Intersected screw and steel plate reinforced internal fixation device in femoral neck

Abstract

The invention relates to a femoral neck internal cross screw and steel plate reinforced internal fixation device, belongs to the technical field of orthopedic medical instruments, and aims to solve the technical problems of internal fixation failure risk and the like of a femoral neck fracture fixation device in the prior art. The technical scheme is characterized in that the femoral neck internal cross screw and steel plate reinforced internal fixation device comprises a main nail, a transverse locking screw and a steel plate; the steel plate is attached to the outer side face of a fracture part, the main nail penetrates through the steel plate and a fracture broken end and goes deep into the fracture part, and the transverse locking screw penetrates through the steel plate and the fracture broken end and goes deep into the fracture part. The tail part of the main nail is connected with the steel plate; the transverse locking screw further penetrates through the middle of the main nail to form a triangular fixing structure with the main nail.

Description

Technical Field

[0001] This invention relates to the field of orthopedic medical device technology, specifically to a femoral neck internal cross screw and plate-reinforced internal fixation device. Background Technology

[0002] Femoral neck fractures (FNF) are a common clinical trauma, accounting for 3.6% of all fractures. They are more common in the elderly, while the incidence is much lower in young and middle-aged patients, accounting for approximately 2% to 3% of all femoral neck fractures. Surgical treatment for femoral neck fractures in young and middle-aged patients primarily involves fracture reduction and internal fixation. This preserves the anatomical structure of the hip joint and restores hip joint function, while avoiding the risk of needing a second surgery due to the limited lifespan of replacement prostheses. Currently, there are various treatment methods for femoral neck fractures in young and middle-aged patients, such as dynamic hip screws, cannulated screws, intramedullary nails, proximal femoral locking plates, and the recently introduced femoral neck system (FNS).

[0003] Due to the biomechanical characteristics and unique vascular structure of the femoral head and neck, traditional treatment methods, although achieving some success in clinical applications, still have a high incidence of complications, such as internal fixation failure, femoral neck shortening, and femoral neck varus deformity, especially in Pauwels type II / III fractures.

[0004] Relevant patent documents retrieved:

[0005] This patent, published in China with publication number CN213588452U and publication date July 2, 2021, discloses a three-pronged internal fixation device for treating femoral neck fractures. It includes a lateral fixation plate, a first femoral neck locking screw, a second femoral neck locking screw, a third femoral neck locking screw, and a femoral shaft fixation screw. The head of the first femoral neck locking screw passes through a first threaded locking hole and is fixed to the femoral head via the femoral neck. The first femoral neck locking screw has a first side hole and a second side hole. The head of the second femoral neck locking screw passes through the second threaded locking hole and the first side hole sequentially and is fixed to the femoral head via the femoral neck. This patent utilizes the self-interlocking locking among the three femoral neck locking screws and the locking of each screw to the lateral fixation plate to form a mechanically stable three-dimensional spatial structure. This results in uniform stress distribution and effectively prevents femoral head rotation, femoral neck collapse, varus deformity, screw displacement, and cutting of the femoral head.

[0006] This patent, published in China with publication number CN117653303A and publication date March 8, 2024, discloses a triangular internal fixation and reinforcement device for femoral neck fractures. It includes a main plate and an auxiliary plate. A head screw is inserted into the surface of the main plate, and a rotor is rotatably connected to the upper surface of the head screw. An auxiliary screw is inserted into the surface of the main plate, and a locking component is provided on the inner surface of the inserted screw. The locking component is used to fix the relative position between the rotor and the inserted screw. A connecting component is rotatably connected to the surface of the auxiliary plate, and the connecting component is used to fix the relative position between the main plate and the auxiliary plate. By setting the inserted screw, locking component, and connecting component, the inserted screw can improve the stability of the head screw; the rotor can facilitate the doctor's positioning of the insertion hole on the rotor surface; the locking component can make the head screw and the inserted screw more stable; and the connecting component can not only facilitate the doctor's fixation of the auxiliary plate to the lateral surface of the femur, but also fix the position of the auxiliary plate.

