A bone cement pedicle screw with a closed guiding front end

Abstract

The present invention relates to a bone cement pedicle screw with a closed guiding front end, comprising a screw cap and a screw body, wherein the screw cap is detachably connected to the screw body, and the screw cap has a U-shaped groove, wherein the innovation lies in that the screw body has an axial bone cement channel, and the bone cement channel is connected to the U-shaped groove, a plurality of bone cement through holes are arranged on the peripheral wall of the screw body and along the circumferential direction and from top to bottom, and the plurality of bone cement through holes are all connected to the bone cement channel, and a guide groove forming an angle with the axis of the screw body is arranged on the outer wall at one end of the screw body. The present invention is not only more convenient to assemble, but also effectively improves the risk of bone cement overflowing at the front edge of the cone, and better ensures the dispersibility of bone cement in the cone.

Description

Technical Field

[0001] The invention relates to a bone cement pedicle screw, in particular to a bone cement pedicle screw with a closed guiding front end. Background Art

[0002] Osteoporosis (OP) has become one of the interdisciplinary diseases that affect people's health after diabetes and hypertension. With the progress of population aging, this kind of problem has become more prominent in my country. Osteoporosis leads to low bone mass, bone microstructure damage, increased bone brittleness, and easy fractures in the patient population. It also poses a serious threat to the treatment of spinal degenerative diseases. Lumbar pedicle screw internal fixation and fusion has become the gold standard for the treatment of lumbar degenerative diseases. It has many advantages such as ensuring decompression effect, stabilizing the spine, promoting fusion and early rehabilitation. It is widely used in the treatment of lumbar spinal stenosis, lumbar spondylolisthesis, lumbar degenerative scoliosis, lumbar disc herniation and other diseases. However, the reduction of vertebral bone density in osteoporotic patients will directly affect the fixation strength of pedicle screws, resulting in loosening, extraction, cutting of vertebral bodies, and failure of internal fixation reduction of pedicle screws, which has become a potential risk of surgery.

[0003] How to solve the problem of insufficient pedicle screw fixation strength caused by osteoporosis? The current methods of improvement through research mainly include: (1) increasing the length and diameter of the pedicle screw; (2) improving the design of the pedicle screw's own thread, such as using double-threaded screws; (3) self-expansion screws; (4) double-cortical screw fixation technology; (5) cortical bone screw technology; (6) pedicle screw bone cement screw channel strengthening technology. Among them, pedicle screw bone cement screw channel strengthening technology is the most effective method to improve the stability of pedicle screw fixation.

[0004] With the continuous updating of surgical instruments, the emergence of advanced medical imaging equipment and the application of intraoperative computer-assisted navigation, minimally invasive technology has developed rapidly in spinal surgery. At present, for the convenience of installation, ordinary surgery has a large operating area, large surgical trauma, slow healing, and is prone to complications on the wound surface. Minimally invasive refers to a surgical or examination method that achieves the best surgical effect with minimal invasion and minimal physiological interference. The most important feature is the minimization of trauma. As a planned trauma, the surgeon should strive to reduce the trauma of the surgery to a minimum to achieve the purpose of minimally invasive surgery. Minimally invasive surgery reduces the operation time, reduces the incidence of complications, reduces intraoperative tissue damage and bleeding, shortens the patient's recovery time, reduces surgical pain, makes the incision beautiful, shortens the hospitalization and rehabilitation time, and reduces the economic cost of drug use and hospitalization. In short, minimally invasive surgery meets the requirements of a harmonious society for public medical and health care from the two aspects of medical professional attributes and social attributes. With the development of science and technology, minimally invasive spinal technology will become a major trend in the development of spinal internal fixation technology as part of traditional surgical technology.

[0005] Judging from the mainstream products currently on the market, bone cement nails used for minimally invasive surgery are all hollow throughout, and the bone cement holes are of uniform size and evenly distributed. After the pedicle screws are driven into the vertebral body, when the bone cement is driven in during the operation, there may be a risk of bone cement overflowing at the front edge of the vertebral body due to the hole at the front end of the screw body and the diffusion of bone cement. In addition, the uniform hole design means that when the bone cement is injected, the bone cement cannot overflow from the hole evenly due to the different pressures in the front and back, and the ideal effect cannot be achieved.

