阅读说明：本技术 一种高把持力低损缓释药骨螺钉 (High-holding-force low-loss slow-release medical bone screw ) 是由 宋仁才 于 2020-05-23 设计创作，主要内容包括：一种高把持力低损缓释药骨螺钉,包括螺母头,螺杆,螺杆是柱状空心结构,底端开口所述螺母头上开有凹槽,凹槽底面开有与螺杆内腔连通的螺纹通孔；还包括一个内螺钉,内螺钉穿过螺纹通孔,内螺钉的顶部与螺纹通孔螺纹配合；内螺钉的直径是螺杆空腔内径的1/2-1/3；内螺钉为空心结构,其底端的锥头由多个首尾固定连接,中部分离的金属条组成。螺杆上开设多个均匀分布的通孔,还包括一个弹性金属卷,其位于螺杆内,弹性金属卷在压缩状态下外壁与螺杆内壁装填生长因子颗粒。该骨螺钉能够有效释放生长因子,加快骨骼愈合。(A high-holding-force low-loss slow-release medical bone screw comprises a nut head and a screw rod, wherein the screw rod is of a cylindrical hollow structure, a groove is formed in the nut head at the opening of the bottom end of the screw rod, and a threaded through hole communicated with an inner cavity of the screw rod is formed in the bottom surface of the groove; the screw is inserted into the threaded through hole, and the top of the screw is in threaded fit with the threaded through hole; the diameter of the inner screw is 1/2-1/3 of the inner diameter of the cavity of the screw; the inner screw is of a hollow structure, and the conical head at the bottom end of the inner screw is composed of a plurality of metal strips which are fixedly connected end to end and separated at the middle. The screw rod is provided with a plurality of through holes which are uniformly distributed, and the screw rod also comprises an elastic metal coil which is positioned in the screw rod, wherein the outer wall of the elastic metal coil and the inner wall of the screw rod are filled with growth factor particles in a compressed state. The bone screw can effectively release growth factors and accelerate bone healing.)

1. A high-holding-force low-loss slow-release medical bone screw comprises a nut head and a screw rod, and is characterized in that the screw rod is of a cylindrical hollow structure, the bottom end of the screw rod is provided with an opening, the nut head is provided with a groove, and the bottom surface of the groove is provided with a threaded through hole communicated with the inner cavity of the screw rod;

the screw is inserted into the threaded through hole, and the top of the screw is in threaded fit with the threaded through hole;

the diameter of the inner screw is 1/2-1/3 of the inner diameter of the cavity of the screw;

the inner screw is of a hollow structure, and a conical head at the bottom end of the inner screw is composed of a plurality of metal strips which are fixedly connected end to end and separated from each other in the middle;

the screw is provided with a plurality of uniformly distributed through holes, the through holes corresponding to the same axial position are in a group, each group is provided with 3-5 through holes, 4-12 groups are uniformly distributed in the axial direction, the aperture of each through hole is 0.5-1mm, the through holes are horizontal or inclined downwards, the included angle between each through hole and the horizontal plane is 10-20 degrees, the screw further comprises an elastic metal coil which is positioned in the screw, the outer wall of the elastic metal coil is tightly attached to the inner wall of a cavity of the screw in a natural state, growth factor particles are filled in the outer wall and the inner wall of the screw in a compression state, the particle size of the growth factor particles is in the range of 0.05-0.075mm and is not larger than the inner diameter of the through holes, the top end of the screw is in a reverse.

2. The high-holding-force low-loss slow-release medicated bone screw as claimed in claim 1, wherein the wall thickness of the screw is 1/8-1/6 of the diameter thereof, and the external diameter of the screw thread of the screw is 1/7-1/5 of the diameter of the screw.

3. The high-holding-force low-loss slow-release medicated bone screw according to claim 1, wherein the thread pitch of the top of the inner screw is 1/3-1/2 of the other part of the thread pitch.

4. The high-holding-force low-loss slow-release medical bone screw according to claim 1, wherein the inner screw is obliquely inserted into the screw rod.

5. The high-holding-force low-loss slow-release medical bone screw according to claim 1, wherein the inner screw is coaxial with the screw rod.

6. The high-holding-force low-loss slow-release medical bone screw as claimed in claim 1, wherein the metal strip of the conical head is made of memory metal, and the maximum outer diameter of the conical head is larger than the diameter of the inner screw by bending deformation at 36 degrees.

