main nail 200, a cross locking nail 400, and a compression screw 300 for compressing the lag screw 100. As can be seen in particular in fig. 7 and 8, the main nail 200 has a proximal portion 210, an intermediate portion 220 and a distal portion 230 integrally connected, the lag screw 100 passing transversely through the proximal portion 210 via a first tunnel 213, and the transverse locking nail 400 passing transversely through the distal portion 230 via a second tunnel 217.

Fig. 3-5 illustrate a schematic structural view of a lag screw in one embodiment. With continued reference to fig. 3-5, a medical implant lag screw 100 includes a screw body having a first head portion 110 and a first tail portion 120. Wherein, the outer wall surface of the first head 110 is provided with a first thread 130 for implantation, and the first thread 130 has a plurality of reverse threads. The distance from the tip of the reverse thread to the outer wall surface of the first head part 110 decreases in order in the direction from the first head part 110 to the first tail part 120.

Under the action of the reverse screw teeth, the deeper the reverse screw teeth are implanted, the better the fastening effect is, the holding force is increased, and the Z effect is reduced. In addition, by arranging the reverse threads with gradually reduced sizes, the bone of a patient can be prevented from being damaged too much after the lag screw 100 is implanted while a good fastening effect is ensured.

In one embodiment, the first head 110 has a trapezoidal longitudinal section, and the connecting line of the top ends of the reverse threads is parallel to the central axis of the first head 110. In this manner, damage to the patient's bone after lag screw 100 is implanted is further reduced while avoiding the "Z" effect. Of course, in another embodiment, a line connecting the top ends of the respective reverse threads and the central axis of the first head portion 110 may have an inclination angle, and a line connecting the top ends of the respective reverse threads and the first tail portion 120 may form an obtuse angle.

In one embodiment, the first tail portion 120 of the lag screw 100 is provided with a plurality of first cut-outs 140 that match the threads of the compression screw 300. As shown in fig. 3 and 5, the first slot 140 is a longitudinal slot, and the slot direction thereof may be approximately perpendicular to the central axis direction of the lag screw 100. In this manner, by providing the first notch 140 that matches the threads on the compression screw 300, the security of the connection between the lag screw 100 and the compression screw 300 is enhanced, further reducing the occurrence of the "Z" effect.

In one embodiment, the first tail portion 120 of the lag screw 100 is further provided with a second slot 170 for limiting relative rotation between the lag screw and the main nail. The second cutting groove 170 may be a long circular arc groove arranged along the axial direction of the lag screw 100, and the strength is improved better by the circular arc design. In the present embodiment, the second incision 170 may be disposed opposite to the first incision 140. In other embodiments, the position of the second slot 170 can be adjusted accordingly.

In order to improve the therapeutic effect of the intramedullary nail, at least one implant injection hole 150 may be provided between the adjacent reverse threads on the first head 110. As shown in fig. 4 and 5, an implant injection hole 150 may be formed between some adjacent counter threads, the implant injection hole 150 is formed on an outer wall surface of the first head 110 of the lag screw 100, and at least the first head 110 of the lag screw 100 has a hollow structure, so that an implant can be conveniently injected into a bone of a patient through an end opening of the first head 110 after being injected from the corresponding implant injection hole 150, thereby improving the bone strength of the patient. Of course, a plurality of implant injection holes 150 may be respectively provided between the adjacent reverse threads. The implant injection holes 150 may be arranged in a specific order, for example, they may be alternately arranged up and down in the drawing or in another order, and of course, the implant injection holes 150 may be arranged randomly.

In one embodiment, the implant injection hole 150 includes, but is not limited to, a cement hole. Besides the bone cement hole, the bone cement hole can also be used as other implant holes, and the problem of poor treatment effect caused by osteoporosis is reduced by implanting other implants which can be implanted into bones and can enhance the bone density and strength.

In one embodiment, as shown in fig. 5, the first tail portion 120 of the lag screw 100 may be provided with a first tool slot 160 for facilitating the tightening of a mating tool, and the compression screw 300 may be conveniently implanted or removed through the first tool slot 160 for convenient use. The first tool slot 160 may be a conventional slot type that matches existing tools, such as a straight slot, an inner quincunx, an inner circle, an inner polygon, and so on.

