CN214966488U

CN214966488U - Intramedullary fixation device

Info

Publication number: CN214966488U
Application number: CN202022474238.1U
Authority: CN
Inventors: 郑光亮; 许华; 缪荣芹
Original assignee: Changzhou Orthmed Medical Instrument Co Ltd
Current assignee: Changzhou Orthmed Medical Instrument Co Ltd
Priority date: 2020-10-30
Filing date: 2020-10-30
Publication date: 2021-12-03
Anticipated expiration: 2030-10-30

Abstract

The utility model discloses an intramedullary fixing device, which comprises a main nail, a tension screw, an anti-rotation nail and a pressurizing locking nail; the near end of the main nail is provided with an anti-rotation hole; the front end of the lag screw is provided with an external thread for connecting the femoral head, and the side wall of the lag screw is provided with an axially extending notch; the anti-rotation nail is in surface contact with a notch of the lag screw, a limiting boss extending into the lag screw is arranged on the contact surface of the anti-rotation nail, and a step is arranged at the rear end of the anti-rotation nail to limit the degree of freedom of forward movement of the anti-rotation nail; the pressurizing locking nail is connected with the lag screw through the internal thread, when the front end of the pressurizing locking nail abuts against the limiting boss, the pressurizing locking nail is rotated continuously to drive the lag screw to move backwards, and pressure is applied to the fracture line. The intramedullary fixation device provided by the utility model can effectively resist the torsional stress and the axial load, prevent the rotation of the head of the femur, pressurize the fracture part and dynamically promote the healing of the hip fracture.

Description

Intramedullary fixation device

Technical Field

The utility model relates to the technical field of medical equipment, especially, relate to an intramedullary fixing device.

Background

The hip (groin area) is the area where the trunk connects with the legs, which makes the trunk and legs move forward, backward and sideways. Since the hip is the center of a series of physical movements, it is prone to potential strain and fracture. The intramedullary nail belongs to an orthopedic internal fixation instrument in medical instruments, is a preferred internal fixation instrument for hip fracture (such as femoral head and neck fracture), can control the axial force line of a fracture part, can prevent fracture rotation deformity by the interlocking intramedullary nail, and further reduces the risk of fracture of an implant. However, in most of the existing intramedullary nails, due to design defects, the fracture end is often rotated and separated and displaced during and after the operation, the broken end is unstable, the lag screw is cut out from the head of the femoral head, and the like, and the problems are often solved by re-operation, which causes pain to the patient and wastes medical resources.

SUMMERY OF THE UTILITY MODEL

An object of the present invention is to overcome the drawbacks of the prior art, and to provide an intramedullary fixation device that effectively resists torsional stress and axial load, prevents rotation of the femoral head, and can apply pressure to the fracture site, dynamically promoting the healing of hip fractures.

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

an intramedullary fixing device comprises a main nail, a lag screw and an anti-rotation nail which are parallelly arranged at the near end of the main nail in a penetrating way, and a pressurizing locking nail;

the proximal end of the main nail is provided with an anti-rotation hole which is in a gourd shape and is respectively matched with the lag screw and the anti-rotation nail;

the lag screw is of a hollow structure, the front end of the lag screw is provided with an external thread used for connecting a femoral head, the rear end of the lag screw is provided with an internal thread used for connecting the pressurizing locking nail, and the side wall of the lag screw is provided with an axially extending notch;

the anti-rotation nail is in surface contact with the notch, a limiting boss extending into the notch is arranged on the contact surface of the anti-rotation nail, the limiting boss can slide back and forth along the notch along with the movement of the anti-rotation nail, and a step is arranged at the rear end of the anti-rotation nail to limit the degree of freedom of forward movement of the anti-rotation nail;

the pressurizing locking nail is connected with the lag screw through the internal thread, when the front end of the pressurizing locking nail abuts against the limiting boss, the pressurizing locking nail is driven to move backwards by continuous rotation, and pressure is applied to the fracture line.

As an implementation, the notch extends from the rear end of the lag screw to the external thread of the lag screw.

As a practical way, the anti-rotation nail is arranged with the same length as the notch.

As a practical way, the pressurizing locking nail is in a frustum shape, and the diameter of the external thread of the pressurizing locking nail is gradually reduced from front to back.

As a practical way, the distal end of the main nail is also provided with a cortical bone screw.

As an implementable manner, the step end of the anti-rotation nail is provided with a groove adapted to the installation tool.

As an implementable manner, the shape of the groove is a straight line, a cross, an internal angle of a hexagon or a quincunx.

