CN107280748B

CN107280748B - Femur intramedullary nail

Info

Publication number: CN107280748B
Application number: CN201710620712.7A
Authority: CN
Inventors: 宋合新; 王迎举; 洪念国; 高雁行; 郝攀峰; 宋小花
Original assignee: Jiaozuo Xingang Medical Equipment Co ltd
Current assignee: Jiaozuo Xingang Medical Equipment Co ltd
Priority date: 2017-07-27
Filing date: 2017-07-27
Publication date: 2023-07-04
Anticipated expiration: 2037-07-27
Also published as: CN107280748A

Abstract

A femoral intramedullary nail, said femoral comprising a femoral head, a femoral intramedullary nail, said femoral intramedullary nail comprising a main nail, a core nail, and an anti-rotation blade, said main nail comprising a head and a shank, said head and shank comprising a hollow cavity therein, said shank having a free end comprising at least two blade channels, said core nail being received in said hollow cavity, said anti-rotation blade comprising a connecting rod, at least two bearings, and at least two blades, said free ends of said at least two blades being received in said at least two blade channels, respectively, said anti-rotation blade being inserted into said femoral head. Because the anti-rotation blade can be inserted into the femoral head, the external aiming device of the traditional intramedullary nail is not needed, the installation difficulty is reduced, the installation time is shortened, the fixing failure in the traditional locking mode is avoided, and the safety and the effectiveness are improved.

Description

Femur intramedullary nail

Technical Field

The invention relates to an orthopedic internal fixation instrument, in particular to a femoral intramedullary nail.

Background

The orthopedic medical instruments in the prior art are provided with a self-locking anti-rotation intramedullary nail which is generally a quincuncial intramedullary nail, the quincuncial structure of the external nail is complex, the anti-rotation performance is poor, and the application range is small. The side wings of the inner nails and the outer nails are quite inconvenient to install and operate in a matched mode. The setting position of the effective lock expansion points of the inner nail and the outer nail is difficult to ensure proper, so that the self-locking force is smaller. Sometimes the self-locking effect of the intramedullary nail is not firm. The upper end self-locking device designed by the intramedullary nail has a complex structure, is excessively harmful to the thigh of the limb, and has no function of pressurizing the fracture. There is also an interlocking intramedullary nail which, although having the advantages of anti-rotation and stable fixation, has a complex structure, complex installation and operation, high technical requirements, and requires operation under X-rays, which also has radiation injuries to both the doctor and patient.

Disclosure of Invention

In view of the above, the present invention provides a femoral intramedullary nail to solve the above-mentioned problems.

An intramedullary nail for femur comprises a main nail, a core nail arranged in the main nail, and an anti-rotation blade arranged at one end of the core nail. The main nail comprises a nail head and a nail rod connected with the nail head. The nail head and the nail rod comprise a communicated hollow cavity. The free end of the shank includes at least two blade guide slots. The core nail is slidingly accommodated in the hollow cavity. The anti-rotation blade comprises a connecting rod arranged at the axial end part of the core nail, at least two bearings arranged on the free end of the connecting rod, and at least two blades respectively and rotatably arranged on the bearings. The at least two blades are respectively accommodated in the at least two blade guide grooves.

Further, the stud includes an internal thread disposed on a sidewall of the hollow cavity.

Further, the two axial ends of the core nail respectively comprise a first round platform and a second round platform, and the first round platform is used for arranging the anti-rotation blade.

Further, the second round table is provided with an inner hexagonal hole.

Further, the anti-rotation blade further comprises at least two clamp springs, wherein each clamp spring is sleeved on the bearing and enables the corresponding blade to rotate in a direction away from the central shaft of the core nail.

Further, the nail head comprises a mounting groove which is arranged along the axial direction perpendicular to the nail rod.

Further, the nail head comprises a plurality of clamping teeth which are uniformly distributed on the outer side wall of the nail head.

