Dynamic sliding compression anti-distraction screw, femoral neck fracture fixing instrument and fixing plate

Abstract

The utility model discloses a dynamic sliding pressurization anti-distraction screw, a femoral neck fracture fixing instrument and a fixing plate. The anti-distraction screw comprises a screw body, the screw body comprises a screw head threaded section, the screw head threaded section is arranged at the screw head end, a single-circle threaded structure of the screw head threaded section comprises a screw-in guiding curved surface and a screw-out blocking anchoring surface, and the second end of the screw-in guiding curved surface is connected with the screw-out blocking anchoring surface; the diameter of the first end of the guide nail feeding curved surface is smaller than that of the second end of the guide nail feeding curved surface; a single-circle thread structure of the screw tail thread section comprises a screw retreating guiding curved surface and a screw feeding blocking anchoring surface, the second end of the screw retreating guiding curved surface is connected with the screw feeding blocking anchoring surface, and the diameter of the first end of the screw retreating guiding curved surface is smaller than that of the second end of the screw retreating guiding curved surface; the thread direction of the screw head thread section is consistent with that of the screw tail thread. The anti-distraction screw is applied to femoral neck fracture fixing instruments and fixing plates. The setting can promote the healing of the fracture surface, reduce the nail withdrawing amplitude and avoid nail feeding.

Description

Technical Field

[0001] The utility model belongs to the technical field of medical devices, and particularly relates to a fixing device for femoral neck fractures, specifically to a dynamic sliding compression anti-traction screw, a fixing device for femoral neck fractures, and a fixing plate. Background Art

[0002] Femoral fractures are a common type of fracture, and femoral neck fractures also account for a relatively large proportion in femoral fractures, which can occur in all age groups.

[0003] Currently, in clinical practice, multiple or single fixing nails are usually used to reduce and fix the fractured femoral neck. After the reduction and fixation of the femoral neck fracture, there are three key factors promoting fracture healing. The first is unobstructed blood circulation, the second is the stability of the bone surface, and the third is bone surface compression. And bone surface compression is a relatively well-controlled factor. How to effectively ensure the continuous existence of bone surface compression is of great significance for the recovery of the femoral neck.

[0004] The utility model provides a dynamic sliding compression anti-traction screw, a fixing device for femoral neck fractures, and a fixing plate for the above technical problems. Summary of the Utility Model

[0005] A dynamic sliding compression anti-traction screw, which comprises: a screw body, the end entering the body first is the nail head end, and the opposite end is the nail tail end, and correspondingly provided thereon is

[0006] a nail head thread section, arranged at the nail head end, the single-thread structure of the nail head thread section includes a guiding nail-inserting curved surface and a blocking nail-withdrawing anchoring surface. The first end of the guiding nail-inserting curved surface is close to the nail head end, the second end of the guiding nail-inserting curved surface is far from the nail head end, the second end of the guiding nail-inserting curved surface is connected to the blocking nail-withdrawing anchoring surface, and the diameter of the first end of the guiding nail-inserting curved surface is smaller than the diameter of the second end of the guiding nail-inserting curved surface;

[0007] a nail tail thread section, arranged at the nail tail end, the single-thread structure of the nail tail thread section includes a guiding nail-withdrawing curved surface and a blocking nail-inserting anchoring surface. The first end of the guiding nail-withdrawing curved surface is close to the nail tail end, the second end of the guiding nail-withdrawing curved surface is far from the nail tail end, the second end of the guiding nail-withdrawing curved surface is connected to the blocking nail-inserting anchoring surface, and the diameter of the first end of the guiding nail-withdrawing curved surface is smaller than the diameter of the second end of the guiding nail-withdrawing curved surface;

[0008] The thread directions of the nail head thread section and the nail tail thread are the same.

[0009] Note: The proximal fracture bone block is the bone block corresponding to the femoral head, and the distal fracture bone block is the bone block far from the femoral head.

[0010] Further, except for the transitional thread structure at the edge, the guiding screw-in surface and the guiding screw-out surface on the middle thread structure are the same or similar in shape; the anti-screw-out anchoring surface and the anti-screw-in anchoring surface are the same or similar in shape; the anti-screw-out anchoring surface faces the screw tail end, and the anti-screw-in anchoring surface faces the screw head end.

