阅读说明：本技术 一种防旋防退的双螺纹空心钉 (Anti-rotation anti-retreat double-thread hollow nail ) 是由 孙令胜 周中位 罗爱民 于 2020-12-30 设计创作，主要内容包括：本申请涉及医用螺钉的领域,尤其是涉及一种防旋防退的双螺纹空心钉,包括内部中空且两端为开口的螺钉主体,螺钉主体包括柱状杆体以及一体成型于柱状杆体一端的钉尾,柱状杆体靠近钉尾一端的外壁上加工有尾部外螺纹,柱状杆体远离钉尾一端的外壁上加工有头部多线螺纹,尾部外螺纹的导程大于或小于头部多线螺纹的导程。本申请中尾部外螺纹和头部多线螺纹的设置,使得双螺纹空心钉在旋入骨头时,形成位移差,从而起到加压、抗拔的作用,降低了双螺纹空心钉在植入后出现退钉及旋转的可能性；同时通过在螺钉主体内设置实心杆内芯,使得空心螺钉的强度大大提高。(The utility model belongs to the technical field of medical screw and specifically relates to a prevent two screw thread hollow nail that move back soon is related to, be open-ended screw main part including inside cavity and both ends, the screw main part includes the column body of rod and integrated into one piece in the nail tail of column body of rod one end, and the column body of rod is close to and is processed the afterbody external screw thread on the outer wall of nail tail one end, and processing has the multi-thread screw thread of head on the outer wall of nail tail one end is kept away from to the column body of rod, and the helical pitch of afterbody external screw thread is greater than or. According to the double-thread hollow screw, due to the arrangement of the tail external thread and the head multi-thread, when the double-thread hollow screw is screwed into a bone, a displacement difference is formed, so that the effects of pressurization and pulling resistance are achieved, and the possibility of screw withdrawing and rotation of the double-thread hollow screw after being implanted is reduced; meanwhile, the solid rod inner core is arranged in the screw main body, so that the strength of the hollow screw is greatly improved.)

1. The utility model provides a prevent revolving and prevent double thread hollow nail that moves back, a serial communication port, be open-ended screw main part (1) including inside cavity and both ends, screw main part (1) includes the column body of rod (11) and integrated into one piece in nail tail (12) of the column body of rod (11) one end, processing has afterbody external screw thread (13) on the outer wall that the column body of rod (11) is close to nail tail (12) one end, processing has head multi-thread (14) on the outer wall of nail tail (12) one end is kept away from in the column body of rod (11), the helical pitch of afterbody external screw thread (13) is greater than or is less than the helical pitch of head multi-.

2. A rotation-proof and back-proof double-thread hollow nail according to claim 1, characterized in that: the nail tail (12) is a self-tapping three-edge.

3. A rotation-proof and back-proof double-thread hollow nail according to claim 1, characterized in that: one end of the columnar rod body (11) far away from the nail tail (12) is inwards processed with a first inner hexagonal socket (15) and a first threaded hole (16) in sequence.

4. A rotation-proof and back-proof double-thread hollow nail according to claim 3, characterized in that: the novel bolt is characterized in that a solid rod inner core (2) is arranged in the columnar rod body (11), and the solid rod inner core (2) and the bolt main body (1) are connected into a whole locking piece (3).

5. A rotation-proof and back-proof double-thread hollow nail according to claim 4, characterized in that: one end of the solid rod inner core (2) is internally provided with a second threaded hole (21) along the axial direction;

the locking piece (3) comprises a locking head (31) and a first threaded rod (32) and a second threaded rod (33) which are sequentially and integrally formed at one end of the locking head (31) and are coaxially arranged, the first threaded rod (32) is in threaded connection with the first threaded hole (16), and the second threaded rod (33) is in threaded connection with the second threaded hole (21).

6. A rotation-proof and back-proof double-thread hollow nail according to claim 4, characterized in that: a communication groove (24) and a limiting groove (25) penetrating through one side of the solid rod inner core (2) are sequentially processed inwards along the axial direction at one end of the solid rod inner core (2) far away from the inserted link (22);

the locking piece (3) comprises a lock head (31), a first threaded rod (32), a polished rod (41) and a limiting column (42) which are coaxially arranged and integrally formed in sequence, the diameter of the limiting column (42) is larger than that of the polished rod (41), and a limiting groove (25) is matched with the limiting column (42).