[0007] Non-patent literature retrieved: The journal title is *Chinese Journal of Bone and Joint Injury*, and the article title is "Comparative Study on Early Efficacy of Dynamic Cross-Neck Screw and Hollow Screw Internal Fixation for Pauwels Type III Femoral Neck Fractures in Young and Middle-aged Patients," Volume 40, Issue 6, published on June 15, 2025. This article discloses that compared to three CCS (Chronic Cross-Screw) inverted triangular internal fixation, FNS (Functional Neck Screw) internal fixation for Pauwels Type III femoral neck fractures in young and middle-aged patients has a lower incidence of postoperative complications, earlier fracture healing time, and earlier time to full weight-bearing, which is beneficial for hip joint function recovery.

[0008] The prior art represented by the aforementioned patents or documents has at least the following unresolved technical problems or defects: Traditional three-cannulated screw fixation for femoral neck fractures is widely used in fracture treatment and is suitable for femoral neck fractures with no significant or slight displacement. Its advantages include simple operation, minimal invasiveness, and ideal fixation effect. However, its stability is insufficient in complex fractures or fractures with high shear force, easily leading to increased risks of internal fixation failure, nonunion, or femoral head necrosis. While cross-nail internal fixation (FNS), as a newer internal fixation system, has mechanical advantages in rotational and angular stability, it still carries the risk of internal fixation failure during treatment. Furthermore, its removal has a more significant impact on the mechanical properties of the proximal femur than that of cannulated screws. Therefore, this application provides a cross-nail internal fixation system and reinforcement device for femoral neck fractures to meet these needs. Summary of the Invention

[0009] The purpose of this invention is to provide: An internal fixation device for femoral neck fractures, consisting of an internally crossed screw and a plate, is proposed to address the risk of internal fixation failure in existing femoral neck fracture fixation devices.

[0010] Terminology Explanation: Unless otherwise defined, all technical terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. Unless otherwise stated, all patents, patent inventions, and disclosures cited throughout this document are incorporated herein by reference in their entirety. If multiple definitions exist for terms herein, the definitions provided in this chapter shall prevail.

[0011] It should be understood that the above brief description and the following detailed description are exemplary and for illustrative purposes only, and do not limit the subject matter of the invention in any way. In this invention, the singular is used in conjunction with the plural unless otherwise specifically stated. It should also be noted that, unless otherwise stated, the use of “or” or “or” means “and / or”. Furthermore, the use of the term “comprising” and other forms such as “including,” “containing,” and “contains” are not limiting.

[0012] The terms “optional / arbitrary” or “optionally / arbitrarily” mean that the event or situation described below may or may not occur, including both the occurrence and non-occurrence of the event or situation.

[0013] This invention provides a femoral neck internal cross screw and plate reinforced internal fixation device, comprising: a main screw, a transverse locking screw, and a plate; the plate is attached to the lateral surface of the femur between the greater trochanter and the lesser trochanter; the main screw passes through the plate and the fracture end, and penetrates into the femoral head but does not penetrate the femoral head cartilage layer; the transverse locking screw passes through the plate and the fracture end, and penetrates into the femoral head but does not penetrate the femoral head cartilage layer. The tails of both the main nail and the transverse locking screw are connected to the steel plate; the transverse locking screw also passes through the middle of the main nail to form a triangular fixing structure with the main nail.

[0014] Furthermore, the transverse locking screw is located above the master nail and is cross-connected to the master nail; the coronal plane angle between the transverse locking screw and the master nail is 35°-50°, and the sagittal plane angle between the transverse locking screw and the master nail is 3°-5°.

[0015] Furthermore, the main pin includes an inner core, an outer sleeve, and a tail pin. The outer sleeve is fitted over the outside of the inner core, and the tail pin is disposed at the tail of the inner core. The outer surface of the front end of the inner core has external threads. The inner core is hollow, and one end of the tail pin is embedded in the tail of the inner core and can rotate relative to the inner core; the outer surface of the part of the tail pin that protrudes from the inner core has threads. When the outer sleeve is fitted onto the inner core, the front end of the inner core with external threads is exposed; the tail end of the outer sleeve has internal threads, and the internal threads of the tail end of the outer sleeve are connected to the external threads of the tail pin.