7. The high-holding-force low-loss slow-release medical bone screw according to any one of claims 1 to 6, it is characterized by also comprising a gasket, the gasket comprises a cylindrical cavity, the bottom of the cylindrical cavity is a bottom plate, the center of the negative plate is provided with a through hole for the screw to pass through, the negative plate is provided with a plurality of nail holes which are uniformly distributed, straight nails are inserted in the nail holes, the negative plate is fixed with an outer ring and an inner ring, the outer ring is tightly attached to the side wall of the cylindrical cavity and the negative plate, the inner diameter of the inner ring is the same as the diameter of the central through hole of the negative plate, the bottom wall of the inner ring is tightly attached to the upper surface of the bottom plate, the upper surfaces of the outer ring and the inner ring are fixed with annular metal sheets, the height of the outer ring and the inner ring is within the range of 0.5-1mm, and a screen mesh is fixed on the outer ring and the inner ring, the thickness of the screen mesh is 0.5-1mm, the nail holes correspond to screen meshes of the screen mesh, a vertically arranged sliding groove is formed in the inner side wall of the cylindrical cavity, and the lower end of the nut head is fixed on a protrusion matched with the sliding groove.

8. The high-holding-force low-loss slow-release medical bone screw as claimed in claim 7, wherein the central connecting line of the nail holes on the bottom plate is vertical to the axis of the bottom plate and is a group, 2-4 nail holes are arranged in each group, 4-8 groups are arranged, and the nail holes in each group are uniformly distributed at intervals along the axis of the bottom plate.

9. A distractor for fitting a bone screw according to claims 1-5 and 7-8, comprising a conduit with a bottom end communicating with a rubber ball, the conduit being insertable into the inner screw and the rubber ball being insertable into the conical head.

10. A milling assembly for cooperating with the bone screw of claims 1-8, comprising a core hole drilling means for drilling a drill string hole in the bone and a core hole bottom milling means; the core hole bottom grinding device comprises a fixing rod, the fixing rod is hollow, the bottom end of the fixing rod is fixedly communicated with a saccule, the saccule is in an ellipsoid shape or a fusiform shape after being expanded, and a grinding sheet is fixed on the outer wall of the saccule.

Technical Field

The invention relates to a bone screw, in particular to a bone screw for fracture surgery.

Background

The bone screw is expected to be free of dislocation during the treatment period when in use, which requires the bone screw to have high holding force and good mechanical bending resistance and tensile resistance. Usually, the mechanical properties are all satisfactory. However, the key point is the holding force, and the performance of the holding force is directly related to the structure of the screw and the characteristics of the bone in which the screw is located. Generally, dislocation of the screw mostly occurs in the cancellous bone, if the thread pitch of the screw is small, the difference between the inner diameter and the outer diameter of the thread is small, so that the cancellous bone is easily broken or extruded and deformed by the thread in the cancellous bone, and the axial movement or circumferential rotation of the screw is easily generated instead of the stable embedded thread.

In order to obtain a high holding force, the screw thread is usually large, and the diameter of the screw is also large, so that the bone is greatly damaged by the screw. Therefore, how to obtain stable holding force with less damage becomes an important point in designing the bone screw.

Disclosure of Invention

The present invention aims to provide a bone screw with less damage and high holding power.

In order to achieve the purpose, the nut comprises a nut head and a screw rod, wherein the screw rod is of a cylindrical hollow structure, the bottom end of the screw rod is provided with an opening, the nut head is provided with a groove, and the bottom surface of the groove is provided with a threaded through hole communicated with the inner cavity of the screw rod;

the screw is inserted into the threaded through hole, and the top of the screw is in threaded fit with the threaded through hole;

the diameter of the inner screw is 1/2-1/3 of the inner diameter of the cavity of the screw;

the inner screw is of a hollow structure, and a conical head at the bottom end of the inner screw is composed of a plurality of metal strips which are fixedly connected end to end and separated from each other in the middle;

the screw is provided with a plurality of uniformly distributed through holes, the through holes corresponding to the same axial position are in a group, each group is provided with 3-5 through holes, 4-12 groups are uniformly distributed in the axial direction, the aperture of each through hole is 0.5-1mm, the through holes are horizontal or inclined downwards, the included angle between each through hole and the horizontal plane is 10-20 degrees, the screw further comprises an elastic metal coil which is positioned in the screw, the outer wall of the elastic metal coil is tightly attached to the inner wall of a cavity of the screw in a natural state, growth factor particles are filled in the outer wall and the inner wall of the screw in a compression state, the particle size of the growth factor particles is in the range of 0.05-0.075mm and is not larger than the inner diameter of the through holes, the top end of the screw is in a reverse.