A femoral set using a femoral intramedullary nail, the femur comprising a femoral head, a femoral intramedullary nail inserted in the femoral head. The femoral head includes an upper end and a femoral body coupled to the upper end. The femur body is internally provided with a femoral marrow cavity. The femoral intramedullary nail is inserted from the upper end in the femoral intramedullary cavity. The femoral intramedullary nail comprises a main nail, a core nail arranged in the main nail, and an anti-rotation blade arranged at one end of the core nail. The main nail comprises a nail head and a nail rod connected with the nail head. The nail head and the nail rod comprise a communicated hollow cavity. The free end of the shank includes at least two blade guide slots. The core nail is accommodated in the hollow cavity. The anti-rotation blade comprises a connecting rod arranged at the axial end part of the core nail, at least two bearings arranged on the free end of the connecting rod, and at least two blades respectively and rotatably arranged on the bearings. The at least two blades are respectively accommodated in the at least two blade guide grooves. The anti-rotation blade is inserted into a sidewall of the femoral medullary cavity.

Further, during insertion of the femoral intramedullary nail into the femoral head cavity of the femoral head, the free end of the anti-rotation blade is received in the blade guide slot.

Further, during insertion of the femoral intramedullary nail into the femoral medullary cavity of the femoral head, a maximum distance of the anti-rotation blade in a direction perpendicular to an axial direction of the nail shaft is smaller than a diameter of the femoral medullary cavity of the femoral head.

Compared with the prior art, as the femur using the femur intramedullary nail is provided with the anti-rotation blade, the self-locking effect can be achieved, the fixing screw is not required to be equipped, the required installation tool is very common and simple, the number of the installation tools is greatly reduced, and the operation is simple and convenient. Meanwhile, as the anti-rotation blade can be inserted into the femoral head, an in-vitro aiming device of a traditional intramedullary nail is not needed, the installation difficulty is reduced, the installation time is shortened, the fixing failure in the traditional locking mode is avoided, and the safety and the effectiveness are improved. In addition, since the femoral intramedullary nail only needs to be opened at the upper end of the femoral head, damage to the skin and bones of the patient is reduced.

Drawings

Embodiments of the invention are described below with reference to the accompanying drawings, in which:

fig. 1 is a schematic cross-sectional view of a femur using the femoral intramedullary nail.

Fig. 2 is a schematic view of an exploded structure of the intramedullary nail of the femur of fig. 1 using the intramedullary nail.

Description of the embodiments

Specific embodiments of the present invention will be described in further detail below based on the drawings. It should be understood that the description herein of the embodiments of the invention is not intended to limit the scope of the invention.

Referring to fig. 1 and 2, a schematic diagram of a femur 100 using a femoral intramedullary nail is provided. The femur 100 using the femoral intramedullary nail includes a femoral head 10, and a femoral intramedullary nail 20 inserted into the femoral head 10. It should be noted that the femoral head 10 also includes many other organisms such as periosteum, bone marrow, bone mass, etc., and tissues attached to bone such as blood vessels, nerves, etc. Since it is not important to the present invention, it is not described in detail nor shown in the accompanying drawings.

The femoral head 10 is a bone of a human calf and comprises an upper end 11, a lower end 12, and a bone body 13 connected between the upper end 11 and the lower end 12. The upper end 11 is connected to a hip joint (not shown) and has structures for coupling to the hip joint, such as a femoral neck, greater trochanter, lesser trochanter, and intertrochanteric wires. The lower end 12 is connected to a knee joint (not shown) and has a structure called a femoral styloid process. The bone 13 is slightly curved and is connected between the upper end 11 and the lower end 12. The bone body 13 has a femoral medullary cavity 131 for receiving bone marrow.

The intramedullary nail 20 is inserted from the upper end 11 into a femoral cavity 131 of the bone body 13 and comprises a main nail 21, a core nail 22 arranged in the main nail 21, and a rotation preventing blade 23 arranged at one end of the core nail 22.