7. A rotation-proof and back-proof double-thread hollow nail according to claim 5, characterized in that: and a second inner hexagon (34) is processed on the lock head (31).

8. A rotation-proof and back-proof double-thread hollow nail according to claim 5, characterized in that: one end, far away from the second threaded hole (21), of the solid rod inner core (2) is provided with a deformable insert rod (22), and the free end of the insert rod (22) is provided with a guide inclined plane (23);

a notch (17) communicated with the outside and used for the insertion rod (22) to extend out is formed in the outer wall of one end, close to the nail tail (12), of the columnar rod body (11), a guide cutting surface (18) gradually inclining from inside to outside is formed on one side, close to the nail tail (12), of the notch (17), and the lowest point of the guide cutting surface (18) is lower than the highest point of the guide inclined surface (23).

9. A rotation-proof and back-proof double-thread hollow nail according to claim 8, characterized in that: the profile of the edge of the guide inclined plane (23) far away from the solid rod inner core (2) is a feeding edge.

10. A rotation-proof and back-proof double-thread hollow nail according to claim 8, characterized in that: the locking piece (3) comprises a sleeve (35) which is fixedly connected with one end of the solid rod inner core (2) far away from the inserted link (22) and is coaxially arranged with the solid rod inner core (2), a slide rod (36) which always slides in the sleeve (35), an end cap (37) which is fixedly connected with one end of the slide rod (36) far away from the sleeve (35) and covers the slide rod (36) and the sleeve (35), a spring (38) which is sleeved outside the slide rod (36) and the sleeve (35) and two ends of which are respectively abutted against the inner wall of the end cap (37) and the end part of the solid rod inner core (2), and a clamping block (39) which is symmetrically and fixedly connected on the outer side wall of, and an operating ring (40) fixedly connected to one end of the end cap (37) far away from the spring (38), when the spring (38) is in a natural state, the sliding rod (36) extends out of the sleeve (35) to a limit position, and a movable gap is formed between the end cap (37) and the solid rod inner core (2);

the inner wall of the columnar rod body (11) is provided with a guide groove (5) for the clamping block (39) to slide inwards along the axial direction of the columnar rod body (11), an annular groove (6) communicated with the guide groove (5) and arranged along the inner circumference of the columnar rod body (11), and a clamping groove (7) communicated with the annular groove (6) and extending outwards along the axial direction of the columnar rod body (11), when the inserted rod (22) is installed in place, the clamping block (39) is still positioned in the guide groove (5), and the movable gap is larger than the distance of the clamping block (39) entering the annular groove (6).

Technical Field

The application relates to the field of medical screws, in particular to a double-thread hollow screw capable of preventing screwing and retreating.

Background

The hollow screw is mainly used for the operation of limb fracture and fracture fragment fixation. The hollow screw is usually made of stainless steel or titanium materials, the interior of the hollow screw is of a hollow structure, and a kirschner wire can penetrate through the hollow screw, so that the hollow screw can be conveniently implanted in place.

Cannulated screw implantation is generally divided into three steps: firstly, driving a Kirschner wire into a bone fracture nail; secondly, sleeving a hollow screw on the Kirschner wire, and twisting the hollow screw into a bone along the Kirschner wire to a fixed position; and thirdly, taking out the Kirschner wire.

However, according to clinical experience for many years, the inventor finds that the hollow screw may be loosened and rotated due to improper movement of the patient during the recovery period of the patient, thereby causing fixing failure.

In view of the above-mentioned related art, the inventor believes that the conventional cannulated screw has the defects of nail withdrawing and rotation.

Disclosure of Invention

In order to reduce double thread hollow nail appear moving back the nail and the rotatory possibility after implanting, this application provides a prevent preventing soon that double thread hollow nail moves back.