[0011] Further, the guiding screw-in surface and the guiding screw-out surface on the middle thread structure are the same in size; the anti-screw-out anchoring surface and the anti-screw-in anchoring surface are the same in shape and size; the anti-screw-out anchoring surface faces the screw tail end, and the anti-screw-in anchoring surface faces the screw head end.

[0012] Further, except for the different orientations, the number of turns of the thread structure on the screw head thread section and the screw tail thread section is the same, and the relative thread structures of the screw head thread section and the screw tail thread section are the same; such a setting ensures that the pressures exerted by the screw head thread section and the screw tail thread section on the bone surface are basically the same, avoiding adverse effects on the bone surface due to different pressures on the bone surface.

[0013] Further, the anti-screw-out anchoring surface is perpendicular to the longitudinal axis of the screw body, or the anti-screw-out anchoring surface inclines from the outside to the inside towards the first end of the screw head thread section; the anti-screw-in anchoring surface is perpendicular to the longitudinal axis of the screw body, or the anti-screw-in anchoring surface inclines from the outside to the inside towards the first end of the screw tail thread section.

[0014] Further: A tail cap is provided at the fixed screw tail end. The first end of the tail cap is the end in the direction of the screw tail end, and the screw tail thread section starts from the end position of the second end of the tail cap.

[0015] Further, the first end of the screw head thread section is the screw head end, and a plurality of inclined grooves one for constructing self-tapping tips are provided at the first end of the screw head thread section, preferably 2 - 3 inclined grooves one.

[0016] Further, the first end of the screw tail thread section is the end far from the screw tail end, and inclined grooves two for constructing a self-tapping structure are provided at the first end of the screw tail thread section, and 2 - 3 inclined grooves two are provided.

[0017] The present utility model also discloses a fixing device for femoral neck fractures. The fixing device includes 1 such dynamic sliding compression anti-traction screw or 2 parallel dynamic sliding compression anti-traction screws.

[0018] The present utility model also discloses a fixing plate including the above anti-traction screw. A screw hole is provided on the fixing plate, and the traction screw enters the femur through the screw hole and combines with the fixing plate to complete the reduction and fixation of the femur.

[0019] The present utility model also discloses a fixing plate including the above-mentioned anti-traction screw. A sleeve is arranged on the fixing plate, and the traction screw enters the femur through the sleeve and combines with the fixing plate to complete the reduction and fixation of the femur; the first end of the sleeve is the end in the direction of the screw tail section; the traction screw extends out from the second end of the sleeve, and the threaded section of the screw tail also extends out from the end of the second end of the sleeve.

[0020] The beneficial effects of the present utility model are as follows:

[0021] 1) During the screwing-in process of the anti-traction screw, after both the threaded section of the screw head and the threaded section of the screw tail are screwed into the femur, because the guiding screw-in structure and the guiding screw-out structure are respectively arranged at the screw head and the screw tail positions, and are correspondingly connected with the setting of the anti-screw-out anchoring surface and the anti-screw-in anchoring surface, a screw-out force is applied to the anti-screw-out anchoring surface at the screw head end through the guiding screw-out structure at the screw tail end, and a screw-in force is applied to the anti-screw-in anchoring surface at the screw tail end through the guiding screw-in structure at the screw head end. In this way, there will be a movement trend of the proximal fracture bone block with the threaded section of the screw head and the distal fracture bone block with the threaded section of the screw tail approaching each other, thereby increasing the contact pressure of the fracture surface; this setting achieves the effect of applying pressure to the fracture surface in two directions.

[0022] 2) During the screw-out process when the supporting force takes effect, the fixing screw slides out by the drive of the guiding screw-out curved surface. During the screw-out, due to the existence of the anti-screw-out anchoring surface, the anti-screw-out anchoring surface will give the proximal fracture bone block a force in the screw-out direction, and this force can apply pressure to the fracture section, increasing the pressure will promote the healing of the fracture section. In addition, due to the setting of the guiding screw-out curved surface, the return resistance of the guiding screw-out curved surface that needs to be overcome during the screw-out process effectively reduces the amplitude of the screw-out, and can also effectively avoid the problem of femoral neck shortening caused by the direct sliding out of the fixing screw.

