CN218128707U - Non-locking hollow bone screw - Google Patents

Abstract

The application discloses non-lock hollow bone screw relates to the bone screw field, and it includes pin fin, nail pole and nail tail, offers the through-hole that runs through intercommunication pin fin and nail tail in the nail pole, and the nail tail is the toper of pointed end orientation nail pole, and the nail tail is located the tip of through-hole and has seted up the rotating recess, and first screw thread portion has been laid to the outer wall of nail pole, and second screw thread portion has been laid to the outer wall of nail tail. This application is the toper with the design of nail tail, sets up the rotating recess at the tip that the nail tail is located the through-hole and revolves the screw with the cooperation screwdriver, and the screw thread is all laid to the outer wall of nail pole and nail tail, can reach stronger mechanical stability in the internal fixation treatment of scaphoid fracture, need not to cooperate the coaptation board locking again, and the toper nail tail cooperatees with second screw thread portion, can be fast with under the distal articular surface of screw tail screw in scaphoid, in scaphoid internal fixation treatment, better practicality has.

Description

Non-locking hollow bone screw

Technical Field

The present application relates to the field of bone screws, and more particularly, to a non-locking cannulated bone screw.

Background

With the development of economic construction and the rise of extreme sports, the incidence rate of high-energy trauma is in a relatively obvious rising trend, and sports medicine related to the high-energy trauma is increasingly refined. The bone screw is used as internal fixing device for treating bone fracture, belongs to the field of biological inert material, and is combined with bone to form mechanical locking.

Among the bones of the carpal bones, fractures of the scaphoid are most common. The scaphoid is a small bone of the wrist joint, which is close to the radius of the lower row and is shaped like a boat, irregular, long and narrow on the back, rough and uneven. The large part around the scaphoid is a cartilage surface without periosteum attachment, the scaphoid can be connected only by endogenous callus after fracture, the fracture healing of the scaphoid waist, especially the proximal scaphoid, is slow, and the plaster has long braking time. In recent years, there has been a clinical attempt to treat non-displaced or slightly displaced scaphoid fracture by using percutaneous compression screw internal fixation, which can greatly shorten the healing time of scaphoid fracture, improve the healing effect, reduce the incidence of nonunion and reduce joint stiffness caused by long-term braking.

The bone screw in the related technology comprises a nail head, a nail rod and a nail tail, wherein the nail rod is a titanium alloy hollow nail body, the nail rod comprises a threaded section close to the nail head and a non-threaded section close to the nail tail, and a screw cap is formed at the outer edge of the nail tail and is matched with a bone fracture plate with a nail hole for use so as to provide good holding force and stability.

Aiming at the related technologies, the inventor finds that the size and shape of the scaphoid of a Chinese person are relatively small, the diameter of the scaphoid is relatively smaller than that of the scaphoid, the bone screw for scaphoid fracture is less and incomplete in model, and the problem that the tip or tail end of the implanted screw protrudes out of the joint surface and abrades the joint surface due to improper screw selection can be clinically seen; in addition, in the bone screw in the related art, the screw tail cannot be completely embedded under the cartilage in the treatment of scaphoid fracture, the healing effect is not good, and there is a need for improvement.

SUMMERY OF THE UTILITY MODEL

In order to provide a bone screw suitable for percutaneous intranavicular fixation, the present application provides a non-locking cannulated bone screw.

The application provides a non-locking hollow bone screw adopts following technical scheme:

the non-locking hollow bone screw comprises a screw head, a screw rod and a screw tail, wherein a through hole penetrating and communicating the screw head and the screw tail is formed in the screw rod, the screw tail is in a conical shape with a tip end facing the screw rod, a rotating groove is formed in the end part, located at the through hole, of the screw tail, a first thread part is arranged on the outer wall of the screw rod, and a second thread part is arranged on the outer wall of the screw tail.

Through adopting above-mentioned technical scheme, it is the toper to design the nail tail, the tip that is located the through-hole at the nail tail is seted up the rotating recess and is twisted the screw with the cooperation screwdriver, the screw (first screw thread portion and second screw thread portion promptly) is established to the outer wall equipartition of nail pole and nail tail, can reach stronger mechanical stability in the internal fixation treatment of scaphoid fracture, need not to cooperate the coaptation board locking again, and the toper nail tail cooperatees with second screw thread portion, can be fast with screw in scaphoid distal (the great one end of scaphoid diameter) joint face 2 mm department down, stronger practicality has.