The application provides a pair of prevent revolving double thread hollow nail who moves back adopts following technical scheme:

the utility model provides a prevent two screw thread hollow nail that move back soon, is open-ended screw main part including inside cavity and both ends, and the screw main part includes the column body of rod and integrated into one piece in the nail tail of column body of rod one end, and the column body of rod is close to and processes on the outer wall of nail tail one end has the afterbody external screw thread, and processing has the multi-thread screw thread of head on the outer wall of nail tail one end is kept away from to the column body of rod, and the helical pitch of afterbody external screw thread is greater than or is less.

Through adopting above-mentioned technical scheme, the back is implanted to double thread hollow nail, afterbody external screw thread and the many thread of head all with bone in close contact with, because the helical pitch of afterbody external screw thread is greater than or is less than the helical pitch of the many thread of head, consequently, the axial precession displacement inequality of afterbody and head when the screw in, form the displacement poor to play the pressurized effect, improve the resistance to plucking ability of double thread hollow nail simultaneously, reduce the double thread hollow nail appear moving back nail and rotatory possibility after implanting.

Preferably, the nail tail is a self-tapping three-edge.

Through adopting above-mentioned technical scheme, be convenient for reduce the resistance that the nail tail received at the jacking in-process, need not the tapping in advance when necessary.

Preferably, one end of the columnar rod body, which is far away from the nail tail, is internally provided with a first inner hexagon and a first threaded hole.

Through adopting above-mentioned technical scheme, make things convenient for medical personnel screw in screw main part.

Preferably, a solid rod inner core is arranged in the columnar rod body, and the solid rod inner core and the screw main body are connected into an integral locking piece.

Through adopting above-mentioned technical scheme, the latch fitting is connected solid pole inner core and screw main part for a unified atress is whole to improved the structural strength of screw main part greatly, reduced the crooked or cracked possibility of double thread hollow nail.

Preferably, a second threaded hole is machined in one end of the solid rod inner core along the axial direction of the solid rod inner core;

the latch fitting includes tapered end and first threaded rod and the second threaded rod of integrated into one piece in tapered end one end and coaxial line setting in proper order, first threaded rod and first screw hole threaded connection, second threaded rod and second screw hole threaded connection.

Through adopting above-mentioned technical scheme, during the installation, first threaded rod and first screw hole threaded connection, second threaded rod and second screw hole threaded connection for solid core rod inner core and screw main part are connected as a whole.

Preferably, a communication groove and a limiting groove penetrating through one side of the solid rod inner core are sequentially processed inwards along the axial direction at one end of the solid rod inner core, which is far away from the inserted rod;

the latch fitting comprises a lock head, a first threaded rod, a polished rod and a limiting column which are coaxially arranged in sequence and are integrally formed, the diameter of the limiting column is larger than that of the polished rod, and a limiting groove is matched with the limiting column.

Through adopting above-mentioned technical scheme, during the installation, spacing post and spacing groove cooperation, first threaded rod and the cooperation of first screw hole for it is whole to be a unified atress to be connected between latch fitting, solid core and the screw main part, has improved the structural strength of double thread hollow nail greatly.

Preferably, a second inner hexagon is machined on the lock head.

Through adopting above-mentioned technical scheme, make things convenient for medical personnel to pass through supporting instrument installation latch fitting.

Preferably, a deformable insert rod is processed at one end, far away from the second threaded hole, of the solid rod inner core, and a guide inclined plane is processed at the free end of the insert rod;

the outer wall of the columnar rod body close to one end of the nail tail is provided with a notch communicated with the outside for the insertion rod to extend out, one side of the notch close to the nail tail forms a guide cutting surface gradually inclining from inside to outside, and the lowest point of the guide cutting surface is lower than the highest point of the guide inclined plane.

By adopting the technical scheme, the insertion rod, the guide inclined plane and the guide cutting surface are arranged, so that the insertion rod can extend out of the incision and be inserted into the bone in the installation process, and is fixed with the screw main body by forming an horns, the contact area of the hollow screw and the bone is increased, and the rotation prevention and retreat prevention effects are achieved; simultaneously, the structural strength of the double-thread hollow nail can also be improved due to the arrangement of the inner core of the solid rod.