[0023] 3) During the screw-in trend process when the stretching force takes effect, the stretching force gives the fixing screw a force to move inward. After receiving the force, the anti-screw-in anchoring surface will give the distal fracture bone block a force to move inward. This inward movement force will promote the fracture bone surface to maintain a pressurized effect. The anti-screw-in anchoring surface also provides a large resistance to the inward stretching of the fixing screw, and this resistance offsets the stretching force, achieving the effect of preventing the fixing screw from moving inward by stretching.

[0024] 4) Except for the different orientations, the number of turns of the thread structure of the threaded section of the screw head and the threaded section of the screw tail are the same, and the relative thread structure settings of the threaded section of the screw head and the threaded section of the screw tail are the same, ensuring that the guiding force and the anchoring force provided are consistent, and ensuring that the forces during the screw-in and screw-out processes are consistent.

[0025] 5) The technical solution in which the anchoring surface is perpendicular or inclined to the screw body ensures that the anchoring surface can effectively and stably form an anchoring effect.

[0026] 6) Start to set the nail tail thread section from the end position of the second end of the tail cap to ensure that the nail tail thread section effectively plays a role within the bone mass.

[0027] 7) The above settings of the inclined groove 1 and the inclined groove 2 ensure that both the nail head thread section and the nail tail thread section form a self-tapping effect, ensuring the rotation and self-tapping entry of the entire fixing nail. Description of the Drawings

[0028] Figure 1 It is a schematic diagram of the overall structure of the screw of the present utility model;

[0029] Figure 2 It is a schematic diagram of the longitudinal sectional structure of the screw of the present utility model;

[0030] Figure 3 It is a schematic diagram of the structure of the lower side view of the partial enlargement of the nail head thread section of the present utility model;

[0031] Figure 4 It is a schematic diagram of the partial enlargement of the longitudinal section of the nail head thread section of the present utility model;

[0032] Figure 5 It is a schematic diagram of the partial enlargement of the nail tail thread section of the present utility model;

[0033] Figure 6 It is a schematic diagram of the partial enlargement of the longitudinal section of the nail tail thread section of the present utility model;

[0034] Figure 7 It is a schematic diagram of the femoral structure when the fixing device of the second embodiment of the present utility model is set to the position of femoral neck fracture;

[0035] Figure 8 It is a schematic diagram of the force sequence of the nail head part of the fixing nail after internal fixation of femoral neck fracture with complete support of the medial cortex of the femoral calcar. Note: ① The medial cortex of the femoral calcar supports and exerts the main pressure trabecular bone support force, generating a nail withdrawal trend; ② The nail head part of the fixing nail is stretched by the varus stress in the femoral head and exerts the main tensile trabecular bone stretching force, generating an inward movement trend; Main reference numeral description

[0036] 1. Nail head thread section; 11. Guiding nail entry curved surface; 12. Blocking nail withdrawal anchoring surface; 13. Inclined groove 1; 2. Nail tail thread section; 21. Guiding nail withdrawal curved surface; 22. Blocking nail entry anchoring surface; 23. Inclined groove 2; 3. Intermediate section; 4. Tail cap; 41. Operation hole. Detailed implementation manners

[0037] Clinically, for femoral fractures in the femoral head region such as femoral neck or femoral trochanter, the commonly used methods include setting intramedullary nails into the medullary cavity for fixation, directly using fixation nails for direct fixation, and using osteotomy plates in combination with fixation nails for fixation, which are divided into intramedullary fixation and extramedullary fixation. However, whether it is intramedullary fixation or extramedullary fixation, there are two processes during the reduction fixation treatment and rehabilitation process. The first process is the withdrawal of the fixation nail; the second process is that after the nail withdrawal reaches a certain degree, the nail withdrawal stops, and instead, a process of the fixation nail re-entering the bone will occur. Through years of clinical observation, it has been found that the withdrawal of the fixation nail promotes bone surface compression and has a positive promoting effect on the healing of the femoral neck. However, a large degree of nail withdrawal will cause shortening of the femoral neck, and the reverse nail entry after the nail withdrawal stops will result in varus of the fracture cross-section, causing the loss of compression effect on the bone surface of the fracture and having an inhibitory effect on the healing of the femoral neck.