[0016] Furthermore, the inner core has a limiting platform on its outer surface near the front end, one end face of the outer sleeve is correspondingly provided with the limiting surface of the limiting platform, and there is a gap between one end face of the outer sleeve and the limiting surface of the limiting platform.

[0017] Furthermore, the inner core has a transverse locking screw hole in the middle for the transverse locking screw to pass through; the outer sleeve also has a hole for the transverse locking screw to pass through.

[0018] Furthermore, the inner wall of the tail portion of the inner core has a step, and one end of the tail pin has a retaining ring, which is engaged within the step.

[0019] Furthermore, the tail of the inner core has an opening for inserting the tail pin in the radial direction from the inner core.

[0020] Furthermore, the thread direction on the outer surface of the tail screw is opposite to the thread direction at the front end of the master screw.

[0021] Furthermore, the diameter of the threaded portion at the front end of the inner core gradually decreases from the tail end of the inner core towards the front end.

[0022] Furthermore, the outer surface of the tail end of the jacket is threaded, and the jacket is threadedly connected to the steel plate through the external thread at its tail end.

[0023] Furthermore, the tail pin has a slot at its tail end, and the cross-section of the slot is quadrilateral, hexagonal, octagonal, etc.

[0024] Furthermore, the diameter of the main nail is 9mm-12mm, and the length of the main nail is 70mm-120mm.

[0025] Furthermore, the transverse locking screw is a solid screw, and the transverse locking screw is a fully threaded screw or a partially threaded screw.

[0026] Furthermore, the tail of the transverse locking screw has an external thread that connects with the threaded connection of the steel plate.

[0027] Furthermore, the femoral neck internal cross screw and plate-reinforced internal fixation device also includes a lower locking screw, which is located below the lesser trochanter of the femur during use.

[0028] Furthermore, the femoral neck internal cross screw and plate-reinforced internal fixation device also includes: an external aiming device, which includes a support rod, an arc ruler, and an aiming block. One end of the support rod is inserted into the slot of the tail screw; the other end of the support rod is fixedly connected to the arc ruler, which has a sliding groove. The lower surface of the aiming block has a locking block, which is slidably embedded in the sliding groove. The aiming block has a through hole, the axial direction of which coincides with the axial direction of the transverse locking screw.

[0029] Furthermore, the steel plate also has Kirschner wire positioning holes.

[0030] Furthermore, the steel plate is made of a flexible material.

[0031] Furthermore, when the fracture type is subcapital fracture or transcervical fracture, the intersection of the main nail and the transverse locking screw is located on the outer side of the fracture end.

[0032] Furthermore, when the fracture type is a basal fracture, the intersection of the main nail and the transverse locking screw is located inside the fracture ends.

[0033] In addition, the present invention also provides a method for using a femoral neck internal cross screw and plate-reinforced internal fixation device, comprising: S1. Traction reduction of the femoral neck fracture site, reducing the fracture ends; S2. Based on the fracture type and location, determine the position of the main nail. Then, insert one Kirschner wire from the lateral side of the femur through the femoral neck to the femoral head. S3. Determine the length of the main pin, place and fix the steel plate according to the position of the Kirschner wires, screw the main pin along the first Kirschner wire, and lock the main pin to the steel plate. S4. Drive two lower locking screws into the far end of the steel plate; S5. Use the external sight to drive in the horizontal locking screw and lock the horizontal locking screw and the steel plate; S6. Remove all Kirschner wires and apply secondary pressure to the main nail through the tail screw of the main nail to bring the fracture ends closer together. At the same time, apply secondary pressure to achieve transverse locking pressure.

[0034] Compared with the prior art, the present invention has at least the following beneficial effects: 1. Structural stability: In this invention, the main nail and the transverse locking screw cross within the femoral neck, and the main nail and the transverse nail have a certain angle in both the coronal and sagittal planes, which can enhance the angular and rotational stability of the internal neck cross fixation system. At the same time, in conjunction with the lateral locking plate fixation, the angular and rotational stability can be further enhanced. In addition, the internal neck cross nail fixation system, in conjunction with the lateral plate and the femoral lesser trochanter screw, closely conforms to the "Zhang's N-triangle theory" and the "lever reconstruction balance theory" of the proximal femur.