Preferably, the edge profile of the guide inclined surface far away from the solid rod inner core is a feeding edge.

By adopting the technical scheme, the insertion rod is mainly used for reducing resistance so that the part of the insertion rod extending out of the incision is inserted into bone.

Preferably, the locking piece comprises a sleeve fixedly connected to one end, far away from the inserted link, of the solid rod inner core and arranged coaxially with the solid rod inner core, a sliding rod sliding in the sleeve all the time, an end cap fixedly connected to one end, far away from the sleeve, of the sliding rod and covering the sliding rod and the sleeve in the sleeve, a spring sleeved outside the sliding rod and the sleeve and having two ends respectively abutted to the inner wall of the end cap and the end part of the solid rod inner core, clamping blocks symmetrically and fixedly connected to the outer side wall of the end cap, and an operating ring fixedly connected to one end, far away from the spring, of the end cap, when the spring is in a natural state, the sliding rod extends out of the;

the inner wall of the columnar rod body is provided with a guide groove for the fixture block to slide inwards along the axial direction of the columnar rod body, an annular groove communicated with the guide groove and arranged along the inner circumference of the columnar rod body, and a clamping groove communicated with the annular groove and extending outwards along the axial direction of the columnar rod body, when the inserted rod is installed in place, the fixture block is still positioned in the guide groove, and the movable gap is larger than the distance of the fixture block entering the annular groove.

By adopting the technical scheme, when the solid rod inner core is installed, the solid rod inner core is pushed to be inserted into the columnar rod body in a sliding manner through a special matched tool, and in the inserting process, the clamping block slides inwards along the guide groove; when the inserted link extends out of the notch and is inserted into the sclerotin, the clamping block is still positioned in the guide groove, at the moment, the end cap is pressed, so that the end cap moves towards the direction of the solid rod inner core and enters the annular groove from the guide groove, and the spring is gradually compressed in the process; the end cap is rotated, when the clamping block slides to the clamping groove along the annular groove, the end cap is loosened, and at the moment, the end cap drives the clamping block to be clamped into the clamping groove under the action of the restoring force of the spring, so that firm fixation is realized.

In summary, the present application includes at least one of the following beneficial technical effects:

1. after the double-thread hollow nail is implanted, the tail external thread and the head multi-thread are in close contact with the bone, and the lead of the tail external thread is larger than or smaller than that of the head multi-thread, so that axial screwing displacement of the tail part and the head part is unequal during screwing, and displacement difference is formed, so that the double-thread hollow nail plays a role in pressurization after being screwed into the bone, the pulling resistance of the double-thread hollow nail is improved, and the possibility of nail withdrawal and rotation of the double-thread hollow nail after being implanted is reduced;

2. the solid rod inner core is arranged in the screw main body, and the solid rod inner core and the screw main body are connected into a unified stressed whole through the locking piece, so that the structural strength of the screw main body is greatly improved, and the possibility of bending or breaking of the double-thread hollow screw is reduced;

3. due to the arrangement of the inserting rod, the guide inclined plane and the guide cutting surface, the inserting rod can extend out of the incision and be inserted into the bone in the installation process, an angle is formed between the inserting rod and the screw main body for fixation, the contact area of the hollow screw and the bone is increased, and the rotation preventing and retreating preventing effects are achieved.

Drawings

FIG. 1 is a schematic view of the overall structure of a double-threaded hollow nail according to embodiment 1 of the present application;

FIG. 2 is a cross-sectional view showing the assembly of the screw body, solid rod core and locking element;

FIG. 3 is a sectional view showing a detailed structure of a screw body;

FIG. 4 is a sectional view showing the natural state of the core of the solid rod;

FIG. 5 is a schematic view showing the construction of a lock;

FIG. 6 is a schematic view showing a specific structure of a lock member in embodiment 2 of the present application;

FIG. 7 is a cross-sectional view showing the position and connection among a guide groove, an annular groove and a locking groove formed in a columnar rod body;

figure 8 is an exploded view of the present application showing the locking element in mating relationship with the solid rod core in example 3.

