CN212281585U

CN212281585U - Proximal side parallel double-screw type proximal femoral intramedullary nail

Info

Publication number: CN212281585U
Application number: CN202021346391.XU
Authority: CN
Inventors: 周春; 李占玉; 董宇启
Original assignee: Renji Hospital Shanghai Jiaotong University School of Medicine
Current assignee: Renji Hospital Shanghai Jiaotong University School of Medicine
Priority date: 2020-07-10
Filing date: 2020-07-10
Publication date: 2021-01-05
Anticipated expiration: 2030-07-10

Abstract

A proximal end side-by-side double-screw type proximal femoral intramedullary nail comprises a main intramedullary nail, proximal head and neck screws and a distal locking screw, wherein the main intramedullary nail comprises a proximal end part, a transition part and a distal end part; the end part of the proximal end part is also screwed with an internal locking nail for fixing a proximal end head and neck screw, the proximal end part is provided with an internal thread hole matched with the internal locking nail, and the internal thread hole is sealed by a tail cap. The intramedullary nail is provided with the double near-end head and neck screws side by side at the near end part, so that the intramedullary nail has better anti-rotation effect, can effectively resist the inversion trend of the femoral head and neck fracture block, and reduces the stress of the head and neck screws.

Description

Proximal side parallel double-screw type proximal femoral intramedullary nail

Technical Field

The utility model relates to a human daily necessities, in particular to a medical instrument, in particular to a proximal end side-by-side double-screw type proximal femoral intramedullary nail.

Background

With the gradual aging of the population in China and the improvement of the per-capita life span, the number of the disease attack of the intertrochanteric fracture of the femur of the old is rapidly increased every year, and the current treatment idea of the intertrochanteric fracture of the femur is to advocate surgical treatment for patients who can tolerate surgery and fix the fracture by using an internal fixation instrument. The invention relates to an internal fixation instrument for femoral intertrochanteric fracture, which is updated from the invention to the prior for decades, and a proximal intramedullary nail of femur has become the most common internal fixation instrument for treating femoral intertrochanteric fracture due to wide adaptation and definite fixation effect.

The proximal intramedullary nail of the femur belongs to an intramedullary fixing instrument, and compared with extramedullary fixation, the intramedullary fixation has shorter moment arm and smaller moment, so that the intramedullary fixing instrument bears smaller stress and is not easy to generate 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 or subtrochanteric fractures, intramedullary fixation has a stronger anti-inversion effect than extramedullary fixation, and due to these advantages, proximal femoral intramedullary nails are now widely used in the treatment of intertrochanteric fractures.

Since the intertrochanteric fracture of femur is mostly generated in the old, most of the old have osteoporosis, the old with intertrochanteric fracture of femur with osteoporosis can not go to the ground early usually after being fixed by the clinically existing intramedullary nail, once the old goes to the ground before fracture healing, fracture displacement, near-end head and neck screw cutting or threading and internal fixation fracture are easy to occur, and finally internal fixation failure is caused, so that not only is medical cost increased, but also the time of going to the ground and the quality of life of the patient are seriously affected, the risk of complications related to long-term bed rest is increased, and even the patient finally dies.

In the prior art, most of head and neck screws of proximal femoral intramedullary nails are single, the rotation and inversion functions of the proximal femoral intramedullary nails against head and neck fracture blocks are weak, and the stress borne by the single screw is large, so that when a patient walks in the field, the head and neck fracture blocks are easy to invert and displace, rotate and fatigue due to head and neck screws after applying force to the head and neck fracture blocks, and finally fracture displacement, internal fixation cutting or threading and internal fixation fracture are caused. In order to solve the problems, a double-headed neck screw type intramedullary nail with parallel proximal longitudinal distribution has been designed, but in clinical practical application, a Z-shaped effect appears, the effect is not ideal, and the intramedullary nail is gradually eliminated.

Although the currently clinically applied head and neck screws are double proximal femoral intramedullary nails, the two head and neck screws are designed to be longitudinally distributed in parallel and have mutually meshed threads, so that the Z-shaped effect is avoided; however, although the anti-rotation capability of the proximal femoral intramedullary nail with two head and neck screws arranged in parallel in a longitudinal row is improved, the anti-inversion effect of the head and neck fracture is not obviously improved because the two head and neck screws are arranged in the longitudinal row.