[0035] 2. Facilitates later fracture healing: The segmented setting of the main nail allows for additional pressure on the fracture ends after the screw is tightened into place, according to the segmented setting device inside the screw. At the same time, the lateral locking can also apply pressure to the fracture ends again during the insertion process. This is beneficial for the later fracture healing of Pauwels type II / III fractures.

[0036] Furthermore, the main screw and the lateral locking mechanism can both be locked to the lateral plate, and there are also locking screws at the distal end of the lateral plate to fix it to the femoral shaft, which can prevent screw retraction and internal fixation failure.

[0037] 3. Easy to use: The external sight is fixed to the steel plate, which can improve the accuracy and repeatability of the transverse locking pin.

[0038] 4. Easy to remove: The internal thread of the main nail is turned in the opposite direction to the direction in which the main nail is screwed into the bone, which makes it easy to remove the main nail after the fracture heals. This avoids the problem of inconvenient or even impossible removal of internal fixation when removing the nail during PFNA in the existing technology. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the main nail. To illustrate the stepped structure, the tail of the inner core has been cut out. Figure 3 This is a schematic diagram of the cross-sectional structure of the main nail 1; Figure 4 This is a schematic diagram of the longitudinal cross-sectional structure of the main nail 1; Figure 5 This is a schematic diagram of the external sight.

[0040] Explanation of reference numerals in the attached figures: 1. Main screw; 101. Inner core; 1101. Limiting platform; 1102. Lateral locking screw hole; 1103. Step; 1104. Opening; 102. Outer sleeve; 1201. Internal thread; 103. Tail screw; 1301. Snap ring; 1302. Slot; 2. Horizontal locking screw; 3. Steel plate; 4. Lower locking screw; 5. External sight, 501. Support rod, 502. Arc ruler, 503. Sight block, 504. Locking block. Detailed Implementation

[0041] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following content is merely an exemplary description of the scope of protection claimed by the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes should also fall within the scope of protection claimed by the present invention.

[0042] The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all instruments, devices, equipment and other items used in the embodiments of the present invention are obtained through conventional commercial means.

[0043] Example 1 This embodiment provides a femoral neck internal cross screw and plate 3 reinforced internal fixation device, such as Figure 1 As shown, it includes: a main nail 1, a transverse locking screw 2, a steel plate 3, a lower locking screw 4, and an external frame sight 5; the steel plate 3 is attached to the outer surface of the femur between the greater trochanter and lesser trochanter; the main nail 1 passes through the steel plate 3 and the fractured end, and penetrates into the femoral head but does not penetrate the femoral head cartilage layer; the transverse locking screw 2 passes through the steel plate 3 and the fractured end, and penetrates into the femoral head but does not penetrate the femoral head cartilage layer; the tail of the main nail 1 is connected to the steel plate 3; the transverse locking screw 2 also passes through the middle of the main nail 1 and forms a triangular cross fixation structure with the main nail 1.

[0044] The structure of main nail 1 is as follows: Figure 1 and Figure 2 The main screw 1 is a hollow screw, comprising an inner core 101, an outer sleeve 102, and a tail screw 103. The outer sleeve 102 is fitted over the inner core 101, and the tail screw 103 is disposed at the tail of the inner core 101. The outer surface of the front end of the inner core 101 has external threads. The inner core 101 is hollow, and one end of the tail screw 103 is embedded in the tail of the inner core 101 and can rotate relative to the inner core 101. The outer surface of the portion of the tail screw 103 extending out of the inner core 101 has threads. When the outer sleeve 102 is fitted over the inner core 101, the front end of the inner core 101 with external threads is exposed. The tail of the outer sleeve 102 has internal threads 1201, and the tail of the outer sleeve 102 is threadedly connected to the tail screw 103.

[0045] The inner core 101 has a front end, a middle part, and a tail end, but the inner core 101 is a one-piece machined part, and the outer surface of the front end of the inner core 101 has external threads; the diameter of the front end of the inner core 101 gradually decreases from the tail end to the front end. This can reduce the impact on the blood supply to the femoral head.