Description of reference numerals: 1. a screw body; 11. a columnar rod body; 12. nailing tail; 13. tail external threads; 14. the head is provided with multiple threads; 15. a first inner hexagon; 16. a first threaded hole; 17. cutting; 18. guiding the cutting surface; 2. an inner core of the solid rod; 21. a second threaded hole; 22. inserting a rod; 23. a guide slope; 24. a communicating groove; 25. a limiting groove; 3. a lock; 31. a lock head; 32. a first threaded rod; 33. a second threaded rod; 34. a second inner hexagon; 35. a sleeve; 36. a slide bar; 37. an end cap; 38. a spring; 39. a clamping block; 40. an operating ring; 41. a polish rod; 42. a limiting column; 5. a guide groove; 6. an annular groove; 7. a clamping groove.

Detailed Description

The present application is described in further detail below with reference to figures 1-8.

Example 1

The embodiment of the application discloses a double-thread hollow nail capable of preventing screwing and retreating. Referring to fig. 1 and 2, the double-thread hollow nail comprises a screw main body 1, a solid rod inner core 2 and a locking piece 3, wherein the screw main body, the solid rod inner core 2 and the locking piece 3 are all made of titanium alloy materials, and the titanium alloy materials have good biocompatibility and better strength and toughness and meet medical requirements.

The screw main body 1 is hollow and has openings at two ends, and is positioned and guided by a Kirschner screw during installation; after the screw main body 1 is in place, the solid rod inner core 2 is inserted into the screw main body 1 in a sliding manner through a special matching tool, so that the strength of the screw main body 1 is enhanced, and the effects of preventing rotation and stopping backing are achieved, thereby ensuring the stability of the double-thread hollow screw after installation and reducing the probability of complications such as fracture nonunion or bone ischemia necrosis; after the solid rod inner core 2 is in place, the locking piece 3 is installed in the screw main body 1 through a special matched tool and is used for connecting the solid rod inner core 2 and the screw main body 1 into a uniform stress whole.

Referring to fig. 3, the screw body 1 includes the columnar body of rod 11 and integrated into one piece in the nail tail 12 of the columnar body of rod 11 one end, and the nail tail 12 is the self tapping three-edge, and such structural design is convenient for reduce the resistance that the nail tail 12 received in the jacking process. Processing has afterbody external screw thread 13 on the outer wall that the column body of rod 11 is close to 12 one ends of nail tail, processing has head multi-thread 14 on the outer wall that the column body of rod 11 is kept away from 12 one ends of nail tail, head multi-thread 14 also can be single thread, afterbody external screw thread 13's helical pitch is greater than or is less than head multi-thread 14's helical pitch, double thread hollow nail is implanted the back, afterbody external screw thread 13 and head multi-thread 14 all with bone in close contact with, because afterbody external screw thread 13's helical pitch is different with head multi-thread 14's helical pitch, therefore, the axial precession displacement inequality of afterbody and head when the screw in, form the displacement difference, make double thread hollow nail play pressor effect behind the screw in bone, improve double thread hollow nail's resistance to plucking ability simultaneously, reduce double thread hollow nail appear withdrawing nail.

One end of the columnar rod body 11, which is far away from the nail tail 12, is inwards sequentially processed with a first inner hexagon 15 and a first threaded hole 16, wherein the first inner hexagon 15 can also be in an inner hexagon flower type. The columnar rod body 11 is provided with a notch 17 communicated with the outside at the position of the tail external thread 13, and one side of the notch 17 close to the nail tail 12 is provided with a guide cutting surface 18 gradually inclined from inside to outside.