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

the intramedullary fixing device provided by the utility model mainly comprises a main nail, a lag screw, an anti-rotation nail and a pressurizing lock nail, when in use, the main nail is implanted into the medullary cavity of the femoral head, then the front end of the lag screw passes through one hole of the gourd-shaped anti-rotation hole and is connected with the femoral head through screw thread, meanwhile, the anti-rotation nail passes through the other hole of the anti-rotation hole to ensure that the limit boss of the anti-rotation nail is positioned in the notch, and the anti-rotation nail is contacted with the notch surface, then the pressurizing locking nail is screwed in from the rear end of the lag screw with a hollow structure, after the pressurizing lock pin moves forward for a certain distance, the front end of the pressurizing lock pin can abut against the limiting lug boss of the anti-rotation pin, the bone fracture nail can not move forwards continuously, the pulling screw can drive the femoral head to move backwards along with the continuous rotation of the pressurizing locking nail and the limitation of the step of the anti-rotation nail at the anti-rotation hole of the main nail on the forward movement of the anti-rotation nail, so that the pressurization of the bone fracture line is realized.

The anti-rotation nail is inserted, so that the rotational freedom degree of the lag screw relative to the anti-rotation hole is lost, and the reduction loss caused by the fact that the thread on the lag screw drives the femoral head to rotate around the hole on the main nail is avoided; in the application, the matching of the tension screw, the anti-rotation nail and the pressurizing locking nail enables the pressurizing distance to be adjusted in a stepless mode; after the lag screw, the pressurizing nail and the anti-rotation nail are assembled, the tension screw, the pressurizing nail and the anti-rotation nail can move linearly along the anti-rotation hole in a one-way mode. Because of the limitation of the steps in the anti-rotation nail, the whole body can not move forwards and only can move backwards, so that the femoral head can be effectively prevented from being cut by the component moving forwards, the dynamic requirement is realized, and the rapid healing of the fracture is promoted.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural view of an intramedullary fixation device according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of an anti-rotation hole on a main nail according to an embodiment of the present invention;

fig. 3 is a partial cross-sectional view of an intramedullary fixation device provided in accordance with an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a lag screw according to an embodiment of the present invention;

fig. 5 is a schematic structural view of the anti-rotation nail provided in the embodiment of the present invention;

fig. 6 is a schematic structural view of a pressing lock pin according to an embodiment of the present invention.

Description of reference numerals:

1. a main nail; 11. anti-rotation holes; 111. a first through hole; 112. a second through hole; 2. a lag screw; 21. A notch; 3. anti-rotation nails; 31. a limiting boss; 32. a step; 4. pressing the locking nail; 5. cortical bone screws; 6. and (4) a groove.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Furthermore, the technical features mentioned in the different embodiments of the invention described below can be combined with each other as long as they do not conflict with each other.

Referring to fig. 1, the present invention provides an intramedullary fixation device, which includes a main nail 1, a lag screw 2 and an anti-rotation nail 3 parallelly inserted into the proximal end of the main nail 1, and a compression locking nail 4; in the present application, the proximal end refers to an end close to the user, the distal end refers to an end far away from the user, the front end refers to an end close to the femoral head, and the rear end refers to an end far away from the femoral head, wherein, referring to fig. 2, the proximal end of the main nail 1 is provided with an anti-rotation hole 11, the anti-rotation hole 11 is in a gourd shape and comprises a first through hole 111 and a second through hole 112 which are communicated with each other, the first through hole 111 is adapted to the lag screw 2, and the second through hole 112 is adapted to the anti-rotation nail 3; referring to fig. 4, the lag screw 2 is a hollow structure, the front end of the lag screw is provided with an external thread for connecting the femoral head, the rear end of the lag screw is provided with an internal thread for connecting the compression locking nail 4, and the side wall of the lag screw is provided with an axially extending notch 21; referring to fig. 1 or 3, the anti-rotation nail 3 is in surface contact with the notch 21, and referring to fig. 3-6, a limit boss 31 extending into the notch 21 is arranged on the contact surface of the anti-rotation nail 3, the limit boss 31 can slide back and forth along the notch 21 along with the movement of the anti-rotation nail 3, and a step 32 is arranged at the rear end of the anti-rotation nail 3 to limit the degree of freedom of the forward movement of the anti-rotation nail 3; the pressurizing locking nail 4 is connected with the lag screw through internal threads, when the front end of the pressurizing locking nail 4 abuts against the limiting boss 31, the pressurizing locking nail 4 rotates continuously to drive the lag screw 2 to move backwards, and pressure is applied to the fracture line.