[0046] The inner core 101 has a limiting platform 1101 on its outer surface near the front end, that is, the limiting platform 1101 is located between the front end and the middle of the inner core 101. The middle of the inner core 101 has a smooth outer surface, and the outer sleeve 102 is fitted over the middle part. The tail of the inner core 101 has the same outer diameter as the middle part, but the inner wall of the tail of the inner core 101 has a step 1103. One end of the tail pin 103 has a retaining ring 1301, which is engaged in the step 1103.

[0047] One end face of the outer jacket 102 corresponds to the limiting face of the limiting platform 1101, and there is a gap between the one end face of the outer jacket 102 and the limiting face of the limiting platform 1101. This gap is to allow the inner core 101 some room to retract during secondary pressurization. The outer surface of the tail of the outer jacket 102 has threads, and the outer jacket 102 is threaded to the steel plate 3 through these external threads. The inner core 101 has a transverse locking screw hole 1102 in the middle for the transverse locking screw 2 to pass through; the outer sleeve 102 also has a hole for the transverse locking screw 2 to pass through. Typically, the hole on the outer sleeve 102 for the transverse locking screw 2 to pass through can be slightly larger, and the transverse locking screw hole 1102 on the inner core 101 is adapted to the transverse locking screw 2, being slightly larger than the outer diameter of the transverse locking screw 2, allowing the transverse locking screw 2 to pass through smoothly while still locking it in place.

[0048] The inner core 101 has an opening at its tail for the tail pin 103 to be inserted radially into the inner core 101. In this embodiment, half of the tail of the entire ring can be cut off at the tail of the inner core 101, allowing the tail pin 103 to be directly inserted into the tail of the inner core 101 from the side. Furthermore, after the tail pin 103 is inserted into the tail of the inner core 101, the cut-off half can be re-welded to the opening to increase structural stability and prevent the tail pin 103 from coming out.

[0049] Furthermore, the thread direction on the outer surface of the tail screw 103 is opposite to the thread direction at the front end of the main screw 1. This facilitates the subsequent removal of the main screw 1. The tail end of the tail screw 103 has a slot 1302, and the cross-section of the slot 1302 is a polygon such as a quadrilateral, hexagon, or octagon.

[0050] When secondary pressure is required, a wrench or similar tool is inserted into the slot 1302 at the end of the tail screw 103. The tail screw 103 is then tightened. Because the tail screw 103 is threadedly connected to the outer sleeve 102, and the outer sleeve 102 is fixed to the steel plate 3, the tail screw 103 rotates and retracts backward relative to the steel plate 3. As the tail screw 103 retracts, it carries the inner core 101 backward. The inner core 101 is rotatably engaged with the tail screw 103, so it only retracts linearly without rotation. The front end of the inner core 101 is also threadedly connected to the inside of the fracture. The retraction of the inner core 101 significantly reduces the fracture gap, thus facilitating later healing.

[0051] like Figure 3 As shown, during the secondary pressurization process, to prevent the inner core from rotating and affecting the secondary pressurization, a slide bar 1104 is provided on the outer surface of the inner core, and a groove 1202 is provided on the inner surface of the outer sleeve 102, with the slide bar 1104 embedded in the groove 1202. In this embodiment, two slide bars 1104 are provided on the outer surface of the inner core, the two slide bars 1104 are 180° apart, and both extend along the axis of the inner core. The corresponding groove 1202 is provided inside the outer sleeve 102, so that during the secondary pressurization process, the inner core can only move linearly under the constraint of the groove 1202 and cannot rotate.

[0052] This embodiment is applicable to femoral neck fractures, especially Pauwels type II / III fractures of the femoral neck. The diameter of the main nail 1 is 9mm-12mm, and the length of the main nail 1 is 70mm-120mm. Here, the diameter of the main nail 1 refers to the outer diameter of the outer sleeve 102, and the length of the main nail 1 refers to its total length.

[0053] In addition, the tip of the main nail 1 can also be the same as the tip of the pfna spiral cutter head, with a converging sharp angle.

[0054] The transverse locking screw 2 is a solid screw, and it can be a fully threaded screw or a partially threaded screw. Furthermore, the tail of the transverse locking screw 2 has external threads that connect with the steel plate 3. The tail of the transverse locking screw 2 can be a cap with a slightly larger diameter, or it can be a section of the screw with the same diameter.

