CN108720914B - A femoral neck fracture fixation device - Google Patents

Abstract

The invention discloses a femoral neck fracture fixation device. The femoral neck fracture fixation device comprises: a lateral steel plate, three sleeves, three head screws matched with the sleeves, and at least one cortical bone locking screw ; The inner surface of the lateral plate matches the anatomical shape of the lateral wall of the proximal femur; the cephalad side of the lateral plate is provided with three conical thread locking holes, and the caudal side of the locking plate is provided with at least one a cortical bone screw locking hole; the sleeve is a hollow structure; the tail of the sleeve is matched with the tapered thread locking hole; the cortical bone locking screw is matched with the cortical bone screw locking hole. The femoral neck fracture fixation device provided by the invention has the advantages of small trauma, good fixation effect, simple operation and accurate positioning.

Description

A femoral neck fracture fixation device

technical field

The invention relates to the field of medical instruments, in particular to a femoral neck fracture fixation device.

Background technique

Femoral neck fractures are a common type of fractures that occur in the elderly. Femoral neck fractures have a high incidence, accounting for about 3.6% of total body fractures and 60% of hip fractures. For unstable femoral neck fractures, internal fixation is currently used, but the incidence of postoperative nonunion and femoral head necrosis is high, so unstable femoral neck fractures are called "unresolved fractures". .

In the prior art, the following methods are mainly used for the treatment of femoral neck fractures:

In the first method, three cannulated compression screws (CCS, Cannulated Compressed Screws) are used to fix the femoral neck fracture, as shown in Figure 1. This approach is mostly used for stable femoral neck fractures, and some are used for unstable femoral neck fractures. Three cannulated lag screws are parallel to each other in the femoral neck, and the tails of the screws are arranged with equilateral triangles and inverted triangles. At present, the inverted triangle form is mostly recommended, which can reduce the impact on the blood supply to the femoral head. Three cannulated nails prevent rotation of the femoral head to a certain extent.

During the fixation of stable femoral neck fractures, the lower screw can rely on the "three-point" support of the lateral femoral cortex, medial cortex and subchondral bone to provide a certain compressive capacity.

In the fixation of unstable femoral neck fractures, this method has the following defects: 1. The lateral femoral wall screw lacks sufficient holding force, especially for elderly patients with osteoporosis, the tail of the screw is easy to loosen, which is easy to cause femoral head varus Deformity; 2. For the lower screw, because the fracture line passes through the medial thickened cortex of the femur, the screw loses the "three-point" support, resulting in insufficient medial support and stress concentration at the lesser trochanter, which easily leads to varus deformity of the femoral head and subtrochanteric fracture; 3. Although the spatial arrangement of the three screws has a certain degree of anti-rotation, due to the lack of strong fixation on the lateral wall, the screws are easily twisted and deformed in the femoral neck and lose their anti-rotation; 4. The tail of the screw is fractured in the femoral neck. During the healing process, the screw is easily withdrawn after bone resorption, which will cause local discomfort to the patient, and in severe cases, will lead to nonunion; 5. The three cannulated screws should be placed parallel to each other. On the one hand, the optimal placement of the screw cannot guarantee the best position of the screw; if fluoroscopy is used, the radiation dose received by the patient may be increased.

The second method is to use Dynamic Hip Screw (DHS, Dynamic Hip Screw) to treat femoral neck fracture, see Figure 2. Compared with the first method, the biomechanical strength of this method is significantly improved. The outside angled steel plate provides good compressive properties. The head nail in the femoral neck can slide along the sliding sleeve, which can not only achieve cross-sectional compression during intraoperative reduction, but also can be continuously compressed after operation. Its sufficient biomechanical strength reduces the stress concentration of the lesser trochanter and effectively reduces the incidence of subtrochanteric fractures.