[0006] In addition, in the design of long-arm nails for minimally invasive needs, the rigid extension arm design is suitable for lifting and reduction during surgery, but it is prone to interference during lumbar spine surgery and is not easy to operate during surgery; the flexible extension arm design can solve the above-mentioned interference problem, but it requires the use of multiple tools during reduction, which is more cumbersome. Summary of the invention

[0007] The purpose of the present invention is to provide a bone cement pedicle screw with a guide front end that is not only more convenient to assemble, but also effectively improves the risk of bone cement overflowing at the front edge of the cone and better ensures the diffusion of bone cement in the cone.

[0008] In order to achieve the above-mentioned purpose, the technical solution of the present invention is: a bone cement pedicle screw with a closed guiding front end, comprising a nail cap and a nail body, wherein the nail cap is detachably connected to the nail body, and the nail cap has a U-shaped groove. The innovation point is that: the nail body has an axial bone cement channel, and the bone cement channel is connected to the U-shaped groove, a plurality of bone cement through holes are provided on the peripheral wall of the nail body along the circumferential direction and from top to bottom, and the plurality of bone cement through holes are all connected to the bone cement channel, and a guide groove forming an angle with the axis of the nail body is provided on the outer wall of one end of the nail body.

[0009] In the above technical solution, the bottom of the nail cap has an axial mounting hole connected to the U-shaped groove, and a clamping ring is arranged in the axial mounting hole, and the other end of the nail body is arranged in the clamping ring.

[0010] In the above technical solution, an annular positioning groove is provided on the hole wall of the axial mounting hole of the nail cap, a positioning protrusion is provided on the outer peripheral wall of the clamping ring, and the positioning protrusion is clamped in the annular positioning groove of the nail cap.

[0011] In the above technical solution, the end of the other end of the nail body is provided with a hexagonal hole, and the hexagonal hole is connected to the bone cement channel.

[0012] In the above technical solution, radial U-shaped grooves are provided on the side walls at both ends of the top of the nail cap.

[0013] In the above technical solution, elastic protrusions are provided on the side walls at both ends of the top of the nail cap and above the U-shaped slot, and a rigid assembly hole is provided on the outer side wall of the top of the nail cap.

[0014] In the above technical solution, an internal thread is provided on the inner wall of the U-shaped groove of the nail cap.

[0015] In the above solution, a process groove for breaking the tool is provided on the middle outer wall of the nail cap.

[0016] In the above technical solution, the diameters of the bone cement through holes on the peripheral wall of the nail body decrease from bottom to top.

[0017] In the above technical solution, the axial mounting hole of the nail cap is a first spherical acetabulum, the end of the other end of the nail body is a spherical acetabulum, and a second spherical acetabulum is provided on the clamping washer. The spherical acetabulum of the nail body cooperates with the first spherical acetabulum of the nail cap and the second spherical acetabulum of the clamping washer at the same time.

[0018] The positive effect of the present invention is: after using the bone cement pedicle screw with a guide front end closed according to the present invention, since the nail body of the present invention has an axial bone cement channel, and the bone cement channel is connected to the U-shaped groove, the axial bone cement channel of the nail body makes it a non-hollow design, which can effectively improve the risk of bone cement overflowing at the front edge of the vertebral body. In addition, since a plurality of bone cement through holes are provided on the peripheral wall of the nail body and along the circumferential direction from top to bottom, and the plurality of bone cement through holes are all connected to the bone cement channel, the diffusion of bone cement in the vertebral body can be better guaranteed; and since a guide groove forming an angle with the axis of the nail body is provided on the outer wall of one end of the nail body, it can be more easily installed to the corresponding position according to the previously inserted guide pin in a minimally invasive environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1It is a structural schematic diagram of a specific implementation mode of the present invention;

[0020] Figure 2 yes Figure 1 A magnified schematic diagram of part A;

[0021] Figure 3 It is a three-dimensional structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described below with reference to the accompanying drawings and given embodiments, but is not limited thereto.

[0023] like Figure 1 , 2 As shown in , 3, a method includes a nail cap 1 and a nail body 2, wherein the nail cap 1 is detachably connected to the nail body 2, the nail cap 1 has a U-shaped groove 11, the nail body 2 has an axial bone cement channel 21, and the bone cement channel 21 is connected to the U-shaped groove 11, a plurality of bone cement through holes 22 are provided on the circumferential wall of the nail body 2 and along the circumferential direction from top to bottom, the plurality of bone cement through holes 22 are all connected to the bone cement channel 21, and a guide groove 23 is provided on the outer wall of one end of the nail body 2, which forms an angle with the axis of the nail body 2.

