Fracture reduction fixing anti-retreating screw

Abstract

The utility model discloses a fracture reduction fixing anti-retreating screw which comprises a stud and a movable rod. A through locking cavity is formed in the stud; the movable rod is movably inserted into the locking cavity; a connecting sleeve is coaxially and fixedly arranged at the end part of the stud; appearance variable strips are symmetrically and fixedly arranged at the edge of the end part of the connecting sleeve; an inner movable strip is arranged at the end part of the outer shape variable strip; the inner movable strip is parallel to the central axis of the connecting sleeve, and the movable rod is inserted along the central axis of the locking cavity to push the end part of the inner movable strip, so that the end part of the inner movable strip rotates around the end part of the outer shape variable strip in a mutually separated manner, and the outer shape variable strip is bent towards the direction close to the end part of the stud; the position of the whole stud on the human skeleton is fixed through the deformation effect of the appearance variable strip connected with the connecting sleeve at the end of the stud, so that the appearance variable strip is bent towards a bone cortex layer of a broken bone of a patient to form a limiting structure with the appearance variable strip as a fulcrum, and the stud can be effectively prevented from being separated from a bone tunnel drilled for fracture fixation of the patient.

Description

Technical Field

[0001] The utility model relates to the technical field of medical instruments, in particular to a fracture reduction and fixation screw with anti-retraction function. Background Art

[0002] The anti-backout fixation screws used in orthopedic instruments are for patients with fractures, especially those with long bone fractures who require surgical intervention. Fracture reduction plates are needed to help patients recover. Anti-backout fixation screws play a key role in the fixation process of fracture reduction plates. In addition, due to the different degrees of fractures in patients, the required screws and plate screws are also different.

[0003] In existing orthopedic surgeries, in order to prevent screws from loosening or falling out after surgery, doctors may use special designs on some screws to provide better fixation performance. For example, some screws are designed with a self-locking mechanism on the head to prevent them from loosening after surgery. However, such self-locking screws are inconvenient during use and installation. Not only are they easily dislodged due to external forces, but they also make it impossible for the surgeon to judge the length of the screw during surgery.

[0004] Therefore, it is necessary to provide a fracture reduction and fixation screw with anti-retraction function to solve the technical problem in the prior art that self-locking screws are easy to fall out and difficult to install. Utility Model Content

[0005] The purpose of the utility model is to provide a fracture reduction and fixation anti-retraction screw to solve the technical problems raised in the background technology.

[0006] In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

[0007] The utility model provides a fracture reduction and fixation anti-retreat screw, comprising: a stud, an interior of which is provided with a through locking cavity; a movable rod, which is movably inserted into the interior of the locking cavity; wherein, a connecting sleeve is coaxially fixedly provided at the end of the stud; an outer shape changing strip is symmetrically fixedly provided at the end edge of the connecting sleeve; an inner movable strip is provided at the end of the outer shape changing strip; the inner movable strip is arranged parallel to the central axis of the connecting sleeve, and the movable rod is inserted along the central axis of the locking cavity to push the end of the inner movable strip so that it rotates away from each other around the end of the outer shape changing strip, so that the outer shape changing strip bends in a direction close to the end of the stud.

[0008] Furthermore, the ends of the inner movable bars are provided with slots perpendicular to the wall thereof; wherein, the slots are semicircular; after the inner movable bars are rotated 90° apart, the slots can be used to form a channel between the ends of the inner movable bars to accommodate the entry of the movable rod.

[0009] Furthermore, the ends of the inner movable bars have a wedge-shaped structure; the ends of the inner movable bars are connected to each other via elastic sheets, and the width of the elastic sheets varies with the distance between the ends of the inner movable bars.

[0010] Furthermore, a through hole is provided on the elastic sheet for the movable rod to pass through; wherein the through hole is provided along the central axis of the connecting sleeve.

[0011] Furthermore, thread grooves are respectively provided on the inner walls of the notches and the through holes; wherein screws can be screwed into the notches / through holes to fix the relative positions between the inner movable bars.

[0012] Furthermore, the connecting sleeve may be threadedly connected to the end of the stud.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The utility model fixes the position of the entire stud on the human skeleton by utilizing the deformation effect of the outer shape deforming strip connected to the connecting sleeve at the end of the stud, so that the outer shape deforming strip is bent toward the cortical layer of the patient's broken bone to form a limiting structure with it as a fulcrum, which can effectively prevent the stud from falling out of the bone canal, avoid affecting the patient's fracture recovery and reduce the risk of secondary surgery and recurrence of fractures. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely illustrative, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0016] Figure 1 A cross-sectional view of a fracture reduction and fixation anti-retraction screw provided by the utility model;

[0017] Figure 2 for Figure 1 A three-dimensional structural diagram of the middle connecting sleeve and other components thereon;

[0018] Figure 3 for Figure 2 a cross-sectional view in another state;

[0019] Figure 4 A cross-sectional view of a stud in another embodiment provided by the present invention;

[0020] Figure 5 for Figure 4 Enlarged view of middle Ⅰ.