Disclosure of Invention

The to-be-solved technical problem of the utility model is to prior art's not enough, provide an existing better anti-spiral effect, can effectively counter the enstrophe trend of femoral neck fracture piece again and reduce the near-end of neck screw stress double screw type thighbone near-end intramedullary nail side by side.

The utility model aims to solve the technical problem that a near-end double-screw type proximal femoral intramedullary nail side by side is realized through the following technical scheme, including intramedullary nail main nail, near-end neck screw and distal end locking nail, intramedullary nail main nail include proximal portion, transition portion and distal portion, the transition portion be located between the proximal portion and the distal portion, the quantity of near-end neck screw be two, be provided with the near-end screw passageway that is used for two near-end neck screws to install side by side in the proximal portion along radial, be provided with the distal end screw passageway with distal end locking nail complex in the distal portion along radial; an inner locking nail used for fixing a near-end head and neck screw is screwed in the axial direction of the axis of the near-end part, an inner thread hole matched with the inner locking nail is arranged in the near-end part, and one end of the inner thread hole is sealed through a tail cap.

Further, a camber angle matched with the femoral shaft is formed between the axial direction of the proximal end part and the axial direction of the distal end part.

Furthermore, a near-end head-neck included angle matched with the femoral neck shaft angle of the human body is formed between the axial direction of the near-end head-neck screw and the axial direction of the far-end part.

Furthermore, the near-end head and neck screw is a hollow lag screw.

Furthermore, two near-end neck screws are mutually attached to the near-end part.

Furthermore, one end of the near-end head and neck screw is provided with a threaded area, and the other end of the near-end head and neck screw is provided with a non-threaded area.

Further, the diameter of the distal portion is smaller than the diameter of the proximal portion.

Further, the cross section of the proximal portion is oval, and the front-back diameter of the cross section of the proximal portion is larger than the left-right diameter.

Compared with the prior art, the beneficial effects of the utility model are that:

1. the double-headed neck screws distributed side by side at the near end form non-circular fixation, the anti-rotation effect is enhanced, and the rotation displacement of the head and neck fracture block can be effectively prevented;

2. the supporting area of the double-headed neck screws distributed side by side at the near end to the head and neck fracture block is increased, the anti-inversion function is enhanced, and the inversion displacement of the head and neck fracture block can be effectively prevented;

3. the double-headed neck screws distributed side by side can disperse stress, and effectively prevent the fatigue fracture of the metal screws.

Drawings

Fig. 1 is a schematic structural view of the present invention;

fig. 2 is a side view of the structure of the present invention;

fig. 3 is a top view of the structure of the present invention;

fig. 4 is a cross-sectional view of the intramedullary nail taken along line a-a of fig. 2.

Detailed Description

To make the objects, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings and 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.

Referring to fig. 1-4, a proximal-end side-by-side double-screw type proximal femoral intramedullary nail comprises a main intramedullary nail 1, proximal head and neck screws 5 and a distal locking nail 6, wherein the main intramedullary nail 1 comprises a proximal end portion 2, a transition portion 3 and a distal end portion 4, the number of the proximal head and neck screws is two, a proximal screw channel 9 for installing the two proximal head and neck screws 5 side by side is arranged on the proximal end portion 2, the two proximal head and neck screws 5 are connected with the main intramedullary nail 1 through the proximal screw channel 9, the two proximal head and neck screws 5 are arranged in a front-back side-by-side distribution mode, and the two proximal head and neck screws 5 are mutually attached; the distal end part 4 is provided with a distal screw channel 10 matched with the distal locking nail 6, and the distal locking nail 6 is connected with the intramedullary nail main nail 1 through the distal screw channel 10; an inner locking nail 8 for fixing the near-end head and neck screw 5 is further screwed at the axis of the near-end portion 2, an inner threaded hole matched with the inner locking nail 8 is formed in the end portion of the near-end portion 2, the inner threaded hole is communicated with a near-end screw channel 9, the inner threaded hole is sealed through a tail cap 7, the inner locking nail 8 is fixed with the near-end portion 2 of the main intramedullary nail 1 through threads, the near-end head and neck screw 5 is locked, the near-end head and neck screw 5 is prevented from retreating or rotating, the tail cap 7 is fixed with the end portion of the near-end portion 2 of the main intramedullary nail 1 through threads, the inner threaded hole is sealed, and the tail cap.

A camber angle matched with the femoral shaft is formed between the axial direction of the proximal end part 2 and the axial direction of the distal end part 4, so that the intramedullary nail main nail 1 is better matched with the shape of the femoral shaft, and the intramedullary nail main nail 1 is conveniently inserted into the femoral bone marrow cavity.