[0024] The angle between the axis of the nail body 2 and the guide groove 23 is 0° to 20°.

[0025] Furthermore, the angle between the axis of the nail body 2 and the guide groove 23 is 13° to 15°.

[0026] The nail body 2 has a double-start thread, and the cross-sectional diameter of one end of the nail body 2 is smaller than the cross-sectional diameter of the other end thereof, so as to make it easier to install it to the corresponding position according to the previously inserted guide pin.

[0027] like Figure 1 As shown, in order to facilitate the quick assembly of the nail cap 1 and the nail body 2, the bottom of the nail cap 1 has an axial mounting hole 12 connected to the U-shaped groove 11, and a compression ring 3 is provided in the axial mounting hole 12, and the other end of the nail body 2 is arranged in the compression ring 3. The present invention preferably assembles the nail cap 1 and the nail body 2 into one body through the compression ring 3, but is not limited to this, and other assembly forms may also be adopted, such as the nail body reversely mounting the nail cap, the front end clamping ring form; the form of ensuring that the nail body does not fall off after the nail cap is squeezed and deformed, etc.

[0028] like Figure 1 , 2As shown, in order to facilitate rapid limiting positioning and assembly and prevent the clamping ring 3 from falling off the nail cap 1, an annular positioning groove 13 is provided on the hole wall of the axial mounting hole 12 of the nail cap 1, and a positioning protrusion 31 is provided on the outer peripheral wall of the clamping ring 3, and the positioning protrusion 31 is clamped in the annular positioning groove 13 of the nail cap 1.

[0029] like Figure 1 As shown, the other end of the nail body 2 is provided with an inner hexagonal hole 24, and the inner hexagonal hole 24 is connected to the bone cement channel 21. The advantage of this design is that during the operation, the relevant hexagonal nailing tool can directly inject bone cement after the nailing is completed.

[0030] like Figure 3 As shown, in order to facilitate assembly with the rigid extension arm or the flexible extension arm, radial U-shaped grooves 14 are provided on the side walls at both ends of the top of the nail cap 1.

[0031] However, the present invention is not limited thereto. Elastic protrusions 15 are provided on the side walls at both ends of the top of the nail cap 1 and above the U-shaped slot 14 , and a rigid assembly hole 18 is provided on the outer side wall of the top of the nail cap 1 .

[0032] The present invention can simultaneously meet the rigid assembly hole 18 of the rigid extension arm assembly and the elastic protrusion 15 of the flexible extension arm assembly, and can be assembled with different tools during surgery, providing the best surgical plan for different vertebrae and different indications, which is safe and effective.

[0033] like Figure 1 , 3 As shown, in order to facilitate the fixation after being threadedly connected with the set screw in spinal surgery, an internal thread 16 is provided on the inner wall of the U-shaped groove 11 of the nail cap 1.

[0034] like Figure 1 As shown, in order to facilitate the use of a tool to break off the portion of the nail cap 1 above the process groove 17 after the operation is completed, a process groove 17 for breaking the tool is provided on the middle outer wall of the nail cap 1.

[0035] The circumferential wall of the nail body 2 of the present invention is provided with three bone cement through holes, which are evenly distributed at 120°. The aperture of the bone cement through holes 22 on the circumferential wall of the nail body 2 decreases from bottom to top, which can effectively improve the uneven pressure of the bone cement during injection, so that the bone cement can be evenly dispersed in the vertebral body. Of course, it is not limited to this, and the bone cement through holes can also be designed to be evenly distributed at 90°, or with different spacings, etc.

[0036] like Figure 2As shown, in order to further optimize the assembly structure of the nail cap 1 and the nail body 2 through the clamping ring 3 of the present invention, the axial mounting hole 12 of the nail cap 1 is a first spherical acetabulum, the end of the other end of the nail body 2 is a spherical acetabulum, and a second spherical acetabulum is provided on the clamping washer 3. The spherical acetabulum of the nail body 2 cooperates with the first spherical acetabulum of the nail cap 1 and the second spherical acetabulum of the clamping washer 3 at the same time.