The design principle of the present application please refer to fig. 1, after the main nail 1 is implanted, the proximal locking is required. The lag screw 2 is implanted through the first through hole 111 of the anti-rotation hole 11, and at this time, the head of the femur is connected with the lag screw 2 through the external thread of the head. The anti-rotation nail 3 is implanted through the second through hole 112 of the anti-rotation hole 11 and is in plane fit with the notch 21. The insertion of the anti-rotation nail 3 enables the tension screw 2 to lose relative rotational freedom degree with the first through hole 111, and the phenomenon that the external thread on the tension screw 2 drives the femoral head to rotate around the anti-rotation hole 11 on the main nail 1 is avoided, so that the reduction is lost. The anti-rotation nail 3 is inserted until the step 32 thereof contacts with the outer wall of the main nail 1. A compression locking nail 4 is screwed in and is in threaded engagement with the lag screw 2. When the end of the pressurizing locking nail 4 contacts the limiting boss 31 of the anti-rotation nail 3, the pressurizing locking nail is continuously screwed in, the lag screw 2 is forced to linearly retreat along the axis, the head of the femur head also retreats along with the lag screw 2, so that the pressurization of the fracture line is realized, and the pressurizing distance can be steplessly adjusted. After the lag screw 2, the pressurizing lock nail 4 and the anti-rotation nail 3 are assembled, the anti-rotation nail can move along the anti-rotation hole 11 of the main nail 1 in a one-way straight line mode. Due to the limitation of the step 32 of the anti-rotation nail 3, the anti-rotation nail cannot move forwards and only can move backwards. Therefore, the lag screw 2 is effectively prevented from cutting the femoral head forwards, the dynamic requirement is realized, and the rapid healing of the fracture is promoted.

Referring to fig. 4, in the present embodiment, the length of the notch 21 is from the rear end of the tension screw 2 to the external thread of the tension screw 2, and is at least greater than the distance from the limiting boss 31 to the step 32, so as to avoid losing the limiting function of the step, and of course, the length of the notch 21 may be just equal to the distance from the limiting boss 31 to the step 32, so as to limit the forward moving freedom of the limiting boss 31 by the front end of the notch 21 cooperating with the step 32, thereby increasing the service life of the step 32.

Referring to fig. 6, in order to make the compression locking nail 4 lock the assembly composed of the lag screw 2, the anti-rotation nail 3 and the compression locking nail 4, in this embodiment, the compression locking nail 4 is designed to be frustum-shaped, that is, the bottom diameter of the thread of the compression locking nail 4 is conical, and naturally, the diameter of the external thread arranged on the outer wall of the compression locking nail 4 is gradually changed.

Referring to fig. 1, the distal end of the main nail 1 is further provided with a cortical bone screw 5, so that the distal end of the main nail 1 is fixed on the cortical bone 5, and referring to fig. 3-6, for the convenience of installation, the present application further provides a groove 6 adapted to an installation tool at the end of the step 32 of the anti-rotation nail 3. The groove 6 is in the shape of a straight line, a cross, an inner angle hexagon or a quincunx. Of course, the arrangement of the groove 6 is not limited to the step 32 of the anti-rotation nail 3, and may be arranged at the proximal end of the main nail 1 or the rear end of the tension screw 2 or the rear end of the compression locking nail 4.

The lag screw 2, the pressurization nail 4 of this application and prevent revolving 3 back of assembling, can be along preventing 11 one-way rectilinear movement in hole soon. Because of the limitation of the step 32 in the anti-rotation nail 3, the whole body can not move forwards and only can move backwards, thereby effectively preventing the femoral head from being cut by the component moving forwards, realizing the dynamic requirement and promoting the rapid healing of the fracture.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An intramedullary fixing device is characterized by comprising a main nail, a lag screw and an anti-rotation nail which are parallelly penetrated through the near end of the main nail, and a pressurizing locking nail;

2. The intramedullary fixation device of claim 1, wherein the notch extends from a posterior end of the lag screw to an external thread of the lag screw.

3. The intramedullary fixation device of claim 2, wherein the anti-rotation pin is disposed an equal length to the slot.

4. The intramedullary fixation device of claim 1, wherein the compression locking pin is frustoconical and the external thread diameter of the compression locking pin decreases from front to back.

5. The intramedullary fixation device of claim 1, wherein the distal end of the primary nail is further provided with a cortical bone screw.

6. The intramedullary fixation device of claim 1, wherein the stepped end of the rotation prevention nail is provided with a groove adapted to an installation tool.

7. The intramedullary fixation device of claim 6, wherein the groove is in the shape of a straight line, a cross, an internal angle hexagon, or a quincunx.