[0038] Clinically, efforts have been continuously made to find the reasons for the above phenomena. If the principle behind the above phenomena can be understood and corresponding treatment devices and treatment plans can be designed based on the principle, it will play a very good promoting role in the recovery of femoral neck fractures. Based on the lever balance theory, the present utility model inventor combined tower cranes and traditional water pumps in daily life to analyze the above nail withdrawal and nail entry phenomena and discovered the support and tension effect. For the nail body inserted into the femur, when the support force comes into play, there will be a tendency for nail withdrawal, and when the tension force plays a major role, there will be a tendency for nail entry.

[0039] Specifically: For the treatment process of the fixation nail for femoral neck fractures, referring to Figure 8 , it is a treatment plan for treating femoral neck fractures using traditional fixation nails. Specifically: When the fixation nail initially fixes the fracture surface and the patient bears weight on the ground, the fixation nail will be subjected to the supporting force of the main pressure trabecular bone; this supporting force gives the fixation nail a force to slide backward, promoting the occurrence of nail withdrawal. At the same time of nail withdrawal, the bone surface pressure increases, and under the positive stimulation of the bone surface pressure, the bone surface heals (corresponding to A - B in Figure 8 ); once the bone surface heals, the force acting on the fixation nail changes. When bearing weight, the fixation nail is subjected to the tension of the varus stress in the femoral head and plays the role of the main tension trabecular bone, and the fixation nail will receive a force to migrate inward, promoting the fixation nail to have an inward migration tendency. However, this inward tension force will reduce the contact pressure of the fracture surface, and in many cases, one side of the fracture surface will re-fracture (corresponding to Figure 8in B-C). Especially for the fixation nail with a threaded section only at the nail head position, both the nail removal and inward movement are sliding processes, and there is no rotation during the process. It is the threaded section that drives the backward and forward movement of the corresponding bone mass of the femoral head. The backward movement will increase the contact pressure on the fracture surface of the femoral neck. However, if the nail removal amplitude is too large, it will cause the adverse consequence of femoral neck shortening. The forward movement will cause the pressure on the newly restored fracture surface to become smaller, resulting in the opening of the reduced fracture surface and being unfavorable for fracture healing.

[0040] The key factor for femoral neck shortening is that direct sliding out causes severe posterior displacement of the proximal fracture bone mass; the tensile force generated by the varus stress of the femoral head is the key acting force causing the inward movement of the fixation nail, resulting in poor bone surface restoration. Then, in clinical practice, a device is needed that can effectively avoid direct sliding nail removal and can construct a force opposite to the tensile force to effectively offset the tensile force, thereby eliminating the tendency of the fixation nail to move inward, so that the bone surface always maintains contact pressure and promotes healing.

[0041] Embodiment 1

[0042] Reference Figures 1-6 ; A dynamic sliding compression anti-tensile screw, which includes: a screw body, the end that first enters the body is the nail head end, and the opposite end is the nail tail end, and there are correspondingly arranged on it,

[0043] The nail head threaded section 1 is arranged at the nail head end. The single-turn thread structure of the nail head threaded section 1 includes a guiding nail-inserting curved surface 11 and a blocking nail-removing anchoring surface 12. The first end of the guiding nail-inserting curved surface 11 is close to the nail head end, the second end of the guiding nail-inserting curved surface 11 is far from the nail head end, the second end of the guiding nail-inserting curved surface 11 is connected to the blocking nail-removing anchoring surface 12, and the diameter of the first end of the guiding nail-inserting curved surface 11 is smaller than the diameter of the second end of the guiding nail-inserting curved surface 11;