A near-end neck included angle matched with the neck angle of the femur of the human body is formed between the axial direction of the near-end neck screw 5 and the axial direction of the far-end part 4. The human femoral neck shaft angle is an included angle between the longitudinal axis of the femoral shaft and the inner lower part of the femoral neck axis, can increase the motion range of the lower limb and enables the force of the trunk to be transmitted to the wider base part; the included angle between the axial direction of the near-end head and neck screw 5 and the axial direction of the far-end part 4 is consistent with the femoral neck shaft angle of a human body, so that the supporting area between the near-end head and neck screw 5 and the femoral neck is increased conveniently, the femoral neck is better fixed, and the invagination and displacement of a fracture block at the femoral neck are prevented.

The near-end head and neck screw 5 is a hollow lag screw. The hollow lag screw has deeper thread and longer screw body, is particularly suitable for the fracture fixation of the thighbone and has very small damage.

Two pieces of near-end neck screws 5 are mutually attached and arranged on the near-end part 2 and are used for mutually matching and dispersing stress, so that the fatigue fracture of the near-end neck screws 5 is effectively prevented, and the service life is prolonged.

One end of the near-end head and neck screw 5 is provided with a threaded zone 11, and the other end of the near-end head and neck screw 5 is provided with a non-threaded zone 12. The threaded region 11 is used for being meshed and fixed with the femoral head neck part through threads, and the unthreaded region 12 is used for sliding in the proximal screw channel 9, so that the proximal head and neck screw 5 is convenient to mount and fix.

The distal portion 4 has a diameter smaller than the diameter of the proximal portion 2 to better match the intramedullary canal morphology of the femur, facilitating insertion of the distal portion 4 into the femoral intramedullary canal.

The cross section of the proximal part 2 is oval, the front-back diameter of the cross section of the proximal part 2 is larger than the left-right diameter, a non-circular arrangement is formed, and the anti-rotation effect of the intramedullary nail is effectively enhanced.

The beneficial effects of the utility model are that:

Claims

1. The utility model provides a near-end is double screw type thighbone near-end intramedullary nail side by side which characterized in that: the intramedullary nail comprises a main intramedullary nail, proximal head and neck screws and a distal locking nail, wherein the main intramedullary nail comprises a proximal part, a transition part and a distal part, the transition part is positioned between the proximal part and the distal part, the number of the proximal head and neck screws is two, a proximal screw channel for installing the two proximal head and neck screws side by side is arranged in the proximal part along the radial direction, and a distal screw channel matched with the distal locking nail is arranged in the distal part along the radial direction; an inner locking nail used for fixing a near-end head and neck screw is screwed in the axial direction of the axis of the near-end part, an inner thread hole matched with the inner locking nail is arranged in the near-end part, and one end of the inner thread hole is sealed through a tail cap.

2. The proximal intramedullary nail of the proximal femur of claim 1, of the proximal side-by-side double screw type, wherein: a camber angle matched with the femoral shaft is formed between the axial direction of the proximal end part and the axial direction of the distal end part.

3. The proximal intramedullary nail of the proximal femur of claim 1, of the proximal side-by-side double screw type, wherein: a near-end head-neck included angle matched with the neck shaft angle of the femur of the human body is formed between the axial direction of the near-end head-neck screw and the axial direction of the far-end part.

4. The proximal intramedullary nail of the proximal femur of claim 1, of the proximal side-by-side double screw type, wherein: the near-end head and neck screw is a hollow lag screw.

5. The proximal intramedullary nail of the proximal femur of claim 1, of the proximal side-by-side double screw type, wherein: two near-end head and neck screws are mutually attached and arranged in the near-end part.

6. The proximal intramedullary nail of the proximal femur of claim 1, of the proximal side-by-side double screw type, wherein: one end of the near-end head and neck screw is provided with a threaded area, and the other end of the near-end head and neck screw is provided with a non-threaded area.

7. The proximal intramedullary nail of the proximal femur of claim 1, of the proximal side-by-side double screw type, wherein: the distal portion has a diameter less than a diameter of the proximal portion.

8. The proximal intramedullary nail of the proximal femur of claim 1, of the proximal side-by-side double screw type, wherein: the cross section of the proximal part is oval, and the front-back diameter of the cross section of the proximal part is larger than the left-right diameter.