However, using this method to reduce femoral neck fractures has the following disadvantages: 1. The surgical exposure range is large, and the patient loses more blood; Rotational displacement; 3. A single head screw cannot provide sufficient anti-rotation performance, and the femoral head is easily rotated and displaced after surgery, resulting in failure of internal fixation; 4. The failure rate is high. During the placement of the dynamic hip screw, the head screw is required to be in the center of the frontal and lateral views as much as possible, and the apex distance is less than 25mm, otherwise the cutting rate of the screw in the femoral head will be significantly improved.

The third method is to use the proximal femoral locking plate for cannulated screws to treat the fracture of the femoral neck, referring to FIG. 3 . Compared with the previous two methods, this method has a lateral plate attached to the outside of the femoral neck fracture, and the anti-compression and anti-rotation performances have been significantly improved. When the outer steel plate is in a good position, the parallel arrangement of the three screws can be ensured through the side screw hole guidance. At the same time, compared with the dynamic hip screw, the proximal femoral cannulated screw locking plate has a smaller surgical exposure range, and the anti-rotation performance is improved; the size of the apex distance does not need to be considered during the operation, and the operation difficulty is significantly reduced.

However, this method also has certain defects, such as: 1. The spatial arrangement of the three screws is not good, which cannot provide the maximum space-occupying effect; 2. The structure of the three cannulated screws cannot achieve continuous postoperative compression, so To ensure the healing of femoral neck fractures; 3. The lateral plate is non-anatomical, which makes it impossible to achieve rapid and precise positioning during internal fixation placement.

To sum up, all existing fixation devices for femoral neck fractures have certain defects.

SUMMARY OF THE INVENTION

In order to overcome the defects of the existing femoral neck fracture fixation device, the present invention provides a femoral neck fracture fixation device.

According to one aspect of the present invention, there is provided a femoral neck fracture fixation device, the femoral neck fracture fixation device comprising: a lateral steel plate, three sleeves, three head nails matched with the sleeves, at least one cortical bone locking screw;

The inner surface of the lateral plate matches the anatomical shape of the lateral wall of the proximal femur;

The head side of the lateral steel plate is provided with three conical thread locking holes, and the caudal side of the locking plate is provided with at least one cortical bone screw locking hole;

The sleeve is a hollow structure; the tail of the sleeve is matched with the conical thread locking hole;

The cortical bone locking screw is matched with the cortical bone screw locking hole.

According to a specific embodiment of the present invention, a guide hole is provided on the side steel plate;

The guide hole is arranged between the three tapered thread locking holes.

According to another specific embodiment of the present invention, the conical thread locking holes are arranged in an inverted triangle.

According to another specific embodiment of the present invention, the axial direction of the conical thread locking hole and the side steel plate form an included angle of 118°.

According to yet another specific embodiment of the present invention, the outer surface of the side steel plate has a structure with thin ends and a thick middle;

The head side of the side steel plate is a forward-inclined structure.

According to yet another specific embodiment of the present invention, the thickness of the thickest part of the side steel plate is 12 mm.

According to yet another specific embodiment of the present invention, the stud includes: a stud head end and a stud tail;

The head end of the head nail is a threaded structure;

The tail end of the head nail is a straight rod structure.

According to yet another specific embodiment of the present invention, a reverse thread with a diameter of 2.5 mm is provided at the end of the head nail.

According to yet another specific embodiment of the present invention, the bottom of the sleeve has a circular outer edge and an inner edge of a regular hexagonal structure.

According to yet another specific embodiment of the present invention, the diameter of the cortical bone locking screw is 4.5 mm.

In the femoral neck fracture fixation device provided by the present invention, the thickened lateral steel plate according to the tension band effect can provide sufficient support to prevent postoperative femoral head varus. The spatial arrangement of the three head screws (lag screws), on the one hand, can provide good anti-rotation ability to prevent postoperative femoral head rotation; on the other hand, it can achieve the largest space-occupying effect and improve the fracture healing rate. The design of the restricted sliding of 3 head screws along the sleeve can realize continuous pressure on the fracture surface after operation, ensure that the fracture surface can still be closely connected after partial bone resorption during the fracture healing process, and create good conditions for fracture healing. At the same time, the anatomical design of the lateral plate can realize the precise positioning of the internal fixator during the operation, ensure the good position of the head nail inside the femoral neck, reduce the number of X-ray fluoroscopy, and reduce the operation time.