Optionally, the first thread portion has an outer diameter smaller than an outer diameter of the second thread portion.

By adopting the technical scheme, the diameter of the proximal scaphoid is smaller than that of the distal scaphoid, the outer diameter of the first thread part penetrating into the proximal scaphoid is controlled, the narrow and small bone characteristics of the scaphoid can be considered, and the mechanical stability of the scaphoid after the screw is integrally placed in the scaphoid can be improved.

Optionally, the pitch of the second thread portion is smaller than the pitch of the first thread portion.

By adopting the technical scheme, the characteristics of the extremely narrow bone near the scaphoid and the mechanical stability of the scaphoid after the screw is integrally placed are further considered.

Optionally, the thread direction of the first thread part is the same as the thread direction of the second thread part.

Through adopting above-mentioned technical scheme, improve the wholeness of screw, facilitate the use.

Optionally, a rotation-stopping straight surface is formed at an end of the second threaded portion close to the nail head.

Through adopting above-mentioned technical scheme, the tip that is close to the pin fin at second screw thread portion forms the straight face of stopping soon, through designing the straight face of stopping soon to improve bone screw and take place the motion derotation in patient's recovered motion process, lead to the not hard up problem of bone screw.

Optionally, the outer circumferential wall of the nail tail is smoothly connected with the outer circumferential wall of the nail rod.

By adopting the technical scheme, the pain of the patient caused by the screwing-in process of the screw is reduced as much as possible, and the design is more comprehensive.

Optionally, the end of the nail head located at the through hole is provided with a plurality of rotary blades.

Through adopting above-mentioned technical scheme, set up rotatory cutting edge at the pin head tip to self-tapping in the bone when the screw is implanted.

Optionally, the rotating groove is shaped like an inner hexagonal prism.

By adopting the technical scheme, the screw can be conveniently screwed by the hexagonal prism screwdriver, and the operation is easy.

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

1. the screw tail is designed to be conical, the end part of the screw tail, which is positioned at the through hole, is provided with the rotating groove to be matched with a screwdriver to rotate the screw in a rotating mode, threads are arranged on the outer walls of the screw rod and the screw tail, so that stronger mechanical stability can be achieved in internal fixation treatment of scaphoid fracture, locking by a bone fracture plate is not needed, the conical screw tail is matched with the second thread part, the screw can be rapidly rotated to a position 2 mm below the distal joint surface of the scaphoid, and the screw has stronger practicability;

2. the diameter of the proximal scaphoid is smaller than that of the distal scaphoid, so that the external diameter of the first thread part is smaller than that of the second thread part, the external diameter of the first thread part penetrating into the proximal scaphoid is controlled, and the narrow bone characteristics of the proximal scaphoid and the mechanical stability of the scaphoid after the whole screw is implanted can be considered;

3. the thread turning direction of the first thread part is the same as that of the second thread part, and the end part, close to the pin head, of the second thread part forms a rotation stopping straight surface, so that the problem that the bone screw is loosened due to motion derotation of the bone screw in the rehabilitation motion process of a patient can be solved, and the design is more comprehensive.

Drawings

FIG. 1 is a schematic diagram of the overall structure of an embodiment of the present application;

FIG. 2 is a sectional view showing the internal structure of the embodiment of the present application;

FIG. 3 is a schematic view showing the structure of the nail head in the embodiment of the present application;

fig. 4 is a schematic view for showing the structure of the nail tail in the embodiment of the present application.

Reference numerals: 1. a nail head; 2. a nail rod; 3. nailing tail; 4. a through hole; 5. rotating the groove; 6. a first threaded portion; 7. a second threaded portion; 8. a rotation stopping straight surface; 9. the blade is rotated.

Detailed Description

The present application is described in further detail below with reference to figures 1-4.

The embodiment of the application discloses a non-locking hollow bone screw.

Referring to fig. 1, a non-locking cannulated bone screw includes a head 1, a shank 2, and a tail 3.

Referring to fig. 1 and 2, a through hole 4 penetrates through the nail rod 2, and the through hole 4 is communicated with the nail head 1 and the nail tail 3. Referring to fig. 2 and 3, the end of the nail head 1 in the through hole 4 is integrally formed with 3 rotary blades 9,3 which are evenly spaced at the through hole 4 so that the nail head 1 can self-tap in the bone when screwing the implant screw. Referring to fig. 2 and 4, the end of the nail tail 3 at the through hole 4 is provided with a rotating groove 5, the rotating groove 5 is communicated with the through hole 4, and the rotating groove 5 is in a hexagonal prism shape so as to facilitate the operation of screwing the screw by a hexagonal prism screwdriver.

