CN216365227U

CN216365227U - Be applied to osteoporosis's claw shape pedicle of vertebral arch screw

Info

Publication number: CN216365227U
Application number: CN202122256159.8U
Authority: CN
Inventors: 郝定均; 张海平
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-09-16
Filing date: 2021-09-16
Publication date: 2022-04-26
Anticipated expiration: 2031-09-16

Abstract

The utility model discloses a claw-shaped pedicle screw applied to osteoporosis, which comprises an inner screw plug and an outer screw; the outer screw comprises an outer nut and an outer screw rod, a through hole is formed in the outer nut and the outer screw rod and penetrates through the outer nut and the outer screw rod, a thread section, a claw-shaped section and a conical section are sequentially arranged outside the outer screw rod, a first internal thread is arranged in the thread section, a plurality of strip-shaped grooves communicated with the through hole are formed in the claw-shaped section, and a smooth section is arranged in the claw-shaped section; a second internal thread is arranged inside the conical section; the claw-shaped section is made of deformable metal; the inner screw plug comprises an inner nut and an inner screw rod, the inner screw rod is inserted into the through hole, and the inner screw rod is in threaded connection with the first inner thread and the second inner thread; the inner screw rod and the second internal thread are reverse screw threads. According to the utility model, the holding force between the screw and surrounding bone is increased through the inner screw plug, so that the anti-pull-out force of the screw is enhanced.

Description

Be applied to osteoporosis's claw shape pedicle of vertebral arch screw

Technical Field

The utility model relates to the technical field of osteoporosis surgical instruments, in particular to a claw-shaped pedicle screw applied to osteoporosis.

Background

The number of patients with spinal osteoporosis continues to increase as the life expectancy of older adults increases. Due to the weakened bone remodeling capability of the patients and the reduction of the quality of the vertebral body, the spine is easy to have compression fracture, degenerative deformity, stenosis and the like, and the operation is often needed for intervention. Although pedicle screws provide strong fixation for osteopenic patients, in osteoporotic populations, there is often a risk of post-operative screw pullout, loosening and displacement due to a significant decrease in screw retention in osteoporotic bone.

Researchers have attempted to enhance the stability of screws using bone cement to enhance the holding force of the screw in osteoporotic bone. Many researches show that after the bone cement is used for reinforcement, the average withdrawal strength can reach 150-250% of that of the common pedicle screws. However, as the number of cement-reinforced screws used increases, many complications and risks associated with the screws gradually emerge, and the most common of them is leakage of cement (the incidence reported in the literature is up to 26.2%). In addition, there is a risk of other complications including thermal injury to the cement, pulmonary embolism, and compression fracture of the adjacent vertebral body, and revision is difficult.

In order to avoid the risk of complications caused by the use of bone cement, researchers have begun to develop a new screw-expansion screw instead of the bone cement to enhance the holding force of the screw. After the screw is placed in a vertebral body, the contact area of the screw and the surrounding bone is increased through the expansion of the part of the screw positioned in the bone of the vertebral body, and the density of the surrounding bone is increased through compressing the surrounding bone, so that the anti-pull-out force of the screw is obviously enhanced. The expansion screw that early report is mostly the head end inflation, and recent scholars have reported a novel expansion screw (OsseoSecrew backbone internal fixation system), and the inflation position of this screw is close to the pedicle of vertebral arch, is favorable to strengthening its resistance to plucking intensity. Compared with the common pedicle screw, the screw can increase the pullout strength by about 30 percent (increase the pullout strength by about 50 percent in osteoporotic bone), and the rigidity and yield load of the screw are not obviously different from those of the common outer diameter pedicle screw.

Research shows that the expansion screw has the effect of enhancing the fixation stability similar to bone cement, but the screw is still found to have the fracture phenomenon at the root of the vertebral arch when being clinically used; secondly, since the surrounding bone can grow into the expanded region after the screw is implanted and expanded, the removal of the screw is difficult and can easily result in a large vertebral bone defect at a later stage if revision is required, and the fixation section is often required to be lengthened to maintain the stability of the fixation.