[0037] When assembling the present invention, firstly, the nail body 2 is passed through the U-shaped groove 11 of the nail cap 1, and the spherical head acetabulum of the nail body 2 cooperates with the first spherical acetabulum of the nail cap 1; then the clamping ring 3 is inserted, and the second spherical acetabulum of the clamping ring 3 cooperates with the spherical acetabulum of the nail body 2, and the positioning protrusion 31 on the outer peripheral wall of the clamping ring 3 is clamped in the annular positioning groove 13 of the nail cap 1, and the assembled nail body 2 and the clamping washer 3 cannot fall off from the nail cap 1.

[0038] The advantages of the present invention are:

[0039] a. Since the bone cement channel of the nail body is designed as a non-completely hollow hole, the risk of bone cement overflowing at the front edge of the vertebral body can be effectively reduced;

[0040] b. A plurality of bone cement through holes are provided on the peripheral wall of the nail body along the circumferential direction from top to bottom, and the apertures of the bone cement through holes 22 on the peripheral wall of the nail body 2 decrease from bottom to top, which can better ensure the diffusion of bone cement in the vertebral body;

[0041] c. A guide groove is provided on the outer wall of one end of the nail body, which forms an angle with the axis of the nail body, so that it can be more easily installed to the corresponding position according to the previously inserted guide needle in a minimally invasive environment;

[0042] d. When the present invention is used, the elastic protrusion on the top of the nail cap 1 and the structure of the rigid assembly hole provide the surgeon with two different assembly methods, and the surgeon can choose a better solution based on the actual situation during the operation.

[0043] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A bone cement pedicle screw with a closed guide front end, comprising a screw cap (1) and a screw body (2), wherein the screw cap (1) and the screw body (2) are detachably connected, and the screw cap (1) has a U-shaped groove (11), characterized in that: The nail body (2) has an axial bone cement channel (21), and the bone cement channel (21) is connected to the U-shaped groove (11); a plurality of bone cement through holes (22) are provided on the peripheral wall of the nail body (2) along the circumferential direction and from top to bottom; the plurality of bone cement through holes (22) are all connected to the bone cement channel (21); a guide groove (23) is provided on the outer wall of one end of the nail body (2) and forms an angle with the axis of the nail body (2); The axial bone cement channel (21) of the nail body (2) is designed to be non-hollow; The angle between the axis of the nail body (2) and the guide groove (23) is 13° to 15°; The side walls at both ends of the top of the nail cap (1) are provided with radial U-shaped slots (14); Elastic protrusions (15) are provided on the side walls at both ends of the top of the nail cap (1) and above the U-shaped slot (14), and a rigid assembly hole (18) is provided on the outer side wall of the top of the nail cap (1); A process groove (17) for breaking a tool is provided on the middle outer wall of the nail cap; The thickness of the nail cap side wall above the process groove is smaller than the thickness of the nail cap side wall below the process groove.

2. The bone cement pedicle screw with a closed guide front end according to claim 1, characterized in that: The bottom of the nail cap (1) has an axial mounting hole (12) connected to the U-shaped groove (11), and a clamping ring (3) is arranged in the axial mounting hole (12), and the other end of the nail body (2) is arranged in the clamping ring (3).

3. The bone cement pedicle screw with a closed guide front end according to claim 2, characterized in that: An annular positioning groove (13) is provided on the hole wall of the axial mounting hole (12) of the nail cap, a positioning protrusion (31) is provided on the outer peripheral wall of the clamping ring (3), and the positioning protrusion (31) is clamped in the annular positioning groove (13) of the nail cap (1).

4. The bone cement pedicle screw with a closed guide front end according to claim 1, characterized in that: The end portion of the other end of the nail body (2) is provided with a hexagonal hole (24), and the hexagonal hole (24) is in communication with the bone cement channel (21).

5. The bone cement pedicle screw with a closed guide front end according to claim 1, characterized in that: An internal thread (16) is provided on the inner wall of the U-shaped groove (11) of the nail cap (1).

6. The bone cement pedicle screw with a closed guide front end according to claim 1, characterized in that: The diameters of the bone cement through holes (22) on the peripheral wall of the nail body (2) decrease from bottom to top.

7. The bone cement pedicle screw with a closed guide front end according to claim 2, characterized in that: The axial mounting hole (12) of the nail cap (1) is a first spherical acetabular cup, the end of the other end of the nail body (2) is a spherical acetabular cup, and the pressing ring (3) is provided with a second spherical acetabular cup. The spherical acetabular cup of the nail body (2) cooperates with the first spherical acetabular cup of the nail cap (1) and the second spherical acetabular cup of the pressing ring (3) at the same time.

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