[0044] The nail tail threaded section 2 is arranged at the nail tail end. The single-turn thread structure of the nail tail threaded section 2 includes a guiding nail-removing curved surface 21 and a blocking nail-inserting anchoring surface 22. The first end of the guiding nail-removing curved surface 21 is close to the nail tail end, the second end of the guiding nail-removing curved surface 21 is far from the nail tail end, the second end of the guiding nail-removing curved surface 21 is connected to the blocking nail-inserting anchoring surface 22, and the diameter of the first end of the guiding nail-removing curved surface 21 is smaller than the diameter of the second end of the guiding nail-removing curved surface 21;

[0045] The thread directions of the nail head threaded section 1 and the nail tail thread are the same, which is used to achieve a single rotation action to realize the same forward and backward movement of the nail head threaded section 1 and the nail tail threaded section 2.

[0046] Working principle: During the screwing-in process of the anti-distraction screw, after the threaded section 1 of the screw head and the threaded section 2 of the screw tail are both screwed into the femur, because the guiding screw-in structure and the guiding screw-out structure are respectively arranged at the screw head and the screw tail positions, and are correspondingly connected with the anti-screw-out anchoring surface 12 and the anti-screw-in anchoring surface 22, a screw-out force is applied to the anti-screw-out anchoring surface 12 at the screw head end through the guiding screw-out structure at the screw tail end, and a screw-in force is applied to the anti-screw-in anchoring surface 22 at the screw tail end through the guiding screw-in structure at the screw head end. In this way, there will be a tendency for the proximal fracture fragment with the threaded section 1 of the screw head and the distal fracture fragment with the threaded section 2 of the screw tail to move closer to each other, thereby increasing the contact pressure on the fracture surface; this setting achieves the effect of applying pressure to the fracture surface in two directions. Compared with the prior art technical solution of the femoral neck internal fixation screw (CN202211589089) with double threads but different thread pitches, in the prior art, the pitch of the thread at the screw tail end is smaller than that at the screw head end, and the bone surface pressurization effect is provided by the different rotational resistances of the different pitches during the screwing-in process.

[0047] During the screw-out process when the supporting force takes effect, the fixing screw slides out under the drive of the guiding screw-out curved surface 21. During the screw-out process, due to the existence of the anti-screw-out anchoring surface 12, the anti-screw-out anchoring surface 12 will give the proximal fracture fragment a force towards the screw-out direction, and this force can exert pressure on the fracture section, increasing the pressure will promote the healing of the fracture section. In addition, due to the setting of the guiding screw-out curved surface 21, the return resistance of the guiding screw-out curved surface 21 needs to be overcome during the screw-out process, effectively reducing the screw-out amplitude, and can also effectively avoid the problem of femoral neck shortening caused by the direct sliding out of the fixing screw.

[0048] During the screw-in trend process when the distraction force takes effect, the distraction force gives the fixing screw a force to move inward. After receiving this force, the anti-screw-in anchoring surface 22 will give the distal fracture fragment on the fracture surface a force to move inward. This inward moving force will promote a pressurized effect on the fractured bone surface. The anti-screw-in anchoring surface 22 also provides a large resistance to the inward distraction of the fixing screw, and this resistance cancels out the distraction force, achieving the effect of preventing the fixing screw from moving inward by distraction.

[0049] Finally, through the setting of the above structure, when the supporting force and the distraction force act on the fixing screw, the fixing screw will give the fractured bone surface a pressurized force to promote recovery, which can effectively control the screw-out amplitude and avoid femoral neck shortening.

[0050] More preferably, in the embodiment, except for the transitional thread structure at the edge, the guiding screw-in surface 11 and the guiding screw-out surface 21 on the middle thread structure are of the same or similar shape; the blocking screw-out anchoring surface 12 and the blocking screw-in anchoring surface 22 are of the same or similar shape; the blocking screw-out anchoring surface 12 faces the tail end of the screw, and the blocking screw-in anchoring surface 22 faces the head end of the screw. Such a setting ensures that the single-turn thread structure forms a near frustum of a cone structure following the thread direction. The setting of the frustum of a cone structure ensures that the guiding surface thereon forms a power guiding in the first direction and constitutes a resistance anchoring in the opposite direction.