Referring to fig. 3 and 4, the solid rod inner core 2 is cylindrical, the outer diameter of the solid rod inner core is matched with the inner diameter of the screw main body 1, and a second threaded hole 21 is formed in one end of the solid rod inner core 2 along the axial direction of the solid rod inner core. The end of the solid rod core 2 away from the second threaded hole 21 is provided with an insert rod 22 which deforms when subjected to an external force and extends out of the notch 17, and normally, a straight posture is formed between the insert rod 22 and the solid rod core 2. The free end of the insert rod 22 is processed with a guide inclined surface 23 matching with the guide cutting surface 18 in a beveling way, and it should be noted that the inner diameter of the part between the middle part of the notch 17 and the nail tail 12 is smaller than that of the rest part of the screw main body 1, the structure design is such that the lowest point of the processed guide cutting surface 18 is lower than the highest point of the guide inclined surface 23, so that in the process of inserting the solid rod inner core 2 into the screw main body 1, the insert rod 22 can extend out of the notch 17 through the guide matching of the guide cutting surface 18 and the guide inclined surface 23 to be inserted into the bone and forms an included angle of 15 degrees to 30 degrees with the axis of the screw main body 1 to form an angle for fixing, and simultaneously, the contact area with the bone is increased, thereby playing roles of preventing rotation and stopping.

In order to facilitate the insertion of the part of the plunger 22 which projects out of the cutout 17 into the bone, the edge of the guide bevel 23 facing away from the solid rod core 2 is profiled to form a sharp feed edge.

Referring to fig. 2 and 5, the locking member 3 includes a locking head 31, a first threaded rod 32 and a second threaded rod 33 coaxially disposed and integrally formed in sequence, the first threaded rod 32 is in thread fit with the first threaded hole 16, and the second threaded rod 33 is in thread fit with the second threaded hole 21. The end of the tapered end 31 far from the first threaded rod 32 is processed with a second inner hexagon 34 inwards, the second inner hexagon 34 can also be in a hexagon socket flower type, and during installation, the locking piece 3 can be rotated by matching with the second inner hexagon 34 through a matching tool.

The implementation principle of the embodiment 1 of the application is as follows:

firstly, after fixing the Kirschner nail at a designated position of a bone, sheathing the screw main body 1 outside the Kirschner nail and screwing the screw main body 1 by a special matched tool so as to make the screw main body 1 drill into the bone;

secondly, pushing the solid rod inner core 2 to be inserted into the screw main body 1 in a sliding manner through a special matched tool until the solid rod inner core moves to the maximum stroke of the matched tool, wherein in the inserting process, the insertion rod 22 slides along the guide cutting surface 18 through the guide inclined surface 23 and deforms until the feeding blade extends out of the notch 17 and is inserted into the bone, at the moment, an included angle of 15-30 degrees is formed between the insertion rod 22 and the axis of the screw main body 1, and the farthest distance between the insertion rod 22 and the axis of the screw main body 1 is 2-8mm, so that an horning angle is formed between the part of the insertion rod 22 extending out of the notch 17 and the screw main body 1 for fixation, the contact area of the hollow screw and the bone is increased, and the functions of preventing rotation and stopping are achieved;

and thirdly, the locking piece 3 is installed through a special matching tool, in the installation process, the first threaded rod 32 is in threaded connection with the first threaded hole 16, the second threaded rod 33 is in threaded connection with the second threaded hole 21, so that the solid rod inner core 2 and the screw main body 1 are connected into a whole, the strength of the double-threaded hollow screw is enhanced, the effect is matched with the effect of the solid rod inner core 2 in the embodiment, the stability and the reliability of internal fixation of fracture are greatly increased, and the failure occurrence rate of the operation is reduced.

Example 2

The embodiment of the application discloses prevent revolving and prevent double thread hollow nail that moves back, the difference with embodiment 1 lies in the latch fitting.

Referring to fig. 6, latch fitting 3 includes that the rigid coupling is kept away from the sleeve 35 of inserted bar 22 one end and diameter less than solid pole inner core 2 at solid pole inner core 2, sleeve 35 sets up with solid pole inner core 2 coaxial line, it has slide bar 36 to slide in the sleeve 35, be equipped with anti-disengaging structure between slide bar 36 and the sleeve 35, anti-disengaging structure can be for spacing bulge loop and the spacing bulge loop that slide bar 36 is close to solid pole inner core 2 one end on the inner wall that solid pole inner core 2 one end was kept away from to sleeve 35 to the rigid coupling.