Specifically, referring to fig. 1 and 2, a first threaded portion 6 is disposed on the outer wall of the shank 2, and a second threaded portion 7 is disposed on the outer wall of the tail 3. The nail tail 3 is the toper of pointed end towards the nail pole 2, and the periphery wall of nail tail 3 and the periphery wall smooth connection of nail pole 2. When the screw is screwed in from the distal scaphoid, the strength required for screwing the conical nail tail 3 is gradually increased, thereby pushing the distal scaphoid to the proximal scaphoid commissure. The conical nail tail 3 is matched with the second thread part 7, so that a screw can be quickly screwed into a position about 2 mm below the joint surface of the distal navicular pole (the end with the larger diameter of the navicular bone); rely on first screw thread portion 6 and the fixed boat bone of second screw thread portion 7 locking, can reach stronger mechanical stability, in the internal fixation treatment of boat bone fracture, need not cooperation coaptation board locking, have that stability is strong, easily implant, the painful little practical function of patient.

Further, referring to fig. 1 and 2, the first screw part 6 has an outer diameter smaller than that of the second screw part 7, controlling the outer diameter of the first screw part 6 penetrating into the proximal pole of the navicular bone; the thread pitch of the second thread part 7 is smaller than that of the first thread part 6, so that the self-locking strength of the nail tail 3 is improved, and the mechanical stability of the scaphoid after the scaphoid is integrally placed into the screw is considered.

Further, the thread direction of the first thread part 6 is the same as that of the second thread part 7. The end part of the second thread part 7 close to the nail head 1 is provided with a rotation stopping straight surface 8, and the problem of loosening of the bone screw caused by motion reverse rotation of the bone screw in the rehabilitation motion process of a patient is solved through the rotation stopping straight surface 8, so that the design is more comprehensive.

The implementation principle of the non-locking hollow bone screw in the embodiment of the application is as follows: be the toper with the design of nail tail 3, it revolves wrong screw with the cooperation screwdriver to set up rotating recess 5 at the tip that nail tail 3 is located through-hole 4, the screw (first screw thread portion 6 and second screw thread portion 7 promptly) is all laid to the outer wall of nail pole 2 and nail tail 3, can reach stronger mechanical stability in the internal fixation treatment of scaphoid fracture, need not to cooperate the coaptation board locking again, and the cooperation of conical nail tail 3 and second screw thread portion 7, can be fast with under the distal articular surface of screw in scaphoid, easily implant, patient's misery is little, has stronger practicality.

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: equivalent changes in structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims (8)

1. The utility model provides a non-lock hollow bone screw, includes pin fin (1), nail pole (2) and nail tail (3), set up in nail pole (2) and run through the intercommunication through-hole (4) of pin fin (1) with nail tail (3), its characterized in that: nail tail (3) are most advanced orientation the toper of nail pole (2), nail tail (3) are located rotating recess (5) have been seted up to the tip of through-hole (4), first screw thread portion (6) have been laid to the outer wall of nail pole (2), second screw thread portion (7) have been laid to the outer wall of nail tail (3).

2. A non-locking cannulated bone screw according to claim 1, wherein: the first threaded portion (6) has an outer thread diameter smaller than that of the second threaded portion (7).

3. A non-locking cannulated bone screw according to claim 2, wherein: the pitch of the second thread portion (7) is smaller than the pitch of the first thread portion (6).

4. A non-locking cannulated bone screw according to claim 1, wherein: the thread direction of the first thread part (6) is the same as that of the second thread part (7).

5. A non-locking cannulated bone screw according to claim 4, wherein: and a rotation-stopping straight surface (8) is formed at the end part of the second thread part (7) close to the nail head (1).

6. A non-locking cannulated bone screw according to claim 1, wherein: the peripheral wall of the nail tail (3) is smoothly connected with the peripheral wall of the nail rod (2).

7. A non-locking cannulated bone screw according to claim 1, wherein: the end part of the nail head (1) positioned in the through hole (4) is provided with a plurality of rotary blades (9).

8. A non-locking cannulated bone screw according to claim 1, wherein: the rotating groove (5) is in an inner hexagonal prism shape.

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