The main nail 21 comprises a nail head 211, a nail rod 212 connected with the nail head 211, and a hollow cavity 213 which is formed in the nail head 211 and the nail rod 212 and is communicated with each other. The head 211 includes an internal thread 2111 provided on a side wall of the hollow cavity 213, a mounting groove 2112 provided in an axial direction perpendicular to the shank 212, and a plurality of lugs 2113. The internal threads 2111 are used to fixedly mount the core pin 22. The internal threads 2111 and the mounting groove 2112 are adapted to be coupled to an intramedullary nail installation tool (not shown) when the femoral intramedullary nail 20 is inserted into the intramedullary cavity 131 of the bone body 13. That is, in installing the femoral intramedullary nail 20, an intramedullary nail installation tool and the female screw 2111 are first screwed together, and its flanks are inserted into the installation groove 2112 to fix the positional relationship of the installation tool and the main nail 21, and then the femoral intramedullary nail 20 is inserted into the intramedullary cavity 131 using the intramedullary nail installation tool. It should be further noted that the intramedullary nail installation tool should be of the prior art, which is a commonly used standard tool, and will not be described in detail herein. The lugs 2113 are uniformly distributed on the outer sidewall of the head 211 for engagement with the upper end 11 of the femoral head 10 so that the main pin 21 is prevented from rotating. The shank 212 is provided at one end of the head 211 and includes at least two blade guide grooves 2121 provided at the free end side thereof. The length of the pin 212 may be designed according to practical needs, such as the length of the femoral head 10. At the same time, the peg 212 has a curvature according to the structural characteristics of the actual femoral head 10. The blade guide groove 2121 is configured to receive or extend the anti-rotation blades 23, and the number of the blades is equal to the number of the blades of the anti-rotation blades 23. Typically, the pin 212 includes at least two of the blade channels 2121 for uniform force. In this embodiment, the shank 212 includes two symmetrically disposed blade channels 2121. It is contemplated that the shank 212 may also include three blade channels 2121 disposed at 120 degrees and four blade channels 2121 disposed at 90 degrees apart. The length of the blade guide groove 2121 depends on the length of the blade of the anti-rotation blade 23. The hollow cavity 213 is configured to be inserted through the core pin 22, and is a through hole penetrating the pin head 211 and the pin shaft 212.

The core pin 22 includes a first and a second circular

truncated cones

221, 222 and a middle portion 223 connecting the first and the second circular

truncated cones

221, 222 at both axial ends thereof. The first round table 221 is used for setting the anti-rotation blade 23. The second round table 222 is provided with an inner hexagon. The diameter of the middle portion 223 may be smaller than that of the first and second circular tables 221 and 222, so as to reduce the overall weight of the core nail 22, and match the radian of the main nail 21, that is, the middle portion of the core nail 22 may be a straight rod. And since the diameter of the straight rod is smaller than the diameter of the hollow cavity 213, the middle portion 223 of the linear-shaped core pin 22 can be accommodated.

The anti-rotation blade 23 is fixedly disposed at an end of the first circular table 221 of the core pin 22, and includes a connecting rod 231 disposed at an axial end of the core pin, at least two bearings 232 disposed at free ends of the connecting rod 231, and at least two blades 233 rotatably disposed on the bearings 232, respectively. The connecting rod 231 may be fixed to the first circular table 221 by welding or may be connected by screw. In this embodiment, the connecting rod 231 is disposed on the axial direction of the first round table 221 by a screw. In this embodiment, the anti-rotation blade 23 includes two bearings 232 and two blades 233. The bearing 232 may be disposed at an end of the connecting rod 231 by welding. The two blades 233 are respectively sleeved on the two bearings 232 and can rotate around the respective bearings 232. Each blade 233 may have the same construction and is provided with a cutting edge on its side facing the intramedullary canal 131 of the femoral head 10 to enable its insertion into the femoral head 10 to fix the relative position of the anti-rotation blade 23. To fix the relative position of each of the blades 233, the free ends of the blades 233 are received in the blade channels 2121. That is, the anti-rotation blade 23 is received in the blade guide groove 2121 during the insertion of the femoral head 10 by the intramedullary nail 20, that is, the maximum distance of the anti-rotation blade 23 in the direction perpendicular to the axial direction of the nail shaft 212 during the insertion of the femoral head 10 by the intramedullary nail 20 is smaller than the diameter of the intramedullary cavity 131 of the femoral head 10. When the main nail 21 is mounted on the proper position of the femoral head 10 under the action of the intramedullary nail mounting work, the internal hexagonal wrench is used for pushing the core nail 22, so that the anti-rotation blade 23 is pushed, the blade 233 extends out of the blade guide groove 2121, and then the core nail 22 is continuously pushed, so that the blade 233 is inserted into the side wall of the intramedullary cavity 131 of the femoral head 10, and the axial anti-shrinkage fixing effect is achieved.

