CN216439296U

CN216439296U - Proximal femoral intramedullary nail with proximal cross nail

Info

Publication number: CN216439296U
Application number: CN202122781684.1U
Authority: CN
Inventors: 周春; 董宇启; 李占玉
Original assignee: Renji Hospital Shanghai Jiaotong University School of Medicine
Current assignee: Renji Hospital Shanghai Jiaotong University School of Medicine
Priority date: 2021-11-15
Filing date: 2021-11-15
Publication date: 2022-05-06
Anticipated expiration: 2031-11-15

Abstract

The proximal femoral intramedullary nail comprises a main nail and a cross nail, wherein the main nail comprises a proximal end part, a transition part and a distal end part, the transition part is arranged between the proximal end part and the distal end part, the cross section of the proximal end part is circular, the cross nail comprises a tension screw and an anti-rotation screw, the tension screw comprises a screw part and a handle part, the cross section of the handle part of the tension screw is circular, a proximal channel penetrating through the proximal end part of the main nail is arranged in the side wall of the proximal end part of the main nail, the handle part of the tension screw is arranged in the proximal channel, a threaded hole is arranged in the side wall of the handle part of the tension screw, the threaded hole penetrates through the handle part of the tension screw, the left end opening of the threaded hole is positioned on the left side of the proximal end part, and the right end opening of the threaded hole is positioned on the right side of the proximal end part. The cross tension screws and the anti-rotation screws can effectively disperse stress, increase the holding force on the fracture block and prevent metal fatigue fracture and fracture displacement.

Description

Proximal femoral intramedullary nail with proximal cross nail

Technical Field

The utility model relates to human living goods, in particular to a medical instrument, in particular to an orthopedic intramedullary fixation technology, and specifically relates to a proximal femoral intramedullary nail with a proximal cross nail.

Background

China is a large population country in the world, the population base is huge, the aging of the population is gradually increased in more than ten years, the number of the aged population is gradually increased year by year, and the number of the patients with hip fracture better developed in the aged is obviously increased year by year. It is estimated that the number of hip fractures in China in 2050 year will be as high as 500-. The inner fixing instrument for the operation treatment of the femoral intertrochanteric fracture is updated from the utility model for decades, and the proximal intramedullary nail of the femur has become the most commonly used inner fixing instrument for the global treatment of the femoral intertrochanteric fracture at present due to wide adaptation and definite fixing effect.

The proximal intramedullary nail of femur mainly comprises a main nail, a proximal head and neck screw and a distal locking nail. The main nail is inserted into a femoral medullary cavity after being opened near a femoral proximal greater trochanter tip, a proximal head and neck screw is fixed with a femoral head neck through a main nail proximal end channel, and a distal locking nail is fixed with a femoral stem or a distal end through a main nail distal end channel. Thus, a set of intramedullary nail device (mainly comprising a main nail, a near-end head-neck screw and a far-end locking nail) can fix two ends of the intertrochanteric fracture of the femur into a whole.

The proximal intramedullary nail of femur belongs to intramedullary fixing apparatus, and compared with extramedullary fixing, the intramedullary fixing has shorter arm of force and smaller moment after stress. Therefore, the intramedullary fixation device is less stressed and less prone to metal fatigue fracture. Meanwhile, the intramedullary nail main nail has a blocking effect on the head and neck fracture block, and can prevent the head and neck fracture block from compressing and shifting along the direction vertical to the fracture line. In addition, for some specific types of proximal femoral fractures, such as intertrochanteric femoral fractures or subtrochanteric fractures, intramedullary fixation has a stronger anti-inversion effect than extramedullary fixation. Due to these advantages, proximal intramedullary nails are now most widely used in the treatment of intertrochanteric fractures.

The intertrochanteric fracture of femur is better to the old people with combined osteoporosis, and the old patients with intertrochanteric fracture of femur with combined osteoporosis can not go to the ground early usually after being fixed by the existing proximal intramedullary nail of femur on the market at present, because once the bone is loaded on the ground before fracture healing, fracture displacement easily occurs, the proximal head and neck screws cut head and neck fracture blocks and internal fixation fracture, and finally internal fixation failure is caused, so that the medical expense is increased, the time to go to the ground and the life quality of the patients are seriously influenced, the related complication risk of long-term bed rest is increased, and even the patients finally die.

The proximal femoral intramedullary nail in the prior art and the head and neck screws are mostly single, the holding force of the proximal femoral intramedullary nail to the head and neck fracture block, the rotation and the inversion of the femoral head and neck fracture block are weak, and after a patient walks in a field and applies force to the femoral head and neck fracture block, the head and neck fracture block is easy to rotate and invert and shift, and finally internal fixation failure is caused. In order to solve the problems, a proximal intramedullary nail for femur, in which proximal head and neck screws are two screws and are distributed in a longitudinal manner, has been designed, but after the proximal intramedullary nail is actually applied to clinic, a Z-shaped effect, namely, the phenomenon that the screws fall off or penetrate into joints, is generated in many cases, the fixation effect is not ideal, and then the proximal intramedullary nail is gradually eliminated. However, the proximal head and neck screws which are still clinically applied at present are double proximal femoral intramedullary nails, the two head and neck screws are designed to be longitudinally distributed, and the threads of the two head and neck screws are mutually occluded, so that the Z-shaped effect is avoided.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a proximal femoral intramedullary nail with a proximal cross nail, which aims to solve the technical problems that the proximal femoral intramedullary nail in the prior art has weak holding force on a head and neck fracture block, weak rotation resistance and weak inversion resistance of the head and neck fracture block.