[0055] The transverse locking screw 2 is located above the main nail 1 and is cross-connected to the main nail 1; the coronal plane angle between the transverse locking screw 2 and the main nail 1 is 35°-50°, and the sagittal plane angle between the transverse locking screw 2 and the main nail 1 is 3°-5°.

[0056] The lower locking screw 4 is a solid screw commonly used in medicine. When in use, it is located near the lesser trochanter of the femur and is driven into the femur almost horizontally.

[0057] The steel plate 3 is provided with a main screw hole, a transverse locking hole, a Kirschner wire hole, and a lower locking hole. The steel plate 3 is attached to the outer surface of the femur between the greater trochanter and the lesser trochanter. The material of the steel plate 3 is preferably a flexible material. The shape of the steel plate 3 can be slightly deformed according to the tension of the screw. The flexible deformation of the steel plate 3 can be used to better fit the femoral surface.

[0058] like Figure 3 As shown, the external sight 5 includes a support rod 501, an arc ruler 502, and an aiming block 503. One end of the support rod 501 is inserted into the slot 1302 of the tail pin 103; the other end of the support rod 501 is fixedly connected to the arc ruler 502, which has a sliding groove 1202. The lower surface of the aiming block 503 has a locking block 504, which is slidably embedded in the sliding groove 1202. The aiming block 503 has a through hole, the axis of which coincides with the axis of the transverse locking screw 2.

[0059] When the fracture type is subcapital or transcervical, the intersection of the main nail 1 and the transverse locking screw 2 is located on the outer side of the fracture site. When the fracture type is basal, the intersection of the main nail 1 and the transverse locking screw 2 is located on the inner side of the fracture site.

[0060] For different fracture types, the crossing angles of the transverse locking screw 2 and the main nail 1 may be different. Different steel plates 3 can be configured according to different fracture types, so that the transverse locking holes on different steel plates 3 are different. Alternatively, transverse locking holes in different positions and directions can be set on the same steel plate 3, thereby adapting to fracture fixation with different crossing angles.

[0061] The method of using the present invention includes: S1. Place the patient with a femoral neck fracture on the surgical traction reduction bed and reduce the femoral neck fracture site by traction. Use C-arm fluoroscopy in anteroposterior, lateral and axial views during the operation. After the fracture ends are reduced satisfactorily, the surgical area is routinely disinfected and draped. S2. Based on the fracture type and location, select the approximate location for the main nail 1 from a suitable range on the lateral side of the femur, and then insert a Kirschner wire from the lateral side of the femur through the femoral neck to the femoral head. After repeated fluoroscopy with S3 and C arms until the Kirschner wire is in the femoral neck and femoral head at the angle and depth position that is completely satisfactory, the length of the Kirschner wire is measured to determine the length of the main nail 1; the outer steel is placed according to the position of the Kirschner wire, the main nail 1 is screwed in along the first Kirschner wire, and the main nail 1 is locked to the steel plate 3. S4. Through the pre-drilled Kirschner wire holes in the outer steel plate 3, insert two Kirschner wires to assist in fixation and positioning. After the distal position of the steel plate 3 is adjusted appropriately, insert two distal locking screws to fix the steel plate 3 to the femoral shaft. S5. Use the external sight 5 to drive in the horizontal locking screw 2 and lock the horizontal locking screw 2 and the steel plate 3. S6. Remove all Kirschner wires and apply secondary pressure to the main nail 1 through the tail screw 103 to bring the fracture ends closer together. At the same time, apply secondary pressure to achieve transverse locking pressure.

[0062] During the operation, repeated fluoroscopy confirmed that the main screw 1 and the transverse locking screw were both within the femoral neck cortex and the femoral head cartilage layer, without penetrating or breaking through the femoral head and neck cortex. The operation was then completed. For patients who cannot be reduced by traction on the operating table, the device of this invention can be used after successful open reduction surgery. The procedure for using the device is largely the same, except that during open reduction, if Kirschner wire fixation is required, interference with the insertion of the main screw 1, the transverse locking screw 2, and the matching Kirschner wires should be avoided as much as possible.