FIG. 6 illustrates a schematic view of a compression screw according to an embodiment. As shown in fig. 2 and 6, the compression screw 300 is provided with a second thread 311 engaged with the first thread 130, and the second thread 311 has a span larger than that of the first thread 130 and is capable of engaging with the first notch 140. In one embodiment, the compression screw 300 includes a second head portion 310 and a second tail portion 320, the second head portion 310 is covered with a second thread 311, and the second thread 311 may be a forward thread and/or a reverse thread. The second thread 311 matches the thread of the first thread 130, and through the threaded connection between the two, the compression screw 300 can fix and lock the tension screw 100, and the occurrence of the "Z" effect is reduced.

In the present embodiment, the compression screw 300 is provided at the lower end of the lag screw 100. In other embodiments, the compression screw 300 may be disposed at a side end of the lag screw 100 or other suitable position.

In one embodiment, to facilitate implantation, the trailing end of the second head 310 of the compression screw 300 may be provided with a self-tapping slot 312. The second tail 320 may be provided with a locking mechanism in threaded engagement with a compression screw, which may be a quincunx screw or other conventional locking mechanism.

Fig. 10-12 are schematic structural views of the fixing assembly of the present invention. The intramedullary nail further comprises a fixation assembly 500, the fixation assembly 500 being received in the cavity of the proximal portion 210 of the main nail 200, the second slot 170 provided on the lag screw 100 cooperating with the fixation assembly 500 to limit rotation of the lag screw 100 relative to the main nail.

In one embodiment, with continued reference to fig. 10-12, the fastening assembly 500 includes a locking member 510 and a fastening member 520 coupled to the locking member 510, the locking member 510 being fixedly coupled to the inner wall of the main nail 200. In this embodiment, the locking member 510 and the fixing member 520 may be snap-fit. Of course, in other embodiments, the two may be connected in other ways.

In one embodiment, as shown in fig. 11 and 12, the locking member 510 has an annular groove 511 formed at one end thereof and an external thread formed at the other end thereof, and the main nail 200 has an internal thread formed on an inner wall thereof to match the external thread, and the locking member and the external thread are fixedly coupled to each other by means of a screw.

An open slot 521 is formed at an end of the fixing member 520 close to the locking member 510, and the open slot 521 is matched with the annular slot 511 formed in the locking member 510. The opening 521 may include, but is not limited to, a T-shaped groove, and the fixing member 520 and the locking member 510 are snap-connected through the opening 521 and the annular groove 511. The fixing member 520 is provided at the other end thereof remote from the locking member 510 with a tip 522 inserted into the second slot 170, and the rotation of the lag screw 100 and the main nail 200 is restricted by providing the tip 522. The tip 522 may be shaped to match the second slot 170, although other specific shapes are possible. In the present embodiment, the tip portion 522 is a circular arc-shaped tip portion 522.

In one embodiment, with continued reference to fig. 12, the side wall of the fixing member 520 near one end of the locking member 510 is further provided with a first step 523, and correspondingly, the proximal end portion 210 of the main nail 200 is a cavity and the inner wall is provided with a second step 216 matching with the first step 523 in size. The fixing member 520 and the main nail 200 are abutted by the first step 523 and the second step 216 to limit the movement of the fixing member 520 in the axial direction of the main nail 200. In one embodiment, the fixing assembly 500 further includes at least one spacer 530, the spacer 530 being disposed between the fixing member 520 and the locking member. The gasket 530 includes, but is not limited to, at least one of a round gasket and an elastic gasket. In this embodiment, two spacers 530 are provided, which are a round spacer and an elastic spacer.

Fig. 7-9 illustrate the structure of the main nail of the present invention. The main nail 200 will be described in detail with reference to the accompanying drawings.

The main nail design of conventional intramedullary nails is non-circular in cross-section, thus requiring larger sized bores during implantation, causing serious injury to the patient's bone. To this end, we redesigned the main nail structure.

In one embodiment, as shown in fig. 9, the projection shape of the proximal end portion 210 of the main nail 200 in the axial direction is circular. Preferably, the proximal end portion 210 of the main nail 200 may be a cylindrical structure. Thus, by providing the main nail 200 with a rounded end, the size of the drilled hole required can be reduced, thereby mitigating damage to the patient's bone.