The utility model relates to a proximal femoral intramedullary nail with a proximal cross nail, which comprises a main nail and a cross nail, wherein the main nail comprises a proximal part, a transition part and a distal part, the transition part is arranged between the proximal part and the distal part, the section of the proximal part is circular, the included angle between the axis of the proximal part and the axis of the distal part is set as a camber angle, the camber angle is an acute angle, the cross nail comprises a lag screw and an anti-rotation screw, the lag screw comprises a screw part and a handle part, the section of the handle part of the lag screw is circular, a proximal channel penetrating through the proximal part of the main nail is arranged in the side wall of the proximal part of the main nail, the handle part of the lag screw is arranged in the proximal channel, a threaded hole is arranged in the side wall of the handle part of the lag screw, the threaded hole penetrates through the handle part of the lag screw, and the left end opening of the threaded hole is positioned on the left side of the proximal part, the right-hand member opening of screw hole is located the right side of proximal portion, and anti-thread screw's afterbody and screw hole threaded connection, lag screw and anti-thread screw constitute the contained angle, and the contained angle of the axle center of lag screw and the axle center of the distal portion of main nail sets up to the nape angle, and the nape angle is the obtuse angle, is provided with the distal end passageway in the distal portion lateral wall of main nail, is provided with distal end locking nail in the distal end passageway of main nail, has the hood through threaded connection in the up end of the proximal portion of main nail.

Further, the diameter of the distal end part of the main nail is smaller than that of the proximal end part.

Further, the tail cap is arranged at the center of the upper end face of the proximal end part.

Furthermore, the axis of the main nail, the axis of the lag screw, the axis of the anti-rotation screw and the axis of the far-end locking nail are all located on the same plane.

Compared with the prior art, the utility model has positive and obvious effect.

1. The lag screw and the anti-rotation screw form a cross nail, the cross section of the handle part of the lag screw is circular, the lag screw and the anti-rotation screw form cross fixation, the anti-rotation effect is enhanced, and the rotation displacement of the head and neck fracture block can be effectively prevented.

2. The cross tension screws and the anti-rotation screws can effectively disperse stress, increase holding force on the fracture block, and prevent fatigue fracture of metal and inward turning displacement of the internal fixation cutting head and neck fracture block and the fracture block.

3. The anti-rotation screws are connected and fixed through the threaded holes in the handles of the lag screws, so that the areas of footprints of the crossed screws on the main screws and the thighbone can be reduced, and the fatigue fracture and the iatrogenic fracture of the main screws are effectively prevented.

4. The lag screw and the anti-rotation screw which form the cross screw form a certain angle, the tail part is meshed and fixed through threads, and once the cross screw is placed in the screw, the cross screw can be effectively prevented from moving back.

Drawings

Fig. 1 is a front view of a proximal intramedullary nail of a femur having a proximal cross pin according to the present invention.

Fig. 2 is a side view of a proximal femoral intramedullary nail with a proximal cross pin of the present invention.

Fig. 3 is a top view of a proximal femoral intramedullary nail with a proximal cross pin of the present invention.

Fig. 4 is a front view of a cross pin in a proximal femoral intramedullary nail having a proximal cross pin in accordance with the present invention.

Detailed Description

Example 1

The present invention will be further described with reference to the drawings and examples, but the present invention is not limited to the examples, and all similar structures and similar variations using the present invention shall fall within the scope of the present invention.

As shown in fig. 1, 2, 3 and 4, the proximal intramedullary nail for femur with proximal cross nail of the present invention comprises a main nail 1 and a cross nail 2, wherein the main nail 1 comprises a proximal portion 5, a transition portion 6 and a distal portion 7, the transition portion 6 is disposed between the proximal portion 5 and the distal portion 7, the proximal portion 5 has a circular cross section, an included angle between an axial center of the proximal portion 5 and an axial center of the distal portion 7 is set as a camber angle 13, the camber angle 13 is an acute angle, the cross nail 2 comprises a lag screw 8 and an anti-rotation screw 9, the lag screw 8 comprises a screw portion and a shank portion, the shank portion of the lag screw 8 has a circular cross section, a proximal channel 10 penetrating through the proximal portion 5 of the main nail 1 is disposed in a sidewall of the proximal portion 5 of the main nail 1, the shank portion of the lag screw 8 is disposed in the proximal channel 10, a threaded hole 12 is disposed in a sidewall of the shank portion of the lag screw 8, a threaded hole 12 penetrates through the handle of a tension screw 8, the left end opening of the threaded hole 12 is positioned on the left side of a proximal part 5, the right end opening of the threaded hole 12 is positioned on the right side of the proximal part 5, the tail part of an anti-rotation screw 9 is in threaded connection with the threaded hole 12, in the operation process, the tension screw 8 firstly penetrates through a proximal end channel 10 from the right side and is screwed into a fixed head and neck fracture block, then the anti-rotation screw 9 penetrates through the threaded hole 12 from the right side, the head part of the anti-rotation screw 9 is screwed into the fixed head and neck fracture block, the tail part of the anti-rotation screw 9 is in threaded connection with the threaded hole 12, an included angle is formed by the tension screw 8 and the anti-rotation screw 9, the included angle between the axis of the tension screw 8 and the axis of a distal part 7 of a main screw 1 is set as a shaft angle 14, the shaft angle 14 is an obtuse angle, a distal end channel 11 is arranged in the side wall of the distal part 7 of the main screw 1, and a distal end locking screw 3 is arranged in the distal end channel 11 of the main screw 1, a tail cap 4 is screwed into the upper end face of the proximal end portion 5 of the main nail 1.