The anti-rotation blade 23 may further comprise at least two snap springs 234. Each of the snap springs 234 is sleeved on the bearing 232 and rotates the corresponding blade 233 in a direction away from the central axis of the core pin 22. Under the action of the clamp spring 234, when the blade 233 is in the hollow cavity 213, the clamp spring 234 is in a compressed state, and when the blade 233 enters the blade guide groove 2121, the blade 233 is unfolded and abuts against the inner wall of the intramedullary canal 131 of the femoral head 10 under the action of the clamp spring 234. And then inserted into the inner wall by external force, thereby fixing the position of the femoral intramedullary nail 20. It is contemplated that due to the presence of the snap spring 234, the two blades 233 of the anti-rotation blade 23 will automatically unwind when the core 22 is pushed.

When the femoral intramedullary nail 20 is installed, the intramedullary nail installation tool is first connected with the installation groove 2112 through the internal thread 2111 and the installation groove 2112 of the main nail 21, at this time, the anti-rotation blade 23 is in a closed state, namely, is accommodated in the blade guide groove 2121, and is passed through the center of the upper end 11 of the femoral head 10, and after entering the intramedullary cavity 131 of the femoral head 10, the intramedullary nail installation tool is removed. Then, the hexagonal wrench is inserted into the inner hexagon of the second round table 222 of the core rod 22, the core rod 22 is pushed, the anti-rotation blade 23 is pushed, and the blade 233 of the anti-rotation blade 23 is blocked in the blade guide groove 2121 and cannot advance, so that the blade 233 is spread to form a cross and is fixed in the femoral head 10, and the effects of radial anti-rotation and axial anti-shortening are achieved. After the fixing is completed, the hexagonal wrench can be removed, and the installation is completed.

Compared with the prior art, as the femur 100 using the femur intramedullary nail is provided with the anti-rotation blade 23, the self-locking effect can be achieved, the installation tool is not required to be equipped with a fixing screw, the installation tool is very common and simple, the number of the installation tools is greatly reduced, and the operation is simple and convenient. Meanwhile, as the anti-rotation blade 23 can be inserted into the femoral head 10, an external aiming device of a traditional intramedullary nail is not needed, the installation difficulty is reduced, the installation time is shortened, the fixing failure in the traditional locking mode is avoided, and the safety and the effectiveness are improved. In addition, since the femoral intramedullary nail 20 only needs to be open at the upper end 11 of the femoral head, damage to the skin and bone of the patient is reduced.

The above is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalent substitutions or improvements within the spirit of the present invention are intended to be covered by the claims of the present invention.

Claims

1. An intramedullary nail for femur, characterized in that: the femoral intramedullary nail comprises a main nail, a core nail arranged in the main nail, and an anti-rotation blade arranged at one end of the core nail, wherein the main nail comprises a nail head and a nail rod connected with the nail head, the nail head comprises a plurality of clamping teeth which are uniformly distributed on the outer side wall of the nail head, a communicated hollow cavity is formed in the nail head and the nail rod, the free end of the nail rod comprises at least two blade guide grooves, the core nail is slidingly accommodated in the hollow cavity, the anti-rotation blade comprises a connecting rod arranged at the axial end part of the core nail, at least two bearings arranged at the free end of the connecting rod, and at least two blades respectively arranged on the bearings in a rotating mode, the anti-rotation blade further comprises at least two clamping springs, each clamping spring is sleeved on the bearing, and the corresponding blade is enabled to rotate in the direction far away from the central shaft of the core nail.

2. The femoral intramedullary nail of claim 1, wherein: the stud includes an internal thread disposed on a sidewall of the hollow cavity.

3. The femoral intramedullary nail of claim 2, wherein: the axial both ends of core nail include a first, second round platform respectively, first round platform is used for setting up anti-rotation blade.

4. A femoral intramedullary nail according to claim 3, wherein: the second round table is provided with an inner hexagonal hole.

5. The femoral intramedullary nail of claim 1, wherein: the nail head comprises a mounting groove which is arranged along the axial direction perpendicular to the nail rod.