[0021] Figure 6 for Figure 5a cross-sectional view in another state;

[0022] Figure 7 for Figure 6 Enlarged view of middle II;

[0023] Figure 8 This is a schematic structural diagram of the cooperation between the elastic sheet and the screw in another embodiment provided by the utility model.

[0024] The numbers in the figure represent the following:

[0025] 1. Stud; 11. Locking cavity; 12. Connecting sleeve; 13. External shape changing strip; 14. Internal movable strip; 141. Notch; 142. Elastic sheet; 143. Through hole; 2. Movable rod; 3. Screw; 4. Cortical bone layer. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] like Figure 1 As shown, the utility model provides a fracture reduction and fixation screw to prevent nail withdrawal, comprising:

[0028] The stud 1 has a through locking cavity 11 formed therein;

[0029] The movable rod 2 is movably inserted into the locking cavity 11;

[0030] Among them, a connecting sleeve 12 is coaxially fixed to the end of the stud 1; an outer shape changing strip 13 is symmetrically fixed at the end edge of the connecting sleeve 12; an inner movable strip 14 is provided at the end of the outer shape changing strip 13; the inner movable strip 14 is arranged parallel to the central axis of the connecting sleeve 12, and the movable rod 2 is inserted along the central axis of the locking cavity 11 to push the end of the inner movable strip 14 so that it rotates away from each other around the end of the outer shape changing strip 13, so that the outer shape changing strip 13 bends toward the direction close to the end of the stud 1.

[0031] The present invention aims to fix the stud 1 as a whole at the fracture site by means of the deformation effect of the outer shape changing strip 13 connected to the connecting sleeve 12 at the end of the stud 1, so as to prevent the stud 1 from falling out in the reverse direction and avoid the risk of secondary surgery for the patient; specifically, the screw provided by the present invention is screwed into the hole pre-drilled on the patient's broken bone through the thread on the stud 1. When the stud 1 reaches the preset depth, the movable rod 2 is pushed so that one end of the inner movable strip 14 pushes the inner movable strip 14, so that the inner movable strip 14 gradually produces a rotational movement in the direction of separation from each other with the end of the outer shape changing strip 13 as the fulcrum, and then the outer shape changing strip 13 is bent toward the bone cortical layer 4 of the patient's fracture site to form a limiting structure with it as the fulcrum, which can effectively prevent the stud 1 from falling out of the bone channel drilled for internal fixation of the fracture.

[0032] During actual use of the fracture reduction, fixation and anti-retreat screw provided by the present invention, it should be noted that since the stud 1 is embedded in the vicinity of the human fracture and is subjected to axial pressure, a load is generated relative to the stud 1. Therefore, the diameter of the locking cavity 11 in the stud 1 should be as small as possible relative to the stud 1, so as not to affect the entry of the movable rod 2 and to ensure the strength of the stud 1, thereby avoiding the problem of the stud 1 breaking and failing during the load-bearing process; on the other hand, in order to minimize the trauma caused to the patient's muscle tissue by the outer shape variable strip 13 during the rotation process, the length of the outer shape variable strip 13 should be as small as possible relative to the stud 1, and the length ratio of the outer shape variable strip 13 to the stud 1 is about 10:1, so that the outer shape variable strip 13 can stably fit the bone cortical surface and play a stabilizing role in the insertion of the stud 1, thereby reducing the trauma caused to the patient's muscle tissue during the rotation process by the outer shape variable strip 13.

[0033] In the above embodiment, since the displacement of the stud 1 in the bone canal cannot be observed by the surgeon in real time, it is difficult for the surgeon to grasp the force and depth of the stud 1 inserted into the bone canal, which may easily cause the patient to find that the screw is too long or too short after the screw is inserted, resulting in damage to the muscle tissue around the fracture end, which is even more detrimental to the growth and recovery of the fracture end of the patient.

[0034] In order to solve the above problems, Figure 2-3 As shown, in the preferred embodiment provided by the present invention based on the above embodiment, a notch 141 perpendicular to the wall surface of the inner movable bar 14 is provided at the end thereof;

[0035] wherein the notch 141 is semicircular; after the inner movable bars 14 are rotated 90° apart, the notch 141 can be used to form a channel between the ends of the inner movable bar 14 for accommodating the entry of the movable rod 2 .

[0036] In this embodiment, the channel for accommodating the movable rod 2 is formed by the groove 141 provided at the end of the inner movable bar 14, so that after the inner movable bar 14 rotates 90°, the blocking effect of the inner movable bar 14 on the movable rod 2 is removed when the stud 1 is limited, so that the movable rod 2 can move inside the locking cavity 11 with extremely small resistance, so that medical staff can judge the position of the movable rod 2 and whether the outer shape variable bar 13 has formed a stable limiting structure in the patient's body according to the resistance of the movable rod 2 in the locking cavity 11, and thus can enable the surgeon to remove the movable rod 2 as soon as possible after using the screw provided by the utility model to fix the broken bone of the patient, without having to repeatedly test in the patient's body to confirm whether the limiting structure has taken effect, further improving the surgeon's surgical efficiency when using screws to fix fractures.