Preferably, the wall thickness of the screw is 1/8-1/6 of the diameter of the screw, and the external diameter of the screw thread is 1/7-1/5 of the diameter of the screw;

preferably, the top thread pitch of the inner screw is 1/3-1/2 of the other part pitch.

Preferably, the inner screw is inserted into the screw at an inclination.

Preferably, the inner screw is coaxial with the screw.

Furthermore, the metal strip of the conical head is made of memory metal, and the maximum outer diameter of the conical head is larger than the diameter of the inner screw through bending deformation at 36 degrees.

The gasket further comprises a cylindrical cavity, the bottom of the cylindrical cavity is a bottom plate, a through hole for a screw to pass through is formed in the center of the cylindrical cavity, a plurality of uniformly distributed nail holes are formed in the bottom plate, straight nails are inserted into the nail holes, an outer ring and an inner ring are fixed on the bottom plate, the outer ring is tightly attached to the side wall of the cylindrical cavity and the bottom plate, the inner diameter of the inner ring is the same as the diameter of the through hole in the center of the bottom plate, the bottom wall of the inner ring is tightly attached to the upper surface of the bottom plate, annular metal sheets are fixed on the upper surfaces of the outer ring and the inner ring, the heights of the outer ring and the inner ring are within the range of 0.5-1mm, a screen is fixed on the outer ring and the inner ring, the thickness of the screen is 0.5-1mm, the nail holes correspond to screen holes of the screen, a vertically-.

Preferably, the central connecting line of the nail holes on the bottom plate is vertical to the axis of the bottom plate to form a group, 2-4 nail holes are arranged in each group, 4-8 groups are arranged, and the nail holes in each group are uniformly distributed at intervals along the axis of the bottom plate.

A spreader comprises a conduit with the bottom end communicated with a rubber ball, wherein the conduit can be inserted into an inner screw, and the rubber ball can be inserted into a conical head.

A grinding assembly comprises a core hole punching device and a core hole bottom grinding device, wherein the core hole punching device is used for drilling a drill string hole in a skeleton; the core hole bottom grinding device comprises a fixing rod, the fixing rod is hollow, the bottom end of the fixing rod is fixedly communicated with a saccule, the saccule is in an ellipsoid shape or a fusiform shape after being expanded, and a grinding sheet is fixed on the outer surface of the saccule.

The invention has the beneficial effects that:

1. the hollow screw rod can reduce the volume of punching holes on the skeleton and reduce the damage to the skeleton;

2. the fixed connection inner screw is added in the hollow screw, so that the holding force of the screw can be effectively improved;

3. the grinding device is matched, a cavity with the diameter larger than the outer diameter of the inner screw can be ground at the lower end of the inner screw, the opener is matched to open the conical head at the bottom end of the inner screw in the cavity, a fixing anchor is formed in a skeleton, and the integral anti-pulling capacity of the screw is effectively improved.

4. When the inner screw is obliquely inserted into the bone, the pulling resistance can be effectively improved.

5. The gasket is fixed by self is accomplished by a plurality of tiny straight nails, avoids dense bone or the bone bark breakage, and can effectively guarantee that the screw can not take place to rotate.

6. The natural pressure of metal is utilized to continuously deliver growth factors into the skeleton, and the healing of broken bones is accelerated.

Drawings

Fig. 1 is a schematic view of a bone screw in a bone.

FIG. 2 is a schematic view of the structure of the ring hole punching device.

FIG. 3 is a schematic view of the bottom structure of the ring hole puncher.

FIG. 4 is a schematic view of a core hole drilling apparatus.

Fig. 5 is a schematic structural diagram of a core hole bottom grinding device.

Fig. 6 is a partially enlarged view of fig. 5.

Fig. 7 is a schematic structural view of the inner screw.

Fig. 8 is a partially enlarged view of fig. 7.

Fig. 9 is a schematic structural view of the inner screw in a bottom-end expanded state.

FIG. 10 is a schematic view of the inner screw bottom end spreader.

Fig. 11 is a schematic view of a gasket construction.

FIG. 12 is a schematic view of a gasket chassis configuration.

Fig. 13 is a partially enlarged view of fig. 11.

Fig. 14 is a schematic view of a resilient metal roll structure.