SUMMERY OF THE UTILITY MODEL

In order to avoid the risk of various complications caused by using bone cement and expansion screws, the utility model provides the claw-shaped pedicle screw applied to osteoporosis.

In order to achieve the above object, the present invention provides the following technical solutions.

A claw-shaped pedicle screw applied to osteoporosis comprises an inner screw plug and an outer screw;

the outer screw comprises an outer nut and an outer screw rod, a through hole is formed in the outer nut and the outer screw rod and penetrates through the outer nut and the outer screw rod, a thread section, a claw-shaped section and a conical section are sequentially arranged outside the outer screw rod, a first internal thread is arranged in the thread section, a plurality of strip-shaped grooves communicated with the through hole are formed in the claw-shaped section, and a smooth section is arranged in the claw-shaped section; a second internal thread is arranged inside the conical section; the claw-shaped section is made of deformable metal; a first external thread is arranged on the thread section, and the thread direction of the first internal thread is opposite to that of the second internal thread; the thread directions of the first external thread and the second internal thread are the same;

the inner screw plug comprises an inner nut and an inner screw rod, the inner screw rod is inserted into the through hole, second external threads are arranged on the inner screw rod, the second external threads of the inner screw rod are connected with the first internal threads, and the second external threads are connected with the second internal threads under the action of reverse rotation to extrude the claw-shaped sections to expand.

As a further improvement of the utility model, the outer screw rod is of a conical structure, and the thread pitch of the first outer thread from the thread section to the outer nut is gradually reduced, and the thread diameter is gradually increased.

As a further development of the utility model, the first thread tail has a hydroxyapatite sprayed coating.

As a further improvement of the utility model, the inner nut is provided with a second wrench operation groove.

As a further improvement of the utility model, the length of the inner screw is equal to the length of the outer screw after the second internal thread is removed.

As a further improvement of the utility model, the device also comprises an operating tool, wherein the operating tool comprises a locking nut and an operating rod;

the outer nut is provided with a locking groove, and locking threads are arranged inside the outer nut;

when the locking device is used, the operating rod is arranged in the locking groove and is in threaded connection with the locking thread through the locking nut to lock the operating rod.

As a further improvement of the present invention, the lock nut is provided with a first wrench operation groove.

As a further improvement of the utility model, the operating rod is perpendicular to the axial direction of the outer screw.

As a further improvement of the utility model, the claw-shaped section is made of pure titanium, and the thread section is made of titanium alloy.

As a further improvement of the utility model, the strip-shaped grooves are uniformly arranged on the claw-shaped section along the axial direction of the claw-shaped section.

Compared with the prior art, the utility model has the following beneficial effects:

the utility model provides a claw-shaped pedicle screw applied to osteoporosis, and designs a claw-shaped pedicle spraying screw.

Drawings

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes, the proportional sizes, and the like of the respective members in the drawings are merely schematic for facilitating the understanding of the present invention, and do not specifically limit the shapes, the proportional sizes, and the like of the respective members of the present invention. In the drawings:

FIG. 1 is a schematic view of a paw-shaped pedicle screw for use in osteoporosis;

FIG. 2 is a cross-sectional view of a pedicle screw in the form of a claw for use in osteoporosis;

FIG. 3 is a cross-sectional view of an outer screw applied to an osteoporotic claw pedicle screw;

FIG. 4 is an exploded view of a paw-shaped pedicle screw as applied to osteoporosis;

fig. 5 is a schematic view showing the use state of the claw-shaped pedicle screw applied to osteoporosis.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the drawings in the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a single embodiment.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the utility model herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The utility model provides a claw-shaped pedicle screw applied to osteoporosis, which comprises an inner screw plug 100 and an outer screw 200;

the outer screw 200 comprises an outer nut 210 and an outer screw rod 220, through holes penetrating through the outer nut 210 and the outer screw rod 220 are formed in the outer nut 210 and the outer screw rod 220, a thread section 221, a claw-shaped section 222 and a conical section 223 are sequentially arranged outside the outer screw rod 220, a first inner thread 224 is formed in the thread section 221, a plurality of strip-shaped grooves 226 communicated with the through holes are formed in the claw-shaped section 222, and a smooth section is formed in the claw-shaped section 222; a second internal thread 227 is arranged inside the conical section 223; the claw-shaped section 222 is made of deformable metal; the threaded section 221 is provided with a first external thread 225, and the first internal thread 224 is opposite to the second internal thread 227 in thread direction; the first external thread 225 and the second internal thread 227 have the same thread direction;