To sum up, the femoral neck fracture fixation device provided by the present invention can expand the applicable population range of the internal fixator for the treatment of femoral neck fractures, significantly reduce the incidence of postoperative nonunion and femoral head necrosis, and significantly improve the prognosis of patients with femoral neck fractures. Quality of Life.

Description of drawings

Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

1 is a schematic structural diagram of a femoral neck fracture fixation device in the prior art;

2 is a schematic structural diagram of another femoral neck fracture fixation device in the prior art;

3 is a schematic structural diagram of another femoral neck fracture fixation device in the prior art;

4 is a schematic structural diagram of a specific embodiment of a femoral neck fracture fixation device provided according to the present invention;

5 is a front view of a specific embodiment of a lateral steel plate of a femoral neck fracture fixation device provided according to the present invention;

Figure 6 shows a side view of the side steel plate shown in Figure 5;

7 is a schematic structural diagram of a specific embodiment of the head nail of a femoral neck fracture fixation device provided by the present invention;

8 is a schematic structural diagram of a specific embodiment of a sleeve of a femoral neck fracture fixation device provided according to the present invention;

FIG. 9 is a top view of a specific embodiment of the bottom of a sleeve of a femoral neck fracture fixation device provided according to the present invention;

Fig. 10 is a rear view of the sleeve and head nail of a femoral neck fracture fixation device provided according to the present invention.

The same or similar reference numbers in the drawings represent the same or similar parts.

Detailed ways

The following disclosure provides many different embodiments or examples for implementing different structures of the invention. In order to simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Furthermore, the present invention may repeat reference numerals and/or letters in different instances. This repetition is for the purpose of simplicity and clarity and does not in itself indicate a relationship between the various embodiments and/or arrangements discussed. It should be noted that the components illustrated in the figures are not necessarily drawn to scale. Descriptions of well-known components and processing techniques and processes are omitted from the present invention to avoid unnecessarily limiting the present invention.

The present invention provides a femoral neck fracture fixation device, see FIGS. 4 to 10 . The femoral neck fracture fixation device includes: a lateral steel plate 10 , three sleeves 20 , three head screws 30 matched with the sleeves 20 , and at least one cortical bone locking screw 40 .

The lateral steel plate 10 is designed according to the anatomical shape of the proximal femur of a normal person, and the light source on its inner surface matches the anatomical shape of the lateral wall of the proximal femur. The outer surface of the side steel plate 10 has a structure with thin ends and a thick middle, as shown in FIG. 6 . Preferably, the thickness of the thickest part of the side steel plate 10 is 12 mm. In order to better fit the femur, both ends of the lateral plate 10 are slightly raised. In order to make the cephalic side 11 of the lateral steel plate more in line with the anteversion angle of the femoral neck of the human body, preferably, the cephalic side 11 of the lateral steel plate is an anteverted structure. This will better keep the head nail 30 well positioned in the femoral neck.

The head side 11 of the side steel plate is provided with three conical thread locking holes 13 , and the conical thread locking holes 13 are arranged 16 in an inverted triangle. It is worth noting that the inverted triangle arrangement 16 is a non-isosceles triangle, and in actual operation, the position of the tapered threaded locking hole 13 at the posterior and superior position of the femur is slightly lower.

The anatomical shape of the lateral steel plate 10 and the inverted triangular arrangement 16 of the conical threaded locking holes 13 can achieve fast and precise positioning during the operation, ensure the optimal distribution of the head nails 30 in the space, and achieve the maximum space-occupying effect. The gripping force of the nails 30 is maximized, thereby enhancing the fixation effect.