Further, the diameter of the distal portion 7 of the main nail 1 is smaller than that of the proximal portion 5, so as to match the intramedullary canal shape of the femur and facilitate the insertion of the distal portion 7 into the intramedullary canal of the femur.

Further, as shown in fig. 3, the tail cap 4 is disposed at the center of the upper end surface of the proximal end portion 5.

Further, as shown in fig. 2, the axial center of the main nail 1, the axial center of the lag screw 8, the axial center of the anti-rotation screw 9, and the axial center of the distal end locking nail 3 are all located on the same plane.

The working principle of the embodiment is as follows:

when in use, the cross nail 2 is occluded and fixed with the neck part of the femoral head, and the distal locking nail 3 is occluded and fixed with the femoral stem part or the distal end. The proximal femoral intramedullary nail with the proximal cross nail has good fracture block holding force and can effectively resist rotation and inversion displacement of the femoral head and neck fracture block.

Compared with the prior art, the utility model has the main advantages that:

1. the lag screw 8 and the anti-rotation screw 9 form a cross nail 2, the cross section of the handle part of the lag screw 8 is circular, the lag screw 8 and the anti-rotation screw 9 form cross fixation, the anti-rotation effect is enhanced, and the rotation displacement of the head and neck fracture block can be effectively prevented.

2. The tension screws 8 and the anti-rotation screws 9 which are distributed in a crossed mode can effectively disperse stress, increase holding force on a fracture block, and prevent fatigue fracture of metal and inward turning displacement of the internal fixation cutting head and neck fracture block and the fracture block.

3. The anti-rotation screws 9 are connected and fixed through the threaded holes 12 in the handles of the lag screws 8, so that the areas of footprints of the cross screws 2 on the main screw 1 and the femur can be reduced, and the fatigue fracture and iatrogenic fracture of the main screw 1 can be effectively prevented.

4. A certain angle is formed between the lag screw 8 and the anti-rotation screw 9 which form the cross nail 2, the tail part is occluded and fixed through threads, and once the cross nail 2 is placed in the screw, the back nail of the cross nail 2 can be effectively prevented.

Claims

1. A proximal femoral intramedullary nail with a proximal cross pin, characterized by: the cross nail comprises a main nail and a cross nail, wherein the main nail comprises a proximal portion, a transition portion and a distal portion, the transition portion is arranged between the proximal portion and the distal portion, the cross section of the proximal portion is circular, an included angle between the axis of the proximal portion and the axis of the distal portion is set to be a camber angle, the camber angle is an acute angle, the cross nail comprises a lag screw and an anti-rotation screw, the lag screw comprises a screw portion and a handle portion, the cross section of the handle portion of the lag screw is circular, a proximal end channel penetrating through the proximal portion of the main nail is arranged in the side wall of the proximal portion of the main nail, the handle portion of the lag screw is arranged in the proximal end channel, a threaded hole is arranged in the side wall of the handle portion of the lag screw, the threaded hole penetrates through the handle portion of the lag screw, the left end opening of the threaded hole is located on the left side of the proximal portion, the right end opening of the threaded hole is located on the right side of the proximal portion, and the tail portion of the anti-rotation screw is in threaded connection with the threaded hole, the lag screw and the anti-rotation screw form an included angle, the included angle between the axis of the lag screw and the axis of the distal end part of the main screw is set to be a neck trunk angle, the neck trunk angle is an obtuse angle, a distal end channel is arranged in the side wall of the distal end part of the main screw, a distal end locking screw is arranged in the distal end channel of the main screw, and a tail cap is connected to the upper end face of the proximal end part of the main screw through threads.

2. The proximal intramedullary nail of claim 1, wherein: the diameter of the distal part of the main nail is smaller than that of the proximal part.

3. The proximal intramedullary nail of claim 1, wherein: the tail cap is arranged at the center of the upper end surface of the proximal end part.

4. The proximal intramedullary nail of claim 1, wherein: the axis of the main nail, the axis of the lag screw, the axis of the anti-rotation screw and the axis of the far-end locking nail are all located on the same plane.