the inner plug 100 includes an inner nut 110 and an inner screw 120, the inner screw 120 is inserted into the through hole, the inner screw 120 is provided with a second external thread 121, the second external thread 121 of the inner screw 120 is connected with the first internal thread 224, and under the action of reverse rotation, the second external thread 121 is connected with the second internal thread 227 to extrude the claw-shaped section 222 to expand.

The principle is as follows: the reverse-threaded screw moves upward as the screw is advanced, thereby compressing and expanding the jaw section 222.

In a preferred embodiment, the outer screw 220 has a tapered configuration, and the first external thread 225 has a gradually decreasing pitch and a gradually decreasing diameter from the thread section 221 toward the outer nut 210.

Preferably, the tail of the first external thread 225 is provided with a hydroxyapatite sprayed layer 228.

Preferably, the length of the inner screw 120 is equal to the length of the outer screw 220 after the second inner thread 227 is removed. The design is such that after the inner screw plug 100 is screwed into the outer screw 200, it is just caught on the top of the second internal thread 227, and when a reverse rotation force is applied, the inner screw plug 100 and the second internal thread 227 start to be screwed, so that the claw-shaped sections 222 are expanded to form a plurality of claw-shaped structures.

Further, the inner screw 120 extends out of the outer screw 220, and the lower end of the inner screw 120 may be fixed to an osteoporosis site in the body.

Further comprises a lock nut 400 and an operating rod 300;

the outer nut 210 is provided with a locking groove 211, and a locking thread 212 is arranged inside the outer nut 210;

the operation lever 300 is disposed in the locking groove 211, and the operation lever 300 is locked by screwing the locking nut 400 and the locking screw 212.

The lock nut 400 is provided with a first wrench operation groove. For screwing it into the interior of said outer nut 210 using a tool, into threaded connection with the locking thread 212. The first wrench operating slot is preferably hexagonal.

The inner nut 110 is provided with a second wrench operation groove. For screwing it into the outer screw 200 using a tool with a corresponding thread. The second wrench operating slot is preferably hexagonal.

In a preferred embodiment, the claw-shaped section 222 of the outer screw 200 is made of variable pure titanium, and the thread section 221 is made of titanium alloy. The two ends are made of different materials and have different hardness, so that under subsequent acting force, the claw-shaped section 222 is divided into a plurality of parts to expand along the strip-shaped groove 226 to form a plurality of claw-shaped structures.

In a preferred embodiment, the strip-shaped grooves 226 are uniformly arranged on the claw section 222 along the axial direction of the claw section 222. Preferably, three strip-shaped grooves 226 are provided, which are expanded to form a shape similar to clover.

The utility model is applied to the structure and implantation mode of the claw-shaped pedicle screw (clawScrew screw) for osteoporosis to explain specifically:

the clawscreenw screw is composed of three parts,

the first part is that the outer screw 200 has an inner screw plug 100 structure, and the inner screw plug 100 is responsible for expanding claw-shaped mechanical structures outside the screw and increasing the holding force of the screw in a vertebral body;

the second part is that 2cm of outer screw 200 tail is processed with hydroxyapatite spraying, which increases bone growth and reduces screw loosening, displacement and extraction;

the third part is that the outer screw 200 is designed to be a conical structure, the diameter of the inner shaft part gradually becomes a thickening state, the inner diameter is designed to be 3mm at the front end, the thread pitch is 5mm, the thread pitch is reduced by 0.1mm every time the inner shaft part is increased by one circle, and the diameter of the inner shaft is increased by 0.05 mm. The inner core part of the screw is designed to have a thickening trend, and the fracture of the screw caused by metal fatigue after the screw is implanted is reduced.