The tail of the sleeve 20 is matched with the conical thread locking hole 13 . The tail of the sleeve 20 is tightly locked with the lateral steel plate 10 through the conical threaded locking hole 13, thereby ensuring that the head nail 30 will not lose its position and rotate deformity in the femoral neck, and ensure that it has sufficient anti-rotation performance. Therefore, the angle formed between the axial direction of the conical thread locking hole 13 and the side steel plate 10 needs to conform to the neck stem angle of the human body. Therefore, preferably, the axial direction of the conical thread locking hole 13 and the The side steel plates 10 form an included angle of 118°. That is, the axial direction of the sleeve 20 and the side steel plate 10 form an included angle of 118°.

The sleeve 20 is a hollow structure, and is used for inserting the head nail 30 therein for matching use. Preferably, the diameter of the sleeve 20 is 6.5 mm. The hollow sleeve 20 can not only ensure the smooth sliding of the head nail 30 but also ensure the stability of the angle between the head nail 30 and the side steel plate 10 .

The bottom of the sleeve 20 has a circular outer edge, the inner edge of the tail end of the sleeve 20 has a regular hexagonal structure, and the inner shape is consistent with the straight rod structure at the tail end of the head nail. The proximal end can be locked on the side steel plate 10 to ensure the positions of the three head nails 30 and their anti-compression and anti-rotation properties.

The length of the sleeve 20 is equivalent to the distance from the lateral wall of the greater trochanter to the base of the femoral neck along the direction of the head nail 30 , so preferably, the sleeve 20 is 38 mm long.

The head nail 30 is matched with the sleeve 20 . The head nail 30 is a solid nail, which is composed of two parts: the head end of the head nail and the tail end of the head nail. Wherein, the head end of the head nail is a threaded structure; the tail end of the head nail is a straight rod structure, as shown in FIG. 7 . The cross section of the straight rod structure at the top and tail ends is composed of two upper and lower opposite arcs and a straight edge between the two arcs. This structure can not only ensure the restricted sliding of the stud 30 in the sleeve 20, but also prevent the stud 30 from rotating in the sleeve 20, as shown in FIG. 10 .

The restricted sliding design between the sleeve 20 and the head screw 30 can provide screw sliding caused by bone resorption during the postoperative fracture healing process, but avoid significant shortening of the femoral neck caused by continuous sliding. At the same time, it can also avoid local discomfort of the patient caused by the removal of the screw.

In order to match with the sleeve 20, preferably, the diameter of the head end of the stud is 6.5 mm, and the diameter of the tail end of the stud is 4.5 mm. The length of the head nail 30 ranges from 85mm to 110mm. According to different characteristics of different human bodies, the head nails 30 are usually selected from the following lengths: 85mm, 90mm, 95mm, 100mm, 105mm and 110mm.

In order to pressurize the fractured end with a screwdriver during the operation to further increase the stability and firmness of the fixation, preferably, a reverse thread with a diameter of 2.5 mm is provided at the end of the head nail 30 .

The caudal side 12 of the locking plate is provided with at least one cortical screw locking hole 14 . The cortical bone locking screw 40 is matched with the cortical bone screw locking hole 14 . The cortical bone locking screw 40 is used to further fix the lateral plate 10 and the femoral neck. In order to enhance the fixation effect and enhance the stability, preferably, two cortical bone locking screw holes 14 are provided on the caudal side 12 of the locking plate, as shown in FIG. 5 . Preferably, the diameter of the cortical bone locking screw 40 is 4.5 mm.

In order to facilitate early perspective positioning and later connection with the guide, preferably, one guide hole 15 is provided on the side steel plate 10 . The guide holes 15 are arranged between the three tapered thread locking holes 13 . Preferably, the outer diameter of the guide hole 15 is 5 mm, and the inner diameter is 2.5 mm.