Detailed Description

The invention is described in detail below with reference to the accompanying drawings. The materials used for the bone screw are all common metal materials used for producing the bone screw.

As shown in fig. 1 to 14, a high-holding-force low-loss slow-release medical bone screw 10 comprises a nut head 11 and a screw 12, and is characterized in that the screw 12 is of a cylindrical hollow structure, the bottom end of the screw is open, the wall thickness of the screw is preferably 1/8-1/6 of the diameter of the screw through tests, and the external diameter of the screw 12 is 1/7-1/5 of the diameter of the screw 12; a groove 13 is formed in the nut head 11, and a threaded through hole communicated with an inner cavity of the screw 12 is formed in the bottom surface of the groove 13;

the screw thread structure further comprises an inner screw 60, wherein the inner screw 60 penetrates through the threaded through hole, the top of the inner screw 60 is in threaded fit with the threaded through hole, and the thread pitch of the thread matched with the threaded through hole is 1/3-1/2 of the thread pitch of other parts;

the diameter of inner screw 60 is 1/2-1/3 of the inner diameter of the cavity of screw 12.

The positions of the inner screw 60 and the axis of the screw 12 are two, one is that the inner screw 60 is coaxial with the screw 12, and the other is that the inner screw 60 is obliquely inserted into the screw 12. The inclined insertion into the screw 12 is more advantageous in increasing the holding force.

When two broken bones are connected, a hole which is communicated with the two broken bones needs to be formed in the two broken bones, since the screw 12 is arranged into a hollow structure, only a complete through hole is formed in the broken bone which is close to the head of the nut, only one annular hole is formed in the other broken bone, and medicines or growth factors which promote the growth of the bones are generally used for improving the growth of the broken bones. The difficulty in using these solid particles of growth factors is how to effectively release them into the bone. Therefore, a plurality of through holes are uniformly distributed on the screw 12, preferably the through holes corresponding to the same axial position are in a group, each group has 3-5 through holes, and 4-12 groups are uniformly distributed in the axial direction, the aperture of the through holes is between 0.5-1mm, the through holes are horizontally arranged or inclined downwards, the included angle between the through holes and the horizontal plane is 10-20 degrees, the elastic metal roll 14 is positioned in the screw 12, the outer wall of the elastic metal roll 14 is tightly attached to the inner wall of the cavity of the screw 12 in a natural state, growth factor particles 15 are filled in the outer wall of the elastic metal roll 14 and the inner wall of the screw 12, the particle size of the growth factor particles 15 is within the range of 0.05-0.075mm, and the particle size is not larger than the inner diameter of the through holes, so that the elastic metal roll 14 is. The structure of the resilient metal coil 14 is substantially the same as the spring coil. The elastic metal sheet 14 can be inserted into the cavity of the screw 12 in a compressed state from the threaded through hole without being completely inserted, and the length thereof is controlled to be shorter than the distance between the bone section and the nut head, and then the growth factor particles are injected from the injection hole 16 formed in the bottom surface of the groove 13, and then the elastic metal sheet is completely inserted, so that there is sufficient growth factor between the outer wall of the middle and lower portion of the elastic metal roll 14 and the inner wall of the screw to restrict the relaxation of the elastic metal roll 14, and then the growth factor is filled between the elastic metal roll 14 and the inner wall of the screw from the injection hole 16. The growth of disconnected bone can produce the hematoma, and the hematoma can constantly dissolve growth factor, and under the pressure of elastic metal book 14, can constantly be with the growth factor extrusion that the hematoma dissolved, avoid the hematoma deposit in the screw rod cavity, and can accelerate growth factor's output, improve the growth rate of disconnected bone.

Meanwhile, in order to avoid the leakage of growth factors, the top end of the screw 12 is in an inverted cone shape, and part of the conical surface is pressed into the mounting hole.

As shown in fig. 9 and 10, in order to further improve the pulling resistance of the inner screw, the inner screw 60 is also provided with a hollow structure, the conical head 61 at the bottom end of the hollow structure is composed of a plurality of metal strips which are fixedly connected end to end and separated from each other in the middle. After the internal screw is screwed into a bone, the internal screw is inserted by using the spreader 70, the spreader 70 is a conduit with the bottom end communicated with a rubber ball, the rubber ball of the spreader 70 extends into the conical head of the internal screw 60 and then liquid is injected into the rubber ball or the rubber ball is blown up to spread the conical head 61, and the maximum diameter of the spread conical head is larger than the diameter of the internal screw 60.