Further, the cross-sectional shape of the proximal portion 210 in the direction toward the end face of the proximal portion 210 is a tapered circle. Through the gradual change type circular design of the end part, the strength of the hole wall position of the near end can be ensured, the end part is gradually reduced, more sclerotin can be obtained, and the stability of internal fixation can be better enhanced.

Further, at least a part of the outer wall surface of the proximal portion 210 near the intermediate portion 220 has a curved surface 211 that is concave. This reduces the stress on the outer wall after implantation and after operation of the intramedullary nail. Further, in one embodiment, the intermediate portion 220 may be provided with a groove 212 disposed along the axis. Thus, the pressure on the outer side wall after the intramedullary nail is implanted and after the operation can be further reduced.

In one embodiment, the wall of distal portion 230 is provided with a plurality of diverging slots 231. Thus, by providing the bifurcating groove 231, the distal end portion 230 has a certain elasticity so that it can be bent. In this manner, stress fractures due to irritation of the bone wall are avoided by providing the bifurcating groove 231 to reduce stress on the distal end portion 230 of the main nail 200. In the present embodiment, the number of the branch grooves 231 may be 4 evenly distributed. In other embodiments, the branched slot 231 may be distributed in other ways.

With continued reference to fig. 7 and 8, the first channel 213 is a "8-like" channel, and both the lag screw 100 and compression screw 300 traverse the first channel 213. In the present embodiment, the compression screw 300 is provided at the lower end of the lag screw 100 and passes through the first passage together with the lag screw 100. Further, an orifice platform 214 is provided at the first porthole 213. In this manner, by providing the orifice land 214 in the "8" -like tunnel, stress concentrations are reduced, preventing the main nail 200 from breaking there.

In one embodiment, with continued reference to fig. 7, an in-hole platform 215 is further disposed at the first hole 213, and a pressure platform 330 is disposed on the pressure screw 300 and matches with the in-hole platform 215. In this embodiment, the pressing platform 330 is disposed at the junction of the second leading portion 310 and the second trailing portion 320. In this way, during the process of implanting the compression screw 300, the compression platform 330 contacts the platform 215 in the hole of the lag screw 100, so as to limit the relative displacement between the compression screw 300 and the main nail 200, and if the compression screw 300 is further tightened, the compression screw 300 converts the acting force into the relative movement which drives the lag screw 100, thereby realizing the compression.

In one embodiment, as shown in fig. 1 and 2, the intramedullary nail may further include a tail pin 600 thereon, the tail pin 600 being received in the proximal portion 210. The tail nail 600 may be threadably coupled with the main nail 200 to close the proximal end 210 of the main nail 200.

The following describes in detail the partial mounting and implantation procedure of the intramedullary nail of the above embodiment:

1) the washer 530 is inserted into the locking member 510, the annular groove 511 of the locking member 510 is snapped into the open groove 521 of the fixing member 520, after the assembly, the fixing member 520 and the locking member are inserted into the proximal portion 210 of the main nail 200 together, and are slowly screwed into the locking member 510, and the first step 523 of the fixing member 520 abuts against the second step 216 of the proximal portion 210 of the main nail 200, so as to lock the fixing assembly 500.

2) The lag screw 100 is inserted through the first bore 213 and screwed into the bone of the patient, and the tip 522 of the fixing member 520 is inserted into the second recess 170 of the lag screw 100 to restrict the relative rotation of the lag screw 100 and the main nail 200.

3) The compression screw 300 is threaded through the first bore 213 and into the bone of the patient to limit further advancement of the compression screw 300 after the compression platform 330 on the compression screw 300 contacts the intra-bore platform 215 at the first bore 213. At this time, the compression screw 300 is further screwed in, and the second thread 311 of the compression screw 300 is engaged with the first cut 140 of the lag screw 100, so that the lag screw 100 moves relative to the screwing direction of the compression screw 300, and the lag screw 100 is further advanced toward the bone part to perform compression fixation on the fracture part.

4) The transverse screw may be threaded into the patient's bone through the second bore 217 to complete the implantation of the intramedullary nail.

The utility model also provides a medical implantation fixing system, which comprises the intramedullary nail.