In the femoral neck fracture fixation device provided by the present invention, the three head screws 30 are stabilized at an angle with the lateral steel plate 10 through the sleeve 20, and the thickened lateral steel plate 10 tightly holds the cortical bone through the distal cortical bone locking screw 14, It is ensured that the three head screws 30 have sufficient compressive performance to prevent varus deformity of the femoral head after operation. At the same time, stress concentration at the lesser trochanter is avoided, thereby reducing the occurrence of subtrochanteric fractures.

In the actual application process, when the femoral neck fracture fixation device is placed, the incision and exposure of the affected area are small, and the blood loss is small. At the same time, with the support of a series of supporting tools and guidance, the intraoperative operation is simple, the X-ray radiation is reduced, and the operation time is significantly shortened.

The femoral neck fracture fixing device provided by the invention is simple in operation, accurate in positioning and good in anti-rotation; the operation time is effectively shortened; and the incidence of postoperative nonunion and femoral head necrosis is greatly reduced.

Although the exemplary embodiments and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit of the invention and the scope of protection defined by the appended claims. For other examples, those of ordinary skill in the art will readily understand that the order of the process steps may be varied while remaining within the scope of the present invention.

Furthermore, the scope of application of the present invention is not limited to the process, mechanism, manufacture, composition of matter, means, method and steps of the specific embodiments described in the specification. From the disclosure of the present invention, as those of ordinary skill in the art, it will be easily understood by those of ordinary skill in the art that there are currently existing or will be developed in the future for the process, mechanism, manufacture, composition of matter, means, method or step, wherein they perform the same as the present invention. Corresponding embodiments described that function substantially the same or achieve substantially the same results can be applied in accordance with the present invention. Accordingly, the appended claims of the present invention are intended to include within their scope such processes, mechanisms, manufacture, compositions of matter, means, methods, or steps.

Claims (5)

1. A femoral neck fracture fixation device, comprising: the side steel plate, 3 sleeves, 3 head nails matched with the sleeves and at least 1 cortical bone locking screw;

the inner surface of the lateral steel plate is matched with the anatomical form of the outer side wall of the proximal femur;

the outer surface of the lateral steel plate is of a structure with two thin ends and a thick middle part; the head side of the lateral steel plate is of a forward tilting structure;

the head side of the side steel plate is provided with 3 tapered thread locking holes, and the tail side of the side steel plate is provided with at least 1 cortical bone screw locking hole; the axial direction of the tapered thread locking hole and the lateral steel plate form an included angle of 118 degrees;

the conical thread locking holes are arranged in an inverted triangle; the inverted triangles are arranged into non-isosceles triangles, and the positions of the conical threaded locking holes at the upper rear position of the femur are inclined downwards;

the sleeve is of a hollow structure; the tail part of the sleeve is matched with the tapered thread locking hole;

the length of the sleeve is equivalent to the distance from the outer side wall of the greater trochanter to the base of the femoral neck along the direction of the head nail;

the cortical bone locking screw is matched with the cortical bone screw locking hole;

the stud includes: a head end of the head nail and a tail end of the head nail;

the head end of the head nail is of a thread structure;

the tail end of the head nail is of a straight rod structure; the cross section of the straight rod structure consists of an upper arc, a lower arc and a straight edge between the two arcs;

the tail end of the head nail is provided with a reverse thread with the diameter of 2.5 mm.

2. A femoral neck fracture fixation device as in claim 1, wherein 1 guide hole is provided on the side steel plate;

the guide hole is arranged among the 3 conical thread locking holes.

3. A femoral neck fracture fixation device as in claim 1, wherein the thickness of the side steel plates at the thickest is 12 mm.

4. A femoral neck fracture fixation device as in claim 1, wherein the bottom of the sleeve has a rounded outer edge and a regular hexagonal configuration at an inner edge.

5. A femoral neck fracture fixation device as in claim 1, wherein the cortical bone locking screw is 4.5mm in diameter.

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