The diameter of the conical head needs to be enlarged to clamp the column bone, so that the holding force is improved, therefore, the metal strip of the conical head can be made of memory metal and is bent and deformed at 36 degrees, and the maximum outer diameter of the conical head is larger than the diameter of the inner screw. In order to avoid the memory metal from deforming too early when being screwed into the bone, the spreader 70 can also be used as a cooling metal, the rubber ball of which is filled with cooling liquid, so that the temperature of the conical head 61 is always lower than 36 ℃, and when the inner screw is screwed to a preset position, the spreader is pulled out. When the conical head is heated by the temperature of the human body, the memory metal is naturally bent.

In order to avoid the cracking or damage of the cancellous bone caused by the expansion of the conical head 61, a core hole punching device 40 is needed for punching the mounting hole of the inner screw 60, and a core hole bottom grinding device 50 is added, and comprises a fixing rod, the fixing rod 50 is hollow, the bottom end of the fixing rod is fixedly communicated with the balloon 51, the balloon 51 is in an ellipsoid shape or a fusiform shape after being expanded, and the grinding sheet 52 is fixed on the outer surface of the balloon 51, as shown in fig. 6, the grinding sheet 52 is a metal grinding sheet, and preferably, the length direction of the grinding sheet is parallel to the axis of the balloon 51.

In order to avoid the rotation of the screw, a gasket 30 is sleeved at the bottom of the nut head 11, the gasket 30 comprises a cylindrical cavity, the bottom of the cylindrical cavity is a bottom plate 31, a through hole for the screw 12 to pass through is formed in the center of the cylindrical cavity, a plurality of uniformly distributed nail holes 32 are formed in the bottom plate 31, straight nails are inserted into the nail holes 32, an outer ring 311 and an inner ring 312 are fixed on the bottom plate 31, the outer ring is tightly attached to the side wall of the cylindrical cavity and the bottom plate 31, the inner diameter of the inner ring is the same as the diameter of the through hole in the center of the bottom plate 30, the bottom wall of the inner ring is tightly attached to the upper surface of the bottom plate 31, annular metal sheets 33 are fixed on the upper surfaces of the outer ring and the inner ring, the height of the outer ring and the height of the inner ring are within the. A screen 34 is fixed on the outer ring and the inner ring, the thickness of the screen 34 is 0.5-1mm, the nail holes 32 correspond to the screen holes of the screen 34, a vertically arranged sliding groove is formed in the inner side wall of the cylindrical cavity, and the lower end of the nut head 11 is fixed on a protrusion matched with the sliding groove. When the nut head 11 is screwed into the skeleton, the protrusion of the nut head is in the sliding groove to drive the gasket to rotate. The straight nail has not yet contacted the bone, and when the straight nail is screwed to the last circle, the straight nail starts to contact the bone, and because the surface of the bone is not flat, the straight nail close to the bone can be subjected to more pressure, and the pressure far from the bone is small. Because the metal sheet is very thin, the straight nail close to the skeleton can jack up the metal sheet, so that certain pressure can be buffered, and a fixing effect can be achieved.

The design is that the common gasket only has a circle of fixing nails at the outermost side, so that in order to ensure that the gasket has enough fixing force, the fixing nails of the gasket are relatively large, and the distance between the fixing nails and the screw fixing holes is relatively short, so that bones at the fixing positions of the fixing nails are easy to break, damage is caused, and meanwhile, the fixing force is weakened. Therefore, the central connecting line of the nail holes on the bottom plate 31 is vertical to the axis of the bottom plate to form a group, 2-4 nail holes are arranged in each group, 4-8 groups are arranged, and the nail holes in each group are uniformly distributed at intervals along the axis of the bottom plate 31.

In order to form a ring suitable for the screw 12, a ring punching device 20 is required, which has an outer diameter slightly smaller than the outer diameter of the screw, an inner diameter slightly larger than the inner diameter of the ring 12, and a crushing tooth at the bottom end.

When the internal screw 60 is to be screwed out after the bone is healed, the lower end of the conical head 61 of the internal screw can be pressed downwards by using a metal rod, so that the maximum diameter of the conical head is reduced, and the internal screw can be pulled out from the mounting hole of the internal screw 60. Of course, if the cone head is made of memory metal and is made of two-way memory metal, that is, there is one stable form above a certain temperature and another stable form below the certain temperature, the rubber ball of the spreader can be used to cool the cone head again to shrink the cone head.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.