It should be noted that the detailed contents and benefits of the intramedullary nail can be found in the above description, and are not repeated herein for brevity.

While the foregoing description shows and describes the preferred embodiments of the present invention, it is to be understood that the invention is not limited to the forms disclosed herein, but is not intended to be exhaustive or to exclude other embodiments and may be used in various other combinations, modifications, and environments and is capable of changes within the scope of the inventive concept as expressed herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. But that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention, which is to be limited only by the claims appended hereto.

Claims (10)

1. A medical implant lag screw, comprising:

a screw body having a first head (110) and a first tail (120);

the outer wall surface of the first head part (110) is provided with a first thread (130) used for implantation, the first thread (130) is provided with a plurality of reverse threads, and the distances from the top ends of the reverse threads to the outer wall surface of the first head part (110) are sequentially reduced in the direction from the first head part (110) to the first tail part (120).

2. The medical implant lag screw of claim 1, wherein the longitudinal section of the first head (110) is trapezoidal, and a line connecting the tips of the respective reverse threads is parallel to the central axis of the first head (110).

3. The medical implant lag screw of claim 1 or 2, wherein at least one implant injection hole (150) is provided between adjacent reverse threads on the first head (110);

the first tail part (120) is provided with a plurality of first cutting grooves (140) matched with the threads of the compression screw.

4. Intramedullary nail, comprising a lag screw (100) according to any one of claims 1 to 3, a main nail (200), a cross-locking nail (400) and a compression screw (300) for compressing the lag screw (100), the main nail (200) having a proximal portion (210), an intermediate portion (220) and a distal portion (230) integrally connected, the lag screw (100) being passed transversely through the proximal portion (210) via a first bore (213), the cross-locking nail (400) being passed transversely through the distal portion (230) via a second bore (217).

5. Intramedullary nail according to claim 4, characterized in that the first tail (120) of the lag screw (100) is provided with a number of first slots (140) cooperating with the thread of the compression screw (300);

the intramedullary nail further comprises a fixing component (500), the fixing component (500) is accommodated in the cavity of the proximal end part (210) of the main nail (200), and a second notch (170) matched with the fixing component (500) is arranged on the first tail part (120) of the lag screw (100).

6. The intramedullary nail according to claim 5, characterized in that the fixation assembly (500) comprises a locking member (510) and a fixation member (520) connected to the locking member (510), the locking member (510) being fixedly connected to the inner wall of the main nail (200), the fixation member (520) comprising a tip (522), the tip (522) being insertable into the second slot (170) to limit the relative rotation of the lag screw (100) and the main nail (200);

the fixing piece (520) is further provided with a first step (523), and the inner wall of the proximal end portion (210) is provided with a second step (216) matched with the first step (523) so as to limit the movement of the fixing piece (520) along the axial direction of the main nail (200).

7. Intramedullary nail according to claim 6, characterized in that said compression screw (300) is provided with a second thread (311) cooperating with said first thread (130), said second thread (311) having a span greater than the span of said first thread (130) and being able to cooperate with said first incision (140);

the intramedullary nail further comprises a tail nail (600), and the tail nail (600) is accommodated in the proximal part (210).

8. Intramedullary nail according to any one of claims 4 to 7, characterized in that the cross-sectional shape of said proximal portion (210) in the direction of the end face of the proximal portion (210) is a circle of decreasing diameter,

at least part of the outer wall surface of the proximal end portion (210) close to the middle portion (220) is provided with an inwards concave curved surface (211), the middle portion (220) is provided with a groove (212) arranged along the axial direction, and the distal end portion (230) is provided with a plurality of branched grooves (231).

9. Intramedullary nail according to any one of claims 4 to 7, characterized in that said first hole (213) is a "8" -like hole, said lag screw (100) and compression screw (300) both crossing said first hole (213), at said first hole (213) there being provided an orifice platform (214) for reducing stress concentrations;

an in-hole platform (215) is further arranged at the first hole channel (213), and a pressurizing platform (330) matched with the in-hole platform (215) is arranged on the pressurizing screw (300) so as to limit the pressurizing screw (300) to advance.

10. A medical implant fixation system comprising an intramedullary nail according to any one of claims 4 to 9.