[0063] The above specific embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A femoral neck internal cross screw and plate-reinforced internal fixation device, characterized in that, include: The system includes a main nail, a transverse locking screw, and a plate. The plate is attached to the outer surface of the femur between the greater trochanter and the lesser trochanter. The main nail passes through the plate and the fracture ends, penetrating deep into the femoral head. The transverse locking screw passes through the plate and the fracture ends, penetrating deep into the femoral head. The tails of both the main nail and the transverse locking screw are connected to the steel plate; the transverse locking screw also passes through the middle of the main nail to form a triangular fixing structure with the main nail.

2. The femoral neck internal cross screw and plate-reinforced internal fixation device according to claim 1, characterized in that, The transverse locking screw is located above the master nail and is cross-connected to the master nail; the coronal plane angle between the transverse locking screw and the master nail is 35°-50°, and the sagittal plane angle between the transverse locking screw and the master nail is 3°-5°.

3. The femoral neck internal cross screw and plate-reinforced internal fixation device according to claim 1, characterized in that, The main pin includes an inner core, an outer sleeve, and a tail pin. The outer sleeve is fitted over the outside of the inner core, and the tail pin is located at the tail of the inner core. The outer surface of the front end of the inner core has external threads. The inner core is hollow, and one end of the tail pin is embedded in the tail of the inner core and can rotate relative to the inner core; the outer surface of the part of the tail pin that protrudes from the inner core has threads. When the outer sleeve is fitted onto the inner core, the front end of the inner core with external threads is exposed; the tail end of the outer sleeve has internal threads, and the internal threads of the tail end of the outer sleeve are connected to the external threads of the tail pin.

4. The femoral neck internal cross screw and plate-reinforced internal fixation device according to claim 3, characterized in that, The inner core has a limiting platform on its outer surface near the front end. One end face of the outer sleeve is correspondingly provided with the limiting surface of the limiting platform, and there is a gap between one end face of the outer sleeve and the limiting surface of the limiting platform.

5. The femoral neck internal cross screw and plate-reinforced internal fixation device according to claim 3, characterized in that, The inner core has a transverse locking screw hole in the middle for the transverse locking screw to pass through; the outer sleeve also has a hole for the transverse locking screw to pass through. The inner wall of the tail portion of the inner core has a step, and one end of the tail pin has a retaining ring, which is engaged within the step.

6. The femoral neck internal cross screw and plate-reinforced internal fixation device according to claim 3, characterized in that, The direction of the thread on the outer surface of the tail screw is opposite to the direction of the external thread at the front end of the main screw; The diameter of the threaded portion at the front end of the inner core gradually decreases from the tail end of the inner core towards the front end.

7. The femoral neck internal cross screw and plate-reinforced internal fixation device according to claim 3, characterized in that, The outer surface of the tail of the jacket has threads, and the jacket is connected to the steel plate by the external threads at its tail. The tail pin has a slot at its tail end, and the cross-section of the slot is quadrilateral, hexagonal or octagonal. The diameter of the main nail is 9mm-12mm, and the length of the main nail is 70mm-120mm.

8. The femoral neck internal cross screw and plate-reinforced internal fixation device according to claim 1, characterized in that, The transverse locking screw is a solid screw, and the transverse locking screw is a fully threaded screw or a partially threaded screw; The tail of the transverse locking screw has an external thread that connects with the threaded connection of the steel plate.

9. The femoral neck internal cross screw and plate-reinforced internal fixation device according to claim 1, characterized in that, It also includes: a lower locking screw, which is located below the lesser trochanter of the femur when in use; An external sight includes a support rod, an arc ruler, and an aiming block. One end of the support rod is inserted into a slot in the tail pin; the other end of the support rod is fixedly connected to the arc ruler, which has a sliding groove. The lower surface of the aiming block has a locking block, which is slidably embedded in the sliding groove. The aiming block has a through hole, the axis of which coincides with the axis of the transverse locking screw.

10. The femoral neck internal cross screw and plate-reinforced internal fixation device according to claim 1, characterized in that, The steel plate also has Kirschner wire positioning holes; The steel plate is made of a flexible material; When the fracture type is subcapital fracture or transcervical fracture, the intersection of the main nail and the transverse locking screw is located on the outer side of the fracture end; When the fracture type is a basal fracture, the intersection of the main nail and the transverse locking screw is located inside the fracture ends.

Images