The implantation mode is as follows:

the pedicle screw path is prepared by adopting the conventional technology, after the screw is implanted, an operator uses a special internal screw plug wrench to screw in the screw plug, when the internal screw plug is screwed in the claw-shaped section, the claw-shaped section is continuously opened along with the screw plug after being screwed in, the gap between the outer layers of the screw is gradually filled by the central screw plug, and in the process, attention needs to be paid to monitoring the expansion condition of the screw in the vertebral body under the perspective condition.

It should be noted that, in the description of the present invention, the terms "first", "second", and the like are used for descriptive purposes only and for distinguishing similar objects, and no precedence between the two is considered as indicating or implying relative importance. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

It is to be understood that the above description is intended to be illustrative, and not restrictive. Many embodiments and many applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the present teachings should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are hereby incorporated by reference for all purposes. The omission in the foregoing claims of any aspect of the subject matter that is disclosed herein is not intended to forego such subject matter, nor should the applicants be construed as having contemplated such subject matter as being part of the disclosed subject matter.

Claims

1. A claw-shaped pedicle screw applied to osteoporosis is characterized by comprising an inner screw plug (100) and an outer screw (200);

the outer screw (200) comprises an outer nut (210) and an outer screw rod (220), a through hole penetrating through the outer nut (210) and the outer screw rod (220) is formed in the outer screw rod (220), a threaded section (221), a claw-shaped section (222) and a conical section (223) are sequentially arranged outside the outer screw rod (220), a first internal thread (224) is formed in the threaded section (221), a plurality of strip-shaped grooves (226) communicated with the through hole are formed in the claw-shaped section (222), and a smooth section is formed in the claw-shaped section (222); a second internal thread (227) is arranged inside the conical section (223); the claw-shaped section (222) is made of deformable metal; a first external thread (225) is arranged on the threaded section (221), and the thread direction of the first internal thread (224) is opposite to that of the second internal thread (227); the thread direction of the first external thread (225) is the same as that of the second internal thread (227);

the inner screw plug (100) comprises an inner nut (110) and an inner screw (120), the inner screw (120) is inserted into the through hole, a second outer thread (121) is arranged on the inner screw (120), the second outer thread (121) of the inner screw (120) is connected with the first inner thread (224), and under the action of reverse rotation, the second outer thread (121) is connected with the second inner thread (227) to extrude the claw-shaped section (222) to expand.

2. The pedicle screw for osteoporotics according to claim 1, wherein the outer screw rod (220) has a tapered configuration, and the first external thread (225) has a gradually decreasing pitch and a gradually decreasing diameter from the thread section (221) toward the outer nut (210).

3. The pedicle screw for use in osteoporosis of the talar type according to claim 1, wherein the first external thread (225) has a hydroxyapatite sprayed layer (228) at a tail portion thereof.

4. The pedicle screw of paw shape for osteoporosis as claimed in claim 1,

the inner nut (110) is provided with a second wrench operation groove.

5. The pedicle screw of paw shape for osteoporosis as claimed in claim 1,

the length of the inner screw (120) is equal to the length of the outer screw (220) after the second internal thread (227) is removed.

6. The pedicle screw of paw shape for osteoporosis as claimed in any one of claims 1 to 5,

the operation tool comprises a locking nut (400) and an operation rod (300);

the outer nut (210) is provided with a locking groove (211), and a locking thread (212) is arranged inside the outer nut (210);

when the locking device is used, the operating rod (300) is arranged in the locking groove (211), and the operating rod (300) is locked through the threaded connection of the locking nut (400) and the locking thread (212).

7. The pedicle screw of paw shape for osteoporosis as claimed in claim 6,

the locking nut (400) is provided with a first wrench operation groove.

8. The pedicle screw of paw shape for osteoporosis as claimed in claim 6,

the operating rod (300) is axially vertical to the outer screw (200).

9. The pedicle screw of paw shape for osteoporosis as claimed in claim 1,

the claw-shaped section (222) is made of pure titanium, and the thread section (221) is made of titanium alloy.

10. The pedicle screw of paw shape for osteoporosis as claimed in claim 1,

the strip-shaped grooves (226) are uniformly arranged on the claw-shaped section (222) along the axial direction of the claw-shaped section (222).