[0051] More preferably, in the embodiment, the guiding screw-in surface 11 and the guiding screw-out surface 21 on the middle thread structure are of the same size; the blocking screw-out anchoring surface 12 and the blocking screw-in anchoring surface 22 are of the same shape and size; the blocking screw-out anchoring surface 12 faces the tail end of the screw, and the blocking screw-in anchoring surface 22 faces the head end of the screw. The same setting ensures that the provided guiding force and anchoring force are consistent, and the forces during screw-in and screw-out are consistent.

[0052] More preferably, in the embodiment, except for the different orientations, the number of turns of the thread structure of the head thread section 1 and the tail thread section 2 of the screw is the same, and the relative thread structures of the head thread section 1 and the tail thread section 2 are the same; such a setting ensures that the pressures exerted by the head thread section 1 and the tail thread section 2 on the bone surface are basically the same, avoiding adverse effects on the bone surface due to different pressures on the bone surface.

[0053] More preferably, in the embodiment: the fixing screw includes an intermediate section 3, which is arranged between the head thread section 1 and the tail thread section 2; no thread is provided on the intermediate section 3, and the difference between the maximum diameter of the thread section and the intermediate section 3 is 1-2 mm.

[0054] More preferably, in the embodiment, the blocking screw-out anchoring surface 12 is perpendicular to the longitudinal axis of the screw body, or the blocking screw-out anchoring surface 12 inclines from the outside to the inside towards the first end of the head thread section 1; the blocking screw-in anchoring surface 22 is perpendicular to the longitudinal axis of the screw body, or the blocking screw-in anchoring surface 22 inclines from the outside to the inside towards the first end of the tail thread section 2. The above methods ensure that the anchoring surface can effectively and stably form an anchoring effect, avoiding the phenomenon of non-rotational screw-out.

[0055] More preferably, in the embodiment, the fixing screw is a hollow fixing screw, which is convenient to guide the fixing screw into the fracture position through a Kirschner wire.

[0056] More preferably, in the embodiment: a tail cap 4 is arranged at the tail end of the fixing screw, an operation hole 41 is arranged at the first end of the tail cap 4, and the tail thread section 2 starts to be arranged at the position of the second end of the tail cap 4. Such a setting ensures that the tail thread section is effectively arranged in the bone mass and will not enter the bone cavity, ensuring that the tail thread section can effectively play its role.

[0057] In a more preferred embodiment, the number of thread turns of the nail head thread section 1 and the nail tail thread section 2 ranges from 5 to 7 turns, and the specific number of turns is selected according to the bone condition of the patient.

[0058] In a more preferred embodiment, the nail head thread section 1 and the nail tail thread section 2 have the same length, and the length range is 1 - 4 cm.

[0059] In a more preferred embodiment, the first end of the nail head thread section 1 is the end in the nail head direction, and a plurality of inclined grooves 13 for constructing self - tapping tips are arranged at the first end of the nail head thread section 1, preferably 2 - 3 inclined grooves 13 are arranged. In this way, a plurality of self - tapping tips are constructed to ensure that the fixing nail is a self - tapping fixing nail.

[0060] In a more preferred embodiment, the inclined grooves are arranged on the first two turns of the thread structure of the nail head thread section 1. And the sizes of the first two turns of the thread structure are smaller than those of the other turns of the thread structure. This setting ensures the formation of effective self - tapping tips and also enables effective transition of the threads. In a more preferred embodiment: the inclined groove 13 is formed by two surfaces with an included angle and is inclined from the nail head end to the nail tail end, and the inclined directions of the inclined grooves 13 are the same. This way is more conducive to the formation of the self - tapping structure. The self - tapping structure is an inclined self - tapping tip constructed by the inclined groove 13, and the inclined direction of the inclined groove 13 is the same as the inclined direction of the thread. This setting ensures that when rotating, the formed self - tapping tip has a guiding trend of self - entering the tissue.