Referring to fig. 6 and 7, one end of the sliding rod 36, which is far away from the sleeve 35, is fixedly connected with a cylindrical end cap 37, the outer diameter of the end cap 37 is matched with the inner diameter of the cylindrical rod body 11, one side of the end cap 37, which faces the solid rod inner core 2, is provided with a cavity in which the sliding rod 36 and the sleeve 35 are covered, a spring 38 is arranged in the cavity, the spring 38 is sleeved outside the sliding rod 36 and the sleeve 35, and two ends of the spring 38 are respectively abutted against the inner wall of the end cap 37 and the end of the solid rod inner core 2, when the spring 38 is in a natural state, the sliding rod 36 extends out of the sleeve 35 to a limit position, and.

A pair of clamping blocks 39 are symmetrically butted on the outer side wall of the end cap 37, an operation ring 40 is fixedly connected on the outer wall of one end of the end cap 37, which is far away from the spring 38, and medical personnel can be matched with the operation ring 40 through a special matching tool so as to press or rotate the end cap 37; the inner wall of the columnar rod body 11 is provided with a guide groove 5 extending inwards along the axial direction of the columnar rod body 11, an annular groove 6 communicated with one end of the guide groove 5 far away from the first inner hexagon 15 and arranged along the inner circumference of the columnar rod body 11, and a clamping groove 7 communicated with the annular groove 6 and extending outwards along the axial direction of the columnar rod body 11, corresponding to the two clamping blocks 39.

The implementation principle of embodiment 2 of the present application is as follows: when the solid rod inner core 2 is installed, the solid rod inner core 2 is pushed by a special matched tool to be inserted into the columnar rod body 11 in a sliding manner, and in the inserting process, the clamping block 39 slides inwards along the guide groove 5; when the inserted rod 22 extends out of the cut 17 and is inserted into the bone, the clamping block 39 is still positioned in the guide groove 5, at the same time, the end cap 37 is pressed, so that the end cap 37 moves towards the solid rod inner core 2 and enters the annular groove 6 from the guide groove 5, and the spring 38 is gradually compressed in the process; the end cap 37 is rotated, when the clamping block 39 slides to the clamping groove 7 along the annular groove 6, the end cap 37 is loosened, and at the moment, the end cap 37 drives the clamping block 39 to be clamped into the clamping groove 7 under the restoring force of the spring 38, so that firm fixation is realized.

Example 3

The embodiment of the application discloses prevent revolving and prevent double thread hollow nail that moves back, the difference with embodiment 1 lies in latch fitting and solid pole inner core.

Referring to fig. 8, the locking member 3 includes a locking head 31, a first threaded rod 32, a polished rod 41 and a limiting post 42 coaxially arranged and integrally formed in sequence, wherein the diameter of the limiting post 42 is smaller than that of the first threaded rod 32 and larger than that of the polished rod 41; one end of the solid rod inner core 2, which is far away from the inserted link 22, is processed with a communicating groove 24 and a limiting groove 25 along the axial direction inwards in sequence, the limiting groove 25 is matched with the limiting column 42, and the communicating groove 24 and the limiting groove 25 are communicated by one radial side of the solid rod inner core 2.

Referring to fig. 3 and 8, when the solid rod inner core 2 is installed, the limiting column 42 is placed in the limiting groove 25, the solid rod inner core 2 is pushed by a special matching tool to slide towards the columnar rod body 11, when the solid rod inner core slides to the limiting position, the lock head 31 is rotated to enable the first threaded rod 32 to be in threaded connection with the first threaded hole 16, in the process of threaded connection, the inserting rod 22 continues to push inwards until the feeding blade of the inserting rod 22 extends out of the notch 17 to be inserted into a bone, and forms an included angle of 15 degrees to 30 degrees with the axis of the screw main body 1 to form corner fixation, and meanwhile, the contact area with the bone is increased, so that the effects of rotation prevention and retreat prevention are achieved.

Through spacing post 42 and the cooperation of spacing groove 25 on the latch fitting 3 in this application embodiment, first threaded rod 32 and the cooperation of first screw hole 16 for it is whole to be a unified atress to be connected between latch fitting 3, solid core 2 and the screw main part 1, has improved the structural strength of double thread hollow nail greatly.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.