[0037] In the above embodiment, the inner movable bars 14 are separated from each other. When they are subjected to the thrust of the movable rod 2, they are easily dislocated due to uneven force, which causes the movable rod 2 to be unable to push the two inner movable bars 14 at the same time, affecting the limiting stability of the stud 1.

[0038] In order to solve the above problems, Figure 4-6 As shown, in another embodiment provided by the present invention, the end portion of the inner movable bar 14 has a wedge-shaped structure;

[0039] The ends of the inner movable bar 14 are connected to each other via an elastic sheet 142 , and the width of the elastic sheet 142 varies with the distance between the ends of the inner movable bar 14 .

[0040] In this embodiment, the inner movable bars 14 are elastically connected by using elastic sheets 142, so that the relative positions of the two can be limited to avoid dislocation during the movement due to external forces. While ensuring that the movable rod 2 has a stable pushing effect on the inner movable bar 14, it can also further ensure that the limiting stability of the stud 1 at the patient's broken bone is not affected.

[0041] In order to enable medical staff to control the force and depth of the movable rod 2 inserted into the patient's body, Figure 8 As shown, in the preferred embodiment provided by the present invention based on the above embodiment, a through hole 143 for the movable rod 2 to pass through is provided on the elastic sheet 142;

[0042] The through hole 143 is opened along the central axis of the connecting sleeve 12 .

[0043] In order to improve the stability of the limiting structure formed by the outer shape changing strip 13 and the inner movable strip 14, Figure 8 As shown, in the preferred embodiment provided by the present invention based on the above embodiment, thread grooves are respectively provided on the inner walls of the notch 141 and the through hole 143;

[0044] The screws 3 may be screwed into the slots 141 / through holes 143 to fix the relative positions of the inner movable bars 14 .

[0045] In this embodiment, by screwing the screw 3 into the notch 141 / through hole 143, the position between the ends of the inner movable bar 14 can be relatively fixed, preventing the stud 1 from being pulled by external forces, causing the outer deforming bar 13 and the inner movable bar 14 to produce similar rotational deformation away from the end of the stud 1, which would result in poor positioning of the stud 1 at the patient's broken bone and affect the patient's recovery. Specifically, the tail ends of the stud 1 and the screw 3 both have cross-shaped notches for removing and nailing. When nailing, use a large screwdriver to clamp one side of the cross-shaped notch at the tail end of the stud 1, and a small screwdriver to completely clamp the cross-shaped notch at the tail end of the screw 3 and rotate it a certain angle, and vice versa.

[0046] In order to ensure that the connecting sleeve 12 can be stably connected to the stud 1 , the connecting sleeve 12 can be screwed to the end of the stud 1 .

[0047] The above embodiments are merely exemplary embodiments of the present application and are not intended to limit the scope of the present application. The scope of protection of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and scope of protection of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the scope of protection of the present application.

Claims

1. A fracture reduction and fixation screw to prevent nail withdrawal, characterized in that: include: A stud (1) having a through locking cavity (11) formed therein; A movable rod (2) movably inserted into the interior of the locking cavity (11); Wherein, a connecting sleeve (12) is coaxially fixed to the end of the stud (1); The end edge of the connecting sleeve (12) is symmetrically fixed with an outer shape changing strip (13); An inner movable strip (14) is provided at the end of the outer shape variable strip (13); The inner movable strip (14) is arranged parallel to the central axis of the connecting sleeve (12), and the movable rod (2) is inserted along the central axis of the locking cavity (11) to push the end of the inner movable strip (14) so ​​that it rotates away from each other around the end of the outer shape changing strip (13), so that the outer shape changing strip (13) bends in a direction close to the end of the stud (1).

2. A fracture reduction and fixation screw according to claim 1, characterized in that: The end of the inner movable bar (14) is provided with a notch (141) perpendicular to its wall surface; Wherein, the notch (141) is semicircular; After the inner movable bars (14) are rotated 90 degrees apart, the ends of the inner movable bars (14) can form a channel for accommodating the movable rod (2) to enter by utilizing the notch (141).

3. The fracture reduction and fixation screw according to claim 2, characterized in that: The end of the inner movable strip (14) has a wedge-shaped structure; The ends of the inner movable strips (14) are connected to each other via an elastic sheet (142), and the width of the elastic sheet (142) varies with the distance between the ends of the inner movable strips (14).

4. The fracture reduction and fixation anti-retraction screw according to claim 3, characterized in that: The elastic sheet (142) is provided with a through hole (143) for the movable rod (2) to pass through; The through hole (143) is opened along the central axis of the connecting sleeve (12).

5. A fracture reduction and fixation screw according to claim 2 or 4, characterized in that: The notch (141) and the inner wall of the through hole (143) are respectively provided with a thread groove; Wherein, a screw (3) can be screwed into the notch (141) / through hole (143) to fix the relative positions between the inner movable bars (14).

6. The fracture reduction and fixation screw according to claim 5, characterized in that: The connecting sleeve (12) can be screwed onto the end of the stud (1).

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