[0061] In a more preferred embodiment, the first end of the nail tail thread section 2 is the end far from the nail tail direction, and inclined grooves 23 for constructing a self - tapping structure are arranged at the first end of the nail tail thread section 2, and 2 - 3 inclined grooves 23 are arranged. Preferably, the inclined grooves 23 are arranged on the first 2 - 3 turns of the thread structure of the nail tail thread section 2. This setting ensures that when the nail tail structure enters the posterior bone block of the fracture surface, it provides an effective force for self - tapping into the bone block and avoids the problem of rotation - entry stagnation. The inclined groove 23 is formed by two surfaces with an included angle and is inclined from the nail head end to the nail tail end, and the inclined directions of the plurality of inclined grooves 23 are the same, and the inclined direction of the inclined groove 23 is the same as the inclined direction of the thread.

[0062] Through the above settings of the inclined groove 13 and the inclined groove 23, it is ensured that both the nail head thread section 1 and the nail tail thread section 2 have a self - tapping effect, ensuring the rotation and self - tapping entry of the entire fixing nail.

[0063] In a more preferred embodiment: adjacent turns of the thread structure are connected by an arc structure. In this way, the damage to the tissue caused by sharp connections is effectively avoided, and it can also provide a buffer guidance for the guiding nail - in surface 11 and the guiding nail - out surface 21.

[0064] Example 2

[0065] Reference Figure 7, a fixation device for femoral neck fractures, the fixation device includes 1 dynamic sliding compression anti-traction screw involved in Embodiment 1 or 2 parallelly arranged dynamic sliding compression anti-traction screws involved in Embodiment 1.

[0066] A more preferred embodiment is that the length of the screw is the same as that of the fixation screws for femoral neck fractures currently on the market; the lengths of the threaded section 1 of the screw head and the threaded section 2 of the screw tail are the same, and the length range is 2-4 cm.

[0067] A more preferred embodiment is to arrange 2 dynamic sliding compression anti-traction screws in parallel.

[0068] Embodiment 3

[0069] A fixing plate including the anti-traction screw in Embodiment 1, with screw holes provided on the fixing plate, and the traction screw enters the femur through the screw holes and combines with the fixing plate to complete the reduction and fixation of the femur.

[0070] Alternatively, a fixing plate including the anti-traction screw in Embodiment 1, with a sleeve provided on the fixing plate, and the traction screw enters the femur through the sleeve and combines with the fixing plate to complete the reduction and fixation of the femur; the first end of the sleeve is the end in the direction of the screw tail section; the traction screw extends out from the second end of the sleeve, and the threaded section of the screw tail also extends out from the end of the second end of the sleeve.

[0071] The technical solutions in the embodiments of the present invention are clearly and completely described above through specific specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention is also implemented or applied through other different specific implementation manners. Without conflict, the above embodiments and the features in the embodiments are combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

Claims

1. A dynamic sliding compression anti-traction screw, comprising: The screw body has a nail head end at the end that first enters the body and a nail tail end at the opposite end. It is characterized in that the screw body includes a nail head thread section provided at the nail head end. The single - turn thread structure of the nail head thread section includes a guiding nail - driving curved surface and a blocking nail - withdrawing anchoring surface. The first end of the guiding nail - driving curved surface is close to the nail head end, and the second end of the guiding nail - driving curved surface is far from the nail head end. The second end of the guiding nail - driving curved surface is connected to the blocking nail - withdrawing anchoring surface, and the diameter of the first end of the guiding nail - driving curved surface is smaller than that of the second end of the guiding nail - driving curved surface; a nail tail thread section provided at the nail tail end. The single - turn thread structure of the nail tail thread section includes a guiding nail - withdrawing curved surface and a blocking nail - driving anchoring surface. The first end of the guiding nail - withdrawing curved surface is close to the nail tail end, and the second end of the guiding nail - withdrawing curved surface is far from the nail tail end. The second end of the guiding nail - withdrawing curved surface is connected to the blocking nail - driving anchoring surface, and the diameter of the first end of the guiding nail - withdrawing curved surface is smaller than that of the second end of the guiding nail - withdrawing curved surface; the thread directions of the nail head thread section and the nail tail thread section are the same; except for the transitional thread structure at the edge, the guiding nail - driving curved surface and the guiding nail - withdrawing curved surface on the middle thread structure have the same shape; the blocking nail - withdrawing anchoring surface and the blocking nail - driving anchoring surface have the same shape. The blocking nail - withdrawing anchoring surface faces the nail tail end, and the blocking nail - driving anchoring surface faces the nail head end; except for the different orientations, the number of turns of the thread structure of the nail head thread section and the nail tail thread section, and the corresponding thread structures on the nail head thread section and the nail tail thread section are set the same.

2. The screw according to claim 1, characterized in that, The fixing nail includes an intermediate section which is arranged between the nail head thread section and the nail tail thread section; no thread is provided on the intermediate section.

3. The screw according to claim 2, characterized in that, The difference between the maximum diameter of the thread section and the diameter of the intermediate section is 1 - 2 mm.

4. The screw according to claim 2, characterized in that, The fixing nail is a hollow fixing nail.

5. The screw according to claim 2, characterized in that, The number of thread turns of the nail head thread section and the nail tail thread section ranges from 5 to 7 turns; the nail head thread section and the nail tail thread section have the same length, and the length range is 1 - 4 cm.

6. The screw according to claim 2, characterized in that, Adjacent two - turn thread structures are connected by an arc - shaped structure.

7. The screw according to claim 1, characterized in that, The blocking nail - withdrawing anchoring surface is perpendicular to the longitudinal axis of the screw body, or the blocking nail - withdrawing anchoring surface inclines from the outside to the inside towards the first end of the nail head thread section; the blocking nail - driving anchoring surface is perpendicular to the longitudinal axis of the screw body, or the blocking nail - driving anchoring surface inclines from the outside to the inside towards the first end of the nail tail thread section.

8. The screw according to claim 1, characterized in that, A tail cap is provided at the tail end of the fixing nail. An operation hole is provided at the end of the first end of the tail cap, and the nail tail thread section starts from the position at the end of the second end of the tail cap.

9. The screw according to claim 1, characterized in that, The first end of the nail head thread section is the nail head end. Multiple inclined grooves one for constructing self - tapping tips are provided at the first end of the nail head thread section, and 2 - 3 inclined grooves one are provided.

10. The screw according to claim 9, characterized in that, The inclined grooves one are arranged on the first two turns of the thread structure of the nail head thread section, and the sizes of the first two turns of the thread structure are smaller than those of other turns of the thread structure.

11. The screw according to claim 9, characterized in that, The inclined groove one is surrounded by two surfaces with an included angle and inclines from the nail head end to the nail tail end direction, and the inclined directions of the inclined grooves one are the same.

12. The screw according to claim 9, characterized in that, The inclined direction of the inclined groove one is the same as the inclined trend of the thread.

13. The screw according to claim 9, wherein, The first end of the nail tail thread section is the end far from the nail tail end. Inclined grooves two for constructing self - tapping structures are provided at the first end of the nail tail thread section, and 2 - 3 inclined grooves two are provided.

14. The screw according to claim 13, characterized in that, The inclined grooves two are arranged on the first 2 - 3 turns of the thread structure of the nail tail thread section.

15. The screw according to claim 13, wherein, The inclined groove two is surrounded by two surfaces with an included angle and inclines from the nail head end to the nail tail end direction, and the inclined directions of the multiple inclined grooves two are the same.

16. A fixation device for femoral neck fractures, characterized in that, The fixation device includes one or two dynamic sliding compression anti-traction screws according to any one of claims 1-6.

17. The fixing device according to claim 16, characterized in that, The two anti-traction screws arranged are arranged in parallel.

18. A fixing plate for femoral neck fractures, characterized in that, It includes the anti-traction screw according to claim 1. A screw hole is provided on the fixing plate. The traction screw enters the femur through the screw hole and combines with the fixing plate to complete the reduction and fixation of the femur; or, a sleeve is provided on the fixing plate. The traction screw enters the femur through the sleeve and combines with the fixing plate to complete the reduction and fixation of the femur. The first end of the sleeve is the end in the direction of the screw tail section; the traction screw extends out from the second end of the sleeve, and the threaded section of the screw tail also extends out from the end of the second end of the sleeve.

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